Immunophenotypic Spectrum and Genomic Landscape of Refractory Celiac Disease Type II

xloma.fota13 shared this article with you from Inoreader Immunophenotypic Spectrum and Genomic Landscape of Refractory Celiac Disease Type II Via The American Journal of Surgical Pathology - Published Ahead-of-Print Refractory celiac disease type II (RCD II), also referred to as "cryptic" enteropathy-associated T-cell lymphoma (EATL) or "intraepithelial T-cell lymphoma," is a rare clonal lymphoproliferative disorder that arises from innate intraepithelial lymphocytes. RCD II has a poor prognosis and frequently evolves to EATL. T he pathogenesis of RCD II is not well understood and data regarding the immunophenotypic spectrum of this disease and underlying genetic alterations are limited. To gain further biological insights, we performed comprehensive immunophenotypic, targeted next-generation sequencing, and chromosome microarray analyses of 11 RCD II cases: CD4−/CD8− (n=6), CD8+ (n=4), and CD4+ (n=1), and 2 of 3 ensuing EATLs. Genetic alterations were identified in 9/11 (82%) of the RCD II cases. All 9 displayed mutations in members of the JAK-STAT signaling pathway, including frequent, recurrent STAT3 (7/9, 78%) and JAK1 (4/9, 44%) mutations, and 9/10 evaluable cases expressed phospho-STAT3. The mutated cases also harbored recurrent alterations in epigenetic regulators (TET2, n=5 and KMT2D, n=5), nuclear factor-κB (TNFAIP3, n=4), DNA damage repair (POT1, n=3), and immune evasion (CD58, n=2) pathway genes. The CD4−/CD8− and other immunophenotypic subtypes of RCD II exhibited similar molecular feat ures. Longitudinal genetic analyses of 4 RCD II cases revealed stable mutation profiles, however, additional mutations were detected in the EATLs, which occurred at extraintestinal sites and were clonally related to antecedent RCD II. Chromosome microarray analysis demonstrated copy number changes in 3/6 RCD II cases, and 1 transformed EATL with sufficient neoplastic burden for informative analysis. Our findings provide novel information about the immunophenotypic and genomic characteristics of RCD II, elucidate early genetic events in EATL pathogenesis, and reveal potential therapeutic targets. Conflicts of Interest and Source of Funding: S.H. received honoraria from Illumina, Loxo Oncology, and Medscape; research funding from Bristol Myers Squibb. A.A.G. is a co-investigator with Seattle Genetics, Innate Pharma. Investigator and consultant with StemLine. P.H.G. is on the Advisory board of Johnson & Johnson/Janssen, ImmunogenX, ImusanT. The remaining authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article. Correspondence: Govind Bhagat, MD, Department of Pathology and Cell Biology, Columbia University Irving Medical Center, VC14-228, 630 West 168th Street, New York, NY 10032 (e-mail: gb96@cumc.columbia.edu). Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved. View on the web Inoreader. Take back control of your news feed. Follow us on Twitter and Facebook.