Phenotyping of clinically significant blood group antigens among the South Indian donor population

ABSTRACT Introduction: Data on the prevalence of clinically significant antigens (Rh, Kell, Kidd, Duffy, MNSs, Lewis, P and Lutheran) among the Indian donor population is sparse. Objective: This prospective study was aimed at determining the prevalence of 21 clinically significant antigens for the first time in the South Indian donor population. Method: A total of 672 regular O group blood donors were enrolled for Rh (C, c, E, e) and Kell (K) antigens typing. Of these, 188 donors were typed for other clinically significant antigens (k, Kpa, Kpb, Jka, Jkb, Fya, Fyb, M, N, S, s, P1, Lea, Leb, Lua and Lub). Results: Antigen frequencies were expressed in percentages. In our study, R1R1 and rr were the most common phenotypes among D+ and D− donors, respectively. Among the Rh antigens, the e antigen was expressed by 97.5% and 100% of D+ and D− donors, respectively. The K antigen was found in only 0.15% of donors. In the Duffy and Kidd blood group system, Fy (a+b+) and Jk (a+b+) were the most frequent phenotypes, respectively. In the MNSs blood group system, M+N+ and S−s+ were the most common phenotypes reported. The Le (a−b+) was found to be the phenotype with the highest prevalence in the Lewis blood group system. The Lu (a−b+) was the only phenotype found in the Lutheran blood group system. Conclusion: Knowledge regarding the prevalence of antigens in a given population is essential in developing cost-effective in-house panels and a rare donor registry comprising donors typed negative for a high-frequency antigen or a combination of common multiple antigens.

Early-onset hypoproliferative anemia in an intrauterine-transfused neonate with severe Rh hemolytic disease.

A fetus with features of hydrops was given intra-uterine transfusion at 27 weeks and 31 weeks of gestation. Mother had been alloimmunized with anti-D and anti-C antibodies. At birth, laboratory investigations revealed bone marrow suppression along with features of hemolytic anemia. The neonate was started on a combination of phototherapy and intravenous immunoglobulin. During the course, the neonate was transfused with one unit of packed red cells (top-up transfusion). Neonatal hyperbilirubinemia responded to phototherapy and the bone marrow activity spontaneously resumed after 3 weeks of life. In neonates with anemia at birth who have history of multiple intra-uterine transfusions, early-onset hypoproliferative anemia should be considered.

Serological characteristics of Lewis antibodies and their clinical significance - A case series.

INTRODUCTION: Lewis antibodies have been thought to play a small role in clinical transfusion practice, but recent reports suggest that they have gained more importance in the context of transfusion and transplantation. Data regarding the prevalence of Lewis antibodies and their clinical significance in the Indian context is very limited. Hence, this study was aimed at analyzing the serological characteristics and clinical significance of Lewis antibodies encountered in our patient and donor populations. METHODS: The retrospective data analyzed the records of red cell antibody screening results and the additional serological evaluation performed on the donor and patient samples included in the study. RESULTS: A total of 26 study subjects were noted to have Lewis antibodies (including 6 healthy donors and 20 patients). Of them, 13 individuals had anti-Leb, 10 had anti-Lea and the remaining three had an anti-Lea/Leb mixture. IgG Lewis antibodies were detected in 7 individuals. All cases of IgM Lewis antibodies detected were reacting at 37°C. Two patients were suspected of having hemolytic transfusion reactions due to Lewis antibodies. Antigen-negative cross-match compatible units were provided for transfusion in the recipients. CONCLUSION: Lewis antibodies of the IgM class reacting at 37°C should be regarded as clinically important. The present study findings urge that the lab personnel look for the thermal amplitude of Lewis antibodies, irrespective of the fact that the antibody class and antigen-negative crossmatch compatible units should be provided to avoid hemolytic transfusion reactions.

Phenotyping of clinically significant blood group antigens among the South Indian donor population.

