CTLA4 exon 1 polymorphism, rheumatoid arthritis and autoimmune endocrinopathy

Excerpt

We read with interest the apparently contradictory findings of two recent studies published in your journal concerning the allelic association of the single nucleotide polymorphism (CTLA4A/G) in exon 1 of the cytotoxic T-lymphocyte antigen-4 (CTLA4) gene with rheumatoid arthritis (RA) in Chinese populations from two different areas of Taiwan. In the first study, Lee et al., based in Northern Taiwan, describe an increased frequency of the G allele in association with RA in comparison to a control group that had no history of autoimmune disease [1]. However, in a separate study based in Southwest Taiwan, Liu et al. found no such association in comparison to a control group of healthy hospital employees [2]. Though this discrepancy might be explained by a lack of power in these studies, particularly since the study by Liu et al. has a small number of cases and controls, it is also possible that these investigators failed to adequately account for the effects of coexistent autoimmune endocrinopathy in their RA patients. …