Evaluating the Role of HLA-DRB1 Alleles in Genetic Predisposition to Psoriatic Arthritis in Patients with Psoriasis

Psoriasis is considered a chronic disease among the most common inflammatory autoimmune skin diseases. Psoriatic arthritis PsA is the most important systemic manifestation of psoriasis and often appears after the onset of psoriasis. HLA genes are considered the most important predisposing genetic factors associated with psoriasis, especially HLA-C*06, but the association between HLA-DRB1 alleles and psoriasis, in addition to the risk of developing PSA has not been widely studied since this association tends to differ between ethnic groups. The HLA-DRB1 alleles were identified in 50 patients with psoriasis in addition to 30 healthy patients using the sequence-specific primers PCR. Psoriasis patients were classified into two groups according to the presence of arthritis. 40% of patients had arthritis. Susceptibility to psoriasis in this study sample was significantly associated with HLA-DRB1*07, *11 and *10 (odds ratio (OR) 8.5, 4 and 3, p-value= 0.002, 0.02 and 0.01 respectively), While a negative association was found with HLA-DRB1*03 ((OR) 0.1). It was also observed that the presence of alleles *07, *11 and *01 is associated with a high risk of developing PsA in psoriasis patients ((OR) 14, 4.88 and 4.84, respectively). In contrast, alleles *03 and *14 were considered protective alleles against developing PSA in psoriasis patients ((OR) 0.14 and 0.2, respectively). Genetic associations identified in psoriasis have been found to be significantly associated with PsA. It is important to conduct genetic studies to determine the genetic factors involved in the pathogenic mechanism and thus reach a more effective treatment.