The Frequency of Hla-Dq2/Dq8 Haplotypes and Celiac Disease Among the First-Degree Relatives of Patients With Celiac Disease Publisher

Summary: Research suggests HLA typing might not predict celiac disease in relatives of patients, as only 3% were diagnosed. Should serological tests take precedence? Findings challenge existing beliefs. #CeliacDisease #Genetics

Mansouri M^{1, 2} ; Dadfar M¹ ; Rostaminejad M³ ; Ekhlasi G¹ ; Shahbazkhani A⁴ ; Shahbazkhani B¹
Source: Gastroenterology and Hepatology from Bed to Bench Published:2021

Abstract

Aim: We evaluated the frequency of human leukocyte antigen (HLA) DQ2/DQ8 haplotypes as well as celiac disease (CD) among the first-degree relatives (FDRs) of CD patients, compared with healthy controls, and compared the HLA typing with serologic tests in this population. Background: Until now, no study has examined the frequency of HLA-DQ2/DQ8 haplotypes among the FDRs of Iranian patients with CD. Methods: In the current case-control study, 100 FDRs of CD patients and 151 healthy controls were included. Demographic characteristics were assessed using a research-made questionnaire. A blood sample was collected from each participant for HLA-DQ typing and measuring serum levels of anti-gliadin and anti-transglutaminase (anti-tTG) antibodies. Results: The mean age of the FDRs of CD patients and controls was 30 and 35 years, respectively. Also, 51% (n=51) of the FDRs and 51.7% (n=78) of controls were female. CD was diagnosed among 3% (n=3) of the FDRs of CD patients. No significant difference was found in terms of the frequency of HLA-DQ alleles between the FDRs of CD patients and controls. Out of 100 FDRs of CD patients, 40% had HLA-DQ2 allele, 16% carried HLA-DQ8 allele, and 4% had both alleles. Surprisingly, the CD was diagnosed in three subjects among 60 FDRs of CD patients with HLA-DQ2 allele (3% of the whole population). This diagnosis was based on the results of serological tests as well as endoscopy and intestinal biopsy. Conclusion: CD was confirmed among 3% (n=3) of the FDRs of CD patients. We found that HLA typing is not effective in predicting CD among FDRs of CD patients. Other methods such as serological tests have a higher priority compared with HLA-DQ typing. © 2021 RIGLD, Research Institute for Gastroenterology and Liver Diseases.