Antígenos del sistema sanguíneo ABO como factor de riesgo para la gravedad de la infección por SARS-CoV-2 / Blood system ABO antigens as risk factor for severity of SARS-CoV-2 infection

Resumen Introducción: Se desconoce si existe una influencia del sistema sanguíneo ABO en susceptibilidad y gravedad de la enfermedad. Objetivo: Analizar si existe una asociación entre los antígenos del sistema ABO y la susceptibilidad y gravedad de la infección por SARS-CoV-2. Material y métodos: Se compararon las frecuencias de los antígenos del sistema ABO en 73 casos confirmados de infección por SARS-CoV-2 y 52 donadores clínicamente sanos. La gravedad de la infección se evaluó comparando la frecuencia de los antígenos por gravedad de la enfermedad y la mortalidad. Resultados: El riesgo de padecer infección por SARS-CoV-2 se incrementa en sujetos con antígeno A vs los no-A (OR=1.45; IC95 %:1.061-1.921). El fenotipo sanguíneo O disminuye el riesgo de padecer infección por SARS-CoV-2 (OR=0.686; IC95 %: 0.522-0.903). No se encontraron diferencias entre la gravedad de la enfermedad. En los pacientes graves, el riesgo de mortalidad se incrementó en sujetos con antígeno A vs los no-A (OR= 3.34; IC95 %: 1.417-8.159). Conclusión: El grupo sanguíneo A es un factor de riesgo para padecer infección por SARS-CoV-2, no así en la gravedad de la enfermedad, pero en los pacientes graves fue un factor de riesgo para la mortalidad.

Abstract Introduction: Whether there is an influence of the ABO blood system on susceptibility to the disease and its severity is unknown. Objective: To analyze if there is an association between the ABO blood system phenotypes and susceptibility to SARS-CoV-2 infection and its severity. Material and methods: The frequency of ABO antigens was compared in 73 confirmed cases of SARS-CoV-2 infection and 52 clinically healthy donors. The severity of the infection was evaluated by comparing the frequency of antigens by severity of the disease and mortality. Results: The risk of SARS-CoV-2 infection is increased in subjects with antigen A vs non-A subjects (OR=1.45; 95 %: 1.061-1.921). Blood phenotype O decreases the risk of SARS-CoV-2 infection (OR= 0.686; 95 % CI: 0.522-0.903). No differences were found regarding disease severity. The mortality risk is increased in subjects antigen A vs non-A (OR= 3.34; 95% IC: 1.417-8.159). Conclusion: Blood group A is a risk factor for SARS-CoV-2 infection, but not for disease severity, although in critically ill patients it is a risk factor for mortality.

Comparison of Total and IgG ABO Antibody Titers in Healthy Individuals by Using Tube and Column Agglutination Techniques

BACKGROUND: Most immune reactions related to transfusion and transplantation are caused by IgM ABO antibodies. However, IgG also plays an important role in these reactions. Therefore, a method to measure antibodies, including IgG, is necessary. We investigated ABO antibody titers of healthy individuals using a column agglutination technique (CAT) with or without dithiothreitol (DTT) and compared them with titers obtained using a conventional tube method. METHODS: Among healthy adults who underwent a medical examination, 180 individuals (60 with blood group A, 60 with group B, and 60 with group O) were selected. Antibody titrations were performed using the immediate spin (IS) tube, anti-human globulin (AHG) tube, and CAT with or without DTT methods. RESULTS: Higher median values of anti-B and anti-A titers in groups A and B individuals, respectively, were obtained using the IS method than using the AHG method. Higher values for group O individuals were obtained using the AHG method. Higher median titers of anti-B and anti-A in group O individuals were obtained using CAT without DTT than using the AHG method. Median titers of anti-B and anti-A in all blood groups were higher in CAT without DTT than in CAT with DTT, especially for group O individuals. CONCLUSIONS: We recommend CAT with and without DTT for titration of anti-A and anti-B, especially in group O individuals, to provide more sensitive results that include IgG data. Adjustment of insurance coverage of fees associated with antibody titration might be necessary, considering the actual cost of reagents and personnel.

