DIAGNOSTIC ACCURACY OF IGA ANTI-TISSUE TRANSGLUTAMINASE ANTIBODY IN THE DIAGNOSIS OF CELIAC DISEASE TAKING HISTOPATHOLOGY AS GOLD STANDARD

Abstract

Objective: To determine the diagnostic accuracy of IgA anti-tissue transglutaminase antibody in the diagnosis of celiac disease taking histopathology as gold standard.

Study Design: Cross-sectional validation study.

Place and Duration of Study: Department of Pediatrics, Pak Emirates Military Hospital Rawalpindi, from Apr 2015 to Jul 2016.

Methodology: Ninety five consecutive children presenting with suspicion of celiac disease were included into this study after taking written informed consent. A predesigned proforma was used to record patient’s demographic details. Anti-tTG level of ≥25 U/ml was taken as diagnostic of celiac disease while results of histopathology on endoscopic biopsy were taken as gold standard.

Results: The mean age of the patients was 6.48 ± 3.20 years and majority 53 (55.8%) of the children were aged between 5-10 years. There were 47 (49.5%) male and 48 (50.5%) female children in the study group. The serum Anti-tTG level ranged from 8.0 U/ml to 759.0 U/ml with a mean of 298.75 ± 225.51 U/ml. Taking a cut-off value of ≥25 U/ml for anti-tTG, 81 (85.3%)
children were suspected of celiac disease. Histopathology of endoscopic biopsy confirmed celiac disease in 68 (71.6%) children with 62 true positive, 19 false positive, 6 false negative and 8 true negative cases. It yielded 91.18% sensitivity, 29.63% specificity and 73.68% accuracy for anti-tTG (≥25 U/ml) in the diagnosis of celiac disease with positive and negative predictive
values of 76.54% and 57.14% respectively.

Conclusion: IgA anti-tissue transglutaminase antibody (≥25 U/ml) was found to be 91.18% sensitive, 29.63% specific and 73.68% accurate in the diagnosis of celiac disease taking histopathology as gold standard with positive and negative predictive values of 76.54% and 57.14% respectively.