Evaluación del parámetro BACT-info del citómetro de flujo UF-5000 (Sysmex) para la clasificación gram en infección del tracto urinario / Evaluation of Sysmex UF-5000 flow cytometer flag BACT-info for Gram discrimination in urinary tract infection

Introducción: El urocultivo como gold standard para diagnóstico de infección del tracto urinario (ITU) supone una carga de trabajo considerable en los Servicios de Microbiología Clínica, debido al elevado número de muestras recibidas que finalmente serán negativas. Por ello, utilizar sistemas de cribado que además reduzcan el tiempo de respuesta del diagnóstico de ITU es necesario. El nuevo citómetro de flujo UF-5000 (Sysmex Corporation) es capaz de diferenciar entre bacterias gramnegativas y grampositivas mediante el parámetro BACT-info según el fabricante. El objetivo de nuestro estudio fue evaluar la capacidad de discriminación gram del citómetro UF-5000. Métodos: Estudio prospectivo de 449 orinas recogidas de forma consecutiva, en el período 7/3/2022-27/5/2022, en las que se comparó el flag BACT-info con el urocultivo como método de referencia. Resultados: La sensibilidad obtenida tanto para bacterias gramnegativas como positivas fue superior al 95%. Sin embargo, en el caso de bacterias grampositivas, el índice Kappa moderado (0,49) y el valor predictivo positivo bajo (37,1%) indicó que la correlación entre el flag BACT-info y el urocultivo no era aceptable, por lo que no sería recomendable informarlo al clínico peticionario. Conclusión: El uso del citómetro UF-5000 supone un adelanto en la orientación etiológica de las ITUs causadas por bacterias gramnegativas. Informar la morfología gram en la muestra de orina reduce el tiempo de respuesta en el diagnóstico microbiológico de ITU, lo que tendría un impacto en la disminución y optimización del tratamiento empírico, y, por ende, en la generación de resistencias antimicrobianas. (AU)

Introduction. Urine culture as a gold standard for the diagnosis of urinary tract infection (UTI) involves a considerable workload in Clinical Microbiology Departments, due to the high number of samples received that will ultimately be negative. Therefore, it is necessary to use screening systems that also reduce the turnaround time for UTI diagnosis. The new flow cytometer UF-5000 (Sysmex Corporation) is able to differentiate between Gram-negative and Gram-positive bacteria using the BACT-info parameter according to manufacturer. The aim of our study was to evaluate the gram discrimination ability of the UF-5000 cytometer. Methods. A prospective study with 449 urine samples collected consecutively was conducted, in the period 7/3/2022- 27/5/2022, in which the BACT-info flag was compared with urine culture as the reference method. Results. The sensitivity obtained for both Gram-negative and Gram-positive bacteria was above 95%. However, for Gram-positive bacteria, the moderate Kappa index (0.49) and the low positive predictive value (37.1%) indicated that the correlation between BACT-info flag and urine culture was not acceptable and should not be reported to the requesting clinician. Conclusion. Implementation of the third generation UF5000 cytometer represents a significant advance in the aetiological orientation of UTIs caused by Gram-negative bacteria. Reporting the Gram morphology in the urine samples reduces the response time in the microbiological diagnosis of UTI, which would have an impact on the reduction and optimisation of empirical treatment, and thus on the generation of antimicrobial resistance. (AU)

Macroencapsulation of Limosilactobacillus reuteri DSPV002C as nutritional supplement for piglets: Storage stability and survival in gastrointestinal conditions.

The aim of this study was to evaluate the protective effect of the encapsulation of Limosilactobacillus reuteri DSPV002C in macrocapsules made from industrial materials during production, storage and under simulated gastrointestinal conditions in vitro and in vivo. The production of macrocapsules involved the evaluation of different wall materials (matrix), namely, gelatin and pregelatinized starch, different inoculums, matrix ratios, and diverse cryoprotectants (whey permeate and maltodextrin). The different macrocapsules were arranged in molds of similar size to pig pelleted food and lyophilized. Then, the viability of the macrocapsules was assessed over time during storage at different temperatures (freezing, refrigeration and room temperature) and atmospheres (vacuum and non-vaccum). The macrocapsules with 10% w/v gelatin+5% w/v pregelatinized starch, permeated (10%, w/v), with a 9:1 inoculum:matrix ratio (GS7.5P9), stored under freezing conditions and vacuum, exhibited the highest viability of L. reuteri DSPV002C (9.3 log CFU/cap until 210 d). Under simulated gastrointestinal conditions, the encapsulated inoculum showed less viability loss (0.58±0.09 log CFU/ml, 26.53%), compared to the free culture (1.56±0.16 log CFU/ml, 2.85%). Finally, by administering GS7.5P9 to pigs, the tolerance of the bacteria to the gastrointestinal environment was verified, with viable counts equal to or greater than 3.72 log CFU/g of fecal matter throughout the trial. In this study, a high-density carrier probiotic macrocapsule of L. reuteri DSPV002C was obtained, which displayed a long shelf life, a suitable shape to be included in pig feed and an adequate survival of viable cells at the site of action.

Estudio del líquido cefalorraquídeo en pacientes con neoplasias hematológicas malignas

Introducción: La infiltración del sistema nervioso central por células malignas constituye una complicación grave de algunas neoplasias hematológicas, principalmente leucemias agudas y linfomas agresivos. Objetivo: Resumir la base científica y la significación clínica de los métodos de estudio del líquido cefalorraquídeo para el diagnóstico y el seguimiento de la infiltración neuromeníngea en pacientes con neoplasias hematológicas. Métodos: Se buscó información durante abril de 2021 en las bases de datos PubMed, ScienceDirect y SciELO. Se seleccionaron las publicaciones en base a su tipología, actualidad, alcance y las limitaciones de los estudios. Conclusiones: El estudio citomorfológico del líquido cefalorraquídeo se considera el método estándar para el diagnóstico y el seguimiento de la infiltración neuromeníngea. La citometría de flujo resulta más sensible para la detección de infiltración oculta que la citología convencional; pero aún existen reservas sobre su significación clínica. Se investiga también la sensibilidad de otros estudios moleculares como el uso de la reacción en cadena de la polimerasa y la detección de biomarcadores.

Introduction: Infiltration of the central nervous system by malignant cells constitutes a serious complication of some hematological malignancies, mainly acute leukemias and aggressive lymphomas. Objective: To summarize the scientific basis and clinical significance of cerebrospinal fluid study methods for the diagnosis and follow-up of neuromeningeal infiltration in patients with hematologic malignancies. Methods: Information was searched during April 2021 in PubMed, ScienceDirect and SciELO databases. Publications were selected based on their typology, timeliness, scope, and study limitations. Conclusions: The cytomorphological study of cerebrospinal fluid is considered the standard method for the diagnosis and follow-up of neuromeningeal infiltration. Flow cytometry is more sensitive for the detection of occult infiltration than conventional cytology, but there are still reservations about its clinical significance. The sensitivity of other molecular studies such as the use of PCR and biomarker detection is also investigated.

