Early Detection and Diagnostic Approach Through Automated Hematological Analysis for Plasma Cell Leukemia.

Plasma cell leukemia (PCL) is a clinically aggressive variant of multiple myeloma, characterized by a high burden of circulating plasma cells, necessitating swift and accurate diagnosis due to its poor prognosis. The conventional diagnostic criteria, including the recent recommendation by the International Myeloma Working Group (IMWG) of > 5% circulating plasma cells as positive, have evolved over time. In this context, we present a detailed case report that underscores the pivotal role of the ADVIA 2120 automated hematology counter in detecting plasma cells through cytogram analysis, along with the significance of routine peripheral blood smear analysis and the utility of a large unstained cells (LUCs) threshold of > 4.5% as an indicator for PCL. The case involves a 64-year-old patient with relapsed multiple myeloma and stable paraprotein levels who experienced sudden renal impairment. In this case report, we highlight how ADVIA analysis and cytochemistry assisted in the diagnosis, and further explore ADVIA's utility in this challenging leukemia.

Enfermedad de Castleman: un enfoque integral a propósito de un reporte de caso / Castleman's Disease: A Comprehensive Approach Regarding a Case Report

Resumen Se presenta el caso clínico de una paciente del sexo femenino, de 30 años, con adenopatías supraclaviculares y axilares ipsilaterales, quien fue sometida a biopsia excisional con posterior estudio. El análisis histopatológico de la muestra de tejido resecado reveló una serie de características distintivas asociadas con la enfermedad de Castleman variante hialinovascular. La presentación de este caso no solo proporciona información detallada sobre la evolución clínica de la paciente, sino que también sirve como base para ilustrar los aspectos clave del diagnóstico histopatológico y las implicaciones inmunohistoquímicas en la enfermedad de Castleman. Además de hacer una revisión de tema respecto a esta patología poco común, en la cual los informes de casos son fundamentales para aumentar la comprensión de su variabilidad clínica y su abordaje diagnóstico, ilustrando los desafíos en el diagnóstico diferencial y como deben abordarse los mismos.

Abstract The clinical case of a 30-year-old female patient with supraclavicular and ipsilateral axillary lymphadenopathy who underwent excisional biopsy with subsequent study is presented. Histopathological analysis of the resected tissue sample revealed a series of distinctive features associated with hyalinevascular variant Castleman disease. The presentation of this case not only provides detailed information about the clinical evolution of the patient, but also serves as a basis to illustrate Key aspects of histopathological diagnosis and immunohistochemical implications in Castleman disease. In addition to making a review of the topic regarding this rare pathology in which case reports are essential to increase the understanding of its clinical variability and its diagnostic approach, illustrating the challenges in differential diagnosis and how they should be addressed.

CD138 immunohistochemistry identifies more plasma cells compared with hematoxylin and eosin staining in autoimmune hepatitis. An observational study.

INTRODUCTION: Autoimmune hepatitis (AIH) is associated with periportal infiltration by plasma cells. Plasma cell detection is routinely performed through hematoxylin and eosin (H&E) staining. The present study aimed to assess the utility of CD138, an immunohistochemical plasma cell marker, in the evaluation of AIH. MATERIALS AND METHODS: A retrospective study was conducted, in which cases consistent with AIH, within the time frame of 2001 and 2011, were collected. Routine H&E-stained sections were used for evaluation. CD138 immunohistochemistry (IHC) was performed to detect plasma cells. RESULTS: Sixty biopsies were included. In the H&E group, the median and interquartile range (IQR) was 6 (4-9) plasma cells/high power field (HPF) and was 10 (IQR 6-20) plasma cells/HPF in the CD138 group (p < 0.001). There was a significant correlation between the number of plasma cells determined by H&E and CD138 (p = 0.31, p = 0.01). No significant correlation was found between the number of plasma cells determined by CD138 and IgG level (p = 0.21, p = 0.09) or stage of fibrosis (p = 0.12, p = 0.35), or between IgG level and stage of fibrosis (p = 0.17, p = 0.17). No significant correlation was found between the treatment response and the number of plasma cells determined by H&E (p = 0.11, p = 0.38), CD138 (p = 0.07, p = 0.55), or stage of fibrosis (p = 0.16, p = 0.20). CD138 expression was different between the treatment response groups (p = 0.04). CONCLUSION: CD138 increased the detection of plasma cells in liver biopsies of patients with AIH, when compared with routine H&E staining. However, there was no correlation between the number of plasma cells determined by CD138 and serum IgG levels, stage of fibrosis, or response to treatment.

Análise do transcriptoma de diferentes tipos de células únicas do sangue periférico de pacientes infectados com o vírus da Dengue para detalhamento da massiva geração de células secretoras de anticorpos / Evaluation of the tryptophan metabolism in the massive generation of antibody-secreting cells in Dengue patients through the transcriptome of single blood cells

