DIAGNOSTIC ACCURACY OF ANTI-TISSUE TRANSGLUTAMINASE IGA ANTIBODY IN THE DIAGNOSIS OF CELIAC DISEASE TAKING SMALL BOWEL BIOPSY AS A GOLD STANDARD IN CHILDREN

Abstract

Background: Celiac disease (CD) is a chronic immune-mediated enteropathy triggered by gluten ingestion in genetically susceptible individuals and affects approximately 1% of the global population (Sabenca et al., 2021). The disease is associated with growth failure, chronic diarrhea, anemia, malnutrition, and impaired quality of life in children if diagnosis is delayed (Al-Toma et al., 2019). Although small bowel biopsy remains the gold standard for diagnosis, anti-tissue transglutaminase immunoglobulin A (anti-tTG IgA) has emerged as a highly sensitive and specific non-invasive diagnostic test and is recommended as the initial screening modality in pediatric patients (Gülseren et al., 2019; Bashir et al., 2022).

Objective: To determine the diagnostic accuracy of anti-tissue transglutaminase IgA antibody in the diagnosis of celiac disease by taking small bowel biopsy as the gold standard in children.

Methods: A descriptive cross-sectional study was conducted at the Department of Pediatric Medicine, Balochistan Institute of Child Health Services, Quetta. A total of 144 children aged 2– 12 years presenting with suspected celiac disease were enrolled through non-probability consecutive sampling. Serum anti-tTG IgA levels were measured using enzyme-linked immunosorbent assay (ELISA), and all participants underwent upper gastrointestinal endoscopy with small bowel biopsy. Histopathological findings were considered the reference standard. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall diagnostic accuracy were calculated using a 2×2 contingency table.

Results: A total of 144 children were included in the study. The mean age was 6.9 ± 2.8 years, and 82 (56.9%) were males. Histopathological examination confirmed celiac disease in 44 (30.6%) children. Anti-tTG IgA was positive in 51 (35.4%) participants. The test demonstrated a sensitivity of 90.9%, specificity of 88.0%, positive predictive value of 78.4%, and negative predictive value of 95.7%. The overall diagnostic accuracy was 88.9%.

Conclusion: Anti-tissue transglutaminase IgA antibody showed high sensitivity and specificity in the diagnosis of pediatric celiac disease. These findings support its utility as an effective noninvasive diagnostic tool that may reduce the need for intestinal biopsy in selected children while facilitating early diagnosis and management