Standardization of ABO Antibody Titer Measurement at Laboratories in Korea

BACKGROUND: Measurement of the ABO antibody (Ab) titer is important in ABO-incompatible transplantation. However, to the best of our knowledge, no standard protocol or external survey program to measure the ABO Ab titer has been established in Korea. We investigated the current status of ABO Ab titer measurements at various laboratories in Korea and the impact of the protocol provided to reduce interlaboratory variations in the methods and results of ABO Ab titers. METHODS: The Korean external quality assessment of blood bank laboratories sent external survey samples with a questionnaire to 68 laboratories across Korea for the measurement of ABO Ab titers in May 2012. After 6 months, a second set of survey samples were sent with a standard protocol to 53 of the previously surveyed laboratories. The protocol recommended incubation at room temperature only and use of the indirect antihuman globulin method for the tube test as well as and the column agglutination test (CAT). RESULTS: Several interlaboratory variations were observed in the results, technical procedures, and methods selected for measurement. We found that 80.4% laboratories hoped to change their protocol to the provisional one. Additionally, CAT showed significantly lower variation among laboratories (P=0.006) than the tube test. CONCLUSIONS: Our study provides baseline data regarding the current status of ABO Ab titer measurement in Korea. The standard protocol and external survey were helpful to standardize the technical procedures and select methods for ABO Ab titer measurement.

Comparison of ABO Antibody Titers on the Basis of the Antibody Detection Method Used

BACKGROUND: Detection methods for ABO antibody (Ab) titers vary across laboratories, and the results are different depending on the method used. We aimed to compare titer values using different detection methods for the measurement of ABO Ab titers. METHODS: For ABO Ab detection, pooled group A or B red blood cells (RBCs) were reacted with each of 20 sera from blood groups A, B, or O without dithiothreitol treatment. The room-temperature (RT) incubation technique and the indirect antiglobulin test (IAT) were used in the tube test and gel card test. Flow cytometry (FCM) was performed by using anti-IgM and anti-IgG Abs. RESULTS: Regardless of the blood groups tested, the FCM assay with anti-IgM showed the highest titer compared to the tube test and gel card test with RT incubation in both. The tube test with IAT showed a higher titer than the gel card test with IAT (Gel-IAT) or FCM with anti-IgG in blood group A and B, while Gel-IAT showed the highest titer relative to the other tests, only for the anti-A Ab in blood group O. CONCLUSIONS: There were significant differences in the titers depending on the detection method used, and each method showed a different detection capacity for each ABO Ab depending on the ABO blood group tested. Therefore, caution should be exercised in interpreting ABO Ab titer results, taking into consideration the detection method used and the blood group.

Preoperative Selective Desensitization of Live Donor Liver Transplant Recipients Considering the Degree of T Lymphocyte Cross-Match Titer, Model for End-Stage Liver Disease Score, and Graft Liver Volume

Several studies have suggested that a positive lymphocyte cross-matching (XM) is associated with low graft survival rates and a high prevalence of acute rejection after adult living donor liver transplantations (ALDLTs) using a small-for-size graft. However, there is still no consensus on preoperative desensitization. We adopted the desensitization protocol from ABO-incompatible LDLT. We performed desensitization for the selected patients according to the degree of T lymphocyte cross-match titer, model for end-stage liver disease (MELD) score, and graft liver volume. We retrospectively evaluated 230 consecutive ALDLT recipients for 5 yr. Eleven recipients (4.8%) showed a positive XM. Among them, five patients with the high titer (> 1:16) by antihuman globulin-augmented method (T-AHG) and one with a low titer but a high MELD score of 36 were selected for desensitization: rituximab injection and plasmapheresis before the transplantation. There were no major side effects of desensitization. Four of the patients showed successful depletion of the T-AHG titer. There was no mortality and hyperacute rejection in lymphocyte XM-positive patients, showing no significant difference in survival outcome between two groups (P=1.000). In conclusion, this desensitization protocol for the selected recipients considering the degree of T lymphocyte cross-match titer, MELD score, and graft liver volume is feasible and safe.