A Dengue induz uma resposta exacerbada e transitória das células secretoras de anticorpos (ASCs) no sangue de pacientes cerca de sete dias após o início dos sintomas. A frequência dessas ASCs chega a representar mais de 50% de todas as células B circulantes neste período. No entanto, ainda é desconhecido se a magnitude dessa resposta tem relação com a gravidade da Dengue. Nosso grupo de pesquisa já mostrou que a cultura de células nucleares do sangue periférico (PBMCs) de indivíduos saudáveis com partículas do vírus da Dengue (DENV), por 7 dias, levava a diferenciação de células B em ASCs em magnitude similar àquelas estimuladas por mitógenos. Essas culturas apresentavam um consumo significativamente maior de triptofano (TRP), associado à maior expressão das enzimas IDO1 e IDO2, e, consequentemente, maior síntese de quinurenina (KYN) em relação ao estímulo por mitógenos. Considerando que as concentrações de TRP e KYN detectadas nos sobrenadantes dessas culturas eram diretamente proporcionais ao aumento de ASCs, decidimos investigar o papel desse metabolismo do TRP e de seus respectivos metabólitos na diferenciação das ASCs. Para isso, análises do transcriptoma público de células únicas do sangue periférico de pacientes com Dengue (estudo E-MTAB- 9467) foram realizadas para inferir a real participação do metabolismo do TRP na geração de ASCs. Com o programa R foram executadas análises de Downstream. Identificamos um aumento massivo das ASCs nas amostras dos pacientes infectados com Dengue. No entanto, os principais genes desencadeadores da ativação do metabolismo do TRP (IDO1 e IDO2) não foram expressos nas subpopulações de células B, mas sim em células dendríticas e monócitos CD14+ respectivamente. Isso sugeriria que esta via não seria ativada nos linfócitos B. Por outro lado, genes codificadores de outros participantes da via do TRP (HSD17B10, ECHS1 e SIRT3) foram detectados em células B e podem estar relacionados com a proliferação das ASCs. Além disso, a análise de enriquecimento mostrou uma aumentada expressão de genes associados com moléculas de MHC de classe II em plasmablastos e plasmócitos de pacientes com Dengue. Porém, com a expressão aumentada de ENTPD1 nessas células durante a fase sintomatológica, nossos dados sugerem também que um eventual papel de plasmablastos e plasmócitos como apresentadoras de antígenos na Dengue poderia induzir uma resposta supressora de células T

Dengue can cause an exacerbated and transient antibody-secreting cell (ASC) response in the blood of patients nearly 7 days of symptomatology. The ASC frequency reaches more than 50% of all circulating B cells during that period. However, it is still unknown whether the magnitude of this response may be directly related to the severity of Dengue. Our research group has already shown that the culture of peripheral blood mononuclear cells (PBMCs) from healthy individuals with Dengue virus (DENV) particles for 7 days led to a differentiation of B cells into ASCs to a magnitude similar to those stimulated by mitogens. These cultures showed significantly higher consumption of tryptophan (TRP), associated with higher expression of enzymes IDO1 and IDO2, and consequently, higher synthesis of quinurenine (KYN) compared to mitogen stimulation. The concentrations of TRP and KYN detected in the supernatants of these cultures were directly proportional to ASC frequency increase. Thus, we have decided to investigate the role of TRP metabolism and its respective metabolites in ASC differentiation. For this, we performed an analysis of single-cell transcriptome with peripheral blood from Dengue patients (dataset from E-MTAB-9467 study). Downstream analyses were performed with R software. Corroborating with literature, we identified a massive increase in ASC frequency of Dengue infected patients. However, the main genes triggering TRP metabolism activation (IDO1 and IDO2) were not expressed in B-cell subsets, but in dendritic cells and CD14+ monocytes, respectively. This would suggest that this pathway would not be activated in B lymphocytes. Nevertheless, genes encoding other participants in the TRP pathway (HSD17B10, ECHS1, and SIRT3) were detected in B cells and may be related to ASC proliferation. Futhermore, a Gene Ontology analysis showed an increased expression of genes associated with MHC class II molecules in plasmablasts and plasma cells of Dengue patients. As these cells also presented an increased expression of ENTPD1 during the symptomatic phase, our data suggest a potential role of plasmablasts and plasma cells as antigen-presenting cells associated with a suppressive T cell response in Dengue

Clinical characterization and outcomes of a cohort of colombian patients with AL Amyloidosis.

Background: Amyloid light chain (AL) amyloidosis is characterized by amyloid fibril deposition derived from monoclonal immunoglobulin light chains, resulting in multiorgan dysfunction. Limited data exist on the clinical features of AL amyloidosis. Objective: This study aims to describe the clinical characteristics, treatments, and outcomes in Colombian patients with AL amyloidosis. Methods: A retrospective descriptive study was conducted at three high-complexity centers in Medellín, Colombia. Adults with AL amyloidosis diagnosed between 2012 and 2022 were included. Clinical, laboratory, histological, treatment, and survival data were analyzed. Results: The study included 63 patients. Renal involvement was most prevalent (66%), followed by cardiac involvement (61%). Multiorgan involvement occurred in 61% of patients. Amyloid deposition was most commonly detected in renal biopsy (40%). Bortezomib-based therapy was used in 68%, and 23.8% received high-dose chemotherapy with autologous hematopoietic stem cell transplantation (HDCT-ASCT). Hematological response was observed in 95% of patients with available data. Cardiac and renal organ responses were 15% and 14%, respectively. Median overall survival was 45.1 months (95% CI: 22.2-63.8). In multivariate analysis, cardiac involvement was significantly associated with inferior overall survival (HR 3.27; 95% CI: 1.23-8.73; p=0.018), HDCT-ASCT had a non-significant trend towards improved overall survival (HR 0.25; 95% CI: 0.06-1.09; p=0.065). Conclusions: In this study of Colombian patients with AL amyloidosis, renal involvement was more frequent than cardiac involvement. Overall survival and multiorgan involvement were consistent with data from other regions of the world. Multivariate analysis identified cardiac involvement and HDCT-AHCT as possible prognostic factors.

