CTLA-4 gene polymorphisms and systemic lupus erythematosus in a population-based study of whites and African-Americans in the southeastern United States.

Epidemiology Branch, A3-05, NIEHS, NIH, DHHS, PO Box 12233, Durham, North Carolina 27709-12233, USA.
Lupus (Impact Factor: 2.48). 10/2004; 13(10):784-91. DOI: 10.1191/0961203304lu1085oa
Source: PubMed

ABSTRACT Cytotoxic lymphocyte antigen-4 (CTLA-4) plays an important role in regulating T cell activation, and may help to limit T cell response under conditions of inflammation. Genetic variability in CTLA-4 has been implicated in the development of several autoimmune diseases. Some studies have described associations between CTLA-4 polymorphisms and systemic lupus erythematosus (SLE), but findings have been inconsistent. We examined polymorphisms in the CTLA-4 gene promoter region (-1722T/C, -1661 A/G, -318C/T) and exon I (+49G/A) with respect to SLE in a population-based case-control study in the southeastern US. Genotypes from 230 recently diagnosed cases and 276 controls were examined separately for African-Americans and whites. We observed no overall associations between SLE and the four CTLA-4 polymorphisms examined. Subgroup analyses revealed effect modification by age for the presence of the -1661G allele, yielding a significant positive association with SLE in younger (<35 years) African-Americans (OR = 3.3). CTLA-4 genotypes also interacted with HLA-DR2 and GM allotype to contribute to risk of SLE. These findings suggest allelic variation in this region of CTLA4 is not a major independent risk factor for SLE, but may contribute to risk of disease in younger African-Americans or in the presence of certain immunogenetic markers.

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