The First Known Case of Blood Group Chimerism in Monochorionic Dizygotic Twins in Korea

No abstract available.

Role of Plasma Exchange in ABO-incompatible Kidney Transplantation

BACKGROUND: In the past, ABO incompatibility was an absolute contraindication for solid organ transplantation. However, multiple recent trials have suggested strategies for overcoming the reactions between graft antigens and recipient antibodies that cause graft rejection. In this study, we determined the usefulness of plasma exchange (PE) for removing anti-A/B antibodies that cause hyperacute/acute humoral graft rejection in patients undergoing ABO-incompatible kidney transplantation. METHODS: In our study, 12 patients underwent ABO-incompatible kidney transplantation. All recipients received pre-transplantation conditioning by PE or intravenous immunoglobulin (IVIG) administration. After pre-transplantation conditioning, anti-A/B antibody titers were evaluated, and transplantation was performed when the titer was below 1:8. To assess the transplantation outcome, anti-A/B antibody titers, creatinine level, estimated glomerular filtration rate (eGFR), and proteinuria levels were measured. RESULTS: Anti-A/B antibody titers were below 1:8 in all patients at the time of transplantation. eGFR measured on post-transplant day 14 showed that 10 patients had immediate recovery of graft function, while 2 patients had slow recovery of graft function. Short-term outcomes of ABO-incompatible kidney transplantation (measured as creatinine levels) after reducing anti-A/B antibody titers were similar to those of ABO-compatible kidney transplantation. After transplantation, the anti-A/B antibody titers were below 1:8 in 7 patients, but the remaining 5 patients required post-transplantation PE and IVIG treatment to prevent antigen-antibody reactions. CONCLUSIONS: With the increasing demand for kidney donations, interest in overcoming the ABO incompatibility barrier has increased. PE may be an important breakthrough in increasing the availability of kidneys for transplantation.

Immunodetection of Helicobacter sp. and the associated expression of ABO blood group antigens in the gastric mucosa of captive and free-living New World primates in the Amazon region

The histo-blood group ABH antigens were first described in humans. These antigens are only present on erythrocytes from great apes and humans, while in more primitive animals they are found in tissues and body fluids. The ABH antigens are mainly distributed in tissues exposed to the external environment and potentially serve as ligands for pathogens or inhibitors of tissue connections. The objective of this paper was two-fold: (i) to determine the presence of Helicobacter sp. in the gastric mucosa of 16 captive and 24 free-living New World monkeys and (ii) to evaluate the presence of histopathological alterations related to bacterial infection and the associated expression of ABH antigens in the tissue. Stomach tissues from 13 species of monkey were assessed using haematoxylin-eosin and modified Gram staining (Hucker) methods. An immunohistochemical analysis of the tissue revealed the presence of infectious bacteria that were characteristic of the genus Helicobacter sp. The results demonstrate that various species of monkey might be naturally infected with the Helicobacter sp. and that there is an increased susceptibility to infection. This study serves as a comparative analysis of infection between human and non-human primates and indicates the presence of a new species of Helicobacter.

Seroprevalence of anti-helicobacter pylori and anticytotoxin-associated gene a antibodies according to abo blood groups and rhesus status among hemodialysis patients