Subpoblaciones de linfocitos T en adultos mayores cubanos con leucemia linfoide crónica / Subpopulations of T lymphocytes in Cuban older adults with chronic lymphoid leukemia

Introducción: la inmunosenescencia está asociada con un mayor riesgo de desarrollo de cáncer. Dentro de las hemopatías malignas que afectan a este grupo de edad, está la leucemia linfoide crónica (LLC), caracterizada por trastornos en la inmunidad adaptativa que incluye las subpoblaciones de linfocitos T. Objetivo: Determinar la frecuencia de las subpoblaciones de linfocitos T en los pacientes adultos mayores con leucemia linfoide crónica evaluados en el Instituto de Hematología e Inmunología de Cuba. Métodos: Se realizó un estudio transversal en 30 adultos mayores con leucemia linfoide crónica. Se cuantificaron los linfocitos TCD3+CD4+ y TCD3+CD8+ en sangre periférica por citometría de flujo. Para la lectura y el análisis de los datos se empleó un citómetro de flujo Beckman Coulter Gallios. Se utilizaron los valores porcentuales, la media y la desviación estándar. Se consideró estadísticamente significativo si p≤0.05. Resultados: Hubo un predominio de hombres que representaron el 56,7 por ciento y del grupo de 70-79 años de edad. No se reportó ningún adulto mayor con LLC con valores altos ni normales de linfocitos TCD3+CD4+. Predominaron los hombres con valores bajos porcentuales de linfocitos TCD3+CD4+, TCD3+CD8+ e inversión del índice CD4/CD8 en relación con las mujeres. Conclusiones: Los adultos mayores con LLC presentan alteraciones en el número de las subpoblaciones de linfocitos T. La acción de estas células en relación al crecimiento de células B malignas aún es desconocido y resulta importante determinar si esto puede reflejar un intento de evasión de las células tumorales al control inmunológico(AU)

Introduction: Immunosenescence is associated with an increased risk of cancer development. Among the malignant hemopathies that affect this age group, it is chronic lymphoid leukemia (CLL), characterized by disorders in adaptive immunity, which include subpopulations of T lymphocytes. Objective: To determine frequency of T lymphocyte subpopulations in older adult patients with chronic lymphoid leukemia evaluated at the Institute of Hematology and Immunology of Cuba. Methods: A cross-sectional study was conducted in 30 older adults with chronic lymphoid leukemia. TCD3+CD4+ and TCD3+CD8+ lymphocytes were quantified in peripheral blood by flow cytometry. A Beckman Coulter Gallios flow cytometer was used to read and analyze the data. The percentage values, the mean and the standard deviation were used. It was considered statistically significant if p≤0.05. Results: There was a predominance of men who represented 56.7 percent and the age group of 70-79 years. No older adults with CLL with high or normal values of TCD3+CD4+ lymphocytes were reported. Men predominated with low percentage values of TCD3+CD4+, TCD3+CD8+ lymphocytes and inversion of the CD4/CD8 ratio in relation to women. Conclusions: Older adult with CLL present alterations in the number of T lymphocyte subpopulations. The role of these cells in relation to the growth of malignant B cells it is unknown and it turns out important to determine if this may reflect an attempt to evade tumor cells from immune control(AU)

Linfocitosis monoclonal de células B en familiares de pacientes colombianos con síndromes linfoproliferativos crónicos B

Introducción. La linfocitosis monoclonal de células B, generalmente, precede la leucemia linfocítica crónica y afecta alrededor del 12 % de la población adulta sana. Esta frecuencia se incrementa en familiares de pacientes con síndromes linfoproliferativos crónicos de células B. Objetivo. Determinar la frecuencia de linfocitosis monoclonal B en familiares de pacientes con síndromes linfoproliferativos crónicos B, sus características inmunofenotípicas y citogenéticas, posible relación con agentes infecciosos, y seguimiento a corto plazo de población colombiana. Materiales y métodos. Se estudiaron 50 adultos sanos con antecedentes familiares de síndromes linfoproliferativos crónicos de célula B, empleando citometría de flujo multiparamétrica, pruebas citogenéticas y serológicas, encuesta de hábitos de vida y seguimiento a dos años. Resultados. La frecuencia encontrada de linfocitosis monoclonal B fue del 8 %, con predominio del sexo femenino y edad avanzada, incrementándose al 12,5 % en individuos con antecedentes familiares de leucemia linfocítica crónica. Tres de cuatro individuos presentaron inmunofenotipo de tipo leucemia linfocítica crónica, todas con bajo recuento. A su vez, en estos individuos se observa de manera significativa un mayor número de células/ µl en subpoblaciones linfocitarias T, junto con mayor predisposición a la enfermedad. Las poblaciones clonales descritas aumentan a lo largo del tiempo de manera no significativa. Conclusiones. La frecuencia y comportamiento de la linfocitosis monoclonal de célula B en pacientes con antecedentes familiares de síndromes linfoproliferativos crónicos B es similar a lo encontrado en estudios relacionados, lo que sugiere que no existe afectación de genes de mayor relevancia que puedan desencadenar una proliferación clonal descontrolada, pero que generan desregulación inmunológica que podría indicar un mayor riesgo de infección grave en estos individuos.

Introduction. Monoclonal B-cell lymphocytosis generally precedes chronic lymphocytic leukemia, affecting about 12% of the healthy adult population. This frequency increases in relatives of patients with chronic B-cell lymphoproliferative disorders. Objective. To determine the frequency of monoclonal B-cell lymphocytosis in relatives of patients with chronic B-cell lymphoproliferative disorders, their immunophenotypic/ cytogenetic characteristics, a possible relationship with infectious agents, and short-term follow-up in the Colombian population. Materials and methods. Fifty healthy adults with a family history of chronic B-cell lymphoproliferative disorders were studied using multiparametric flow cytometry, cytogenetic/serological testing, lifestyle survey, and 2-year follow-up. Results. The frequency of monoclonal B-cell lymphocytosis found was 8%, with a predominance of female gender and advanced age, increasing to 12.5% for individuals with a family history of chronic lymphocytic leukemia. Three out of four individuals presented chronic lymphocytic leukemia-type immunophenotype, all with low counts. In turn, a significantly higher number of cells/µΙ is observed in these individuals in T lymphocyte subpopulations, together with a greater predisposition to the disease. The described clonal populations increase over time in a non-significant manner. Conclusions. The frequency and behavior of monoclonal B-cell lymphocytosis in patients with family history of chronic B-cell lymphoproliferative disorders are like those found in related studies, which suggests that there is no involvement of more relevant genes that can trigger uncontrolled clonal proliferation, but that generates immunological deregulation that could justify a greater risk of serious infection in these individuals.

