TCRγδ+ Cells After Gluten-free Diet: A Biomarker for Coeliac Disease?

"* In all patients the investigators will analyse coeliac serology, DQ-genotype, and results of two duodenal biopsy sampling (one at diagnosis before starting the GFD and another sampling during follow-up with GFD) for assessment of both histopathology and intraepithelial lymphocyte subpopulations by T-cell flow cytometry. In addition, clinical, serological, and histological response to GFD will be evaluated.~* T-cell flow cytometry assay is performed as previously described by our group in previous studies. In all patients, an additional duodenal biopsy sample is taken from the second-third portion of the duodenum at the same endoscopic procedure that for histopathology. The normal cut-off values for the IEL cytometric pattern in our laboratory are CD3+TCRγδ+ IEL ≤8.5% (≤mean + 2SD) and CD3- IEL ≥10% (10th percentile). The cut-offs define four intraepithelial lymphogram patterns: normal, isolated decrease in CD3- cells, isolated increase in TCRγδ+ cells, and the coeliac lymphogram."