Leena Das1, Peter C Blumbergs, Jim Manavis, Vidya S Limaye. 1. *Department of Rheumatology, North Manchester General Hospital, Pennine Acute Hospital NHS Trust, Manchester, UK †Department of Neuropathology, Hanson Institute, Institute of Medical and Veterinary Sciences, Adelaide ‡Department of Rheumatology, Royal Adelaide Hospital §Department of Medicine Adelaide University, Adelaide, Australia.
Abstract
INTRODUCTION: We sought to study the intensity and pattern of major histocompatibility complex (MHC) I and II expression in muscle from patients with biopsy-proven idiopathic inflammatory myositis (IIM) including the subgroups, polymyositis (PM), dermatomyositis (DM), and inclusion body myositis (IBM). METHODS: A total of 120 muscle biopsies (61 PM, 14 DM, and 45 IBM) were immunostained for MHC I and II. Staining was graded as follows. 0: no staining, 1+: ≤10% fibers, 2+: 10% to 25%, 3+: 25% to 50%, 4+: 50% to 99%, and 5+ 100%. RESULTS: All IIM biopsies showed MHC I positivity; 93% showed MHC II positivity. The proportion of patients with MHC II score ≥3+ was higher in IBM than DM or PM. In DM, MHC I expression showed a perifascicular pattern. All IBM biopsies were immunopositive for MHC I and II; 30/45 were scored 5+. DISCUSSION: Immunostaining for MHC I and II is a useful adjunctive test in diagnosis and subclassification of IIM.
INTRODUCTION: We sought to study the intensity and pattern of major histocompatibility complex (MHC) I and II expression in muscle from patients with biopsy-proven idiopathic inflammatory myositis (IIM) including the subgroups, polymyositis (PM), dermatomyositis (DM), and inclusion body myositis (IBM). METHODS: A total of 120 muscle biopsies (61 PM, 14 DM, and 45 IBM) were immunostained for MHC I and II. Staining was graded as follows. 0: no staining, 1+: ≤10% fibers, 2+: 10% to 25%, 3+: 25% to 50%, 4+: 50% to 99%, and 5+ 100%. RESULTS: All IIM biopsies showed MHC I positivity; 93% showed MHC II positivity. The proportion of patients with MHC II score ≥3+ was higher in IBM than DM or PM. In DM, MHC I expression showed a perifascicular pattern. All IBM biopsies were immunopositive for MHC I and II; 30/45 were scored 5+. DISCUSSION: Immunostaining for MHC I and II is a useful adjunctive test in diagnosis and subclassification of IIM.
Authors: Corinna Preuße; Barbara Paesler; Christopher Nelke; Derya Cengiz; Thomas Müntefering; Andreas Roos; Damien Amelin; Yves Allenbach; Akinori Uruha; Carsten Dittmayer; Andreas Hentschel; Marc Pawlitzki; Sarah Hoffmann; Sara Timm; Sarah Leonard Louis; Nora F Dengler; Heinz Wiendl; Jan D Lünemann; Albert Sickmann; Baptiste Hervier; Sven G Meuth; Udo Schneider; Anne Schänzer; Sabine Krause; Stylianos Tomaras; Eugen Feist; Rebecca Hasseli; Hans-Hilmar Goebel; Laure Gallay; Nathalie Streichenberger; Olivier Benveniste; Werner Stenzel; Tobias Ruck Journal: Acta Neuropathol Date: 2022-05-25 Impact factor: 15.887