849 Gamma-Delta T-Lymphocytes As Diagnostic Criterium in Latent Celiac Disease

Introduction Flow cytometry is a validated, easy applicable methodology for the determination of intraepithelial lymphocytes (IEL) phenotype in celiac disease (CD). An increase in Gamma-Delta IEL (CD3+TCRγδ+) is a characteristic finding in CD patients yet cut-off values for CD3+TCRγδ+ IEL in CD have not been determined. A validated cut-off value might be helpful in the establishing the diagnosis of CD, especially in those patients with minimal histological abnormalities (i.e., Marsh I) or individuals with positive serology in the absence of histological abnormalities. Methods Flow cytometric immunophenotyping was performed on IELs isolated from fresh small bowel biopsy specimens obtained from histology and serology proven CD patients (n=219) (active CD: n=92, CD in remission: n=127), healthy controls without CD (n=89) and suspected CD (n=14), the latter being defined as Marsh III and/or positive serology. Thirty-one additional patients with non-celiac villous atrophy were included as a disease control group. Follow-up data were available from thirteen CD patients. Percentages of CD3+TCRγδ+ IEL from CD patients and healthy controls were used to calculate a cut-off value for CD3+TCR γδ+ IEL in suspected CD patients using a receiver operating characteristic (ROC) curve. Results A significantly higher percentage of CD3+TCRγδ+ IEL was found in biopsy and serology proven CD patients (median 19.0%, range 1-58%) compared to healthy controls (median 6.0%, range 1-15%) (p 14% CD3+TCRγδ+ IEL might aid in a diagnosis of CD. Furthermore, Flow cytometric immunophenotyping might be helpful in cases of diagnostic doubt on CD in patients compliant to a GFD without the need for a gluten-challenge.