Antecedentes: La amiloidosis por amiloide de cadenas ligeras (AL) se caracteriza por el depósito de fibrillas amiloides derivadas de cadenas ligeras de inmunoglobulinas monoclonales, lo que resulta en disfunción multiorgánica. Existen datos limitados sobre las características clínicas de la amiloidosis AL. Objetivo: Este estudio tiene como objetivo describir las características clínicas, tratamientos y desenlaces en pacientes colombianos con amiloidosis AL. Métodos: Se llevó a cabo un estudio descriptivo retrospectivo en tres centros de alta complejidad en Medellín, Colombia. Se incluyeron adultos con diagnóstico de amiloidosis AL entre 2012 y 2022. Se analizaron datos clínicos, de laboratorio, histológicos, de tratamiento y de supervivencia. Resultados: El estudio incluyó 63 pacientes. La afectación renal fue más prevalente (66%), seguida de la afectación cardíaca (61%). El 61% de los pacientes presentaron afectación multiorgánica. El depósito amiloide se detectó con mayor frecuencia en la biopsia renal (40%). El tratamiento basado en bortezomib se utilizó en el 68%, y el 23.8% recibió altas dosis de quimioterapia con trasplante autólogo de progenitores hematopoyéticos (ADQT-TAPH). Se observó respuesta hematológica en el 95% de los pacientes con datos disponibles. La respuesta de órgano cardíaca y renal fue del 15% y 14%, respectivamente. La mediana de la supervivencia global fue de 45.1 meses (IC del 95%: 22.2-63.8). En el análisis multivariado, la afectación cardíaca se asoció significativamente con una supervivencia global inferior (HR 3.27; IC del 95%: 1.23-8.73; p=0.018), ADQT-TAPH mostró una tendencia no significativa hacia una mejora en la supervivencia global (HR 0.25; IC 95%: 0.06-1.09; p=0.065). Conclusiones: En este estudio de pacientes colombianos con amiloidosis AL, la afectación renal fue más frecuente que la afectación cardíaca. La supervivencia global y la afectación multiorgánica fueron consistentes con datos de otras regiones del mundo. El análisis multivariado identificó la afectación cardíaca y ADQT-TAPH como posibles factores pronósticos.

Humoral and Cellular Immunology in Human Prostate Cancer: Plasma Cells and T and B Lymphocytes / Inmunología Humoral y Celular en el Cáncer de Próstata Humano: Células Plasmáticas y Linfocitos T y B

SUMMARY: In solid and malignant tumors, innate and adaptive immunity are combined in antitumor responses. This study aimed to analyze the activation of plasma cells and the correlation between the infiltration of B and T lymphocytes with the degree of malignancy or Gleason grade in human prostate biopsies diagnosed with cancer. Prostate cancer biopsies were obtained from the Clinical Hospital of Universidad de Chile (n=70), according to the bioethical norms of the institution. Histological sections of 5µm thickness were processed for immunohistochemistry with primary antibodies against BL and total TL (HRP/DAB). Recognition and quantification were performed under a Leica DM750 optical microscope. Microsoft Excel and GraphPad software were used for the statistical study. Correlation coefficient (Pearson) and mean comparison tests (Kruskal-Wallis and Dunn) and p≤ 0.05 were developed. B and T lymphocyte populations were inversely interregulated in prostate cancer (Gleason) (r= -0.46). Their relationship with Gleason grade is variable according to lymphocyte type (LB vs. Gleason r= -0.0.47 and LT vs. Gleason r= -0.21). Histological diagnosis of prostate cancer correlates with a predominance of LT. The malignancy of the pathology correlates with a predominance of LTs, according to the Gleason grade. The increased knowledge of B and T lymphocyte infiltration and plasma cell activation could be used to better target clinical trials on treatments based on immune system responses. Immunotherapy could be a new paradigm to apply better antitumor therapy strategies.

En tumores sólidos y malignos, la inmunidad innata y adaptativa se combinan en respuestas antitumorales. Este estudio tuvo como objetivo analizar la activación de células plasmáticas y la correlación entre la infiltración de linfocitos B y T con el grado de malignidad o grado de Gleason en biopsias de próstata humana diagnosticadas con cáncer. Las biopsias de cáncer de próstata se obtuvieron del Hospital Clínico de la Universidad de Chile (n=70), de acuerdo con las normas bioéticas de la institución. Secciones histológicas de 5 µm de espesor fueron procesadas para inmunohistoquímica con anticuerpos primarios contra LB y LT total (HRP/DAB). El reconocimiento y las cuantificaciones se realizaron bajo un microscopio óptico Leica DM750. Para el estudio estadístico se utilizaron los programas Microsoft Excel y GraphPad. Se desarrollaron pruebas de coeficiente de correlación (Pearson) y comparación de medias (Kruskal-Wallis y Dunn) y p≤ 0.05. Los resultados muestran que las poblaciones de linfocitos B y T están inversamente interreguladas en el cáncer de próstata (r= -0,4578). Su relación con el grado de Gleason es variable según el tipo de linfocito (LB vs Gleason r= -0,47* y LT vs Gleason r= -0,21). Se concluye que la malignidad del cáncer de próstata se correlaciona con un predominio de LT, versus el grado de Gleason. El mayor conocimiento de la infiltración de linfocitos B y T y la activación de células plasmáticas podría aprovecharse para una mejor orientación de ensayos clínicos en tratamientos basados en las respuestas del sistema inmunitario. La inmunoterapia podría ser un nuevo paradigma para aplicar mejores estrategias de terapias antitumorales.

