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

Major and minor subgroup profile of blood in patients receiving multiple transfusions and donors

OBJECTIVE

It was aimed to profile the blood subgroups of our region and to reveal the prevalence of auto/alloimmune sensitization in patients who had to undergo multiple erythrocyte transfusions and to establish the sensitization profile by screening major and minor subgroups.

MATERIALS AND METHODS

In this study, the distribution of ABO and Rh system major subgroups was studied in 100 donor blood. As the patient group, 50 patients who received three or more red blood cell transfusions were included. In addition to this group, Kell, Lewis, Duffy blood group systems were studied.

RESULTS

According to the ABO system, 35% of the donors were in O, 33% in A, 17% in AB, and 15% in B. According to the Rh system, 75% is Dvi positive. Rh system is 99% e positive and 33% E positive in major subgroups and Kell1 positivity is 8%. In the patient group, 22% D(-) was determined compared to Rh blood group. Among the major subgroups of Rh, C was 68%, E was 14%, c was 76%, and e positivity was found to be 100%. The Kell1 negativity rate is 96%. The highest negativity was found in 86% Lea antigen in Lewis system, in 36% S antigen in MNS system, 34% Fyb antigen in Duffy system, and 24% Jka antigen in Kidd system. When inappropriate blood is given for any antigen, a double population is formed. The double negativities we detected in our study occurred as follows according to blood group systems: E 18%, C 12%, c 8%, Cw 2%, Kell 1 2%, M 8%, N 4%, S 18%, s 6%, Fya 8%, Jka 6%, Jkb 22%. Indirect Agglutination Test (IAT) was negative in all patients.

CONCLUSION

IAT negativity in all patient groups suggests that we do not develop alloimmunization, but the high rates of double population suggest a high risk of alloimmunization.

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 In^a and In^b 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 (In^a/IN*01, In^b/IN*02) blood group alleles by Sequence Specific PCR. In^a antigen positivity was confirmed by serology test.

RESULTS

Four donors were found heterozygous for In^a antigen i.e. In (a + b+) by SS-PCR and their In^a positivity were confirmed by in-house polyclonal Anti-In^a reagent. SS-PCR was standardized using known heterozygous sample of a blood donor. The frequency of In^a 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 In^a, such PCR based method would be extremely helpful to prepare rare donor registry by screening blood donors' at large scale. Red cells of In^a positive donors can be used as in-house reagent red cells for screening and identification of corresponding antibody.

SARS-Coronavirus-2 seroprevalence in asymptomatic healthy blood donors: Indicator of community spread

Background

The Corona virus disease 2019 (COVID-19) pandemic caused by SARS -Corona virus-2 (SARS-CoV-2) has been a major concern the world over. Serological surveillance is an important tool to assess the spread of infection in the community. This study attempted to assess the prevalence of antibodies to SARS-CoV-2 among blood donors in Delhi, India during the pre-vaccination period.

Methods

Seroprevalence of SARS-CoV2-2 IgG antibodies were determined in blood donors reporting to the Department of Transfusion medicine at a tertiary care hepatobiliary center, in India from September to October 2020. The SARS-CoV-2 IgG antibodies against spike subunit 1 protein were measured using the enhanced chemiluminescence method.

Results

A total of 1066 blood donors were screened. The overall seropositivity for SARS-CoV-2 IgG antibodies was 27.57 % (294/1066). The highest seropositivity was seen in the age group 26−35 years, 46.6 % (137/492), followed by 18−25 years, 28.2 % (83/260), 36−45 years, 19.4 % (57/244), and more than 45 years, 5.8 % (17/70). The seropositivity in the donors who had donated blood previously was 26.1 % (189/723). There was no statistically significant difference amongst seroprevalence in the blood groups, AB blood group (32.6 %, 95 % CI 23.02−43.3), group B (27.2 %, 95 % CI 22.8−32.09 %), group A (27.1 %, 95 % CI 21.8−32.9 %), and group O (27.02 %, 95 % CI 22.3−32.1 %) (p 0.539).

Conclusions

There was significantly higher seropositivity for SARS-CoV-2 antibodies in the voluntary healthy blood donors indicating community spread and large number of asymptomatic cases in Delhi. Higher seroprevalence in younger adults indicated increased exposure to the virus and lack of COVID appropriate behaviour.

Distribution of Kell antigens K, k, Kpa, and Kpb among blood donors in Jeddah city of Western Saudi Arabia

CONTEXT:

Kell blood group system is considered as the third clinically significant blood group in blood transfusion due to the highly immunogenetic of their antigens. No data are available regarding the frequencies of the Kell blood group antigens in Jeddah city. Knowledge of the antigen and phenotype frequencies is crucial to assess the risk of alloimmunization and to guide the probability of finding antigen-negative donor blood, which can be useful when blood transfusion is required for a patient who has multiple red cell alloantibodies.

