Long-term outcome in polymyositis and dermatomyositis
- I M Bronner1,*,
- M F G van der Meulen2,*,
- M de Visser1,
- S Kalmijn3,
- W J van Venrooij4,
- A E Voskuyl5,
- H J Dinant6,
- W H J P Linssen7,
- J H J Wokke2,
- J E Hoogendijk2
- 1Department of Neurology, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
- 2Department of Neurology, University Medical Centre Utrecht, Utrecht, The Netherlands
- 3Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht
- 4Department of Biochemistry, Centre for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, The Netherlands
- 5Depertment of Rheumatology, Free University Hospital Amsterdam, Amsterdam
- 6Department of Clinical Immunology and Rheumatology, Academic Medical Centre
- 7Department of Neurology, St Lucas Andreas Hospital Amsterdam, Amsterdam
- Correspondence to:
M de Visser
Department of Neurology, Academic Medical Centre, University of Amsterdam, PO Box 22660, 1100 DD Amsterdam, The Netherlands;
- Accepted 30 March 2006
- Published Online First 10 April 2006
Background: Although polymyositis and dermatomyositis are regarded as treatable disorders, prognosis is not well known, as in the literature long-term outcome and prognostic factors vary widely.
Aim: To analyse the prognostic outcome factors in polymyositis and adult dermatomyositis.
Methods: We determined mortality, clinical outcome (muscle strength, disability, persistent use of drugs and quality of life) and disease course and analysed prognostic outcome factors.
Results: Disease-related death occurred in at least 10% of the patients, mainly because of associated cancer and pulmonary complications. Re-examination of 110 patients after a median follow-up of 5 years showed that 20% remained in remission and were off drugs, whereas 80% had a polycyclic or chronic continuous course. The cumulative risk of incident connective tissue disorder in patients with myositis was significantly increased. 65% of the patients had normal strength at follow-up, 34% had no or slight disability, and 16% had normal physical sickness impact profile scores. Muscle weakness was associated with higher age (odds ratio (OR) 3.6; 95% confidence interval (CI) 1.3 to 10.3). Disability was associated with male sex (OR 3.1; 95% CI 1.2 to 7.9). 41% of the patients with a favourable clinical outcome were still using drugs. Jo-1 antibodies predicted the persistent use of drugs (OR 4.4, 95% CI 1.3 to 15.0).
Conclusions: Dermatomyositis and polymyositis are serious diseases with a disease-related mortality of at least 10%. In the long term, myositis has a major effect on perceived disability and quality of life, despite the regained muscle strength.
- CTD, connective tissue disorder
- MRC, Medical Research Council
- MSA, myositis-specific autoantibodies
- s-IBM, sporadic inclusion body myositis
- SIP, Sickness Impact Profile
- SRP, signal recognition particle
↵* These authors contributed equally to this work.
Published Online First 10 April 2006
Competing interests: None.