Flow cytometry-detected changes in megaloblastic anemia secondary to cobalamin deficiency

Introduction: Megaloblastic anemias secondary to Vitamin B12 deficiency are a group of pathologies produced by defective nuclear DNA synthesis. Objective: To describe the maturation alterations found in hematopoietic precursors of the bone marrow in a series of patients with megaloblastic anemia. Methods: Were included patients attended at the Regional Hospital of Concepción with bone marrow samples sent for the study of cytopenia by flow cytometry whose final diagnosis was megaloblastic anemia. The immunophenotype was performed with CD45, CD34, CD117, HLA-DR, markers of neutrophil (CD13, CD11b, CD10, CD16) and/or erythroblast (CD105, CD71, CD36) maturation. Results: From the flow cytometry laboratory database, 8 patients with megaloblastic anemia were identified, and myelodysplastic syndromes (n=9) and normal or reactive bone marrow (n=10) were used as controls. 44% were men, with a median age of 58 years. Megaloblastic anemia was associated with a higher proportion of size and complexity of erythroid and myeloid progenitors compared to lymphocytes compared to controls. The total percentage of erythroblasts and the proportion of CD34+ myeloid cells associated with erythroid lineage was higher in megaloblastic anemia, associated with a maturation arrest in the CD105+ precursor stage (69% vs 19% and 23%, p<0.001). The heterogeneity of CD36 and CD71 in megaloblastic anemia was similar to myelodysplastic syndromes. Conclusions: Megaloblastic anemia produces a heterogeneous involvement of hematopoiesis, characterized by a greater size and cellular complexity of precursors of the neutrophil and erythroid series and a maturation arrest of the erythroblasts.

Introducción: Anemias megaloblásticas secundarias a la deficiencia de vitamina B12 son patologías producidas por una síntesis defectuosa del ADN nuclear. Objetivo: Describir las alteraciones madurativas encontradas en precursores hematopoyéticos de la médula ósea de una serie de pacientes con anemia megaloblástica. Métodos: Se incluyeron pacientes atendidos en el Hospital Regional de Concepción con muestras de médula ósea enviadas para estudio de citopenias por citometría de flujo cuyo diagnóstico fue anemia megaloblástica. El inmunofenotipo se realizó con CD45, CD34, CD117, HLA-DR, marcadores de maduración de serie de neutrófilo (CD13, CD11b, CD10, CD16) y/o eritroblasto (CD105, CD71, CD36). Resultados: Se identificaron 8 pacientes con anemia megaloblástica y como controles se utilizaron síndromes mielodisplásicos (n=9) y médula ósea normal o reactiva (n=10). El 44% eran hombres, con una mediana de edad de 58 años. La anemia megaloblástica se asoció con una mayor proporción de tamaño y complejidad de progenitores eritroides y mieloides con respecto de los linfocitos en comparación a los controles. El porcentaje total de eritroblastos y la proporción de células mieloides CD34+ comprometidas con el linaje eritroide fue mayor en anemia megaloblástica, asociado a una parada madurativa en la etapa de precursor CD105+ (69% vs 19% y 23%, p <0.001). La heterogeneidad de CD36 y CD71 en anemia megaloblástica fue similar a los síndromes mielodisplásicos. Conclusiones: la anemia megaloblástica produce una afectación heterogénea de la hematopoyesis, caracterizada por un mayor tamaño y complejidad celulares de precursores de la serie neutrófilo y eritroide y una detención madurativa de los eritroblastos.

Enfermedad mínima residual en leucemia mieloide aguda no promielocítica: Resultados preliminares de un estudio colaborativo internacional / Minimal residual disease in non-myelocytic acute myeloid leukemia: preliminary results of an international collaborative study

A pesar de los avances en los protocolos de tratamiento y en las medidas de soporte en pacientes con Leucemia Mieloide Aguda (LMA), 27% presentan recaídas de la enfermedad. Esto se debe, entre otras causas, a la persistencia de pequeñas cantidades de células malignas (blastos) resistentes a la terapia. Estas pequeñas cantidades de blastos remanentes se denominan Enfermedad Mínima Residual (EMR). La determinación de EMR requiere de técnicas no solo muy sensibles, sino también específicas, y permite evaluar la respuesta individual a la terapia. La introducción de la EMR como parámetro de respuesta y estratificación está bien definida en Leucemia Linfoblástica Aguda (LLA). Por el contrario, aunque existen publicaciones sobre el impacto pronóstico de la EMR en LMA, aún no se encuentra incluida en forma sistemática en los protocolos nacionales actuales, entre otros motivos, por lo laborioso de la determinación y por la necesidad de validación de la misma. Debe tenerse en cuenta que el inmunofenotipo de los blastos mieloides suele ser más heterogéneo que el de los blastos en LLA, presentando, en muchos casos, subpoblaciones diferentes entre sí, lo cual dificulta su detección certera y no hay consenso definido en cuanto a la metodología más eficaz. En este trabajo describimos una nueva estrategia de marcación y análisis estandarizada en un estudio multicéntrico internacional para LMA y la utilidad de la EMR como parámetro de respuesta y de estratificación. Asimismo, detallamos los resultados preliminares de nuestra cohorte de pacientes (AU)

Despite the improvement in treatment and supportive care of patients with Acute Myeloid Leukemia (AML), 27% of them relapse. This is due to the persistence of small amounts of malignant cells (blasts) resistant to therapy, among other causes. These small amounts of blasts are called Minimal Residual Disease (MRD). The determination of MRD requires not only techniques with high sensitivity but also with high specificity, and allows to evaluate the individual response to treatment. The introduction of MRD as a response parameter is well established in Acute Lymphoblastic Leukemia (ALL), and it is used in current stratification protocols. On the other hand, even though there are some reports regarding the prognostic impact of MRD in AML, it is still not included in the current national protocols due to the lack of validation of the determination, among other causes. This is due to the fact that the immunophenotype of myeloid blasts is more heterogeneous than in ALL, presenting different subpopulations, which difficults their accurate detection. Thus, there is still no consensus regarding the most effective approach. In this article, we describe a new staining and analysis strategy standardized by an international multicentric study, and the utility of EMR as a response and stratification parameter. Additionally, we show the preliminary results of our patient cohort. (AU)

La citometría de flujo aumenta la proporción de muestras valorables en líquido cefalorraquídeo con recuento celular normal en hemopatías malignas

Introducción: El compromiso del líquido cefalorraquídeo (LCR) en hemopatías malignas es un marcador de mal pronóstico y es habitualmente estudiado por citometría de flujo o citología. Ocasionalmente, las muestras de LCR oligocelulares (≤ 5 céls/dL) pueden ser consideradas como no aptas para diagnóstico por la baja cantidad de eventos. Objetivo: Evaluar la proporción de muestras reportadas como valorables para diagnóstico obtenidas por citometría y citología en muestras de LCR oligocelular. Material y Métodos: Se seleccionaron 169 muestras de LCR oligocelular correspondientes a 115 pacientes con hemopatías malignas. Las muestras fueron obtenidas mediante punción lumbar en tubos acondicionados con EDTA y preservante celular (Transfix®). El inmunofenotipo se realizó con panel de 8 colores, 55 (32%) de las cuales se hizo con panel para pequeñas muestras (SST). En todos los casos se incluyó CD14 para identificación de monocitos y CD3 para linfocitos T. La adquisición se realizó en citómetro FACSCantoII® y el análisis en software Infinicyt®. Resultados: La proporción de muestras valorables fue mayor en citometría en comparación con la citología (98% vs 61%, p < 0,000). En la mayoría se identificaron linfocitos T (98%) y/o monocitos (90%). En las muestras con SST, la cantidad de eventos obtenida fue menor en muestras con < de 1 mL (140 vs 556, p < 0,001) y se logró identificar una mediana de 3 poblaciones celulares. Conclusión: La citometría proporciona una mayor cantidad de muestras valorables en los LCR paucicelulares en relación con la citología en muestras de LCR enviadas para estudio de compromiso de LCR por hemopatías malignas.

