HLA-DRB typing among polyarticular juvenile idiopathic arthritis and progressive pseudorheumatoid dysplasia patients

Abstract

Juvenile Idiopathic Arthritis (JIA) is a multi-factorial disease influenced both by environmental and genetic factors. Progressive pseudorheumatoid dysplasia (PPD) is a rare autosomal recessive genetic disorder affecting multiple joints, mimicking JIA. Aim of the work: to reveal the frequency of HLA-DR types among the studied patients and to correlate the different allele variations clinically. Patients and methods: Thirty JIA patients, in addition to 15 molecularly diagnosed PPD patients were subjected to full history taking and clinical examination. HLA-DRB1 typing was performed to 24/30 JIA and 12/15 PPD cases and thirty healthy age and sex matched children who were included as a control group. Results: The JIA patients were 22 females and 8 males with mean age of 15.8 ± 1.96 years and disease duration 5.3 ± 4.4 years. PPD patients were 8 males and 7 females with mean age of 8.7 ± 3.06 years and disease duration 3.95 ± 2.68 years. A significant frequency of HLA-DRB 04 (p = 0.049) among JIA patients was present in comparison to the controls (OR = 2.81, CI:1.02–7.75), other risky alleles were HLA-DRB 10, 13 and 15. However, HLA-DRB 01, 03, 07, 11 and 14 were found to be protective. HLA-DRB 01, 04, 10 and 13 were found to be risky alleles in PPD. However, HLA 03, 07, 11 and 15 were found to be protective alleles among PPD patients. Conclusion: HLA-DRB 04 was found in a higher frequency in JIA patients with a significant difference in comparison to the controls, denoting that it may play a role in the genetic pathogenesis of JIA.