O group is a protective factor for COVID19 in Basque population.

ABO blood groups have recently been related to COVID19 infection. In the present work, we performed this analysis using data from 412 COVID19 patients and 17796 blood donors, all of them from Gipuzkoa, a region in Northern Spain. The results obtained confirmed this relation, in addition to showing a clear importance of group O as a protective factor in COVID19 disease, with an OR = 0.59 (CI95% 0.481-0.7177, p<0.0001) while A, B and AB are risk factors. ABO blood groups are slightly differently distributed in the populations and therefore these results should be replicated in the specific areas with a proper control population.

Personalized collection of plasma from healthy donors: A randomized controlled trial of a novel technology-enabled nomogram.

BACKGROUND: Source plasma is essential to support the growing demand for plasma-derived medicinal products. Supply is short, with donor availability further limited by the coronavirus disease 2019 (COVID-19) pandemic. This study examined whether a novel, personalized, technology-based nomogram was noninferior with regard to significant hypotensive adverse events (AEs) in healthy donors. STUDY DESIGN AND METHODS: IMPACT (IMproving PlasmA CollecTion) was a prospective, multicenter, double-blinded, randomized, controlled trial carried out between January 6 and March 26, 2020, in three U.S plasma collection centers. Donors were randomly assigned to the current simplified 1992 nomogram (control) or a novel percent plasma nomogram (PPN) with personalized target volume calculation (experimental). Primary endpoint was the rate of significant hypotensive AEs. Noninferiority (NI) was tested with a margin of 0.15%. Collected plasma volume was a secondary endpoint. RESULTS: A total of 3443 donors (mean [SD] BMI: 32 [7.74] kg/m2 ; 65% male) underwent 23,137 donations (median [range]: 6 [1-22] per subject). Ten significant hypotensive AEs were observed (six control; four experimental), with model-based AE incidence rate estimates (95% CI) of 0.051% (0.020%-0.114%) and 0.035% (0.010%-0.094%), respectively (p = .58). NI was met at an upper limit of 0.043% versus the predefined margin of 0.15%. There was no statistical difference between total AEs (all AE types: p = .32). Mean plasma volume collected was 777.8 ml (control) versus 841.7 ml (experimental); an increase of 63.9 ml per donation (8.2%; p < .0001). CONCLUSION: This trial showed that a novel personalized nomogram approach in healthy donors allowed approximately 8% more plasma per donation to be collected without impairing donor safety.

Low retention rate of voluntary blood donors: contribution of an original method based on a composite classification (results of a monocentric study in the Democratic Republic of Congo).

INTRODUCTION: in order to improve the safety of blood transfusion, the retention of voluntary donors remains a major concern in the Democratic Republic of Congo. Nevertheless, retention is still difficult to assess because of the lack of local studies. The present study establishes the donors' profile and regularity, as well as regularity-associated factors, at the Provincial Blood Transfusion Centre in Bukavu. METHODS: this descriptive and analytical cross-sectional study included the records of 387 out of 773 blood donors during the period from 2015 to 2017. Donor retention and its associated factors were measured. The composite approach used here considered the number of blood donations, their frequency, the previous regularity of donors and the inter-donation interval. RESULTS: we bring to light an important loss of regular voluntary donors in the centre. Only 23.8% of them were still regular donors in 2017. The majority of donors registered in the centre are young males and have no income. On the contrary, factors associated with the profile of a regular donor in 2017 were: age at least 46 years old, being a woman and working in the formal sector. The composite classification highlighted that an important proportion of former regular donors, namely 72.8% (N=161/221), had not given blood in 2017. CONCLUSION: the use of a composite classification to assess the regularity of voluntary blood donors provides more accurate information that will enable the improvement of donors' awareness and retention as well as the possible reinstatement of former donors.

Effects of RHD gene polymorphisms on distinguishing weak D or DEL from RhD- in blood donation in a Chinese population.