Background: The alteration of cerebrospinal fluid (CSF) in hematologic neoplasms is a poor prognostic marker. The characteristics of CSF are usually analyzed by flow cytometry or cytology. However, paucicellular CSF samples (≤5 cells/dL) can sometimes be considered unsuitable for analysis due to the low number of events. Objective: To evaluate the proportion of samples reported as suitable for analysis obtained by cytometry (FCM) and cytology in paucicellular CSF samples. Material and Methods: 169 samples ofpaucicellular CSF corresponding to 115 patients with hematologic neoplasms were selected. The samples were obtained by lumbar puncture in tubes conditioned with EDTA and Transfix®. We characterized the immunophenotype ofCSF samples with an 8-color panel, and 55 samples (32%) were in a small sample tube (SST). In all cases, monocytes were identified by CD14 labeling and T lymphocytes by CD3 labeling. The acquisition was carried out in a FACSCantoII® cytometer, and the analysis was performed using Infinicyt® software. Results: The proportion of samples suitable for analysis was higher in FCM compared to cytology (98% vs 61%, p < 0.000). We identified the presence of T lymphocytes and/or monocytes in most samples (98% and 90%, respectively). In the SST samples, the number of events recorded in low-volume samples (< 1 mL) was lower than in samples with higher volume (140 vs 556, p < 0.001), with a median of identification of 3 cell populations. Conclusion: FCM allows the analysis of a higher proportion ofpaucicellular CSF samples than cytology in hematologic neoplasms study.

Desenvolvimento de teste sorológico para COVID-19 por citometria de fluxo

The first coronavirus capable of infecting humans was isolated in the 1960s, and for a long time was considered to cause a mild flu condition. Coronaviruses are a family of enveloped viruses, with a single-stranded, non-segmented, positive-sense RNA genome. The envelope is composed of a lipid bilayer to which the spike (S), membrane (M) and envelope (E) proteins are attached. The protein (N) is associated with genomic RNA, and together they make up the nucleocapsid. The flow cytometry technique is capable of identifying several parameters in a single cell or in biological samples. In this work, we started the development of a Cytometric Bead Array (CBA) assay for the simultaneous detection of IgM and IgG antibodies specific for the N proteins of SARS-CoV-2 in human samples, either for diagnosis or for monitoring vaccine efficacy, this method can be easily adapted for the detection of antibodies specific for the spike Protein S1 Receptor-Binding Domain (S1-RBD) in the future. Functional beads CBA A5, kit for performing the CBA flex assay, buffer kit for conjugation of functional beads, mouse monoclonal antibody anti-human IgG conjugated to PE, as well as other materials and reagents necessary for the conjugation of the beads, including Bio-Spin P-30 gel columns and DTT, Sulfo-SMCC, NEM and DMSO reagents. For initial evaluation of the sensitivity and specificity of the test, we used serum samples from rabbits immunized with proteins N (positive controls) and S1-RBD (negative controls), as well as non-immunized (negative control). The results demonstrated that the positive and negative samples were properly recognized in the assay, and that there is no non-specific reaction. We used 37 random serum samples obtained from voluntary donors in order to determine whether it would be possible to detect anti-N antibodies in these samples using the CBA assay. As expected, anti-N antibody titers in the population are low, The only vaccine that so far can produce antibodies against N protein is CoronaVac, from Sinovac, and even so, according to a study by Bochnia 16 (2021), which is reflected in low fluorescence intensity compared to the positive control with commercial antibody. Considering everything that was observed in this work, we can conclude that flow cytometry is an excellent diagnostic method for serological follow-up of the population, either for vaccination follow-up or after infection.Due to the promising results, the test will continue to be developed at the Immunochemistry Laboratory.

O primeiro coronavírus capaz de infectar seres humanos foi isolado na década de 1960, e, durante muito tempo, foi considerado causador de um quadro gripal leve. Os coronavírus são uma família de vírus envelopados, com genoma de RNA fita simples, não segmentado, de sentido positivo. O envelope é composto por uma bicamada lipídica, onde se encontram anexadas as proteínas de espícula (S), membrana (M) e envelope (E). A proteína (N) está associada ao RNA genômico, e juntos compõem o nucleocapsídeo. A técnica de citometria de fluxo é capaz de identificar vários parâmetros em uma única célula ou em amostras biológicas. Nesse trabalho, iniciamos o desenvolvimento de um ensaio de Cytometric Bead Array(CBA) para a detecção simultânea de anticorpos IgM e IgG específicos para a proteínas N do SARS-CoV-2 em amostras humanas, seja para diagnóstico, seja para monitoramento da eficácia vacinal, este método pode ser facilmente adaptada para a detecção de anticorpos específicos para a spike Protein S1 Receptor-Binding Domain(S1-RBD) futuramente. Foram utilizadas beads funcionais CBA A5, kit para realização de ensaio CBA flex, kit de tampões para conjugação de beads funcionais, anticorpo monoclonal de camundongo anti-IgG humana conjugado a PE, bem como demais materiais e reagentes necessários para a conjugação das beads, incluindo colunas Bio-Spin P-30 gel e reagentes DTT, Sulfo-SMCC, NEM e DMSO. Para avaliação inicial da sensibilidade e especificidade do teste, utilizamos amostras de soro de coelhos imunizados com as proteínas N (controles positivos) e S1-RBD (controles negativos), bem como não imunizado (controle negativo). Os resultados demonstraram que as amostras positivas e negativas foram adequadamente reconhecidas no ensaio, e que não há reação inespecífica. Utilizamos 37 amostras de soro aleatórias, obtidas de doadores voluntários, a fim de determinar se seria possível realizar a detecção de anticorpos anti-N nessas amostras, utilizando o ensaio de CBA. Como esperado, os títulos de anticorpos anti-N na população são baixos. A única vacina que até o momento pode produzir anticorpos contra proteína N é a CoronaVac, da Sinovac, e mesmo assim, de acordo com estudo de Bochnia 16 (2021), o que se reflete emintensidade de fluorescência baixa, em comparação ao controle positivo com anticorpo comercial. Considerando tudo que foi observado nesse trabalho, podemos concluir que a citometria de fluxo é excelente método diagnóstico para acompanhamento sorológico da população, seja para acompanhamento vacinal ou após infecção. Devido aos resultados promissores, o teste continuará sendo desenvolvido no Laboratório de Imunoquímica.