Clinical characterization and outcomes of a cohort of colombian patients with AL Amyloidosis

Background: Amyloid light chain (AL) amyloidosis is characterized by amyloid fibril deposition derived from monoclonal immunoglobulin light chains, resulting in multiorgan dysfunction. Limited data exist on the clinical features of AL amyloidosis. Objective: This study aims to describe the clinical characteristics, treatments, and outcomes in Colombian patients with AL amyloidosis. Methods: A retrospective descriptive study was conducted at three high-complexity centers in Medellín, Colombia. Adults with AL amyloidosis diagnosed between 2012 and 2022 were included. Clinical, laboratory, histological, treatment, and survival data were analyzed. Results: The study included 63 patients. Renal involvement was most prevalent (66%), followed by cardiac involvement (61%). Multiorgan involvement occurred in 61% of patients. Amyloid deposition was most commonly detected in renal biopsy (40%). Bortezomib-based therapy was used in 68%, and 23.8% received high-dose chemotherapy with autologous hematopoietic stem cell transplantation (HDCT-ASCT). Hematological response was observed in 95% of patients with available data. Cardiac and renal organ responses were 15% and 14%, respectively. Median overall survival was 45.1 months (95% CI: 22.2-63.8). In multivariate analysis, cardiac involvement was significantly associated with inferior overall survival (HR 3.27; 95% CI: 1.23-8.73; p=0.018), HDCT-ASCT had a non-significant trend towards improved overall survival (HR 0.25; 95% CI: 0.06-1.09; p=0.065). Conclusions: In this study of Colombian patients with AL amyloidosis, renal involvement was more frequent than cardiac involvement. Overall survival and multiorgan involvement were consistent with data from other regions of the world. Multivariate analysis identified cardiac involvement and HDCT-AHCT as possible prognostic factors.

Antecedentes: La amiloidosis por amiloide de cadenas ligeras (AL) se caracteriza por el depósito de fibrillas amiloides derivadas de cadenas ligeras de inmunoglobulinas monoclonales, lo que resulta en disfunción multiorgánica. Existen datos limitados sobre las características clínicas de la amiloidosis AL. Objetivo: Este estudio tiene como objetivo describir las características clínicas, tratamientos y desenlaces en pacientes colombianos con amiloidosis AL. Métodos: Se llevó a cabo un estudio descriptivo retrospectivo en tres centros de alta complejidad en Medellín, Colombia. Se incluyeron adultos con diagnóstico de amiloidosis AL entre 2012 y 2022. Se analizaron datos clínicos, de laboratorio, histológicos, de tratamiento y de supervivencia. Resultados: El estudio incluyó 63 pacientes. La afectación renal fue más prevalente (66%), seguida de la afectación cardíaca (61%). El 61% de los pacientes presentaron afectación multiorgánica. El depósito amiloide se detectó con mayor frecuencia en la biopsia renal (40%). El tratamiento basado en bortezomib se utilizó en el 68%, y el 23.8% recibió altas dosis de quimioterapia con trasplante autólogo de progenitores hematopoyéticos (ADQT-TAPH). Se observó respuesta hematológica en el 95% de los pacientes con datos disponibles. La respuesta de órgano cardíaca y renal fue del 15% y 14%, respectivamente. La mediana de la supervivencia global fue de 45.1 meses (IC del 95%: 22.2-63.8). En el análisis multivariado, la afectación cardíaca se asoció significativamente con una supervivencia global inferior (HR 3.27; IC del 95%: 1.23-8.73; p=0.018), ADQT-TAPH mostró una tendencia no significativa hacia una mejora en la supervivencia global (HR 0.25; IC 95%: 0.06-1.09; p=0.065). Conclusiones: En este estudio de pacientes colombianos con amiloidosis AL, la afectación renal fue más frecuente que la afectación cardíaca. La supervivencia global y la afectación multiorgánica fueron consistentes con datos de otras regiones del mundo. El análisis multivariado identificó la afectación cardíaca y ADQT-TAPH como posibles factores pronósticos.

Pseudotumor inflamatorio hepático: caso clínico y revisión de la literatura / Hepatic Inflammatory Pseudotumor Mimicking Cholangiocarcinoma: A Rare Case and Literature Review

Presentamos el caso de un paciente de 49 años, de sexo masculino, que consulta en el servicio de urgencias por un cuadro de dos meses de evolución, caracterizado por compromiso del estado general, baja de peso, dolor abdominal, sensación febril y elevación de los parámetros inflamatorios. Al estudio imagenológico se observa una voluminosa lesión hepática, asociada a dilatación de la vía biliar y adenopatías en hilio hepático, espacio porto-cavo y retroperitoneales (inter-cavo-aórticos), que plantea dentro de los diagnósticos diferencias un colangiocarcinoma intrahepático. Basados en esta sospecha se realiza una segmentectomía y linfadenectomía regional. El estudio histopatológico e inmunohistoquímico de la pieza quirúrgica, evidencia un proceso inflamatorio linfoplasmocitario, con la presencia de células plasmáticas IgG4 positivas, compatible con una enfermedad asociada a IgG4. Posterior a la resección se decide manejo expectante, evolucionando el paciente de forma favorable, asintomático y sin signos de recurrencia. Presentamos un caso y una breve revisión de la literatura de un pseudotumor inflamatorio hepático, entidad poco frecuente y de comportamiento benigno.

We report the case of a 49-year-old man who attended the emergency department for a two-month history of compromised general condition, weight loss, abdominal pain, fever, and elevated inflammatory parameters. An imaging study demonstrates a bulky liver tumor associated with dilation of the bile duct and retroperitoneal adenopathies (hepatic hilum, intermediate, and right lumbar groups). These findings raise intrahepatic cholangiocarcinoma within the differential diagnoses, reason why segmental hepatectomy and regional lymphadenectomy were performed. Histopathology and immunochemistry revealed a lymphoplasmacytic inflammatory process with IgG4-positive plasma cells compatible with IgG4-associated disease. After the resection, expectant management was decided, with the patient evolving favorably, asymptomatic, and without signs of recurrence. We present a case and a brief literature review of an hepatic inflammatory pseudotumor, a rare entity with a benign behavior.

