Molecular Analysis of HLA-DR and Their Association with Systemic Lupus Erythematosus

Abstract

Systemic lupus erythematosus (SLE) is an autoimmune disease that develops within a complex network of genetic and immunologic factors. Both genetic and environmental factors strongly influence the      development of SLE. But genetic factors are more important both in determining the overall susceptibility to SLE and in influencing immunologic heterogenecity in affected subjects. Now it is accepted that major histocompatibility complex (MHC) genes particularly HLA (Human leukocyte antigen) class II constitute a part of the genetic factor for susceptibility to develop SLE. To determine the association of HLA-DR antigens with SLE, this case-control study was conducted over a period of twelve months from March 2013 in Dhaka. Buccal swabs for HLA-DR typing were collected from 46 SLE cases and 46 age and sex matched unrelated healthy controls. HLA-DR typing was carried out by polymerase chain        reaction (PCR) with sequence specific primers. Among 46 cases, female versus male ration was 22: 1 and mean age at study entry was 27.05 ± 8.17 years, ranging from 12.5 45 years. A total of 10      (HLA-DR1 to DR10) HLA antigens were determined in both cases and controls. The most frequent HLA-DR observed among cases was DR2 (86.96%) followed by DR7 (41.30%). When compared with healthy controls, the HLA-DR2 was significantly associated with SLE (p ?0.05, RR: 4.6914, 95% CI: 1.658 to 13.267). No other HLA-DR had significant association with SLE. No association of HLA-DR was observed with age of onset of disease among SLE cases. Results of the study reveal that HLA-DR2 gene is a risk factor for development of SLE in Bangladeshi population.