<em>HLA-DQ2</em> and <em>HLA-DQ8</em> Alleles in Celiac Disease Patients and Healthy Controls.

OBJECTIVE: To compare HLA-DQ2 and HLA-DQ8 alleles between celiac disease patients and healthy control group.

STUDY DESIGN: Observational cross-sectional study.

PLACE AND DURATION OF STUDY: Department of Immunology, Armed Forces Institute of Pathology (AFIP), from April to December 2018.

METHODOLOGY: Subjects were included: 100 celiac disease patients selected by non-probability consecutive sampling, and 100 healthy subjects. After collecting peripheral blood in EDTA tubes, chromosomal DNA was extracted and amplified, using sequence specific primers. Post-amplification electrophoresis was performed on two per cent agarose gel, followed by ethidium bromide staining; and specific band patterns were recorded under ultraviolet illumination to determine the HLA-DQ alleles. The subtypes of HLA-DQ2, i.e. HLA-DQ2.5 and HLA-DQ2.2 were also assessed. Frequency, percentage, mean and SD were calculated. Post-stratification Chi-square test was applied.

RESULTS: The mean age of celiac disease group and healthy subjects was 14.79 ± 5.32 years and 14.71 ± 5.21 years, respectively. The frequency of HLA-DQ2 and HLA-DQ8 among celiac disease patients was 93% and 4%, respectively. Among HLA-DQ2 positive, HLA-DQ2.5 and HLA-DQ2.2 were found in 92% and 8%, respectively. Statistically significant difference (p <0.05) was observed between the celiac disease patients and healthy group. There was no significant difference observed among different age groups and gender (p >0.05).

CONCLUSION: HLA-DQ2 detection reliably diagnoses celiac disease among all age groups and either gender. It can be used as an effective marker for early diagnosis of celiac disease instead of invasive procedures such as intestinal biopsy. The diagnosis can be pin-pointed by presence of HLA-DQ2.5. Key Words: Celiac disease, HLA-DQ2, HLA-DQ8, HLA-DQ2.5, HLA-DQ2.2.