HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS REGISTER		Author Keyword(s) Vol Page [Advanced]

This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this link to a friend Similar articles in this journal Similar articles in PubMed Add article to my folders Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by van der Pas, J Articles by van Engelen, B G M Search for Related Content PubMed PubMed Citation Articles by van der Pas, J Articles by van Engelen, B G M Related Collections Neuromuscular disease Cytopathology

Diagnostic value of MHC class I staining in idiopathic inflammatory myopathies

¹ Neuromuscular Centre, Institute of Neurology, University Medical Centre, Nijmegen, Netherlands
² Department of Statistics, University of Nijmegen

Correspondence to:
Correspondence to:
Dr G J D Hengstman
Neuromuscular Centre Nijmegen, Institute of Neurology, University Medical Centre Nijmegen, PO Box 9101, 6500 HB Nijmegen, Netherlands; g.hengstman{at}neuro.umcn.nl

Background: Identification of mononuclear cellular infiltrates in skeletal muscle tissue is the histological cornerstone of the diagnosis of idiopathic inflammatory myopathy (IIM). However, these infiltrates are not always present.

Objective: To determine whether MHC class I antigen expression on the sarcolemma, which is absent in normal muscle tissue, is upregulated in IIM and could serve as an additional diagnostic test.

Methods: Expression of MHC class I antigens was studied in 224 muscle samples of 61 adult patients with IIM (9 dermatomyositis, 23 polymyositis, 29 inclusion body myositis) and 163 controls (normal subjects and patients with various neuromuscular disorders) in a prospective blinded manner.

Results: The sensitivity of the test for diagnosing IIM was 78% (95% confidence interval (CI), 66% to 88%), with a specificity of 95% (91% to 98%). The sensitivity before the start of immunosuppressive treatment was 89% (76% to 96%). The sensitivity was not changed by including all patients who had been on immunosuppressive treatment for less than four weeks before muscle biopsy (sensitivity 90% (79% to 97%)). False positive results were found in only seven controls (4%), six of whom had a muscular dystrophy.

Conclusions: Detection of sarcolemmal MHC class I is a valid test for IIM. It is not affected by the short term use of immunosuppressive agents (less than four weeks) and it should be incorporated in the histological evaluation when the diagnosis of IIM is under consideration or needs to be excluded.

Keywords: MHC class I; myositis; histology

This article has been cited by other articles:

				K. P. Ng, C. R. Smith, and D. A. Isenberg Muscular dystrophy mimicking refractory idiopathic inflammatory myositis: a trio of cases Rheumatology, October 1, 2007; 46(10): 1618 - 1619. [Full Text] [PDF]

				G J D Hengstman, H J ter Laak, W T M Vree Egberts, I E Lundberg, H M Moutsopoulos, J Vencovsky, A Doria, M Mosca, W J van Venrooij, and B G M van Engelen Anti-signal recognition particle autoantibodies: marker of a necrotising myopathy Ann Rheum Dis, December 1, 2006; 65(12): 1635 - 1638. [Abstract] [Full Text] [PDF]

				C Dorph, P Englund, I Nennesmo, and I E Lundberg Signs of inflammation in both symptomatic and asymptomatic muscles from patients with polymyositis and dermatomyositis Ann Rheum Dis, December 1, 2006; 65(12): 1565 - 1571. [Abstract] [Full Text] [PDF]

				H. Lindehammar and B. Lindvall Muscle involvement in juvenile idiopathic arthritis Rheumatology, December 1, 2004; 43(12): 1546 - 1554. [Abstract] [Full Text] [PDF]