Association between HLA class II Polymorphism and Knee Osteoarthritis in a Thai Population.

BACKGROUND: Osteoarthritis (OA) is a degenerative joint disease commonly found among elderly populations. Multiple risk factors, including non-clinical and genetic factors, contribute to the etiology and pathogenesis of OA. This study aimed to investigate the association between the human leukocyte antigen (HLA) class II alleles and knee OA occurrence in a Thai population.

METHODS: HLA-DRB1 and -DQB1 alleles in 117 patients with knee OA and 84 controls were determined using the PCR with sequence-specific primer (PCR-SSP) method. The association between knee OA and the presence of certain HLA class II alleles was investigated.

RESULTS: DRB1*07 and DRB1*09 frequencies increased, while DRB1*14, DRB1*15, and DRB1*12 decreased among patients compared with controls. DQB1*03 (DQ9) and DQB1*02 frequencies increased, while DQB1*05 decreased among patients. Notably, the DRB1*14 allele significant decreased (5.6% vs. 11.3%, p = 0.039, OR = 0.461, 95% CI: 0.221 - 0.963), while the DQB1*03 (DQ9) allele significantly increased among patients compared with controls (14.1% vs. 7.1%, p = 0.032, OR = 2.134, 95% CI: 1.067 - 4.265). Moreover, the DRB1*14-DQB1*05 haplotype showed a significant protective effect on knee OA (p = 0.039, OR = 0.461, 95% CI: 0.221 - 0.963). A contrary effect of HLA-DQB1*03 (DQ9) and HLA-DRB1*14 was observed, wherein the presence of HLA-DQB1*03 (DQ9) seemed to promote disease susceptibility, whereas HLA-DRB1*14 appeared to protect against knee OA.

CONCLUSIONS: Knee OA was more pronounced among females than males, especially those aged  60 years. In addition, a contrary effect was found regarding HLA-DQB1*03 (DQ9) and HLA-DRB1*14, in whom the presence of HLA-DQB1*03 (DQ9) seems to promote disease susceptibility, whereas HLA-DRB1*14 appears to be a protective factor against knee OA. However, further study with a larger sample size is suggested.