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Background: In an ethnically diverse country like India, establishing a national rare donor registry is a massive challenge. We aimed to establish a regional rare donor registry at our center by screening the local donor population for rare phenotypes. Methods: Serological testing of O blood group donors was done using monoclonal antisera from Bio-Rad for 23 different blood group antigens, which include Rh subgroups (C,cE,e), Kell (K,k, Kpa, Kpb), P1, Duffy (Fya, Fyb), Kidd (Jka, Jkb), Lewis (Lea, Leb), Lutheran (Lua, Lub), H, M, N, S and s. We categorized the donors with rare blood phenotypes into two categories. Category-I: High-frequency antigen-negative phenotypes with a prevalence of less than 1% in our study population. Category-II: Multiple common antigen-negative phenotypes with a prevalence of less than 1% in our study population. Results: A total of 521 donors with blood group O, meeting the inclusion criteria among a total of 23567 were phenotyped for minor blood group antigens. Out of these, 85.6% (n = 446) were Rh D positive, and 14.4% (n = 75) were Rh D negative. The male-to-female ratio was 9:1. We had identified eight rare phenotypes in category-I and 18 rare phenotypes in Category-II according to the definition adopted in our study. We have noticed a significant decrease in turnaround time in providing rare blood to patients after implementing the registry. Conclusion: This is a first-of-its-kind rare donor registry established in South India. Establishing a national rare donor registry is the need of the hour in India.

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BACKGROUND AND OBJECTIVES: The antigen frequencies vary across different regions and ethnic groups. Hence, we aimed to study the prevalence of blood group antigens in our population and to systemize the zone-wise prevalence of the same across India. MATERIALS AND METHODS: Regular voluntary O group blood donors were screened for 21 blood group antigens; C, c, E, e, K, k, Kpa, Kpb, Jka, Jkb, Fya, Fyb, Lea, Leb, Lua, Lub, P1, M, N, S, s, using commercially available monoclonal antisera by column agglutination technology. A literature search was performed to identify all the studies that reported blood group antigens prevalence to estimate the zone-wise prevalence of these antigens in the country. RESULTS: A total of 521 participants of 9248 O group donors meeting all the inclusion criteria were included. Among the study group, the male-to-female ratio was 9:1 with a mean age of 32.6 years (±10.01) ranging from 18-60 years. The majority of the donors 446 (85.6%) were D positive. The most common phenotypes among Rh, Lewis, Kell, Duffy, Kidd, Lutheran and MNSs were CcDee (34.93%), Le(a-b+) (61.80%), K-k+(98.27%), Fy(a+b-) 43.19%, Jk(a+b+) 42.61%, Lu(a-b+) ( 99.61%), M+N+ (48.17%), S-s+ (45.29%) respectively. The prevalence of D and E antigens was significantly lower in the South zone compared to other zones of India. CONCLUSION: Significant difference in the prevalence of blood group antigens is observed between the South and other zones of India. Zone-wise prevalence of blood group phenotypes is essential in the timely management of alloimmunized patients.

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Atypical hemolytic uremic syndrome (aHUS) is a rare and life-threatening disease that is associated with high mortality and morbidity. The incidence of aHUS is about 1 or 2 cases per 1,000,000 per year. Etiology can be either familial or sporadic. The pathogenesis of aHUS involves dysregulation of the alternative complement pathway, with predisposing mutations in complement genes. aHUS has a poor prognosis and a gradual or a relapsing (30%-86%) clinical course. The disease may present at any age but is mostly seen in children and young adults. Therapeutic plasma exchange (TPE) is one of the primary modalities of treatment in aHUS. This report presents the utilization of cascade plasmapheresis and its advantages over TPE in a patient with relapsed aHUS. There was a 73% decrement in antifactor H antibody levels following cascade plasmapheresis.

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BACKGROUND: RhD expression varies with population and ethnicity. Accurate typing of RhD antigen among blood donors is important to prevent development of anti-D among recipients of blood transfusion. We aimed to screen blood donors for variant D phenotypes and accurately characterize them by genotyping. MATERIAL AND METHODS: We have done prospective study on blood donors by performing RhD typing using three different commercial monoclonal anti-D reagents by both column agglutination and conventional tube techniques. Samples that showed ambiguous results were further screened with the Bio-Rad Partial RhD typing kit. Minor phenotyping for C, c, E, e antigens was performed. Multiplex PCR and Sequencing of all RHD exons with Sanger's sequencing was performed for molecular characterization of variant D. RESULTS: A total of 16,974 blood donors were screened during the study period. Among them, 31 (0.18 %) donors were found to have a RhD variant phenotype. The male to female ratio was 10:1. The presence of 'C' antigen was noted among all RhD variant samples. Serological typing identified two samples as DV phenotype and the rest could not be characterized. Molecular genotyping characterized 90.3 % of the samples as Indian specific weak D type 150 variants. Three samples were subjected to Sangers sequencing and showed wild type pattern. CONCLUSION: The present study showed that the most common variant in this population was Weak D type 150. This study highlights that serological methods may serve as a screening tool, however, molecular techniques are essential for characterization of RhD variants.

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Background: According to the American Society for Apheresis (ASFA) guidelines, thrombocytapheresis is a Category II indication in symptomatic patients and is a Category III indication when used as secondary or prophylactic treatment. The role of thrombocytapheresis is to prevent untoward complications that might occur even before the cytoreductive agents can exert their action. Methods: A retrospective analysis of patients who underwent thrombocytapheresis between 2012 to 2018 was conducted. Demographic details, complete blood counts, diagnosis and indication for thrombocytapheresis were noted. Results: A total of 12 patients with thrombocytosis were included in the study. The cause of thrombocytosis was primary in 3 (25%) patients and secondary in 9 (75%) patients. The average percentage reduction in platelet count was 47.1% (range 12.3%-65.64%). There was a significant decrease in platelet count, platelet crit, and mean platelet volume after the procedure when compared to pre-procedure. Conclusion: Thrombocytapheresis selectively reduces platelet counts with no effect on other cellular and plasma components. The role of thrombocytapheresis in extreme thrombocytosis is to be considered for an immediate decrease in platelet count and to minimize the risks associated with thrombocytosis.