Objectives: To compare the distribution of human leucocyte antigen (HLA) class I and II alleles in patients with erosive hand osteoarthritis (EHOA) to that of patients with non-erosive hand OA (non-EHOA) and in healthy Italian Bone Marrow Donors (IBMDs), in order to evaluate possible immunogenetic associations with EHOA. In the EHOA group we also sought possible associations between HLA alleles and disease severity.
Methods: Ninety-four patients with EHOA (82 women, 12 men; mean age 61.4 ± 8.45 years) and 37 with non-EHOA (28 women, nine men; mean age 59.21 ± 9.07 years) were studied. Disease severity was measured by the number of clinically active joints (NCAJ) and by the radiographic score (RS) using the Kallman scale. HLA typing was undertaken for A, B, C, and DRB1 loci; HLA-DRB1* genotyping was determined using polymerase chain reaction (PCR) with sequence-specific primers. Frequencies were compared with those of the healthy IBMDs.
Results: The alleles found more frequently in EHOA patients than in non-EHOA patients and healthy controls were: A23, A26, and A29; B38, B44, and HLA DRB1*01 and *07. The RS was more severe in the EHOA compared to the non-EHOA group (63.60 ± 23.14 vs. 34.34 ± 20.24, p < 0.001). Within the EHOA group, HLA-DRB1*07 was associated with a higher RS (67.36 ± 23 vs. 64.5 ± 18.5, p = 0.029).
Conclusion: In this study of North Italian patients affected with EHOA, the HLA-DRB1*07 allele was found to be associated with both the development and greater severity of the disease.