BACKGROUND: Weak D or DEL red blood cell units may be mistyped as RhD- by current serology assays, which can lead to incompatible transfusion to RhD- recipients and further cause anti-D immunization. Molecular RHD blood group typing is a very effective method for overcoming current technical limits. The purpose of this study was to identify RHD single-nucleotide polymorphisms (SNPs) and compare the genotype prevalence among confirmed RhD- individuals in a Chinese population as well as explore effective biomarkers for current weak D or DEL detection before blood transfusion. METHODS: In the present study, 125 weak D (1, 2, 3, and 4.1) or DEL and 185 RhD- blood samples from donors detected by current standard serology were collected. Genotyping system was used to analyze the SNPs of RHD in each sample. RESULTS: Seven SNPs (rs592372, rs11485789, rs6669352, rs3118454, rs1053359, rs590787, and rs3927482) were detected in the RHD region. Rs3118454, rs1053359, rs590787, and rs3927482 showed significant differences between the weak D (1, 2, 3 and 4.1) or DEL and RhD- groups. Further combined analysis of the allelic distribution of these four SNPs revealed their higher frequencies in the RhD- group. CONCLUSION: The SNPs rs3118454, rs1053359, rs590787, and rs3927482 in RHD showed a significantly higher frequency among an RhD- Chinese population and are potential biomarkers.

Profile of blood donors who presented adverse reactions to the donation.

OBJECTIVE: identify the adverse reactions presented by blood donors and outline their sociodemographic profile. METHOD: a quantitative, cross-sectional retrospective study of 780 records of blood donors from a public hemocenter in the southern region of Brazil, from December 2015 to January 2016. For the analysis the descriptive statistics was used. RESULTS: it was identified that throughout 12 months, the total blood donors corresponded to 27,300 people, in which 780 developed at least one reaction. They were characterized by female and recurrent donors, single, with a complete average level of education, ranging from 16 to 30 years, who triggered between 1 and 3 reactions. Mild reactions were more frequent, followed by moderate and severe reactions. CONCLUSION: There is a high rate of adverse reactions from donors emphasizing the need for changes in hemotherapy care practices.

Profile of blood donors who presented adverse reactions to the donation / Perfil de los donantes de sangre que presentaron reacciones adversas a la donación / Perfil dos doadores de sangue que apresentaram reações adversas à doação

ABSTRACT Objective: identify the adverse reactions presented by blood donors and outline their sociodemographic profile. Method: a quantitative, cross-sectional retrospective study of 780 records of blood donors from a public hemocenter in the southern region of Brazil, from December 2015 to January 2016. For the analysis the descriptive statistics was used. Results: it was identified that throughout 12 months, the total blood donors corresponded to 27,300 people, in which 780 developed at least one reaction. They were characterized by female and recurrent donors, single, with a complete average level of education, ranging from 16 to 30 years, who triggered between 1 and 3 reactions. Mild reactions were more frequent, followed by moderate and severe reactions. Conclusion: There is a high rate of adverse reactions from donors emphasizing the need for changes in hemotherapy care practices.

RESUMEN Objetivo: identificar las reacciones adversas presentadas por los donantes de sangre y trazar su perfil sociodemográfico. Método: una investigación cuantitativa, retrospectiva transversal, realizada en 780 registros de donantes de sangre de un hemocentro público de la región sur de Brasil, en el período de diciembre de 2015 a enero de 2016. Para el análisis se procedió a la estadística descriptiva. Resultados: se identificó que, en el período de 12 meses, el total de donantes de sangre correspondió a 27.300 personas, en el cual 780 desarrollaron al menos una adversidad. Se caracterizaron por donantes de repetición, del género femenino, solteros, con nivel de escolaridad promedio completo, en el grupo de edad de 16 a 30 años, que desencadenaron entre 1 y 3 adversidades. Las reacciones lleves fueron más recurrentes, seguidas de las reacciones moderadas y graves. Conclusión: se señala un alto índice de reacciones adversas por parte de los donantes enfatizando la necesidad de cambios en las prácticas de los cuidados en hemoterapia.

