Human Leukocyte Antigen: Class I Allele Frequencies and Haplotype Distributionin a Tertiary Care Hospital in Bangladesh

Afzalun Nessa,Shahina Tabassum,Sharmin Sultana

doi:10.3329/bmrcb.v44i1.36798

Abstract

Human leukocyte antigen (HLA) are cell surface glycoproteins encoded by Major Histocompatibility Complex (MHC) geneof human genome. HLA antigen frequency and haplotype distribution are useful for determining disease associations, origin, migration and genetic relationships between populations and predicting the outcome of transplantation. Thus, the present study was carried outto identify HLA class I (HLA-A and HLA-B) antigen and haplotype distribution among a selected Bangladeshi population. This retrospective study was conducted among 1070 individuals who were referred by cliniciansfor HLA typing at the Tissue Typing Laboratory of the Department of Virology, Bangabandhu Sheikh Mujib Medical University (BSMMU) during the period 2009 to 2011. For HLA typing, Blood was collected in heparin containing tube and the laboratory tests were performed by the microlymphocytotoxicity technique according to manufacturer’s instructions.Out of 19 HLA-A and 37HLA-B antigens tested, a total of 19/19 and 36/37 antigens were detectedrespectively in this study. The most frequent antigens of HLA-A and HLA-B detected were A11 (25.4%), A24 (16.6%), B75 (18.1%) and B35 (11.3%). The least antigen frequency detected for HLA-A locus were A69 (0.09%), A26 (0.28%), A34 (0.28%), while for HLA-B locus were B81 (0.09%) and B56 (0.09%). Among the HLA-A and HLA-B antigens, some alleles were found to be homozygote such as A11 (4.0%), A2 (2.7%), A24 (2.1%) andB75 (2.4%), B35 (1.8%), and B44 (1.4%) respectively. The most frequent haplotype in the study populationwereA11: B75 (4.9%). The most frequent antigens of HLA-A and HLA-B detected were A11 (25.4%), B75 (18.1%) respectively. The distribution of HLA haplotypes among the study population indicates that it has the influence of Oriental and Asian populations. Thus, this study will be helpful to provide valuable information for population genetics and HLA disease association analysis.Bangladesh Med Res Counc Bull 2018; 44(1):01-08

Highlights

Bangladesh is located in South Asia, bordered by India to its west, north and east, Myanmar to its southeast and the Bay of Bengal to its south
This retrospective study was conducted among 1070 Bangladeshi individuals who were referred by clinicians for Human leukocyte antigen (HLA) typing at the Tissue Typing Laboratory of the Department of Virology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka during the period of 2009 to 2011
A total of 1070 Bangladeshi population comprising 362 (33.8%) females and 708 (66.2%) males were tested for HLA class I antigen and haplotype distribution

Summary

Introduction

Bangladesh is located in South Asia, bordered by India to its west, north and east, Myanmar to its southeast and the Bay of Bengal to its south. There is admixture of aboriginals like Mundari and Santhals.[1] In the 19th century, “Aryan race” was defined as the subgroup of the Caucasian (or Europoid) race consisting of native speakers of Indo-European languages descended from the original Proto- Indo-Europeans, in modern civilization that resided in different parts of the world including Bangladesh.2Aryan migration brought several different peoples and cultures together. A fusion of Aryan and Dravidians resulted in Indo-Aryan synthesis which reconfigured the Indian population.[3] Genetic study shows that Bengali population (Eastern India) had close ethnic affiliation with Caucasoids.[4] This population formed clusters distinctly from the North-East population groups (ethnic affiliation to Mongoloid), who are possibly descendents of ancestral population of China.[5] the history of Bangladesh combines Indo-Aryan, Austro-Asiatic, Dravidian, Mughal, Arab, Persian, Turkic and British influences.[6]

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