Correlation between Helicobacter pylori infection and blood group typing has been widely evaluated in both patients and healthy population. However, data addressing this correlation in hemodialysis patients are scarce. The aim of this study was to evaluate the prevalence of anti-Helicobacter pylori and anticytotoxin-associated gene A [anti-Cag A] antibodies and their correlations with ABO blood groups and rhesus blood group status in hemodialysis patients. In a cross-sectional study, serum samples of 151 hemodialysis patients were tested for anti-Helicobacter pylori IgG antibody. Anti-Cag A antibody [IgG antibody] was tested in Helicobacter pylori-positive patients. ABO blood groups typing and rhesus status were tested by hemagglutination test. Prevalence of anti-Helicobacter pylori and anti-Cag A antibodies in Helicobacter pylori-positive patients were 65.6% [99 of 151] and 25.3% [25 of 99], respectively. Prevalence of anti-Helicobacter pylori and anti-Cag A antibodies were 69.1% and 36.8% in patients with blood group A, 42.3% and 9.1% in blood group B, 75.0% and zero in blood group AB, 69.4% and 23.3% in blood group O, 59.0% and 30.6% in rhesus-positive status and 89.7% and 11.5% in rhesus-negative status, respectively. There was a significant correlation between the presence of anti-Helicobacter pylori and anti-Cag A antibodies and rhesus status, but no significant relation between ABO blood groups and anti-Cag A antibodies were found. Rhesus status may have an impact on the presence of anti-Helicobacter pylori and anti-Cag A antibodies. More investigations to address this correlation are necessary

Estudio de las variantes alélicas del gen FUT2 en una población de Rosario, Santa Fe / Allele of FUT2 gen variables in a population of Rosario, Argentina

El estado secretor de un individuo está determinado por el gen Secretor (FUT2), responsable de la presencia de antígenos ABH en las secreciones del organismo. El polimorfismo del gen FUT2 muestra una gran variabilidad dependiente del tipo de población. Alrededor del 20% de los individuos caucásicos son no­secretores y presentan la mutación G428A. El objetivo de este trabajo fue estudiar las variables alélicas del gen FUT2 en una población de Rosario. Se trabajó con muestras de sangre periférica de dadores voluntarios (n=1728). Se determinó el estado secretor en plasma y saliva y el fenotipo Lewis. El ADN genómico fue extraído por la técnica de salting-out modificada y fue analizado por ASA-PCR con cebadores específicos para el alelo G428A y para el alelo wild type del gen FUT2. Los resultados obtenidos mostraron que el 77% de los individuos investigados fueron secretores y presentaron el fenotipo Lewis Le(a-b+). El polimorfismo G428A estuvo presente en homocigosis en un 7.5%, valor menor al reportado en la bibliografía para la población caucásica. El análisis molecular del gen FUT2 confirmaría la diversidad genética de la población investigada y podría ser utilizada como un marcador poblacional.

The secretor status is determinate by the secretor gene (FUT2) responsible of the ABH antigens expression in human secretions. About 20% of Caucasian individuals are non-secretors. The aim of this study was to study the allelic varieties of the FUT2 gene by a PCR reaction. We worked with peripheral blood samples of volunteers (n= 1728). We determinated the secretor status in plasma and saliva. The genomic DNA was extracted by an enzymatic digestion method and was analyzed by ASA-PCR with specific primers for the G428A allele and for the wild type allele of the FUT2 gene. The results obtained by serologic and molecular methods showed that the 77% of the investigate individuals were secretors. The G428A polymorphism had present in a 7.5%. The allelic varieties of the other non-secretor individuals different to the G428A might to correspond to other mutations. The molecular analysis of the FUT2 gene confirms the genetic diversity of the investigated population.

Fenómeno de acomodación inmunológica: Trasplante hepático ABO incompatible. Caso clínico / Accomodation process: ABO-incompatible liver transplantation. Report of one case

We report a 33 year-old female with a diagnosis of halothane-induce fulminant hepatic failure who was subjected to a liver transplant with an ABO-incompatible graft. The patient received a therapeutic protocol that included total plasma exchange, splenectomy and quadruple immunosuppression. After 5 years, the patient remains asymptomatic and with normal liver enzymes, while she has been treated with low dose of immunosuppressive drugs. This case demonstrates an example of how the immunological process of accomodation opens the possibility of using ABO-incompatible organs as a definitive grafts.

Murine monoclonal anti-H as typing reagent.