RESUMO Objetivo: identificar as reações adversas apresentadas pelos doadores de sangue e traçar o seu perfil sociodemográfico. Método: pesquisa quantitativa, retrospectiva transversal, realizada em 780 registros de doadores de sangue de um hemocentro público da região sul do Brasil, no período de dezembro de 2015 a janeiro de 2016. Para análise procedeu-se à estatística descritiva. Resultados: identificou-se que, no período de 12 meses, o total de doadores de sangue correspondeu a 27.300 pessoas, no qual 780 desenvolveram ao menos uma adversidade. Caracterizaram-se por doadores de repetição, do gênero feminino, solteiros, com nível de escolaridade médio completo, na faixa etária de 16 a 30 anos, que desencadearam entre 1 e 3 adversidades. As reações leves foram mais recorrentes, seguidas das reações moderadas e graves. Conclusão: Aponta-se um alto índice de reações adversas por parte dos doadores enfatizando a necessidade de mudanças nas práticas dos cuidados em hemoterapia.

Frequency of subgroups of the antigen "a" among volunteer donors / Frecuencia de subgrupos del antígeno A en donantes voluntarios de sangre.

Introduction: The presence of weak variants of blood type A represents a challenge in the practice of immunohematology for discrepancies in the time of the classification. It is common in blood banks to perform a forward and reverse typing for the purpose of confirming the blood type, but not all the people with a subgroup A2 have developed anti-A1 antibodies. Objective: We present a descriptive, observational and transversal study that establishes the proportion of subgroups of A antigen with the analysis of manual tube technique and monoclonal antibodies like anti-A, anti-A1 (Dolichus biflorus lectins extract) and anti-H. Methods: The analysis involved a total of 818 samples of voluntary blood donor, selected by random sampling, which were initially classified as 737 of Type A, and 81 as Type AB, with a confidence level of 95% (alpha error of 5% and 3% of precision). Results: The present study evaluated the existence of the subgroups A1, A2, A1B, A2B, A intermediate and A intB. Conclusions: It is recommended the identification of subgroups in different types of blood in the laboratory and blood banks.

Introducción: La presencia de variantes débiles del grupo sanguíneo A representa un desafío en la práctica de la inmunohematología por las discrepancias en el momento de la tipificación. Es común en bancos de sangre realizar una tipificación directa e inversa con el objetivo de confirmar el grupo sanguíneo; sin embargo, no todas las personas que presentan un subgrupo sanguíneo A2 han desarrollado anticuerpos anti-A1, lo que dificulta la identificación de subgrupos de A. Objetivo: El presente estudio es descriptivo, observacional y transversal, y tiene el objetivo de establecer la proporción de los subgrupos del antígeno A en donantes de sangre mediante la técnica manual en tubo con reactivos hemoclasificadores monoclonales: anti A, anti-A1 (extracto de las lectinas Dolichus biflorus) y anti-H. Métodos: Se analizaron un total de 818 muestras provenientes de donantes de sangre (muestreo aleatorio estratificado), de los cuales 737 fueron tipificados inicialmente como A y 81 como AB, con un grado de confianza del 95% (error alfa del 5% y precisión del 3%). Resultados: Se identificó la existencia de los subgrupos A1, A2, A1B, A2B, A intermedio y A intB en donantes de sangre ecuatorianos. Conclusión: Se recomienda la implementación de la identificación de los subgrupos de A en laboratorios clínicos y bancos de sangre.

Risk Factors for Cytomegalovirus Infection After Allogeneic Hematopoietic Cell Transplantation in Malignancies: Proposal for Classification.

AIM: To identify and classify risk factors for cytomegalovirus (CMV) infection and disease in patients receiving allogeneic hematopoietic stem cell transplantation (allo-HSCT), treated mainly for acute leukemia. MATERIALS AND METHODS: A literature search was performed;eligible trials were clinical studies assessing the risk factors for CMV infection or disease in multivariate analysis. RESULTS: Early reactivation in the setting of allo-HSCT took place mainly in patients without CMV prophylaxis, while late reactivation mainly in those patients who had completed previous prophylaxis or were on anti-CMV strategy based on pre-emptive prophylaxis. We propose classifying risk factors for CMV reactivation and CMV disease in patients after allo-HSCT as major and minor ones. Three major risk factors for CMV reactivation and CMV disease were found: (i) CMV-negative donor CMV-positive recipient serostatus, (ii) acute or chronic graft-versus-host disease, and (iii) unrelated or mismatched donor. CONCLUSION: CMV reactivation should be regarded as a continuous function of recipient and donor CMV-seropositivity and recipient immune suppression, caused by conditioning, immunosuppressive therapy and human leukocyte antigen disparity between donor and recipient.

