Molecular genotyping of Indian blood group antigens amongst regular voluntary blood donors of Surat city, Gujarat, India.

BACKGROUND: There is paucity of data related to the prevalence of the rare blood group antigens amongst South Gujarat blood donor population due to unavailability and high cost of antisera. Therefore it is difficult to screen donors for such rare antigens by gold standard haemagglutination assay. The single nucleotide polymorphism (SNPs) of Ina and Inb antigens is the base of the PCR based detection methods that help to detect these alleles in regular voluntary blood donors. MATERIALS & METHODS: Blood samples of 200 unrelated regular voluntary blood donors wee collected. DNA was extracted using phenol-chloroform method and genotyped for Indian (Ina/IN*01, Inb/IN*02) blood group alleles by Sequence Specific PCR. Ina antigen positivity was confirmed by serology test. RESULTS: Four donors were found heterozygous for Ina antigen i.e. In (a + b+) by SS-PCR and their Ina positivity were confirmed by in-house polyclonal Anti-Ina reagent. SS-PCR was standardized using known heterozygous sample of a blood donor. The frequency of Ina antigen (2.0 %) was higher than Caucasians, lower than Iranians and Arabs while comparable to those reported among Indians of Mumbai city. CONCLUSION: In absence or unavailability of antisera particularly for low frequency alleles like Ina, such PCR based method would be extremely helpful to prepare rare donor registry by screening blood donors' at large scale. Red cells of Ina positive donors can be used as in-house reagent red cells for screening and identification of corresponding antibody.

Comparison of serology and molecular detection of common red cell antigens in multitransfused thalassemia major and sickle cell disease patients.

BACKGROUND: Serological testing for extended RHCcEe, Kell, Kidd and Duffy blood grouping from multitransfused patients may not give correct blood grouping of the recipient. Hence molecular testing for these blood groups was compared with serological groups in a cohort of multitransfused thalassemia mjor and sickle cell anaemia patients. OBJECTIVE: Molecular genotyping of antigens of Rh (D, C, c, E, e), Kell (K, k), Duffy (Fya, Fyb) and Kidd (Jka, Jkb) blood group antigens by PCR and PCR-RFLP methods and comparison of predicted genotypes with their serological phenotypes. MATERIALS AND METHODS: A cohort of multitransfused thalassemia and sickle cell anemia patient were serologically and molecularly tested for RHCc, RHEe, K, k Fya, Fyb, Jka and Jkb antigens and compared. Serological testing was done by tube agglutination and molecular testing was done either by allele specific PCR or by RFLP technique just before next transfusion. RESULTS: In more than 80% of the cases recipient's molecular testing blood groups were at variance with serologically tested blood groups (p < 0.0001). Mixed field reactions in serological typing were common. In sickle cell anemia patients no discrepancy was found. Molecular technique results were checked by Sanger's sequencing. DISCUSSION: Extended phenotyping in multitransfused thalassemia patients by serological technique often donot detect the exact red cell phenotype of the recipient and molecular techniques for such grouping is preferable, especially in multitransfused thalassemia patients where red cells from previous transfusions continues to be present in significant numbers whenever the testing is done.

Comparative study of alloimmunization against red cell antigens in sickle cell disease & thalassaemia major patients on regular red cell transfusion.

BACKGROUND & OBJECTIVES: : Sickle cell disease (SCD) patients require red cell transfusion during different clinical complications of the disease. Such patients are at a high risk for developing alloantibody against red cell antigens. From India, there are limited data available on alloantibody formation in multiply transfused SCD patients. The present study was thus undertaken to fill up this lacunae by looking at the development of red cell alloantibodies in SCD and ß-thalassaemia patients on regular transfusion. METHODS: : All sickle cell disease patients undergoing red cell transfusion between 2008 and 2016, were included. During this period, a large number of ß-thalassaemia major patients also underwent regular red cell transfusion. These thalassaemia patients were also included to compare the tendency of antibody formation between SCD and ß-thalassaemia major patients. All patients before regular transfusion were regularly assessed for the development of red cell antibody. Red cell antigen, antibody screen crossmatch and antibody identification were done using the standard technique. RESULTS: : A total of 138 patients with SCD aged between 4 and 53 yr (mean 17.6 yr) consisting of 83 males and 55 females (male:female, 1.5:1) along with 333 transfusion-dependent ß-thalassaemia patients were studied. Over the last eight years, 15 patients with SCD and four patients with thalassaemia developed alloantibody (P <0.001). Antibody specificity of their alloantibodies was against Rhc, RhE, Kell, Fya and Fyb only. Sickle cell disease patients with and without alloantibody required on the average 11.8 and 8.6 units of red cell concentrate, respectively (P <0.05). INTERPRETATION & CONCLUSIONS: : About 11 per cent of the transfused sickle cells patients developed alloantibodies. The antibody specificity was restricted to Rh, Kell and Duffy blood group systems. Extended antigen matching involving Rh, Kell and Duffy antigens may prevent alloantibody in such patients.