Metastatic extramedullary plasmacytoma in a canine / Plasmocitoma extramedular metastático em um canino

Abstract Plasmocytomas are neoplasms originating from plasma cells and can be subdivided into cutaneous extramedullary, non-cutaneous and multiple myeloma. The involvement of vertebrae can generate clinical signs of pain and neurological alterations according to the affected segment. The present study aims to report a case of extramedullary plasmacytoma in the thoracic spine and with consequent spinal cord compression in addition to metastasis sites, characterizing its clinicopathological aspects. The canine patient was hospitalized, submitted to laboratory and imaging tests, and medicated due to incoordination and loss of perception of limb positioning, but his clinical picture worsened, progressing to loss of movement and fecal and urinary incontinence, resulting in death. The main necropsy findings were the presence of a tumor mass along the external surface of the body of the fifth thoracic vertebra, in addition to light brown foci in the thoracic spinal cord and in the pulmonary and splenic parenchyma. Histologically, the tumor mass and light brown foci consisted of malignant cell proliferation, of plasmacytic origin, densely cellular and largely infiltrative. Thus, through the clinical picture presented, imaging tests and anatomopathological analysis, it was shown that it was a case of extramedullary plasmocytoma originating in the thoracic spine, with sites of metastasis in the spinal cord, lung and spleen.

Resumo Plasmocitomas são neoplasmas originados de plasmócitos e podem ser subdivididos em extramedular cutâneo, não cutâneo e mieloma múltiplo. O envolvimento de vértebras pode gerar sinais clínicos de dor e alterações neurológicas de acordo com o segmento afetado. O presente estudo tem como objetivo relatar um caso de plasmocitoma extramedular em coluna vertebral torácica e com consequente compressão medular além de sítios de metástases, caracterizando seus aspectos clínico-patológicos. O paciente canino foi hospitalizado, submetido a exames laboratoriais e de imagem, e medicado devido a incoordenação e perda da percepção do posicionamento dos membros, mas apresentou piora do quadro clínico evoluindo para perda dos movimentos e incontinência fecal e urinária, ocorrendo o óbito. Os principais achados de necropsia foram a presença de massa tumoral junto à superfície externa do corpo da quinta vértebra torácica, além de focos pardo-claros na medula espinhal torácica e no parênquima pulmonar e esplênico. Histologicamente, a massa tumoral e os focos pardo-claros consistiam em proliferação celular maligna, de origem plasmocitária, densamente celular e amplamente infiltrativa. Assim, através do quadro clínico apresentado, exames de imagem e da análise anatomopatológica evidenciou tratar-se de um caso de plasmocitoma extramedular originado em coluna vertebral torácica, com sítios de metástase em medula espinhal, pulmão e baço.

Mieloma múltiple con IgM de superficie precedido por síndrome mielodisplásico en paciente anciana / Surface membrane IgM multiple myeloma preceded by myelodysplastic syndrome in an elderly patient

Introducción: El mieloma múltiple con expresión de inmunoglobulina M de superficie constituye una enfermedad rara cuya causa es desconocida y se caracteriza por una alta tasa de anormalidades genéticas en las células plasmáticas o sus precursores. Objetivo: Determinar las características clínicas y sus asociaciones con la expresión inmunofenotípica de inmunoglobulina M de superficie e inmunohistoquímica de CD20 en una paciente afectada de mieloma múltiple precedido por síndrome mielodisplásico. Presentación del caso: Paciente femenina, 68 años de edad. Admitida en el Servicio de Hematología Clínica. Al momento del diagnóstico presentó palidez, trombocitopenia, hipercalcemia y lesiones óseas. Inicialmente, mediante citometría de flujo se detectaron patrones aberrantes para granulocitos, neutrófilos, monocitos y serie eritroide, sugerentes de síndrome mielodisplásico. Posteriormente se observó aumento de las células plasmáticas del 18 % en el frotis de médula ósea, exhibiendo una morfología similar a linfocitos. Se reportó una población patológica de 6 % de la celularidad total, mostrando positividad para CD38, CD117 e inmunoglobulina M de superficie, negatividad para CD19 y CD45, fenotipo coherente con células plasmáticas anormales. Adicionalmente resultados de inmunohistoquímica relataron tinción difusa de CD20 en biopsia de médula ósea. La paciente logró recuperarse luego de un trasplante autólogo de células progenitoras hematopoyéticas. Conclusión: Los resultados resaltan la importancia de diagnosticar y monitorear casos únicos que permitan un tratamiento oportuno del paciente.

Introduction: Multiple Myeloma with expression of surface immunoglobulin M is a rare entity, whose cause is unknown, and is characterized by a high rate of genetic abnormalities in plasma cells or their precursors. Objective: To determining the clinical characteristics and their associations with the immunophenotypic expression of surface immunoglobulin M and CD20 immunohistochemistry in a patient affected by Multiple Myeloma preceded by Myelodysplastic syndrome. Case presentation: A 68-year-old female patient is admitted to the Clinical Hematology Service. At the time of diagnosis, she presented pallor, thrombocytopenia, hypercalcemia, and bone lesions. Initially, flow cytometry detected aberrant patterns for neutrophilic granulocytes, monocytes, and the erythroid series suggestive of myelodysplastic syndrome. Subsequently, an 18% increase in plasma cells was observed in the bone marrow smear, exhibiting a lymphocyte-like morphology. A pathological population of 6% of the total cellularity was reported, showing positivity for CD38, CD117 and surface immunoglobulin M, negativity for CD19 and CD45, a phenotype consistent with abnormal plasma cells. Additionally, immunohistochemical results reported diffuse CD20 staining in bone marrow biopsy. The patient managed to recover after an autologous hematopoietic stem cell transplant. Conclusion: The results found highlight the importance of diagnosing and monitoring single cases that allow timely treatment of the patient.

