The influence of the-94 Ins/Del ATTG polymorphism of NFkB on the anti-CCP antibody levels in patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by an inflammatory process that affects mainly synovial tissue in joints, and by the production of cyclic citrullinated peptides (anti-CCP) antibodies. In the inflammatory process the regulation of the nuclear factor kappa B (NFkB) transcription factor activation is a key point in the production of inflammatory cytokines. On the other hand, polymorphisms in several genes could contribute to the promotion of the inflammatory process observed in RA, and the association of the rs28362491 polymorphism in the NFkB gene with RA has been studied in different population. Therefore, it could be one of the interest targets to analyze their association with RA in a Mexican population. This is a case-control study to determine the influence of rs28362491 in the NFkB gene on RA and on clinical features of this disease, such as anti-CCP antibody levels, Disease Activity Score, and Health Assessment Questionnaire-Disability Index. The genotype of rs28362491 in the NFkB gene was determined in 140 RA patients and 135 healthy controls using the polymerase chain reaction-restriction fragment length polymorphism method with the enzyme PflMI. The following clinical variables were also determined: anti-CCP levels, Disease Activity Score, and Spanish version of the Health Assessment Questionnaire Disability-Index. Although no association of the polymorphism as a risk/protection factor with RA was found, the RA patients who carried the Ins/Ins genotype showed higher anti-CCP levels, while those with the Del/Del genotype showed higher Spanish version of the Health Assessment Questionnaire-Disability Index levels, compared to the other genotypes. The NFkB -94 Ins/Del ATTG (rs28362491) polymorphism is, therefore, associated with higher levels of anti-CCP antibodies, though no significant association as a risk or protection factor in RA cases was identified.