Pattern of distribution of 35 red cell antigens in regular voluntary blood donors of South Gujarat, India.

BACKGROUND: Extended phenotyping is one of the important method of reducing red cell alloimmunisation. Extended phenotyping of red cells from voluntary donors have many uses in addition to its application in population genetics. As there was very little data extended phenotyping on a cohort of Indian Voluntary blood donors this project was undertaken. STUDY DESIGN & METHODOLOGY: 200 regular voluntary blood donors having 'O' blood group were included for red cell antigen typing of Rh (D,C,E,c,e), Kell (K, k, Kpa, Kpb), Duffy (Fya, Fyb), Kidd (Jka, Jkb), Lewis(Lea, Leb), P(P1), MNS (M, N,S,s), and Lutheran (Lua, Lub), Colton (Coa, Cob), Diago (Diaa, Wra), Vw and Xga antigens using conventional antisera provided by DIAGAST. Calculations of antigen and phenotypes frequencies were expressed as percentages. RESULTS: Out of 200 'O' group blood donors, 96.5% were Rh D and 2.5% were K positive. Amongst Rh antigens, e was the most common (100%) followed by D, C (91.0%), c (50.5%) and E (16.5%) with DCe/DCe (R1R1, 48.0%) 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 1% of the donors. For Kidd and Duffy blood group systems, Jk (a + b+) and Fy (a + b-) were the most common phenotypes (39.0% and 64.0%, respectively). In the MNS blood group system, M + N+ (67.5%) and S + s+(43.5%) were the most common phenotypes. There were antigens like Cw(3.5%), K(2.3%), Kpa(1.2%), Ina(1.0%), Vw(1.2%), Coa(4.5%), Cob(1%), Lua(1.75%), Dia+(1.2%), and Wra+(0.6%) with frequency < 5% in the donor population. CONCLUSION: Extensively antigen phenotypes group 'O' red cells showed significant variation with other population from India as well as with Caucasian and black population. Extensive phenotyping 'O' group regular blood donors of red cell antigens is very useful to prepare in-house red cell panels for identification of alloantibodies.

Utilization of red cell concentrate from storage centers of South Gujarat.

INTRODUCTION: Blood storage centres in remote areas of the country was started to serve the patients in those locations. Present study analyses the the utilisation of blood from such storage centres under one regional transfusion centre in south Gujrat. MATERIALS AND METHODS: In this retrospective study amount of blood requested, utilised, major reasons for utilisation were studied from available records and analysed. RESULTS: 20 storage centres serving almost 2 million population per year was studied. 2197 - 3089 units of blood were requested from these centres per year with utilisation rates of 100 - 134 units/centre/year. Severe anaemia, Antenatalcare, operations and postpartum. Haemorrhage were important causes for red cell transfusion. DISCUSSION AND CONCLUSION: The storage centres are functioning reasonably well but utilisation of around 2500 - 3500 units packed red cell per year for 2 million population suggests under utlisation of the facility.

Reasons for Discarding of Whole Blood/Red Cell Units in a Regional Blood Transfusion Centre in Western India.

To analyze the reason for discarding whole blood and red cell concentrates in a Regional Blood Transfusion Centre in India. Retrospective analysis of electronic data on collection of blood and reason for discard of whole blood and red cell concentrate between January 2012 and December 2016. 1,70,431 units of blood were collected between January 2012 and December 2016 in various blood donation camps. On an average 6.60% whole blood or red cell units were discarded because of various reasons. Out dating was the single important cause for discarding such units leading to loss of 6.7-7 million rupees (USD 1,00,000) to the blood bank. Infective units, haemolysed units, insufficient amount collected units and leakage were other important causes for discarding the units. Using multiple approaches of donor selection, staff training rescheduling of blood camps and sharing this precious resource with other blood bank can significantly minimize the discard rate. The reasons for discard of blood units varied not only from one blood centre to other but also from one country to another.