The dynamics of genome size and GC contents evolution in genus Nicotiana / A dinâmica do tamanho do genoma e a evolução dos conteúdos de GC no gênero Nicotiana

Abstract Hybridization and Polyploidization are most common of the phenomenon observed in plants, especially in the genus Nicotiana leading to the duplication of genome. Although genomic changes associated with these events has been studied at various levels but the genome size and GC content variation is less understood because of absence of sufficient genomic data. In this study the flow cytometry technique was used to uncover the genome size and GC contents of 46 Nicotiana species and we compared the genomic changes associated with the hybridization events along evolutionary time scale. The genome size among Nicotiana species varied between 3.28 pg and 11.88 pg whereas GC contents varied between 37.22% and 51.25%. The tetraploid species in genus Nicotiana including section Polydiclae, Repandae, Nicotiana, Rustica and Sauveolentes revealed both up and downsizing in their genome sizes when compared to the sum of genomes of their ancestral species. The genome sizes of three homoploid hybrids were found near their ancestral species. Loss of large genome sequence was observed in the evolutionary more aged species (>10 Myr) as compared to the recently evolved one's (<0.2 Myr). The GC contents were found homogenous with a mean difference of 2.46% among the Nicotiana species. It is concluded that genome size change appeared in either direction whereas the GC contents were found more homogenous in genus Nicotiana.

Resumo A hibridização e a poliploidização são os fenômenos mais comuns observados em plantas, principalmente no gênero Nicotiana, levando à duplicação do genoma. Embora as mudanças genômicas associadas a esses eventos tenham sido estudadas em vários níveis, o tamanho do genoma e a variação do conteúdo de GC são menos compreendidos devido à ausência de dados genômicos suficientes. Neste estudo, a técnica de citometria de fluxo foi usada para descobrir o tamanho do genoma e o conteúdo de GC de 46 espécies de Nicotiana, e comparamos as mudanças genômicas associadas aos eventos de hibridização ao longo da escala de tempo evolutiva. O tamanho do genoma entre as espécies de Nicotiana variou entre 3,28 pg e 11,88 pg, enquanto os conteúdos de GC variaram entre 37,22% e 51,25%. As espécies tetraploides do gênero Nicotiana, incluindo as seções Polydiclae, Repandae, Nicotiana, Rustica e Sauveolentes, revelaram aumento e redução do tamanho do genoma quando comparados à soma dos genomas de suas espécies ancestrais. Os tamanhos do genoma de três híbridos homoploides foram encontrados perto de suas espécies ancestrais. A perda da grande sequência do genoma foi observada nas espécies evolutivas mais velhas (> 10 Myr) em comparação com as que evoluíram recentemente (< 0,2 Myr). Os teores de GC foram homogêneos com diferença média de 2,46% entre as espécies de Nicotiana. Conclui-se que a mudança no tamanho do genoma apareceu em ambas as direções, enquanto os conteúdos de GC foram encontrados mais homogêneos no gênero Nicotiana.

The dynamics of genome size and GC contents evolution in genus Nicotiana / A dinâmica do tamanho do genoma e a evolução dos conteúdos de GC no gênero Nicotiana

Hybridization and Polyploidization are most common of the phenomenon observed in plants, especially in the genus Nicotiana leading to the duplication of genome. Although genomic changes associated with these events has been studied at various levels but the genome size and GC content variation is less understood because of absence of sufficient genomic data. In this study the flow cytometry technique was used to uncover the genome size and GC contents of 46 Nicotiana species and we compared the genomic changes associated with the hybridization events along evolutionary time scale. The genome size among Nicotiana species varied between 3.28 pg and 11.88 pg whereas GC contents varied between 37.22% and 51.25%. The tetraploid species in genus Nicotiana including section Polydiclae, Repandae, Nicotiana, Rustica and Sauveolentes revealed both up and downsizing in their genome sizes when compared to the sum of genomes of their ancestral species. The genome sizes of three homoploid hybrids were found near their ancestral species. Loss of large genome sequence was observed in the evolutionary more aged species (>10 Myr) as compared to the recently evolved one’s (<0.2 Myr). The GC contents were found homogenous with a mean difference of 2.46% among the Nicotiana species. It is concluded that genome size change appeared in either direction whereas the GC contents were found more homogenous in genus Nicotiana.

A hibridização e a poliploidização são os fenômenos mais comuns observados em plantas, principalmente no gênero Nicotiana, levando à duplicação do genoma. Embora as mudanças genômicas associadas a esses eventos tenham sido estudadas em vários níveis, o tamanho do genoma e a variação do conteúdo de GC são menos compreendidos devido à ausência de dados genômicos suficientes. Neste estudo, a técnica de citometria de fluxo foi usada para descobrir o tamanho do genoma e o conteúdo de GC de 46 espécies de Nicotiana, e comparamos as mudanças genômicas associadas aos eventos de hibridização ao longo da escala de tempo evolutiva. O tamanho do genoma entre as espécies de Nicotiana variou entre 3,28 pg e 11,88 pg, enquanto os conteúdos de GC variaramentre 37,22% e 51,25%. As espécies tetraploides do gênero Nicotiana, incluindo as seções Polydiclae, Repandae, Nicotiana, Rustica e Sauveolentes, revelaram aumento e redução do tamanho do genoma quando comparados à soma dos genomas de suas espécies ancestrais. Os tamanhos do genoma de três híbridos homoploides foram encontrados perto de suas espécies ancestrais. A perda da grande sequência do genoma foi observada nas espécies evolutivas mais velhas (> 10 Myr) em comparação com as que evoluíram recentemente (< 0,2 Myr). Os teores de GC foram homogêneos com diferença média de 2,46% entre as espécies de Nicotiana. Conclui-se que a mudança no tamanho do genoma apareceu em ambas as direções, enquanto os conteúdos de GC foram encontrados mais homogêneos no gênero Nicotiana.

The dynamics of genome size and GC contents evolution in genus Nicotiana

Abstract Hybridization and Polyploidization are most common of the phenomenon observed in plants, especially in the genus Nicotiana leading to the duplication of genome. Although genomic changes associated with these events has been studied at various levels but the genome size and GC content variation is less understood because of absence of sufficient genomic data. In this study the flow cytometry technique was used to uncover the genome size and GC contents of 46 Nicotiana species and we compared the genomic changes associated with the hybridization events along evolutionary time scale. The genome size among Nicotiana species varied between 3.28 pg and 11.88 pg whereas GC contents varied between 37.22% and 51.25%. The tetraploid species in genus Nicotiana including section Polydiclae, Repandae, Nicotiana, Rustica and Sauveolentes revealed both up and downsizing in their genome sizes when compared to the sum of genomes of their ancestral species. The genome sizes of three homoploid hybrids were found near their ancestral species. Loss of large genome sequence was observed in the evolutionary more aged species (>10 Myr) as compared to the recently evolved ones ( 0.2 Myr). The GC contents were found homogenous with a mean difference of 2.46% among the Nicotiana species. It is concluded that genome size change appeared in either direction whereas the GC contents were found more homogenous in genus Nicotiana.