Development of standard definitions for surveillance of complications related to blood donation.

Standard definitions of donor reactions allow each blood establishment to monitor donor adverse events and compare with other organizations to develop best practices. The ISBT Haemovigilance Working Party leads a multi-organizational effort to update the 2008 ISBT standard for surveillance of complications related to blood donation. Revised definitions have been developed and endorsed by the ISBT, AABB, International Haemovigilance Network (IHN) and other international organizations.

Análisis de la importancia del programa de donación de sangre de cordón umbilical y su relación con la información ofrecida por el personal sanitario / Analysis of the importance of the blood donation program of umbilical cord and its relation with the infomation given by the health workers

La sangre de cordón umbilical (SCU) ofrece una fuente rica de células progenitoras hematopoyéticas, caracterizadas por su capacidad de proliferación, diferenciación y renovación celular de los tejidos sobre los que se encuentran. Los beneficiarios de esta donación son todas aquellas personas con enfermedades de la médula ósea. Desde que en el año 1988 se realizara con éxito el primer trasplante de sangre de cordón umbilical entre hermanos HLA idénticos, se han llevado a cabo numerosas donaciones, de manera que, actualmente, cualquier mujer que dé a luz en alguno de los centros autorizados para ello de nuestro país podrá donar, de forma voluntaria, este material hematopoyético al Banco de Cordón Umbilical más cercano del cual dependa su comunidad. La puesta en marcha del protocolo de recogida de muestras ha sido y es una tarea difícil que ha precisado de formación, motivación y colaboración tanto interprofesional como entre distintos niveles asistenciales, además de suponer un esfuerzo que consideramos aún poco difundido (AU)

Umbilical Cord Blood has a rich source of haematopoietic progenitor cells (HSC) characterized by their capacity for proliferation, differentiation and cell renewal of tissues on which they are located. The beneficiaries of this donation are all these people with diseases of the bone marrow. Since the year 1988 will be held the first successful transplantation of umbilical cord blood from HLA-identical siblings, have conducted numerous donations, so that, today, any woman who gives birth in any of the centers authorized may donate voluntarily to this material hematopoietic to the Cord Blood Bank which depends their community. Sample collection, has been and is a difficult task that has required training, motivation and collaboration both interprofessional and between different levels of care, while making an effort to consider an information still little known (AU)

Prevalence and determinants of declining versus stable hemoglobin levels in whole blood donors.

BACKGROUND: A too short recovery time after blood donation results in a gradual depletion of iron stores and a subsequent decline in hemoglobin (Hb) levels over time. This decline in Hb levels may depend on individual, unobserved characteristics of the donor. STUDY DESIGN AND METHODS: We used a data set of 5388 Dutch blood donors from the Donor InSight study. The statistical analysis is based on a Bayesian growth mixture model, which assumes that each donor belongs to one of several groups. Each group implies a different Hb trajectory, and donors with similar longitudinal trajectories belong to the same group. Analyses were performed for male and female donors separately. RESULTS: For both sexes the model identified four groups of donors. Stable Hb trajectories were found among 14% of male donors and 15% of female donors; declining Hb trajectories were observed in the remaining groups of donors. The percentage of donor deferrals differed strongly between groups. CONCLUSION: The model can be used to predict to which group a donor belongs, and this prediction can be updated after each donation. This is of high practical importance because early identification of donors with declining Hb levels could help to tailor donation intervals and to prevent iron deficiency and donor deferrals.