AIMS:

The aim of this study was to determine the distribution of Kell blood group: K, k, Kp^a, and Kp^b antigens and phenotypes among blood donors in Jeddah city, western Saudi Arabia, to improve the transfusion services in the area.

SUBJECTS AND METHODS:

Seven hundred and fifty-eight blood samples from blood donors were used in the study. The samples were collected from different national blood bank centers in Jeddah city hospitals. Kell antigens were typed through gel card method using commercial antisera.

STATISTICAL ANALYSIS USED:

The gathered data were analyzed using the SPSS program. Frequency and crosstab tests were completed to achieve the objectives of the current study.

RESULTS:

The most frequent Kell phenotype in this study was Kp^(a−b+), followed by K−k+, K+k+, and then Kp^(a+b+), and the less frequent was K+k−. K−k− and Kp^(a+b−) phenotypes were not observed in studied donors.

CONCLUSIONS:

This study is the first report to determine the frequency of Kell antigens and phenotypes among blood donors in Jeddah city. These results appear to be useful in providing better care for patients by implementing tests that should become a routine in blood banks. The Kell system is very important in transfusion medicine practice.

Assessment of rhesus and kell blood group antigens, phenotypes, and their allelic frequencies in North Indian blood donors

BACKGROUND

Prevalence of rhesus (Rh) and Kell antigens in a population vary with race, ethnicity, and geographical location. With advances in immunohematology, non-D antigens, and their corresponding antibodies are increasingly being found to be culprits for alloimmunization.

MATERIALS AND METHODS

Assessment of the phenotype of Rh and Kell blood group antigen in the healthy donor population from North India was done, and estimation of the frequencies of these alleles in our population was performed.

RESULTS

The most common antigen in the North Indian donor population was "e" (95.6%) followed by "C" (89.6%), "c" (57.7%), and "E" (17.29%) in that order. The most prevalent phenotype in the Indian population was found to be "CDe" followed by "CcDe" and "CcDEe." "K" antigen was found to be positive in 1.81% of the population.

DISCUSSION

Knowledge of the Rh antigen profiles in a given population can be very helpful in formulating transfusion guidelines specific to a particular population with an aim to minimize the cost and maximize the benefits. With this aim in mind and considering the problems encountered in developing countries like ours, we conducted Rh and Kell antigen profiling of donors. Comparative analysis with other population studies and implications for transfusion protocols is evaluated.

CONCLUSION

Assessment of Rhesus antigen profile of a particular population is useful to develop cost effective ways of providing maximum benefits of blood transfusion with least resources.

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 (Fy^a, Fy^b) and Kidd (Jk^a, Jk^b) 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 Fy^a, Fy^b, Jk^a and Jk^b 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.

Phenotyping of Rh, Kell, Duffy and Kidd Blood Group Antigens among Non-Tribal and Tribal Population of South Gujarat and its Implication in Preventing Alloimmunization in Multitransfused Patients

Background:Sickle cell anaemia is common amongst Tribal population of south Gujrat. Alloimmunisation in multitransfused sickle cell anaemia patient is 10 times commoner in these patients than beta Thalassemia  major  patients from regular blood donor communities. Study design & methodology: Red cell antigen typing of Rh (D,C,E,c,e ), Kell (K, k), Duffy (Fya, Fyb) and Kidd (Jka, Jkb) were carried out in 222 regular voluntary blood donors who belonged to non-tribal population and in 113 samples of tribal population using conventional antisera.  Results: Rh D antigen frequency was 96.6% in non-tribal and 96.5% in tribal population. 2.4% of K antigen was found in non-tribal population whereas the antigen was absent in tribal population  .Amongst Rh antigens, e was the most common (100%) followed by D, C (91.0%, 85.8%), c (50.5%, 44.2%) and E (16.5%, 17.0%) with DCe/DCe (R1R1, 48.0%, 55.8%) being the most common phenotype in both the groups. In Kell antigens  k antigen was 100% ,Kidd and Duffy antigens  Jk (a+b-) (39.2%, 46.9%) and Fy (a+b-) (64.2%, 52.2%) were the most common phenotypes in non-tribal and tribal population respectively.  Conclusion: There is significant difference in Duffy , Kidd and Kell (k) antigen distribution between non tribal and tribal population . Total absence of Kell antigen in tribalsalong with. E antigen in a significant portion of blood donors and its absence in large number of tribals also increase the risk of alloimmunisation.