Resumo A hibridização e a poliploidização são os fenômenos mais comuns observados em plantas, principalmente no gênero Nicotiana, levando à duplicação do genoma. Embora as mudanças genômicas associadas a esses eventos tenham sido estudadas em vários níveis, o tamanho do genoma e a variação do conteúdo de GC são menos compreendidos devido à ausência de dados genômicos suficientes. Neste estudo, a técnica de citometria de fluxo foi usada para descobrir o tamanho do genoma e o conteúdo de GC de 46 espécies de Nicotiana, e comparamos as mudanças genômicas associadas aos eventos de hibridização ao longo da escala de tempo evolutiva. O tamanho do genoma entre as espécies de Nicotiana variou entre 3,28 pg e 11,88 pg, enquanto os conteúdos de GC variaram entre 37,22% e 51,25%. As espécies tetraploides do gênero Nicotiana, incluindo as seções Polydiclae, Repandae, Nicotiana, Rustica e Sauveolentes, revelaram aumento e redução do tamanho do genoma quando comparados à soma dos genomas de suas espécies ancestrais. Os tamanhos do genoma de três híbridos homoploides foram encontrados perto de suas espécies ancestrais. A perda da grande sequência do genoma foi observada nas espécies evolutivas mais velhas (> 10 Myr) em comparação com as que evoluíram recentemente ( 0,2 Myr). Os teores de GC foram homogêneos com diferença média de 2,46% entre as espécies de Nicotiana. Conclui-se que a mudança no tamanho do genoma apareceu em ambas as direções, enquanto os conteúdos de GC foram encontrados mais homogêneos no gênero Nicotiana.

Ultra-short celiac disease exhibits differential genetic and immunophenotypic features compared to conventional celiac disease / La enfermedad celiaca ultra corta presenta una expresión genética e inmunológica distinta a la de la enfermedad celiaca convencional

Background: Ultra-short coeliac disease (USCD) is a novel celiac disease (CD) subtype limited to the duodenal bulb (D1). HLA haplotypes and flow cytometry have not been assessed yet. Aims: To compare genetic, clinical, serologic, histopathologic and inmmunophenotypic parameters between USCD and conventional celiac disease (CCD) patients. Methods: Prospective single-center study in children and adult patients undergoing duodenal biopsies on a gluten-containing diet. Biopsies for histology and flow cytometry were taken separately from D1 and distal duodenum. Biopsies in seronegative patients with celiac lymphogram were repeated after 2 years on a gluten-free diet. Results: Among 505 included patients, 127 were diagnosed with CD, of whom 7 (5.5%) showed USCD. HLADQ2 was significantly less common in USCD compared to CCD (71% vs. 95%, p 0.003). Likewise, USCD patients showed more frequent non-significant seronegativity (28% vs. 8%, p 0.07) and significantly lower titrations (7–15IU/ml) of tissue transglutaminase antibodies (tTG-IgA) (60% vs. 13%, p<0.001). Biopsies from D1 revealed significant less NK cells down-expression in USCD patients (1.4 vs. 5, p 0.04). Conclusions: Up to 5.5% of CD patients showed USCD. A lower frequency of HLADQ2, along with less serum tTG-IgA titration and duodenal NK cell suppression, were differential features of USCD.(AU)

Antecedentes: La enfermedad celiaca ultracorta (ECUC) es un nuevo fenotipo de la enfermedad celiaca, que afecta exclusivamente al bulbo duodenal (D1), cuyas características genéticas e inmunológicas no han sido descritas. Objetivos: Comparar las características genéticas, clínicas, serológicas, histológicas e inmunológicas entre ECUC y enfermedad celiaca convencional (ECC). Métodos: Estudio prospectivo, unicéntrico, en el que se realizaron biopsias duodenales a pacientes adultos y pediátricos que seguían una dieta con gluten. Se realizó análisis histológico y por citometría de flujo por separado de duodeno distal y D1. En pacientes seronegativos con histología o linfograma concordante con EC, se repitió la biopsia tras 2 años con dieta sin gluten. Resultados: Se incluyeron 505 pacientes, siendo diagnosticados 127 de enfermedad celiaca, de los cuales 7 (5,5%) tenían ECUC. Los pacientes con ECUC expresaron el haplotipo DQ2 con menor frecuencia que en la ECC (71% vs. 95%, p 0,003) y presentaron mayor seronegatividad (28% vs. 8%, p 0,07) y, de manera significativa, titulaciones bajas de anticuerpos antitransglutaminasa (7-15IU/ml) (60% vs. 13%, p < 0,001). Comparado con la ECC, la citometría de flujo en las biopsias bulbares reveló una reducción atenuada significativa de células NK (1,4 vs. 5, p 0,04) en pacientes con ECUC. Conclusiones: Un 5,5% de los pacientes celiacos presentaron ECUC. Comparada con la ECC, las características diferenciales de la ECUC son menor expresión de HLADQ2, títulos más bajos de anticuerpos antitranglutaminasa y menor supresión de células NK a nivel bulbar.(AU)

[Intrathyroidal thymus can cause confusion in the diagnosis of a thyroid mass. A case report]. / Timo intratiroideo: una causa de confusión en el diagnóstico de masas tiroideas infantiles. Reporte de caso.

Intrathyroidal thymus tissue (ITTT) is a rare, benign condition; its diagnosis can prove challenging due to unfamiliarity with this entity. However, it has ultrasonographical and cytological characteristics which can suggest its presence and thus should be considered in the differential diagnosis of thyroid nodules. Presently, immunohistochemistry can be used with fine needle aspiration (FNA) cytology, thus decreasing the need for unnecessary surgery. We discuss the usefulness of immunohistochemistry in thyroid cytology, with reference to a case of a 10-year-old patient, who underwent partial thyroidectomy for a suspicious thyroid nodule which was eventually diagnosed as ITTT by the histopathology of the surgical specimen.

Asociación del inmunofenotipo linfocitario de sangre periférica con la presencia de linfomas no Hodgkin / Association of peripheral blood lymphoid immunophenotype with presence of non-Hodgkin lymphomas

Introducción: Los cambios en el inmunofenotipo de los linfocitos en los pacientes con linfoma no Hodgkin están asociados con el pronóstico y las respuestas terapéuticas. Sin embargo, no se ha establecido sistemáticamente la asociación con la enfermedad y por tanto su contribución al diagnóstico. Objetivo: Evaluar la asociación del inmunofenotipo linfocitario en sangre periférica con la presencia del linfoma no Hodgkin. Métodos: Se analizaron 31 muestras de sangre periférica de pacientes con diagnóstico confirmado de linfoma no Hodgkin y de 68 individuos sanos como controles, durante el período de 2018 a 2020. Se empleó la citometría de flujo multiparamétrica para el inmunofenotipado. Se calculó el área bajo la curva y el índice de Youden para establecer puntos de corte en los porcentajes linfocitarios. La asociación de los cambios inmunofenotípicos con el linfoma no Hodgkin, se realizó mediante cálculos de Odd ratio. Resultados: El aumento de linfocitos TCD8+ y NKCD56opaco se asoció significativamente con la presencia de linfoma no Hodgkin (OR= 3,4 y 2,9; respectivamente). Por el contrario, la disminución de linfocitos TCD4+, T doble positivo, T doble negativo y NKCD56brillante también se asoció con la existencia de linfoma no Hodgkin (OR= 23,0; 10,7; 6,9 y 15,8; respectivamente). Además, la disminución del índice CD4/CD8 también fue asociada con la enfermedad. Conclusiones: Los cambios encontrados en los inmunofenotipos linfocitarios se asociaron de forma significativa con la presencia del linfoma no Hodgkin, lo cual representa una expresión sistémica de la enfermedad y sugiere su valor diagnóstico(AU)

