Polimorfismo −1123G>C en el gen PTPN22 y anticuerpos antipéptido citrulinado cíclico en la artritis reumatoide

Abstract

Background and objectivesThe protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene encodes an important negative regulator of T-cell activation, lymphoid-specific phosphatase –Lyp– and has been associated with different autoimmune disorders. The PTPN22 −1123G>C polymorphism appears to affect the transcriptional control of this gene, but to date, the biological significance of this polymorphisms on rheumatoid arthritis (RA) risk remains unknown. We evaluate the association of PTPN22 −1123G>C polymorphism with anti-cyclic citrullinated protein antibodies (anti-CCP) and risk for RA in population from Western Mexico. Material and methodsA transversal analytic study, which enrolled 300 RA patients classified according to ACR-EULAR criteria and 300 control subjects (CS) was conducted. The −1123 G>C polymorphism was genotyped by PCR-RFLP. The anti-CCP antibodies levels were quantified by ELISA kit. ResultsWe found a higher prevalence of homozygous PTPN22 −1123CC genotype in CS than in RA patients (OR 0.41; 95% confidence interval 0.24-0.71; P=.001), suggesting a potential protective effect against RA. Concerning anti-CCP levels, the CC genotype carriers showed the lowest median levels in RA (P<.05). ConclusionThe PTPN22 −1123CC genotype is a protector factor to RA in a Mexican-mestizo population and is associated with low anti-CCP antibodies.