Association of HLA DRB1 alleles with juvenile idiopathic arthritis in Mexicans

The aim of the study was to investigate association between HLA class II alleles and juvenile idiopathic arthritis (JIA) in Mexican patients.

We typed 120 patients with JIA and 99 healthy controls for HLA class II alleles were performed by PCR-SSO. Differences between the whole group of JIA and its subtypes and controls were calculated by using the Xi2; p-values were corrected (pc) with Bonferroni's test.

The alleles HLA-DRB1*01 (pc= 0.00083) and HLA-DRB1*04 (pc=0.0049) were strongly associated with systemic JIA, while HLA-DRB1*11 and HLA-DRB1*14 were found to have decreased frequencies in the patients with systemic JIA compared to the controls. Two alleles were found to have increased frequencies with JIA oligoarthritis subgroup, HLA-DRB1*11 (p=0.01, pc=NS) and HLA-DRB1*13 (p=0.01, pc=NS). The HLA-DRB1*04 was found increased frequencies with susceptibility for RF negative and RF positive polyarthritis JIA subgroups (p correction resulted in loss of significance). In contrast two alleles HLA-DRB1*07 and HLA-DRB1*14 were found decreased frequencies only patients RF positive polyarthritis JIA subgroup compared to the controls (pc=NS).

The profile of HLA-DRB1 alleles associations in Mexican with JIA were somewhat distinct from association typically found in Caucasians.