Introduction: Lymphocyte immunophenotype changes in non-Hodgkin lymphoma patients are associated with prognosis and therapeutic responses. However, its association with the disease has not been systematically established. Therefor its contribution to the diagnosis process. Objective: To assess the association of lymphocyte immunophenotype in peripheral blood with the presence of non-Hodgkin lymphoma. Methods: 31 peripheral blood samples were analyzed from patients with a confirmed diagnosis of non-Hodgkin lymphoma and from 68 healthy individuals as controls, during the period 2018 to 2020. Multiparametric flow cytometry was used for immunophenotyping. The area under the curve and the Youden index were calculated to establish cut-off points in lymphocyte percentages. The association of immunophenotypic changes with non-Hodgkin's lymphoma was made using Odd ratio calculations. Results: The increase in TCD8+ and NKCD56dim lymphocytes from peripheral blood was significantly associated with the presence of non-Hodgkin lymphoma (OR= 3.4 and 2.9, respectively). Oppositely, the decrease in TCD4+, double positive T, double negative T and NKCD56bright lymphocytes was associated with the existence of non-Hodgkin lymphoma (OR= 23.0, 10.7, 6.9 and 15.8, respectively). Therefore, the decrease in the CD4/CD8 rate was also associated with the disease. Conclusion: The changes found in these lymphocytic immunophenotypes were significantly associated with the presence of non-Hodgkin lymphoma, which represents a systemic expression of the disease and suggests its diagnostic value(AU)

Aspectos técnicos y clínicos de la prueba cruzada de histocompatibilidad en el trasplante de órganos solidos / Technical and clinical aspects of the histocompatibility crossmatch assay in solid organ transplantation

La presencia de anticuerpos dirigidos contra los antígenos leucocitarios humanos (Human Leukocyte Antigens, HLA) que se expresan en las células del donante, es uno de los factores de riesgo más importantes asociados con las complicaciones clínicas después del trasplante. La prueba cruzada es una de las pruebas de histocompatibilidad más eficaces para la detección de anticuerpos específicos contra el donante en los receptores de injertos. En los primeros métodos de la prueba cruzada, se utilizaba la citotoxicidad dependiente del complemento, que es útil para detectar dichos anticuerpos responsables del rechazo hiperagudo del injerto, pero carece de la sensibilidad adecuada. Por ello, se desarrollaron métodos de pruebas cruzadas más sensibles, entre ellas, la prueba cruzada por citometría de flujo que hoy se considera el método preferido. En este artículo se revisa la evolución de la prueba cruzada y los factores más importantes que deben tenerse en cuenta al realizarla y al interpretar los resultados de esta prueba fundamental para la supervivencia a largo plazo del injerto.

The presence of antibodies directed against human leukocyte antigens (HLA) expressed on donor cells is a significant risk factor for serious clinical complications after transplantation. The crossmatch assay is one of the most important tests available for the detection of donor-specific antibodies in potential allograft recipients. Early crossmatch methods utilized complement-dependent cytotoxicity, which is useful for detecting the donor-specific anti- HLA antibodies responsible for hyperacute allograft rejection but lacks adequate sensitivity. Consequently, more sensitive crossmatch methods have been developed, ultimately leading to the flow cytometry crossmatch as the currently preferred methodology. Herein, we review the evolution of the crossmatch assay and the most important factors to consider when performing and interpreting the results of this fundamental assay for ensuring the long-term survival of the transplanted organ.

Ultra-short celiac disease exhibits differential genetic and immunophenotypic features compared to conventional celiac disease.

BACKGROUND: Ultra-short coeliac disease (USCD) is a novel celiac disease (CD) subtype limited to the duodenal bulb (D1). HLA haplotypes and flow cytometry have not been assessed yet. AIMS: To compare genetic, clinical, serologic, histopathologic and inmmunophenotypic parameters between USCD and conventional celiac disease (CCD) patients. METHODS: Prospective single-center study in children and adult patients undergoing duodenal biopsies on a gluten-containing diet. Biopsies for histology and flow cytometry were taken separately from D1 and distal duodenum. Biopsies in seronegative patients with celiac lymphogram were repeated after 2 years on a gluten-free diet. RESULTS: Among 505 included patients, 127 were diagnosed with CD, of whom 7 (5.5%) showed USCD. HLADQ2 was significantly less common in USCD compared to CCD (71% vs. 95%, p 0.003). Likewise, USCD patients showed more frequent non-significant seronegativity (28% vs. 8%, p 0.07) and significantly lower titrations (7-15IU/ml) of tissue transglutaminase antibodies (tTG-IgA) (60% vs. 13%, p<0.001). Biopsies from D1 revealed significant less NK cells down-expression in USCD patients (1.4 vs. 5, p 0.04). CONCLUSIONS: Up to 5.5% of CD patients showed USCD. A lower frequency of HLADQ2, along with less serum tTG-IgA titration and duodenal NK cell suppression, were differential features of USCD.

Caracterização das subpopulações de células mononucleares dos granulomas centrais de células gigantes dos maxilares / Characterization of mononuclear cell subpopulations of central giant cell granulomas of the jaws

O granuloma central de células gigantes (GCCG) dos maxilares é uma lesão intraóssea benigna, que pode apresentar um curso localmente agressivo. Setenta por cento dessas lesões apresentam mutações em TRPV4, KRAS ou FGFR1. Alguns estudos apontam que a população de células mononucleares parece ser o componente proliferativo da lesão. Essa população de células mononucleares é uma população mista, composta tanto por células mononucleares de origem monocítica quanto por células mesenquimais indiferenciadas. Assim, este estudo avaliou se, quando colocadas em cultura, o componente proliferativo da lesão é composto por células de origem mesenquimais ou de natureza monocítica. Foi estabelecida a cultura de células primárias de GCCG, a partir de uma amostra de conveniência composta por uma linhagem oriunda de uma lesão em mandíbula em paciente do sexo masculino, 20 anos. E, as amostras foram incubadas com os anticorpos CD14 e CD51/CD61, e triplicadas amostrais foram submetidas a citometria de fluxo para identificação das subpopulações de células presentes. Foi observado que somente as células mononucleares permaneciam ao longo das passagens. Pela citometria de fluxo, observou-se predominância de células CD14-CD51-CD61- triplamente negativas, compatível com o perfil esperado para células estromais/mesenquimais. Com base nos resultados, reforça-se a ideia de que as células mononucleares CD14- CD51-CD61- são centrais na patogênese dos GCCG, enquanto as células mononucleares de origem monocítica (CD14+) e as células gigantes semelhantes a osteoclastos (CD51+CD61 +) são reativas.