Extrafollicular Plasmablasts Present in the Acute Phase of Infections Express High Levels of PD-L1 and Are Able to Limit T Cell Response.

During infections with protozoan parasites or some viruses, T cell immunosuppression is generated simultaneously with a high B cell activation. It has been described that, as well as producing antibodies, plasmablasts, the differentiation product of activated B cells, can condition the development of protective immunity in infections. Here, we show that, in T. cruzi infection, all the plasmablasts detected during the acute phase of the infection had higher surface expression of PD-L1 than other mononuclear cells. PD-L1hi plasmablasts were induced in vivo in a BCR-specific manner and required help from Bcl-6+CD4+T cells. PD-L1hi expression was not a characteristic of all antibody-secreting cells since plasma cells found during the chronic phase of infection expressed PD-L1 but at lower levels. PD-L1hi plasmablasts were also present in mice infected with Plasmodium or with lymphocytic choriomeningitis virus, but not in mice with autoimmune disorders or immunized with T cell-dependent antigens. In vitro experiments showed that PD-L1hi plasmablasts suppressed the T cell response, partially via PD-L1. Thus, this study reveals that extrafollicular PD-L1hi plasmablasts, whose peaks of response precede the peak of germinal center response, may have a modulatory function in infections, thus influencing T cell response.

Cholecystokinin Outcome on Markers of Intestinal IgA Antibody Response.

Cholecystokinin 8 (CCK8) is an entero-octapeptide that participates in crosstalk with components of intestinal immunity via the CCK receptor (CCKR), but its role in modulation of the IgA response is not fully known under physiological conditions. Male eight-week-old BALB/c mice each were intraperitoneally injected once during 7 days with CCK8, devazapide (CCKR1 antagonist), L365,260 (CCKR2 antagonist) or vehicle (sham group). In intestinal lavages, total and secretory IgA (SIgA) were determined by ELISA; in lamina propria, IgA+ B lymphocytes and IgA+ plasma cells were analyzed by flow cytometry; mRNA levels of polymeric immunoglobulin receptor (pIgR) in epithelial cells and α chain, interleukins (ILs) in lamina propria cells were assessed by qRTPCR. Regarding the sham conditions, IgA+ plasma-cell percentage and IL-2, IL-5, IL-10 and transforming growth factor-ß (TGF-ß) mRNA levels were either increased by CCK8 or decreased by both CCKR antagonists. For IgA/SIgA responses, IL-4/IL-6 mRNA levels were decreased by all drugs and pIgR mRNA was increased by CCK8 and reduced by L365,260. IgA+ B cell percentage and α chain mRNA levels were elicited by CCK8 and L365,260. Data suggested a presumable differential role of CCK/CCKR on the IgA-response; outcome of L365,260 on the elicitation of IgA+ B cells and α chain mRNA needs further examination.

POEMS Syndrome Diagnosis in a Patient with Mixed Polyneuropathy: Case Report.

POEMS syndrome is a rare condition of paraneoplasic origin characterized by the presence of a sensorimotor polyneuropathy associated with the presence of a proliferative disorder of plasmatic monoclonal cells and overproduction of vascular endothelial growth factor. The acronym "POEMS" represents multisystem findings including polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder and skin changes; nevertheless, clinical presentation is heterogeneous. We describe a clinical case, the diagnostic and therapeutic approach in a patient with sensorimotor polyneuropathy in whom POEMS syndrome was diagnosed; to understand this pathology, its clinical and paraclinical manifestations in order to make a diagnosis or to avoid a delayed one and to provide an adequate treatment.

Presentación histopatológica atípica en médula ósea de mieloma múltiple / Atypical histopathological presentation in bone marrow of multiple myeloma

Objetivo: Describir la presentación histopatológica atípica en médula ósea de mieloma múltiple. Reporte de Caso: Presentamos el caso de un varón de 75 años, quien manifiesta lumbalgia de intensidad variable asociada a disminución del flujo urinario, por lo que acude a emergencia. Al examen físico se encuentran funciones vitales dentro de parámetros normales, disminución generalizada del tejido adiposo y palidez terrosa, el resto del examen no contributorio. En estudios de médula ósea se reporta 13% de células plasmáticas, observándose células neoplásicas tetranucleadas con 1 y 2 nucleolos, citoplasma basófilo con presencia de vacuolas; es corroborado en citometría de flujo con fenotipo patológico en relación a neoplasia de células plasmáticas. Paciente recibe esquema terapéutico con ciclofosfamida, dexametasona y talidomida. Conclusión: La presentación tetranucleada es una variante histopatológica del mieloma múltiple poco frecuente; por lo que este hallazgo peculiar, debe ser valorado en el diagnóstico microscópico de la entidad clínica.

Objetive: To describe the atypical histopathologic presentation in bone marrow of multiple myeloma. Case Report: We present the case of a 75-year- old male who manifested low back pain of variable intensity associated with decreased urinary flow, for which he went to the emergency room. On physical examination, vital functions were within normal parameters with generalized decrease in adipose tissue and earthy pallor, the rest of the examination being non-contributory. Bone marrow studies showed 13% of plasma cells with tetranucleated neoplastic cells with 1 and 2 nucleoli, basophilic cytoplasm with presence of vacuoles, which was corroborated in flow cytometry with pathological phenotype in relation to plasma cell neoplasia. The patient receives a therapeutic regimen with cyclophosphamide, dexamethasone and thalidomide. Conclusion: Tetranucleated presentation is a rare histopathologic variant of multiple myeloma, so this peculiar finding should be appreciated in the microscopic diagnosis of this clinical entity.