[Prevalence and incidence of HIV and hepatitis B among blood donors and estimated residual risk of transmission of HIV and HBV virus by blood transfusion. A study at the Provincial General Referee Hospital Bukavu, Democratic Republic of the Congo]. / Prévalence et incidence du VIH et de l'hépatite B chez les donneurs de sang et estimation du risque résiduel de transmission du virus VIH et du virus VHB par la transfusion sanguine. Une étude à l'hôpital provincial général de référence de Bukavu, République démocratique du Congo.

BACKGROUND: To estimate the residual risk of transmission of HIV and HBV virus by blood transfusion in Bukavu. METHODS: Retrospective cohort study designed for exploratory purposes, which took place in Bukavu (DR Congo) between January 2001 and December 2005, among 3292 blood donors. The incidences were estimated by survival curves and Cox models. The adjusted relative risks with their confidence interval at 95% were derived from Cox models. The residual risk of viral transmission associated with the serological window is equal to the incidence rate multiplied by the duration of the serological window divided by 365. RESULTS: The prevalence among blood donors in Bukavu was 1% for HIV and 3.7% for HbsAg. The number of incident cases observed was seven for HIV and 40 for hepatitis B between 2001 and 2005. The incidence rates obtained were 3.57 for 1000 person-years (0.93/1000-6.23/1000) and 25.4 per 1000 person-years (17.6/1000-33.36/1000), respectively for HIV and hepatitis B. The residual risk was 1/4608 donations for HIV or 0.22 (0.02-0.65) and 1/257 donations for HBV or 3.90 (1.20-9.96). Also there were more seroconversions among family blood donors than in volunteer donors. The risk of seroconversion in family donors compared to volunteer donors adjusted for age, sex and residence was 7.09 (3.75-13.39) for HIV and 4.03 (2.63-6.20) for HBsAg. The same result was observed with the survival curves. CONCLUSION: The prevalences of HIV and HBsAg in Bukavu are lower than in most major cities in sub-Saharan Africa. Residual risks are especially important for hepatitis B.

Production of intravenous human dengue immunoglobulin from Brazilian-blood donors

Dengue represents an important health problem in Brazil and therefore there is a great need to develop a vaccine or treatment. The neutralization of the dengue virus by a specific antibody can potentially be applied to therapy. The present paper describes, for the first time, the preparation of Immunoglobulin specific for the dengue virus (anti-DENV IgG), collected from screened Brazilian blood-donations. Production was performed using the classic Cohn-Oncley process with minor modifications. The anti-DENV IgG was biochemically and biophysically characterized and fulfilled the requirements defined by the European Pharmacopoeia. The finished product was able to neutralize different virus serotypes (DENV-1, DENV-2, and DENV-3), while a commercial IgG collected from American blood donations was found to have low anti-dengue antibody titers. Overall, this anti-DENV IgG represents an important step in the study of the therapeutic potential and safety of a specific antibody that neutralizes the dengue virus in humans.

A dengue representa um importante problema de saúde no Brasil, portanto, a identificação de vacina ou tratamento eficaz é uma necessidade urgente. A neutralização do vírus da dengue, por anticorpo específico, tem potencial aplicação terapêutica. Descrevemos aqui, pela primeira vez, a preparação de imunoglobulina específica para o vírus da dengue (IgG anti-DENV), produzida a partir do plasma selecionado de doadores brasileiros. A produção foi realizada utilizando o método clássico de Cohn-Oncley com pequenas modificações. A IgG anti-DENV foi bioquimicamente e biofisicamente caracterizada e cumpriu os requisitos definidos pela Farmacopeia Europeia. O produto final foi capaz de neutralizar diferentes sorotipos do vírus (DENV-1, DENV-2 e DENV-3), enquanto que a IgG comercial, produzida a partir do plasma de doadores americanos, apresentou baixos títulos de anticorpos anti-dengue. No geral, esta IgG anti-DENV representa uma importante etapa para o estudo do potencial terapêutico e segurança da neutralização, por anticorpos específicos, do vírus da dengue em humanos.

[The individual selection of erythrocytes for regional clinics].

The article deals with the results of work of Krasnoyarsk kray blood center immune hematologic laboratory concerning selection of erythrocytes in 2003-2010. In Krasnoyarsk kray, the portion of transfusions of individually selected erythrocytes increases and reached 31.9%. The setting up of register of donors typed by Ab0 and Rhesus systems makes it possible to implement effectively the individual selection of erythrocytes in optimal time-frame and in amount needed in clinics.