INTRODUCTION: Data on the prevalence of clinically significant antigens (Rh, Kell, Kidd, Duffy, MNSs, Lewis, P and Lutheran) among the Indian donor population is sparse. OBJECTIVE: This prospective study was aimed at determining the prevalence of 21 clinically significant antigens for the first time in the South Indian donor population. METHOD: A total of 672 regular O group blood donors were enrolled for Rh (C,c, E, e) and Kell (K) antigens typing. Of these, 188 donors were typed for other clinically significant antigens (k, Kpa, Kpb, Jka, Jkb, Fya, Fyb, M, N, S, s, P1, Lea, Leb, Lua and Lub). RESULTS: Antigen frequencies were expressed in percentages. In our study, R1R1 and rr were the most common phenotypes among D+ and D- donors, respectively. Among the Rh antigens, the e antigen was expressed by 97.5% and 100% of D+ and D- donors, respectively. The K antigen was found in only 0.15% of donors. In the Duffy and Kidd blood group system, Fy (a+b+) and Jk (a+b+) were the most frequent phenotypes, respectively. In the MNSs blood group system, M+N+ and S-s+ were the most common phenotypes reported. The Le (a-b+) was found to be the phenotype with the highest prevalence in the Lewis blood group system. The Lu (a-b+) was the only phenotype found in the Lutheran blood group system. CONCLUSION: Knowledge regarding the prevalence of antigens in a given population is essential in developing cost-effective in-house panels and a rare donor registry comprising donors typed negative for a high-frequency antigen or a combination of common multiple antigens.

Serological characteristics of Lewis antibodies and their clinical significance - A case series

Abstract Introduction Lewis antibodies have been thought to play a small role in clinical transfusion practice, but recent reports suggest that they have gained more importance in the context of transfusion and transplantation. Data regarding the prevalence of Lewis antibodies and their clinical significance in the Indian context is very limited. Hence, this study was aimed at analyzing the serological characteristics and clinical significance of Lewis antibodies encountered in our patient and donor populations. Methods The retrospective data analyzed the records of red cell antibody screening results and the additional serological evaluation performed on the donor and patient samples included in the study. Results A total of 26 study subjects were noted to have Lewis antibodies (including 6 healthy donors and 20 patients). Of them, 13 individuals had anti-Leb, 10 had anti-Lea and the remaining three had an anti-Lea/Leb mixture. IgG Lewis antibodies were detected in 7 individuals. All cases of IgM Lewis antibodies detected were reacting at 37°C. Two patients were suspected of having hemolytic transfusion reactions due to Lewis antibodies. Antigen-negative cross-match compatible units were provided for transfusion in the recipients. Conclusion Lewis antibodies of the IgM class reacting at 37°C should be regarded as clinically important. The present study findings urge that the lab personnel look for the thermal amplitude of Lewis antibodies, irrespective of the fact that the antibody class and antigen-negative crossmatch compatible units should be provided to avoid hemolytic transfusion reactions.

Factors affecting the quality of cryoprecipitate.

BACKGROUND: Many variables affect the quality of cryoprecipitate (CRYO). We investigated the effect of freezing techniques and ABO blood groups on the quality of CRYO with respect to factor VIII: C and fibrinogen levels. MATERIALS AND METHODS: Ninety-six whole blood units each collected from in-house (Group I) and blood donation camps outside the hospital premises (Group II) were processed for CRYO preparation. Within each group, half the number of plasma units was frozen using blast freezer and another half using the conventional freezer. The CRYOs from blood groups A, B, and O were equally distributed, i.e. 32 within each of the Groups I and II. The fibrinogen and factor VIII: C levels in CRYO were analyzed using single-stage clotting assay. RESULTS: In Group I, the mean ± standard deviation percentage recovery of factor VIII levels in CRYO prepared using the conventional freezer and blast freezer were 58.5% ±16.2% and 66.7% ±16.4%, respectively, and in Group II, it was 55.3% ±17.6% and 70.4% ±13.4%, respectively. Recovery of factor VIII was higher in CRYO prepared using blast freezer than that of CRYO prepared using conventional freezer (P < 0.000). In Group II, CRYOs prepared using blast freezer had higher percent recovery of fibrinogen than that of Group I. In both the groups, the mean factor VIII levels in blood group A were higher than that of factor VIII levels in the blood group O CRYO. CONCLUSION: The factor VIII recovery in CRYO improves significantly with higher baseline factor VIII: C levels, blood group A donor, and rapid freezing using blast freezer. Rapid freezing also increases the fibrinogen yield.