Cellular infiltrate in cutaneous leishmaniasis lesions and therapeutic outcome

Abstract Background: The treatment of cutaneous leishmaniasis is a challenge. A better understanding of the in situ mechanisms involved in the evolution and cure of the disease is essential for the development of new therapies. Objective: Correlate histopathological and immunological characteristics of cutaneous leishmaniasis lesions with clinical outcome after different treatment regimens. Methods: The authors analyzed cellular infiltration and immunohistochemistry staining for CD4, CD8 and IL-17 in biopsy samples from 33 patients with cutaneous leishmaniasis before treatment. All patients were recruited in a randomized clinical trial at Corte de Pedra (Bahia-Brazil) and assigned to receive Glucantime®, Glucantime® + Oral Tamoxifen or Glucantime® + Topical Tamoxifen. Patients were followed for 2 to 6 months to define disease outcome. Results: A similar expression of CD4, CD8 and IL-17 was observed in lesion samples regardless of clinical outcome. In general, a higher amount of CD8 cells were observed compared with CD4 cells. An important observation was that all patients whose cellular infiltrate did not contain plasma cells were cured after treatment. Study limitations: Isolated quantification of TCD8 and IL-17 using immunohistochemistry is insufficient to analyze the role of these molecules in the immunopathogenesis of cutaneous leishmaniasis. In addition, the expansion of the immunohistochemistry panel would allow a more complete analysis of the immune response in situ. Conclusions: The absence of plasma cells in cutaneous leishmaniasis lesions was related to a favorable therapeutic outcome.

Solitary plasmacytoma of mandible: an unusual bilateral presentation.

Plasmacytoma is a neoplastic proliferation of monoclonal plasma cells, which can present clinically as solitary bone neoplasm, extramedullary plasmacytoma, and multiple myeloma. The biological behavior of these tumors is variable from periods of clinical latency to rapid growth and progression from localized forms to more disseminated multiple myeloma. We present the case of solitary plasmacytoma of the mandible with rare bilateral involvement in a 65-year-old female patient. This paper highlights the importance of understanding the maxillofacial manifestations of the disease by the dentist for early diagnosis and thus better prognosis.

Cellular infiltrate in cutaneous leishmaniasis lesions and therapeutic outcome.

BACKGROUND: The treatment of cutaneous leishmaniasis is a challenge. A better understanding of the in situ mechanisms involved in the evolution and cure of the disease is essential for the development of new therapies. OBJECTIVE: Correlate histopathological and immunological characteristics of cutaneous leishmaniasis lesions with clinical outcome after different treatment regimens. METHODS: The authors analyzed cellular infiltration and immunohistochemistry staining for CD4, CD8 and IL-17 in biopsy samples from 33 patients with cutaneous leishmaniasis before treatment. All patients were recruited in a randomized clinical trial at Corte de Pedra (Bahia-Brazil) and assigned to receive Glucantime®, Glucantime® + Oral Tamoxifen or Glucantime® + Topical Tamoxifen. Patients were followed for 2 to 6 months to define disease outcome. RESULTS: A similar expression of CD4, CD8 and IL-17 was observed in lesion samples regardless of clinical outcome. In general, a higher amount of CD8 cells were observed compared with CD4 cells. An important observation was that all patients whose cellular infiltrate did not contain plasma cells were cured after treatment. STUDY LIMITATIONS: Isolated quantification of TCD8 and IL-17 using immunohistochemistry is insufficient to analyze the role of these molecules in the immunopathogenesis of cutaneous leishmaniasis. In addition, the expansion of the immunohistochemistry panel would allow a more complete analysis of the immune response in situ. CONCLUSIONS: The absence of plasma cells in cutaneous leishmaniasis lesions was related to a favorable therapeutic outcome.

Inflammatory infiltrates in melanocytic lesions / Infiltrados inflamatorios en lesiones melanocíticas

SUMMARY: Inflammatory infiltrates are frequently present in melanocytic lesions, with different distribution and composition. Much attention has been devoted to tumor-infiltrating lymphocytes (TIL) in the tumor microenvironment, establishing their prognostic and predictive value in many malignancies, including melanoma. However, lymphocytes, albeit the most numerous and consistent presence, constitute only part of the immune microenvironment. Other inflammatory cells, including neutrophils, plasma cells, eosinophils and mast cells, are found in melanoma and other melanocytic lesions.Few studies offer a detailed count of these inflammatory infiltrates across the spectrum of melanocytic lesions. By using whole slide image analysis and open source software, in the present study we report the enumeration of different inflammatory infiltrates in benign melanocytic nevi, dysplastic nevi, melanoma in situ and invasive malignant melanomas. Significant higher numbers of plasma cells and neutrophils were observed in melanoma. These results indicate that composition of the inflammatory infiltrate may contribute to the diagnostic algorithm of melanocytic lesions.