Central giant cell granuloma (CGCG) of the jaws is a benign intraosseous lesion, which may present an aggressive course. Seventy per cent of these lesions present mutations in TRPV4, KRAS or FGFR1. The population of mononuclear cells seems to be the proliferative component of the lesion. This mononuclear cell population is a mixed population, composed of both mononuclear cells of monocytic origin and undifferentiated mesenchymal cells. Thus, this study evaluated whether, when placed in culture, the proliferative component of (CGCG) is composed of mesenchymal cells or monocytic cells. The culture of primary CGCG cells was established from a convenience sample composed of a lineage originated from a mandibular lesion in 20 y.o. male patient. The samples were incubated with CD14 and CD51/CD61 antibodies, and triplicate samples were submitted to flow cytometry to identify the subpopulations of cells. It was observed that only mononuclear cells remained along the passages. By flow cytometry, a predominance of triple negative CD14-CD51-CD61- cells was observed, compatible with the expected profile for stromal/mesenchymal cells. Our results reinforce the idea that the mesenchymal cells (CD14-CD51-CD61-) have central importance in the CGCG pathogenesis, while the mononuclear cells of monocytic origin (CD14+) and the osteoclast-like giant cells (CD51+CD61+) are reactive.

A comparative evaluation of methods for estimating the colostrum quality in sows / Avaliação comparativa de métodos para estimar a qualidade do colostro em porcas

Colostrum is the main source of immunoglobulins (Ig) for neonate piglets and plays a crucial role within the health and growth of the piglet. Currently in pig farming, there are still no widespread practical methods for measuring the Ig concentration in colostrum at herd level. We evaluated sows' colostrum IgG concentration using an optical and a digital Brix refractometer and their performance was correlated to an IgG ELISA test, and flow cytometry. Colostrum concentrations of IgG and IgA averaged 74.05 ± 21.37mg/mL and 20.2 ± 5.32mg/mL respectively. The mean value of the Brix percentages for optical refractometer was 26.32%, and for digital was 28.32%. The Brix refractometer measurements of colostrum samples presented high correlation for IgG content analyzed by ELISA (Optical = 0.74, Digital = 0.87; P <0.001). Considering the immunophenotyping, the values for IgG and IgA lymphoblasts indicated a highly significant relationship to ELISA (IgG=0.77, IgA=0.84; P<0.001). The Brix refractometer can be considered a useful tool to be included in a colostrum monitoring program to improve potentially neonatal health. In addition, we demonstrated that flow cytometry can be an important tool to analyze and characterize the immunological potential of sow colostrum.(AU)

O colostro é a principal fonte de imunoglobulinas (Ig) para leitões recém-nascidos e desempenha um papel crucial na saúde e no crescimento dos leitões. Atualmente, na suinocultura, ainda não existem métodos amplamente utilizados na prática de produção para medir a concentração de imunoglobulinas no colostro suíno. Avaliou-se a concentração de IgG no colostro de porcas usando refratômetros Brix óptico e digital, e o desempenho foi comparado com ELISA e citometria de fluxo. As concentrações de IgG e IgA no colostro foram 74,05 ± 21,37mg/mL e 20,2 ± 5,32mg/mL, respectivamente. A percentagem de Brix média das amostras de colostro para o refratômetro óptico foi 26,32%, e para o digital foi 28,32%. As medições dos refratômetros de Brix apresentaram elevada correlação com a concentrações de IgG medidas por ELISA (óptico=0,74, digital=0,87; P<0,001). Considerando a imunofenotipagem, os valores dos linfoblastos IgG e IgA apresentaram alta correlação com o ELISA (IgG=0,77, IgA=0,84; P<0,001). O refratômetro Brix pode ser considerado uma ferramenta útil para ser incluída em um programa de monitoramento de colostro para melhorar a saúde neonatal. Além disso, foi demonstrado que a citometria de fluxo pode ser uma ferramenta importante para analisar e caracterizar o potencial imunológico do colostro de porcas.(AU)

Phasing out the pre-transplant cytotoxicity crossmatch: Are we missing something? / Exclusão da prova cruzada por citotoxicidade pré-transplante: estamos perdendo algo

Abstract Introduction: The anti-human globulin-enhanced complement-dependent cytotoxicity crossmatch (AHG-CDCXM) assay has been used to assess the presence of donor-specific antibodies (DSA) in recipient's serum before kidney transplantation. The flow cytometric crossmatch (FCXM) assay was first introduced as an additional test. The aim of this study was to clinically validate the single use of the FCXM assay. Methods: This study compared the outcomes of a cohort of kidney transplant patients that underwent FCXM only (FCXM group) versus a cohort of kidney transplant patients that underwent AHG-CDCXM (control group). Results: Ninety-seven patients in the FCXM group and 98 controls were included. All crossmatches in the control group were negative. One patient in the FCXM group had a positive B cell crossmatch. One year after transplantation, there were no significant differences in patient survival (p = 0.591) and graft survival (p = 0.692) between the groups. Also, no significant difference was found in the incidence of Banff ≥ 1A acute cellular rejection episodes (p = 0.289). However, acute antibody-mediated rejections occurred in 3 controls (p = 0.028). Conclusion: The results showed that discontinuing the AHG-CDCXM assay does not modify the clinical outcomes in a 1-year follow-up.

Resumo Introdução: O ensaio de prova cruzada por citotoxicidade dependente do complemento antiglobulina humana (AHG-CDCXM - do inglês anti-human globulin-enhanced complement-dependent cytotoxicity crossmatch) tem sido usado para avaliar a presença de anticorpos específicos contra o doador (DSA - do inglês donor-specific antibodies) no soro do receptor antes do transplante renal. O ensaio de prova cruzada por citometria de fluxo (CFXM) foi introduzido pela primeira vez como um teste adicional. O objetivo deste estudo foi validar clinicamente o uso único do ensaio CFXM. Métodos: Este estudo comparou os resultados de uma coorte de pacientes de transplante renal que foram submetidos apenas ao CFXM (grupo CFXM) contra uma coorte de pacientes de transplante renal submetidos ao AHG-CDCXM (grupo controle). Resultados: Foram incluídos noventa e sete pacientes no grupo CFXM e 98 controles. Todas as provas cruzadas no grupo controle foram negativas. Um paciente no grupo CFXM teve uma prova cruzada positiva para células B. Um ano após o transplante, não houve diferenças significativas na sobrevida do paciente (p = 0,591) e na sobrevida do enxerto (p = 0,692) entre os grupos. Também não foi encontrada diferença significativa na incidência de episódios de rejeição aguda celular (p = 0,289) segundo critério de Banff ≥ 1A. No entanto, rejeições agudas mediadas por anticorpos ocorreram em 3 controles (p = 0,028). Conclusão: Os resultados mostraram que a interrupção do ensaio AHG-CDCXM não modifica os desfechos clínicos em um acompanhamento de 1 ano.