Kinetics and activation requirements of contact-dependent immune suppression by human regulatory T cells.

Naturally occurring regulatory T cells (Tregs) maintain self tolerance by dominant suppression of potentially self-reactive T cells in peripheral tissues. However, the activation requirements, the temporal aspects of the suppressive activity, and mode of action of human Tregs are subjects of controversy. In this study, we show that Tregs display significant variability in the suppressive activity ex vivo as 54% of healthy blood donors examined had fully suppressive Tregs spontaneously, whereas in the remaining donors, anti-CD3/CD2/CD28 stimulation was required for Treg suppressive activity. Furthermore, anti-CD3/CD2/CD28 stimulation for 6 h and subsequent fixation in paraformaldehyde rendered the Tregs fully suppressive in all donors. The fixation-resistant suppressive activity of Tregs operated in a contact-dependent manner that was not dependent on APCs, but could be fully obliterated by trypsin treatment, indicating that a cell surface protein is directly involved. By add-back of active, fixed Tregs at different time points after activation of responding T cells, the responder cells were susceptible to Treg-mediated immune suppression up to 24 h after stimulation. This defines a time window in which effector T cells are susceptible to Treg-mediated immune suppression. Lastly, we examined the effect of a set of signaling inhibitors that perturb effector T cell activation and found that none of the examined inhibitors affected Treg activation, indicating pathway redundancy or that Treg activation proceeds by signaling mechanisms distinct from those of effector T cells.

A PCR-based strategy for Dombrock screening in Brazilian blood donors reveals a novel allele: the DO* A-WL.

BACKGROUND: Determination of the molecular basis underlying the antigens in the Dombrock blood group system has shown various rearrangements between the alleles associated with DO(*) A and DO(*) B. Based on this, we employed a PCR-based strategy to screen DO alleles (DO(*) A, DO(*) B, HY(*) 1, HY(*) 2 and JO) in Brazilians. METHODS: We tested DNA of 278 Brazilian blood donors by PCR-RFLP on plates of 96 wells to determine the 793A/G (DO(*) A/DO(*) B), 323G/T (HY), 350C/T (JO) and 898C/G (HY(*) 1/HY(*) 2) single nucletide polymorphisms. In order to confirm the results sequence analysis was also performed. RESULTS: When samples of these donors were analyzed, a novel allele combination, the DO(*) A allele (793A and 323G) associated with 898G was identified and designated as DO(*) A-WL allele. This new allele encoding 300Val is the same as HY(*) 1 at nucleotide 898 on the molecular background of DO(*) A. Among the 556 alleles analyzed by PCR-RFLP, 3 were DO(*) A-WL and 78 were DO(*) B-WL. This represents an overall frequency of 0.5% for DO(*) A-WL and 14% for DO(*) B-WL across the population studied. CONCLUSION: Molecular screening of Brazilians revealed one novel allele, the DO(*) A-WL. Our data highlight the importance of testing a cohort of different populations to determine DO haplotypes and to establish reliable genotyping tests for predicting Do(a)/Do(b) status.

Systemic lupus erythematosus serum deposits C4d on red blood cells, decreases red blood cell membrane deformability, and promotes nitric oxide production.