BACKGROUND & OBJECTIVE: The antigen H present on the surface of red cells in varying concentration, is maximum in O group red cells, but absent in Bombay phenotype individuals. This differentiation is generally detected by seed extracts of Ulex europaeus. The titre of such an extract is usually low and is subjected to batch variation. Hence, we carried out this study to raise potent murine monoclonal antibody against H antigen. METHODS: Spleen cells of female BALB/c mice immunized with O group red cells were fused in presence of polyethylene glycol (PEG) 1500 with a mouse myeloma cell line Sp2/0 Ag14 in hypoxanthine aminopterine thymidine (HAT) selective medium and incubated at 37 degrees, 5 per cent CO(2) and 95 per cent humidity for a week. RESULTS: The culture supernatants showing anti-H activity, were further subcloned and two clones 3E8A10 and 3E8A11 generated which showed a good potency, avidity and specificity. INTERPRETATION & CONCLUSION: The anti-H clones thus produced indigenously provided a potent reagent in distinguishing normal O group from Bombay phenotype individuals. The unlimited availability makes this reagent cost-effective to ensure a constant supply of hybrid clones with the similar specificities.

Enfermedad hemolítica perinatal por dos aloanticuerpos: presentación de un caso / Alloantibody linked perinatal hemolytic disease: case report

La etiopatogenia de la enfermedad hemolítica del recién nacido está basada en la incompatibilidad de grupo sanguíneo entre la madre y el recién nacido. Los neonatos con enfermedad hemolítica por incompatibilidad ABO usualmente tienen madres de grupo O porque la IgG anti-A y anti-B puede atravesar la placenta y sensibilizar los eritrocitos neonatales. Otros anticuerpos además de los ABO han sido reportados como causa de enfermedad hemolítica del recién nacido, ejemplo: anti-D, anti-C, anti-K, anti-Jk, anti-Fy, anti-S, etc. Presentamos el caso de una mujer de 33 años de edad, que en el segundo trimestre de su segunda gestación presentó una hemorragia que motivó la transfusión de una unidad de concentrado de eritrocitos. No se reportó reacción transfusional. El producto de dicha gestación fue un neonato masculino de 2,5 Kg de peso y apgar 6-8 que presentó íctero a las 24 horas después del parto. El fenotipaje ABO de los eritrocitos maternos y del neonato arrojó que la madre era de grupo O y el neonato de grupo B. La prueba de Coombs directa fue positiva 2+ en el neonato y la prueba de Coombs indirecta resultó positiva 3+ en la madre. Dos aloanticuerpos fueron detectados en el suero materno como causa del íctero neonatal, un anti-A y un anti-Jk b. Los eritrocitos maternos fueron fenotipados como Jk b negativos. El tratamiento con fototerapia al neonato se inició a las 40 horas de edad y se prolongó hasta los 10 días de nacido. Una transfusión simple de concentrado de eritrocitos fenotipados fue administrada al neonato a los 8 días de edad.

Freqüências dos grupos sangüíneos e incompatibilidades ABO e RhD em puérperas e seus recém-nascidos / Frequencies of blood groups, ABO and Rh D incompatibility in post-delivery women and their liveborn

OBJETIVO: Determinar as freqüências fenotípicas e predizer o risco de incompatibilidade e aloimunização materna RhD na população da Zona Oeste de São Paulo, Brasil. MÉTODOS: Estudo descritivo no qual avaliamos 2372 puérperas e seus recém-nascidos vivos, no período de um ano, tipificadas para os sistemas ABO e RhD por meio de teste de aglutinação em tubo. RESULTADOS: O estudo mostrou os seguintes percentuais: grupo sangüíneo O, 50,67 por cento; A, 32,17 por cento; B, 13,45 por cento; AB, 3,71 por cento; RhD(+), 90,34 por cento e RhD(-), 9,66 por cento. A ocorrência de incompatibilidade materno-fetal foi de 18,4 por cento para o sistema ABO e de 7 por cento para o RhD. CONCLUSÃO: O contingente da população Rh negativa com alto risco para aloimunização RhD foi estimado em 82 por cento, denotando a importância da profilaxia da aloimunização RhD.

