Objective: The genetic basis of susceptibility to Henoch-Schönlein purpura (HSP) may be conferred by a number of gene loci, including the MHC. Associations between human leukocyte antigen (HLA) and disease can help to establish a basis for susceptibility and assist in the prediction of the outcome and clinical heterogeneity. We aimed to investigate the implications of the HLA-DRB1 locus and the susceptibility to HSP, and to determine if there are associations with joint, gastrointestinal, and renal manifestations of the disease.
Methods: We studied 110 Turkish patients (men/women: 66/44) with HSP. Patients and ethnically matched controls with respect to age and sex (n = 250) were HLA-DRB1 genotyped from DNA determined using molecular based methods.
Results: HLA-DRB1 genotype differences between patients with HSP and controls were observed. The frequency of HLA-DRB1 11/14 was higher [odds ratio (OR) 1.97, 95% confidence interval (95% CI) 1.25-3.12, p = 0.003; OR = 1.83, 95% CI = 1.02-3.28, p = 0.035, respectively] and the frequency of HLA-DRB1 10/17 was lower (OR = 1.04, 95% CI = 1.01-1.86, p = 0.035; OR = 3.96, 95% CI = 1.17-13.33, p = 0018, respectively) in patients with HSP compared to controls. No HLA-DRB1 associations with gastrointestinal and renal manifestations were found (p > 0.05). In contrast, HLA-DRB1*11 positivity was increased and HLA-DRB1 14 positivity reduced in HSP patients with joint manifestations (OR = 2.68, 95% CI = 1.09-6.66, p = 0.029; OR = 9.34, 95% CI = 3.38-25.64, p = 0.000, respectively). Also, HLA-DRB1 13 positivity was found to be increased in patients with nephrotic proteinuria (OR = 3.76, 95% CI = 1.25-11.23, p = 0.025).
Conclusion: These results suggest that genetic factors from HLA-DRB1 genotypes might be related to the susceptibility to HSP for Turkish children but not to the severity of this disease. Additional studies are required to confirm the association of alleles encoded in the HLA region with the disease progression and severity.