Discriminant Score for Celiac Disease Based on Immunohistochemical Analysis of Duodenal Biopsies

OBJECTIVES: Celiac disease (CD) represents a spectrum, which includes cases with minor histological abnormalities (potential CD). The aim of this work is to evaluate the contribution of immunohistochemical analysis of duodenal biopsies to the diagnosis of gluten-related minor enteropathy. METHODS: Duodenal biopsies from 56 patients with untreated CD and 56 controls were analyzed for CD3 and γδ intraepithelial lymphocyte number, γδ/CD3 ratio, and density of CD25+ lamina propria cells. A discriminant equation was obtained by which 61 more biopsies with normal villous architecture were blindly evaluated. RESULTS: All of the immunohistochemical parameters were significantly different between patients with CD and controls. None of the single parameters showed sufficient specificity for CD. The combination of all of the 4 markers resulted in the following discriminant equation: discriminant score (Dscore) = (CD3 × 0.06) - (γδ × 0.119) + (CD25 × 0.012) + (γδ/CD3 × 0.131) - 4.709. Using this Dscore, patients were correctly classified as celiac or controls in 97.3% of the cases. When this equation was applied to a validation set of 61 patients with normal villous architecture and unknown diagnosis, 92.9% of those with a positive score turned out to be patients with potential CD. A normal score, however, did not exclude this condition. CONCLUSIONS: Immunohistochemistry represents a specific tool for the diagnosis of CD, but does lack sensitivity in detecting all of the potential CD cases.