Genetic Association Between BTN3A1 Polymorphisms and the Risk of Rheumatoid Arthritis in a Chinese Population

BTN3A1 has been associated with systemic lupus erythematosus (SLE) and psoriasis; however, its relationship with rheumatoid arthritis (RA) risk, particularly regarding BTN3A1 polymorphisms and RA susceptibility remains unclear.

A total of 390 age- and sex-matched participants, including RA patients and healthy controls, were enrolled. Demographic, laboratory, and clinical data were collected. Five BTN3A1 polymorphisms (rs1796520, rs3857550, rs3208733, rs6912853, rs10456045) were genotyped. Allele and genotype associations between the groups were analyzed, as well as their associations with clinical and laboratory features in RA patients.

Among RA patients, 79.74% were female and 20.26% were male; among controls, 84.36% were female and 15.64% were male. For rs3208733, the frequencies of the CC genotype and C allele differed significantly between RA patients and controls. For rs6912853, the frequency of the TC genotype differed significantly. For rs10456045, the frequencies of the GG, AG, and GG + AG genotypes differed significantly. Regarding clinical and laboratory associations: for rs1796520, antinuclear antibody (ANA)-positive patients showed higher frequencies of the CC + TC genotype and C allele; anti-Rib-positive patients showed a higher frequency of the C allele. RA patients carrying the CC + TC genotype had fewer swollen joints and higher levels of IL-12p70 and IFN-α than TT carriers. For rs6912853, CC + TC carriers had fewer tender joints and higher levels of C-reactive protein (CRP) and IFN-γ than TT carriers.

BTN3A1 gene polymorphisms are associated with RA risk, suggesting future therapeutic exploration of BTN3A1 in RA.