Protective role of HLA-DRB1*11 against juvenile idiopathic arthritis living in North Eastern Iran.

Objectives: Juvenile idiopathic arthritis (JIA) is one of the most common chronic rheumatic diseases in children. The complex nature of this immune-mediated disease owes itself to several predisposing genes and environmental factors affecting its pathogenesis. Conducted in Iran, this study was originally intended to investigate every possible association between HLA DRB1 alleles and a susceptibility to JIA.

Materials and Methods: In this case-control study, 45 patients with a definite diagnosis of JIA based on International League against Rheumatism (ILAR) criteria were compared against 46 healthy controls. DNA samples taken from both groups were analyzed using PCR-sequence specific primers (PCR-SSP) method. Data analysis including parametric and nonparametric test and multivariate analysis was undertaken using the SPSS 11.5 software. A P-value< 0.05 was regarded as statistically significant.

Results: Mean ages in case group and healthy controls were 14.64±6.21 and 13.73±6.39, respectively with no significant difference between the two groups ( P =0.515). Sex difference between JIA group and healthy controls was also not significant ( P =0.068). The frequency of HLA-DRB1*01 was found the most frequent HLA-RB1 in our patients (33.3%). No significant statistical correlation between various HLA-DRB1 alleles and clinical subtypes of the disease could be established from the data. HLA-DRB1*11 was shown to raise protection to JIA ( P =0.035, OR=2.755, 95% CI=0.963-8.055) in northeastern Iran. In addition, we found that HLA-RB1*09 is nominally associated with an increased risk of JIA ( P =0.56, OR=2, 05, 95% CI=0.18-23.63).

Conclusion: HLA-DRB1*11 was shown to raise protection to JIA in northeastern Iran. The disparity of findings in other ethnicities prompts further investigations with larger sample sizes.