Assessment of diagnostic value of HLA-DQ2/DQ8 typing and anti-tissue transglutaminase antibodies as an alternative to duodenal biopsy in pediatric celiac disease

Abstract

Introduction/Objective. The objective of the paper is to assess the applicability of serum anti-tissue transglutaminase (tTG) antibodies IgA and IgG concentration and HLA-DQ2/DQ8 typing as a non-invasive alternative to duodenal biopsy in diagnosing celiac disease (CD) in pediatric population. Methods. A prospective cohort study included a total of 179 pediatric patients aged 1–18 years. Determination of tTG IgA and tTG IgG antibodies and human leukocyte antigen (HLA) DQ2/DQ8 typing was performed for all patients. Histology of duodenal biopsies was interpreted by the modified Marsh scoring system. Results. The diagnosis of CD was confirmed in 101 (56%) patients of the studied population. In cases of CD, HLA-DQ2/DQ8 was positive in 100 patients (99%). The tTG IgA antibodies in concentration higher than 100 U/ml were detected in 77 (76.2%) of the CD patients and in significantly smaller number for tTG IgG [29 (28.7%)] (p < 0.001). Statistically highly significant association of duodenal lesions Marsh grade 3 with concentration of tTG IgA 10-fold higher than the upper level of normal (ULN) was established (p < 0.001) Conclusion. Concentration of tTG IgA 10-fold higher than ULN is significantly positively correlated with Marsh grade 3 histopathology findings. Specific antibodies determination in combination with HLA-DQ2/ DQ8 typing proves to be sufficient for a diagnosis of CD, supporting the fact that duodenal biopsy may be avoided in a significant majority of patients – 75%.

Keywords

• celiac disease
• tissue transglutaminase antibodies
• hla-dq2/dq8 typing
• non-invasive