OBJECTIVE: This study aimed to assess the frequency of different blood phenotypes and to predict the risk of Rh D alloimmunization and maternal-fetal incompatibility in a Brazilian population living in the West zone of the city of São Paulo - Brazil. METHODS: This descriptive study evaluated 2,372 post-delivery women and their liveborn during one year. Blood types were analyzed by means of tube agglutination tests. RESULTS: The blood type frequencies were: 50.67 O, 32.17 A, 13.45 B, 3.75 AB, 90.34 Rh D(+) and 9.66 Rh D(-). ABO maternal-fetal incompatibility was detected in 18.4 percent and Rh D incompatibility in 7 percent. CONCLUSION: The fraction of Rh D(-) population at high risk for Rh D alloimmunization was 82 percent, emphasizing the importance of Rh D alloimmunization profilaxis.

Detecting ABO blood type of bloodstain with fluorescent antibody method / 法医学杂志

UNLABELLED@#OBJECTIVE To explore the advantage and feasibility of fluorescent antibody method for detection of blood type in biological material.@*METHODS@#According to theory of specific binding of antigen and antibody, at first the anti-A monoclonal antibody (MA) and anti-B MA were labeled with the fluorescent, then fluorescent-labeled antibodies (FLA) were bound with corresponding biological material (such as bloodstain) in the optimum condition, finally the ABO blood type of bloodstain was determined under microscope fluorescent.@*RESULTS@#The fluorescent antibody method is highly sensitive, accurate and simple.@*CONCLUSION@#The fluorescent antibody method is an accurate and reliable method for detection of ABO blood type in biological material.

Production of murine monoclonal anti-B.

BACKGROUND & OBJECTIVE: Monoclonal antibodies against red blood cell antigens used in research and as diagnostics in India are commercially procured from western countries. Indigenously generated potent clones are not available in India. Hence, the objective of the present study was to raise potent murine monoclonal antibodies against A, B and H blood group antigens indigenously and establish a stable clone of anti-B secreting cells. METHODS: Spleen cells of female BALB/c mice immunized with B group red blood cells were fused in presence of polyethylene glycol (PEG) 1500 with a mouse myeloma cell line Sp 2/0 Ag. 14 in hypoxanthine aminopterine thymidine (HAT) selective medium and incubated at 37 degrees C, 5 per cent CO(2) and 95 per cent humidity for a week. RESULTS: The culture supernatant of the wells showing anti-B activity, were further subcloned and a clone 2C4D5F10 was generated which showed a good potency, avidity and specificity. INTERPRETATION & CONCLUSION: The anti-B clones thus produced indigenously provided a useful reagent in blood group typing. The unlimited availability unlike polyclonal antisera makes this reagent more cost-effective. It also ensures a regular supply with the similar specificity.

H antigen presence in an Ascaris lumbricoides extract

Experiencias previas han demostrado los mismos antígenos del Sistema ABO y del Sistema P en extractos de A. lumbricoides y en sus huéspedes. El objetivo fue mostrar el comportamiento de un extracto de A. lumbricoides de un paciente Grupo O frente a anticuerpos monoclonales de diferentes especificidades. Se hicieron pruebas de Inhibición de la Aglutinación enfrentando el extracto contra anticuerpos monoclonales (anti A 2.23; anti B 2.54; anti B 2.62; anti AB 2.39 y anti H 2.72) en dosis óptimas. El sistema revelador fue una suspensión fresca de eritrocitos Grupo O. El extracto sólo inhibió la aglutinación de anti H 2.72 con eritrocitos O. Se hizo la inhibición de la aglutinación semicuantitativa del extracto frente a dos series de diluciones de anti H 272 usando eritrocitos frescos Grupo O como sistema revelador. Se observó una diferencia de 5 diluciones entre los títulos de ambas series y se confirmó significativamente la presencia de antígeno H en el extracto. La no inhibición de la aglutinación del extracto frente a anti A, anti B y anti AB ha corroborado nuestras observaciones previas sobre ausencia de epitopes A y B en extractos de pacientes Grupo O. Los resultados de los estudios previos y de esta experiencia, han demostrado la importancia de los glicoconjugados de membrana en A. lumbricoides, los que podrían estar involucrados en el mimetismo antigénico para este parásito.