De volgende publicatie is verschenen over de TEDDY studie, waarbij kinderen vanaf hun geboorte tot hun 15e levensjaar worden gevolgd, om te achterhalen wie coeliakie krijgt en wie niet, plus welke factoren hierop van invloed zijn. Alle kinderen die deelnemen aan het onderzoek hebben de genotypen HLA-DQ2 en/of HLA-DQ8. Naast deze genotypen zijn er nog andere HLA-genotypen en niet-HLA-genotypen die het risico op het ontstaan van coeliakie beinvloeden. De onderzoekers hebben een ander HLA-genotype ontdekt (HLA-DPB1*04:01), dat de kans op het ontstaan van coeliakie juist kleiner maakt. Kinderen die dit genotype bezitten, naast HLA-DQ2, maken minder kans om immuun te worden voor gluten. Dat was eerder nog niet bekend.
Am J Gastroenterol. 2015 May 26. doi: 10.1038/ajg.2015.150. [Epub ahead of print]
HLA-DPB1*04:01 Protects Genetically Susceptible Children from Celiac Disease Autoimmunity in the TEDDY Study.
Hadley D1, Hagopian W2, Liu E3, She JX4, Simell O5, Akolkar B6, Ziegler AG7, Rewers M8, Krischer JP9, Chen WM10, Onengut-Gumuscu S10, Bugawan TL11, Rich SS10, Erlich H12, Agardh D13; TEDDY Study Group.
OBJECTIVES:
Tissue transglutaminase autoantibodies (tTGAs) represent the first evidence of celiac disease (CD) development. Associations of HLA-DR3-DQA1*05:01-DQB1*02:01 (i.e., DR3-DQ2) and, to a lesser extent, DR4-DQA1*03:01-DQB1*03:02 (i.e., DR4-DQ8) with the risk of CD differ by country, consistent with additional genetic heterogeneity that further refines risk. Therefore, we examined human leukocyte antigen (HLA) factors other than DR3-DQ2 for their contribution to developing tTGAs.
METHODS:
The Environmental Determinants of Diabetes in the Young (TEDDY) study enrolled 8,676 infants at an increased HLA-DR-DQ risk for type 1 diabetes and CD into a 15-year prospective surveillance follow-up. Of those followed up, 21% (n=1,813) carried DR3-DQ2/DR3-DQ2, 39% (n=3,359) carried DR3-DQ2/DR4-DQ8, 20% (n=1701) carried DR4-DQ8/DR4-DQ8, and 17% (n=1,493) carried DR4-DQ8/DQ4. Within TEDDY, a nested case-control design of 248 children with CD autoimmunity (CDA) and 248 matched control children were genotyped for HLA-B, -DRB3, -DRB4, -DPA1, and -DPB1 genes, and the entire cohort was genotyped for single-nucleotide polymorphisms (SNPs) using the Illumina ImmunoChip. CDA was defined as a positive tTGA test at two consecutive clinic visits, whereas matching in those with no evidence of tTGAs was based on the presence of HLA-DQ2, country, and sex.
RESULTS:
After adjustment for DR3-DQ2 and restriction to allele frequency (AF) ≥5%, HLA-DPB1*04:01 was inversely associated with CDA by conditional logistic regression (AF=44%, odds ratio=0.71, 95% confidence interval (CI)=0.53-0.96, P=0.025). This association of time to CDA and HLA-DPB1*04:01 was replicated with statistical significance in the remainder of the cohort using imputation for specific HLA alleles based on SNP genotyping (hazard ratio=0.84, 95% CI=0.73-0.96, P=0.013).
CONCLUSIONS:
HLA-DPB1*04:01 may reduce the risk of tTGAs, an early marker of CD, among DR3-DQ2 children, confirming that additional variants in the HLA region influence the risk for CDA.Am J Gastroenterol advance online publication, 26 May 2015; doi:10.1038/ajg.2015.150.
Bron: Pubmed