Association of HLA-B27, MEFV gene mutations, ERAP1, IL12B and IL23R gene polymorphisms with ankylosing spondylitis.

Objective: Genetic factors have an important role in the pathogenesis of ankylosing spondylitis (AS). The aim of this study was to analyse the association of HLA-B27, MEFV mutations, IL12B, IL23R and ERAP1 polymorphisms in Turkish patients with ankylosing spondylitis. Methods: One hundred AS patients and 100 healthy controls were examined for HLA-B27, 12 common MEFV mutations, IL12B (rs3213120), IL23R (rs11209026), and ERAP1 (rs30187) polymorphisms (SNPs) by allele specific PCR, revers hybridization and sequencing techniques. Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Bath Ankylosing Spondylitis Functional Index (BASFI) scores were calculated. Results: Our results confirmed that HLA-B27 was strongly associated with AS (69% vs 7% in controls) (p<0.001, OR: 29.6, 95% CI: 12.3-71.1). We also found an association between uveitis and HLA-B27 positivity in AS patients (p=0.004). The MEFV mutations were significantly frequent in AS patients (40%) compared with healthy controls (22%) (p=0.006, OR: 2.56, 95% CI: 1.3-4.4). We found that ERAP1 rs30187 was significantly associated with AS patients (p=0.033). The rs30187 CT genotype was associated with increased AS risk compared to CC or TT genotypes (OR: 2.1, 95% CI: 1.2-3.7). However, in patients with AS carrying the C allele increased the risk 1.9 times (95% Cl: 1.1-3.3). There was no association with AS and IL12B (rs3213120) and IL23R (rs11209026). There were no significant differences between HLA-B27, MEFV mutations, ERAP1 (rs30187) and Bath AS Disease Activity Index (BASDAI), Bath AS Functional Index (BASFI) scores. Conclusion: This study showed that HLA-B27, MEFV mutations and ERAP1 (rs30187) are AS genetic susceptibility genes. Interactions between ERAP1 and HLA-B27 and MEFV mutations may play an important role in the AS pathogenesis.