Celiac.com 06/14/2018 - Refractory celiac disease type II (RCDII) is a rare complication of celiac disease that has high death rates. To diagnose RCDII, doctors identify a clonal population of phenotypically aberrant intraepithelial lymphocytes (IELs).
However, researchers really don’t have much data regarding the frequency and significance of clonal T cell receptor (TCR) gene rearrangements (TCR-GRs) in small bowel (SB) biopsies of patients without RCDII. Such data could provide useful comparison information for patients with RCDII, among other things.
They are variously affiliated with the Department of Pathology and Cell Biology, and the Department of Medicine at the Celiac Disease Center, New York Presbyterian Hospital/Columbia University Medical Center, New York, USA. Their team analyzed results of TCR-GR analyses performed on SB biopsies at our institution over a 3-year period, which were obtained from eight active celiac disease, 172 celiac disease on gluten-free diet, 33 RCDI, and three RCDII patients and 14 patients without celiac disease.
Clonal TCR-GRs are not infrequent in cases lacking features of RCDII, while PCPs are frequent in all disease phases. TCR-GR results should be assessed in conjunction with immunophenotypic, histological and clinical findings for appropriate diagnosis and classification of RCD.
The team divided the TCR-GR patterns into clonal, polyclonal and prominent clonal peaks (PCPs), and correlated these patterns with clinical and pathological features. In all, they detected clonal TCR-GR products in biopsies from 67% of patients with RCDII, 17% of patients with RCDI and 6% of patients with gluten-free diet. They found PCPs in all disease phases, but saw no significant difference in the TCR-GR patterns between the non-RCDII disease categories (p=0.39).
They also noted a higher frequency of surface CD3(−) IELs in cases with clonal TCR-GR, but the PCP pattern showed no associations with any clinical or pathological feature.
Repeat biopsy showed that the clonal or PCP pattern persisted for up to 2 years with no evidence of RCDII. The study indicates that better understanding of clonal T cell receptor gene rearrangements may help researchers improve refractory celiac diagnosis.