Objectives: The aim of this study was to compare the linkage disequilibrium parameters and the frequencies of the three-loci HLA haplotypes in children with celiac disease and in a control population within the same geographical area.
Methods: A total of 38 celiac children were studied. HLA typing was performed by microlymphocytotoxicity assay using T and B cells separated by monoclonal antibody labeled immunomagnetic particles (IMB). Three-loci haplotype frequency (pABC) depend on each gene frequency (pA, pB, and pC), and a correction factor (delta) and takes the form: pABC = pA x pB x pC + delta ABC. The existence of a linkage disequilibrium was assessed by chi2 test using 2 x 2 x 2 contingency tables for gametic association.
Results: There was a higher frequency of A1/B8/Cw7, A1/B8/DR3, A1/B8/DQ2, A19/B12/DQ2, B8/Cw7/DR3, B8/Cw7/DQ2, B8/DR3/DQ2, and B12/DR7/DQ2 in celiac children than in the control population.
Conclusions: From the comparative study of celiac and healthy population within the same area, we conclude that these three-loci haplotypes could determine genetic susceptibility to celiac disease.