Aim: Evaluation of Human Leukocyte Antigen (HLA) DQ2/DQ8 in celiac disease (CD) patients compared to healthy controls, and to investigate the presence of specific immunological markers (IL-15, IL-21, and TNFα) in the human serum samples from the study groups, also to detect HLA-DQ2 and HLADQ8 in relation to interleukins IL-15, IL-21, and TNF in CD patients.
Methods: A total of 90 individuals participated in this study, comprising 50 patients clinically and serologically diagnosed with celiac disease and 40 apparently healthy individuals serving as the control group. The participants were carefully selected and matched for age and gender where possible. Genotyping for HLA-DQ2 and HLA-DQ8 was conducted using the polymerase chain reaction (PCR) technique, which allows for accurate detection of specific alleles associated with genetic susceptibility to CD. In addition, enzyme-linked immunosorbent assay (ELISA) was employed to determine the serum concentrations of IL-15, IL-21, and TNF-α in both patient and control groups. Statistical analyses were performed to assess the significance of differences observed between the groups and to explore the relationship between HLA genotypes and cytokine expression levels.
Results: The individuals in the case study group were aged between 1 and 60 years. In terms of gender, the patient group consisted of 18 (36.0%) males and 32 (64.0%) females. Among 50 patients with celiac disease, 76.0% had HLA-DQ2, 20.0% had HLA-DQ8, and 14.0% had both. The majority of alleles encoded for HLADQ2 were significant in CD patients when compared with controls. The serum concentrations of IL-15, TNF-α, and IL-21 in the sick group were statistically significant with P-values of 0.001, 0.018, and 0.0001, respectively.
Conclusion: The HLADQ2 genotype is the most common HLA genotype among celiac patients in Iraq, followed by HLADQ8. Serum levels of IL-15, IL-21, and TNF-α were considerably elevated in individuals with CD compared to the control group.