Keywords : DQA
The Medical Journal of Basrah University,
Volume 32, Issue 1, Pages 43-53
Background: Lichen planus is an inflammatory, pruritic disease of the skin and mucus membranes, which can be either generalized or localized. Many studies indicated that human leukocyte antigens might have a role in lichen planus (LP). As far as my knowledge, no previous study had done in Iraq about HLA-DQA1 and -DQB1 alleles frequencies in patients with lichen planus.
Aim: The aim of the present study is to investigate the additional genetic contribution to lichen planus susceptibility lying on the HLA region, by focusing on the possible differential contribution of the different DQA1 and DQB1 carrying haplotypes.
Method: The present study was carried out in College of Medicine during the period between (2012-2014). 50 patients with lichen planus attending Basrah General Hospital and private clinic, and 50 healthy controls were included in the study, with age group from (13-67) years. 100 DNA samples were purified from the blood samples of patients and controls, and then followed by PCR amplification of HLA-DQA1 and DQB1 genes in Cell Research Unit, Biology Department, College of Science, University of Basrah. The sequencing-PCR was done in Korea, Bioneer sequencing laboratories.
Results & Conclusions: Results indicated statistically significant decreased frequencies of HLA-DQA1*010201 (P<0.005), DQA1*0201 (P < 0.05), and -DQB1*030201 (P < 0.005) alleles in lichen planus patients, which indicated that these alleles might be a protective factors. Results also indicated statistically significant increased frequencies of DQA1*010401 (P<0.005), DQA1*040101 (P<0.005) DQA1*050101 (P<0.005), DQB1*030101 (P<0.005) and DQB1*050101 (P<0.005) alleles in lichen planus patients, which indicated that these alleles might be risk factors and increase the ability of infection. The present study indicates that genetic constitution through HLA-DQ locus determines the mechanism of disease as well as clinical and pathologic outcomes. More studies are necessary to test genetic dependencies on the basis of larger samples which would increase statistical power. An accurate definition of disease susceptible alleles will improve our understanding of antigen presentation mechanisms prevailing in the etiology of the disease. This knowledge is necessary for the design of improved immune intervention strategies to halt lichen planus progression in patients at risk of developing the disease or those who are already suffering from it.