Clinical, electrophysiologic, and histopathologic profile, and outcome in idiopathic inflammatory myositis: An analysis of 68 cases
Open Access
- 1 January 2010
- journal article
- research article
- Published by Medknow in Annals of Indian Academy of Neurology
- Vol. 13 (4), 250-256
- https://doi.org/10.4103/0972-2327.74190
Abstract
Objectives: To study the electroclinical and histopathologic profile of idiopathic inflammatory myositis (IIM) with reference to prognosis and survival rate. Materials and Methods: Diagnosis of IIM was based on the Bohan and Peter criteria. Patients who improved and those whose condition worsened or who expired due to IIM per se at last follow-up were classified to have favorable and poor outcomes, respectively. Fisher's exact test was used for univariate analysis of prognostic factors. Results: The study cohort consisted of consecutive 68 patients with IIM. The mean age at diagnosis was 36.5 years and females constituted 71%. Of these patients, 62% had definite IIM, 49% had polymyositis, 20% had dermatomyositis, and 29% had overlap syndrome. The mean follow-up period was 5.4 years. Prednisolone alone was used in 55 (80%), and azathioprine (1-3 mg/kg/day) alone in 12 (17.6%) as the initial treatment. Relapse of IIM with drug withdrawal was seen in 15 patients (22%); 70% had favorable outcome and 16% had expired. The treatment delay of ≤6 months (P = 0.001), absence of cardiac or lung involvement (P < 0.001), and positive biopsy (P = 0.033) were predictive of a favorable prognosis in the univariate analysis. In multivariate analysis, only the duration of illness of ≤6 months (P = 0.008) and the absence of cardiac or lung involvement (P = 0.001) predicted the favorable outcome at last follow-up. Cumulative survival rate was 95% at 1 year, 86% at the 5th year, and 80% at the 10th year. Conclusions: Approximately, two-thirds of the patients showed good electroclinical and histopathologic correlations and an equal number improved with treatment. The treatment delay (≥6 months), presence of cardiac or pulmonary involvements, and negative muscle biopsy are bad prognostic factors.Keywords
This publication has 37 references indexed in Scilit:
- Correlation of muscle biopsy, clinical course, and outcome in PM and sporadic IBMNeurology, 2008
- Study of idiopathic inflammatory myopathies with special reference to borderland between idiopathic inflammatory myopathies and muscular dystrophiesNeurology India, 2008
- Long-Term Survival of Patients With Idiopathic Inflammatory Myopathies According to Clinical FeaturesMedicine, 2004
- Polymyositis and dermatomyositis: short term and longterm outcome, and predictive factors of prognosis.2001
- Features of polymyositis and dermatomyositis in the elderly: a case-control study.2000
- Clinical profile of polymyositis in Kashmir valley.1999
- Polymyositis, Dermatomyositis, and Inclusion-Body MyositisThe New England Journal of Medicine, 1991
- Prevalence Studies of Multiple Sclerosis, Myasthenia Gravis, and Myopathies in Kumamoto District, JapanNeuroepidemiology, 1987
- Dermatopolymyositis and other connective tissue diseases: a review of 105 cases.1985
- Polymyositis and DermatomyositisThe New England Journal of Medicine, 1975