RESUMEN: Los infiltrados inflamatorios están presentes con frecuencia en las lesiones melanocíticas, con diferente distribución y composición. Se ha prestado mucha atención a los linfocitos infiltrantes de tumores (TIL) en el microambiente tumoral, estableciendo su valor pronóstico y predictivo en muchas neoplasias malignas, incluido el melanoma. Sin embargo, los linfocitos de presencia más numerosa y constante, constituyen solo una parte del microambiente inmunológico. Otras células inflamatorias, incluidos neutrófilos, células plasmáticas, eosinófilos y mastocitos, se encuentran en el melanoma y otras lesiones melanocíticas. Pocos estudios ofrecen un recuento detallado de estos infiltrados inflamatorios en todo el espectro de lesiones melanocíticas. Mediante el uso de análisis de imágenes de diapositivas completas y software de código abierto, en el presente estudio informamos la enumeración de diferentes infiltrados inflamatorios en nevos melanocíticos benignos, nevos displásicos, melanoma in situ y melanomas malignos invasivos. Se observaron números significativamente más altos de células plasmáticas y neutrófilos en el melanoma. Estos resultados indican que la composición del infiltrado inflamatorio puede contribuir al algoritmo diagnóstico de las lesiones melanocíticas.

Detección y cuantificación de células plasmáticas (plasmocitos) en granulomas periapicales inducidos experimentalmente en ratas / Detection and quantification of plasma cells in experimentally induced rat periapical granulomas

Objetivo: En los granulomas periapicales, los plasmocitos (PL) participan activamente mediante la liberación de inmunoglobulinas. El propósito de este ensayo fue identificar y contar el número de PL en diferentes períodos de tiempo en lesiones periapicales experimentales en ratas. Materiales y métodos: Mediante la exposición al medio oral de la pulpa de los primeros molares inferiores izquierdos, se indujeron granulomas periapicales en ratas a las que previamente se les suministró anestesia. La pulpa de los primeros molares inferiores derechos no fue expuesta, y estos dientes se utilizaron como control. Los animales fueron eutanasiados a los 10, 30 y 60 días de la exposición. Los maxilares inferiores fueron removidos, y los primeros molares, junto con los tejidos circundantes, se procesaron para su estudio histológico. Se obtuvieron secciones semiseriadas, posteriormente coloreadas con verde de metilo-pironina (VMP). Cada tres secciones, las tres siguientes fueron coloreadas con hematoxilina y eosina (H-E). Los controles también fueron coloreados con H-E. Resultados: Todos los especímenes experimentales coloreados con H-E revelaron la presencia de granulomas periapicales. Luego de la exposición pulpar, el número de PL que reaccionó positivamente al VMP se incrementó de manera progresiva desde el día 10 hasta los días 30 y 60. A pesar de que a los 60 días el número de PL fue ligeramente menor que a los 30 días, no hubo diferencias estadísticamente significativas entre estos dos períodos. Los especímenes del grupo control coloreados con H-E mostraron que los tejidos periapicales se encontraban dentro de los parámetros normales en todos los períodos de observación. Conclusiones: Los resultados de este estudio revelaron que el número de plasmocitos VMP positivos se incrementa progresivamente en función del tiempo transcurrido pero se estabiliza al finalizar el experimento. También sugieren que el empleo de la coloración de VMP es un procedimiento adecuado para la identificación y la cuantificación de plasmocitos en los granulomas periapicales inducidos experimentalmente en ratas (AU)

Aim: Plasma cells (PL) release immunoglobulin in periapical lesions. The purpose of this assay was to identify and count the number of plasmocytes observed in periapical lesions in rats. Materials and methods: By exposing the pulp of the lower left first molars to the oral environment, periapical granulomas were induced in rats previously anesthetized. The pulp of right mandibular first molars was not exposed and these teeth were used as negative controls. The animals were euthanized at 10, 30 and 60 days after pup exposure. The mandibles were removed and specimens of the molar teeth along with the surrounding tissues were prepared for histology. Semi serial sections of the left first molar were stained with methyl green pyronine (MGP). Every three sections, the following three sections were stained with hematoxilyn and eosin (H-E). Negative control samples were stained with H-E. Results: All the H-E stained experimental samples revealed the presence of periapical granulomas. After pulp exposure, the number of PL increased from day 10 to 30 and 60. In the 60-day samples the number of PL was slightly less than that of the 30-day samples, with no statistically significant difference. The H-E stained control samples showed normal periapical tissues in all observation periods. Conclusions: The results of this study revealed that the number of VMP positive PL, increased progressively with time but it was stabilized at the end of the experiment. In addition, the results suggest that the use of VMP stain is a suitable procedure for the identification and counting of PL in experimentally induced periapical granulomas in rats (AU)

STAT6 signaling pathway controls germinal center responses promoted after antigen targeting to conventional type 2 dendritic cells.

Conventional dendritic cells (cDCs) are antigen-presenting cells specialized in naïve T cell priming. Mice splenic cDCs are classified as cDC1s and cDC2s, and their main functions have been elucidated in the last decade. While cDC1s are specialized in priming type 1 helper T cells (TH1) and in cross presentation, cDC2s prime T follicular helper (TFH) cells that stimulate germinal center (GC) formation, plasma cell differentiation and antibody production. However, less is known about the molecular mechanisms used by cDCs to prime those responses. Here, using WT and STAT6-deficient mice (STAT6 KO), we targeted a model antigen to cDC1s and cDC2s via DEC205 and DCIR2 receptors, respectively, in an attempt to study whether the STAT6 signaling pathway would modulate cDCs' ability to prime helper T cells. We show that the differentiation and maturation of cDCs, after stimulation with an adjuvant, were comparable between WT and STAT6 KO mice. Besides, our results indicate that, in STAT6 KO mice, antigen targeting to cDC2s induced reduced TFH and GC responses, but did not alter plasma cells numbers and antibody titers. Thus, we conclude that the STAT6 signaling pathway modulates the immune response after antigen targeting to cDC2s via the DCIR2 receptor: while STAT6 stimulates the development of TFH cells and GC formation, plasma cell differentiation occurs in a STAT6 independent manner.