A single nucleotide polymorphism in exon 1 of cytotoxic T-lymphocyte-associated-4 (CTLA-4) is not associated with rheumatoid arthritis

Background. Rheumatoid arthritis (RA) is an oligogenic disease for which on ly one susceptibility locus has been identified to date. Genes involved in T-cell regulation are potential candidates. Association to cytotoxic T-lymp hocyte-associated-4 (CTLA-4) protein, a negative regulator of T-cell activa tion, has previously been described in a subset of German RA patients carry ing the HLA DRBI*0401 subtype. Linkage and association with another oligoge nic autoimmune disease, insulin-dependent diabetes mellitus, has also been described in a Spanish population. Objective. To investigate the association of CTLA-4 with RA in Spanish and UK subjects. Methods. Caucasoid UK RA patients (n = 192), UK controls (n = 96), Spanish RA patients (n = 136) and Spanish controls (it = 144) n ere typed for an A/ G bi-allelic polymorphism in exon 1 of CTLA-4 using polymerase chain reacti on-restriction fragment length polymorphism (PCR-RFLP) (enzyme). Results. No significant differences in the frequency of the G allele or the GG genotype were found in either the UK or Spanish RA patients compared wi th controls. Conclusion. No significant evidence was found of an association between RA and CTLA-4.