Clinical characteristics and outcomes of patients with idiopathic inflammatory myopathies from Jordan 1996–2009

Abstract
To describe demographic characteristics, clinical features and outcome of Jordanian patients with idiopathic inflammatory myopathies (IIM), a retrospective chart review of all patients diagnosed with IIM at Jordan University Hospital between 1996 and 2009 was carried out. Thirty patients with IIM were identified. Female to male ratio was 1.7:1, with mean age at diagnosis 34.3 ± 9.2 (10-72) years with bimodal presentation at 21 and 49 years and a mean follow-up of 6.5 ± 5.7 years. Eleven patients had polymyositis (PM); 19 patients had dermatomyositis (DM); 1 patient had DM with malignancy; 2 patients had juvenile DM; and 2 patients had DM/PM with other rheumatologic diseases. Raynaud's phenomenon was present in 26% of patients, dysphagia in 40%, fever in 16%, arthralgia/arthritis in 26%, and dyspnea was present in 26% patients. Positive muscle biopsy and EMG were present in 81% and 92% of patients, respectively. Elevated serum creatinine kinase (CK), AST/ALT and LDH were found in 90%, 72%, and 88% of patients at presentation, respectively. Interstitial fibrosis identified on high-resolution computed tomography (HRCT) was found in 7/14 (50%) patients. Restrictive lung disease was present in 16/21 (76%), low diffusion capacity of lung of carbon monoxide (DLCO) in 10/17 (59%) and pulmonary hypertension in only 3/19 (16%) patients tested. Arab Jordanian patients with IIM showed very low prevalence of malignancy, lower mean age than previous reports, and similar other clinical, laboratory and serologic markers, and survival rate to previous reports. Of interest, we found that extra-muscular manifestations were mainly associated with dermatomyositis.