title: Anti-TCR gamma antibody in celiac disease: the value of count on formalin-fixed paraffin-embedded biopsies.
abstract: Small bowel intraepithelial lymphocytosis (IL) may depend from different causes, including celiac disease (CD). Demonstration of increased number of duodenal T cell receptor gamma-delta (TCRγδ) positive intraepithelial lymphocytes (IELs) has been used to support CD diagnosis on frozen material. This work evaluates a new commercially available anti-TCRγ antibody on formalin-fixed paraffin embedded (FFPE) small bowel biopsies. Anti-CD3 and anti-TCR CγM1 (clone γ3.20) from Thermo Scientific were applied by immunohistochemistry on 59 FFPE biopsies from 18 cases of CD with mild/severe atrophy, 19 cases of IL in CD patients on gluten-free diet (IL-GFD), 14 cases of IL (6/14 with positive CD-related serology), and 8 controls (CTR) with mild duodenitis and negative CD serology and genotyping. IELs/100 epithelial cells were counted in at least six high power fields. CD3+ and TCRγ+ IELs were significantly higher in CD, IL-GFD, and IL compared with CTR, but in contrast to CD3+ IELs, TCRγ+ IELs were significantly increased in CD and IL-GFD compared with IL. Furthermore, TCRγ+ IELs discriminated between IL with negative and positive CD-related serology (p = 0.02). TCRγ+ IELs can be identified on FFPE samples and their evaluation adds useful information for the work-up of small bowel biopsies in CD diagnosis. In fact, TCRγ staining coupled with CD3, may represent an additional tool to recognize cases of latent/potential CD when serology and clinical data are not conclusive or when the histological diagnosis remains equivocal.
authors.affiliation: Department of Molecular and Translational Medicine, Section of Pathology, University of Brescia, Italy. silvia.lona@gmail.com
authors.forename: Silvia
authors.initials: S
authors.lastname: Lonardi
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Villanacci
authors.forename: Luisa
authors.initials: L
authors.lastname: Lorenzi
authors.forename: Alberto
authors.initials: A
authors.lastname: Lanzini
authors.forename: Francesco
authors.initials: F
authors.lastname: Lanzarotto
authors.forename: Nice
authors.initials: N
authors.lastname: Carabellese
authors.forename: Umberto
authors.initials: U
authors.lastname: Volta
authors.forename: Fabio
authors.initials: F
authors.lastname: Facchetti
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D001706:Biopsy; D017252:CD3 Complex / Q000276:immunology / Q000378:metabolism; D002446:Celiac Disease / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D004386:Duodenum / Q000378:metabolism / Q000473:pathology*; D005260:Female; D005557:Formaldehyde; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008875:Middle Aged; D016612:Paraffin Embedding; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology* / Q000378:metabolism; D055815:Young Adult
chemical_list: D000888:Antibodies, Anti-Idiotypic; D017252:CD3 Complex; D016692:Receptors, Antigen, T-Cell, gamma-delta; D005557:Formaldehyde