Study of Autoantibodies and DQ Antigens in Patient with Celiac Disease

Abstract

Introduction: Celiac Disease (CD) is a chronic autoimmune mediated disorder triggered by the ingestion of gluten. It is seen in genetically predisposed person and results in small intestine injury. Its aetiopathogenesis is not clear. Simple histopathology is not able to diagnose the disease many times. Aim: Aim of present study was to assess the prevalence of HLA DQ alleles and autoantibodies in diagnosis of the disease and association of DQ antigens with Type 1 Diabetes mellitus (T1DM) and autoimmune hypothyroidism in CD patients. Materials and Methods: Total 100 cases of CD and 31 healthy controls were studied, within a period of January 2015 to Febuary 2016. Autoantibodies like ANA, anti-tTg, anti-TPO and anti-scl 70 were done by ELISA kits. HLA DQ typing was done in 44 cases of CD, 20 cases of CD with T1DM, 22 cases of CD with autoimmune thyroid disease and 31 healthy controls. HLA DQ typing was done by SSO hybridisation method by Mr. SPOT machine. Results: About 70% patients were children between 6 months to 20 years of age and female formed the maximum number of cases (60%). Anti-tTg ab was positive in all cases (100%), anti-Scl 70 Ab was positive in 25%, anti-TPO ab was found in 22% and ANA was positive in only 10% cases. Most frequent DQβ1 haplotype in CD were DQβ1*02:01 (45.5%, p<0.001) and DQβ1*02:02 (20.5%, p=0.007) while DQ*06:01 was significantly more common in controls suggesting its protective role. Among DQα1 typing DQα1*05:01 (45.5%, p<0.001) and DQα1*05:05 (40.9%, p<0.001) which were significantly more in CD than controls. Contrary to this DQα1*01:01, DQα1*01:03 and DQα1*01:04 were significantly reduced in CD patients. CD patients associated with T1DM and autoimmune thyroid disease had significantly more DQβ1 02:01, DQβ1*02:02, DQα1*05:01 and DQα1*05:05. Conclusion: CD is an autoimmune disease, DQ typing should be kept in diagnostic criteria of CD. Association of autoimmune thyroid diseases and T1DM in CD is due to common sharing of these DQ antigens suggesting its role in predisposing autoimmune diseases.