OBJECTIVE: Systemic lupus erythematosus (SLE) is characterized by intravascular activation of the complement system and deposition of complement fragments (C3 and C4) on plasma membranes of circulating cells, including red blood cells (RBCs). The aim of this study was to address whether this process affects the biophysical properties of RBCs. METHODS: Serum and RBCs were isolated from patients with SLE and healthy controls. RBCs from healthy universal donors (type O, Rh negative) were incubated with SLE or control serum. We used flow cytometry to assess complement fragment deposition on RBCs. RBC membrane deformability was measured using 2-dimensional microchannel arrays. Protein phosphorylation levels were quantified by Western blotting. RESULTS: Incubation of healthy universal donor RBCs with sera from patients with SLE, but not with control sera, led to deposition of C4d fragments on the RBCs. Complement-decorated RBCs exhibited significant decreases in both membrane deformability and flickering. Sera from SLE patients triggered a transitory Ca(++) influx in RBCs that was associated with decreased phosphorylation of ß-spectrin and with increased phosphorylation of band 3, two key proteins of RBC cytoskeleton. Finally, incubation with SLE sera led to the production of nitric oxide by RBCs, whereas this did not occur with control sera. CONCLUSION: Our data suggest that complement activation in patients with SLE leads to calcium-dependent cytosketeletal changes in RBCs that render them less deformable, probably impairing their flow through capillaries. This phenomenon may negatively affect the delivery of oxygen to the tissues.

[Genotyping of 21,000 blood donors in Quebec and RHD analysis]. / Génotypage de 21 000 donneurs de sang au Québec et analyse du RHD.

STUDY GOAL: A repeat blood donor genotyping project was launched by Héma-Québec in October 2007. The objective was to screen 21,000 samples for 22 polymorphisms for red blood cell and platelet blood groups to build a database to easily find compatible donors. MATERIALS AND METHODS: Donors who have donated at least three times during the last year were selected. A drop of blood was spotted on FTA paper and sent to the Pharmacogenomic Centre at the Montreal Heart Institute for analysis. All genotype results were compared to the known phenotype. In parallel, the RHD gene of D negative blood donors was examined. RESULTS: Less than two years were necessary to complete the database. The genotype/phenotype concordance was 99.6% with only 165 discrepancies observed and further analysed. More than 55% of these discrepancies confirmed the initial genotype. The RHD study done on D negative samples found 13 donors positive for a variant RHD gene. Four were RHD*Ψ positive, while the other nine presented variant polymorphisms precluding a reduced expression of the D antigen. CONCLUSION: Thanks to this project, Héma-Québec is able to answer increasing demands for compatible blood more rapidly. The organisation has also demonstrated the security of its D negative inventory.

Phenotype frequencies of blood group systems (Rh, Kell, Kidd, Duffy, MNS, P, Lewis, and Lutheran) in north Indian blood donors.

BACKGROUND: We here report the first study of antigen and phenotype frequencies of various blood group systems by gel technology in north Indian blood donors. STUDY DESIGN AND METHODS: A total of 1240 regular repeat voluntary north Indian blood donors of O blood group were included for red cell antigen typing of Rh (D, C, E, c, e) and Kell (K) blood group systems. Out of these, 317 donors were randomly selected for typing of other blood group antigens: Jk(a), Jk(b), k, Kp(a), Kp(b), Fy(a), Fy(b), M, N, S, s, Le(a), Le(b), P(1), Lu(a), Lu(b) and Xg(a). Calculations of antigen and phenotypes frequencies were expressed as percentages and for allele frequencies under the standard assumption of Hardy-Weinberg equilibrium. RESULTS: Out of 1240 O group blood donors, 93.39% were Rh D and 5.56% were K positive. Amongst Rh antigens, e was the most common (98.3%) followed by D, C (84.76%), c (52.82%) and E (17.9%) with DCe/DCe (R(1)R(1), 43.8%) being the most common phenotype. In Kell blood group system, we found k antigen to be 100% and a rare phenotype Kp (a+b+) was found in 0.95% of the donors. For Kidd and Duffy blood group systems, Jk (a+b+) and Fy (a+b-) were the most common phenotypes (49.21% and 43.85%, respectively). In the MNS blood group system, M+N+S+s+ (19.55%) was the most common whereas M-N+S+s- (1.26%) was least common phenotype found. We found rare Lu (a+b+) and Lu (a-b-) phenotypes in 0.95% and 3.15% of the donors, respectively. Xg(a) antigen was seen in 86.67% and 62.6% of female and male donors, respectively. CONCLUSIONS: Knowledge of red cell antigen phenotype frequencies in a population is helpful in terms of their ethnic distribution, in creating a donor data bank for preparation of indigenous cell panels, and providing antigen negative compatible blood to patients with multiple alloantibodies.