Celiac disease risk HLA-DQ haplotypes in an Egyptian cohort using multiplex ligation-dependent probe amplification.

Abstract

Celiac disease (CD) is one of the most common autoimmune disorders. It is triggered by exposure to dietary gluten proteins resulting in small intestine mucosal injury. Previous studies showed that CD is highly associated with human leukocyte antigens (HLA) class II DQ heterodimers, mainly HLA-DQ2.5 and HLA-DQ8. The aim of the work was to evaluate the distribution of the CD associated risk HLA-DQ haplotypes in CD patients, CD patients with Type 1 diabetes mellitus (T1DM) comorbidity, in at-risk and healthy individuals in an Egyptian cohort. The study included 124 individuals, divided into 4 groups. They were 28 CD patients, 21 CD and T1DM patients diagnosed with T1DM comorbidity, 50 at-risk group including relatives of CD patients and T1DM patients and finally 25 normal individuals as controls. The multiplex ligation-dependent probe amplification (MLPA) assay was performed using peripheral blood DNA. HLA-DQ2.5 was the most frequent haplotype among CD patients (69.3%) and among the combined groups in the cohort population (58.1%), either homozygous or heterozygous (together with HLA-DQ8 or -DQ2.2).HLA-DQ8 was the second most frequent haplotype followed by HLA-DQ2.2 and HLA-DQ7.5. In the control group, two individuals carried HLA-DQ2.3 and one carried a single DQB1*02:01 allele. In the at-risk group, 7 individuals were negative for all the haplotypes investigated. In conclusion, CD is a multifactorial disease where HLA-DQ haplotypes are a major genetic predisposing factor for both development and progress of the CD disease.