Distribution of HLA-DRB1/DQB1 alleles and DRB1-DQB1 haplotypes among Tunisian patients with autoimmune hepatitis

Abstract

Background: Autoimmune hepatitis (AIH) is a chronic inflammatory disease characterized by necrotic inflammation leading to hepatocyte destruction. The association of human leukocyte antigens (HLA) with AIH development and onset is not fully elucidated especially in the Tunisian population. Objectives: The aim of this study was to determine the association of HLA class II alleles and DRB1-DQB1 haplotypes with AIH in Tunisian population. Patients and Methods: A total of 30 AIH patients and 60 healthy controls were included in the study. HLA class II typing was performed by Single-specific-primer polymerase chain reaction (PCR-SSP) technique. Results: Among 13 DRB1 and 5 DQB1 alleles resolved, our results show a positive association of HLA-DRB1∗03 (38.3% vs. 21.6%, OR = 2.24, P = 0.028) and negative association of HLA-DRB1∗11 (3.3% vs. 16.7%, P = 0.019). The analysis of DRB1-DQB1 haplotypes in cases and controls revealed 11-shared haplotypes with a frequency exceeding 1%. HLA-DRB1∗11-DQB1∗03 haplotype showed a decreased frequency in AIH patients (1.6% vs. 15.8%, P = 0.009) and may be considered as an haplotype of resistance to AIH. Conclusions: To our Knowledge, this is the first study performed to detect the HLA-DRB1 and DQB1 alleles associated with predisposition to AIH in Tunisian patients. The search for HLA predisposing genes to AIH may permit an earlier diagnosis allowing a better management and treatment of the disease in order to avoid liver transplantation. Keywords: Autoimmune hepatitis, HLA class II, Case-control study, Haplotypes