title: Lack of association between sCTLA-4 levels in human plasma and common CTLA-4 polymorphisms.
abstract: BACKGROUND
  Cytotoxic T lymphocyte antigen-4 (CTLA-4) is an important downregulatory molecule expressed on both T and B lymphocytes. Numerous population genetics studies have documented significant associations between autoimmune diseases and single nucleotide polymorphisms (SNPs) within and around the CTLA-4 region of chromosome 2 in man. Furthermore, circulating levels of a soluble form of CTLA-4 (sCTLA-4) have been reported in a variety of autoimmune mediated diseases. Despite these findings, the relationship between levels of sCTLA-4 protein, mRNA transcript levels, and SNPs within the CTLA-4 region have not been clearly defined. In order to further clarify this relationship, we have tested four different SNPs within the CTLA-4 region among subjects whom are negative (n = 53) versus positive (n = 28) for sCTLA-4.
  
  
  RESULTS
  Our data do not support a clear association between sCTLA-4 levels and any of the four SNPs tested.
  
  
  CONCLUSIONS
  The variation in the SNPs tested does not appear to effect sCTLA-4 protein levels, despite reports that they affect sCTLA-4 mRNA.
authors.affiliation: Transplant Research Laboratory, Aurora St, Luke's Medical Center, Milwaukee, WI 53215, USA. aberry@wisc.edu
authors.forename: Andrew
authors.initials: A
authors.lastname: Berry
authors.forename: Matt
authors.initials: M
authors.lastname: Tector
authors.forename: Martin K
authors.initials: MK
authors.lastname: Oaks
mesh_terms: D000328:Adult; D015703:Antigens, CD / Q000097:blood* / Q000235:genetics*; D001327:Autoimmune Diseases / Q000097:blood / Q000235:genetics; D060908:CTLA-4 Antigen; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D011110:Polymorphism, Genetic; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; D012333:RNA, Messenger