title: A common CTLA4 haplotype associated with coeliac disease.
abstract: Coeliac disease is a common enteropathy with a strong inherited risk characterised by dietary wheat, rye and barley induced T-cell activation. Although there is replicated linkage to 2q33, results are inconsistent from association studies of the most promising candidate genes: the CD28/CTLA4/ICOS cluster. CTLA4 plays a key role in regulating T lymphocyte mediated inflammatory responses, and variants in the 3' region influence development of diabetes and thyroid disease. We genotyped CTLA4 variants (-1722 C/T, -658 T/C, -318 C/T, +49 A/G, +1822 C/T, CT60 A/G) to tag all common haplotypes (>5% frequency) and an ICOS variant (IVS+173 C/T) in 340 white UK Caucasian coeliac disease cases. Strict ascertainment criteria for coeliac cases required both villous atrophy at diagnosis and positive serology. In total, 973 healthy controls were available for SNP, and 705 for CTLA4 haplotype, based association analyses. Coeliac disease showed weak association with the CTLA4 +1822T (P=0.019) and CT60 G (P=0.047) alleles. Strong association was seen with a common CTLA4 haplotype (P=0.00067, odds ratio 1.41) of frequency 32.7% in coeliac disease and 25.5% in healthy controls. A common CTLA4 haplotype shows strong association with coeliac disease, and contains multiple alleles reported to affect immunological function. Loss of tolerance to dietary antigens in coeliac disease may be mediated in part by heritable variants in co-signalling genes regulating T-cell responses.
authors.affiliation: Department of Gastroenterology, Imperial College London, Du Cane Road, London W12 0NN, UK.
authors.forename: Karen A
authors.initials: KA
authors.lastname: Hunt
authors.forename: Dermot P B
authors.initials: DP
authors.lastname: McGovern
authors.forename: Parveen J
authors.initials: PJ
authors.lastname: Kumar
authors.forename: Subrata
authors.initials: S
authors.lastname: Ghosh
authors.forename: Simon P L
authors.initials: SP
authors.lastname: Travis
authors.forename: Julian R F
authors.initials: JR
authors.lastname: Walters
authors.forename: Derek P
authors.initials: DP
authors.lastname: Jewell
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Playford
authors.forename: David A
authors.initials: DA
authors.lastname: van Heel
mesh_terms: D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000235:genetics*; D060908:CTLA-4 Antigen; D016022:Case-Control Studies; D002446:Celiac Disease / Q000453:epidemiology / Q000235:genetics*; D015331:Cohort Studies; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006239:Haplotypes / Q000235:genetics*; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000235:genetics; D007166:Immunosuppressive Agents; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; D007141:Immunoglobulin Fc Fragments; D007166:Immunosuppressive Agents