Clinical Analysis of Misdiagnosis of 25 Cases of Idiopathic Inflammatory Myopathies as Liver Disease

YAO Dong-yun; HUO He-shui; ZHAO Wen-min; QIN Chen-man; WEI Qiu-jin; SUN Kai

doi:10.3969/j.issn.1002-3429.2015.06.008

Abstract：Objective To investigate the cause of misdiagnosis of idiopathic inflammatory myopathies( IIM) as liver disease to improve diagnosis and treatment. Methods The clinical symptom, serum muscle enzymes, inflammatory parame-ters, and follow-up information of 25 cases confirmed as IIM which had long been misdiagnosed as hepatic injury were retro-spectively studied. Results There were 19(76%) patients who ran a fever in this study. Characteristic rash,muscle pain, symmetric proximal muscle weakness,diffuse interstitial lung disease(ILD) were present in 64%(16/25), 72%(18/25), 96%(24/25), 76%(19/25)of all the patients. Electromyography(EMG) showed myogenic abnormality in 96% (24/25)of the patients. Muscle biopsy showed myogenic abnormality in 60%(15/25)of the patients. Serum muscle enzymes showed ris-ing concentration of all the cases ( 25/25 ) cases of creatine kinase ( CK ) , aspartate aminotransferase ( AST ) , alanine amin-otransferase(ALT). The ratios of AST to ALT of all the cases were greater than 1. There was a significant liner correlation be-tween AST and CK(r=0. 934,P<0. 01), or between ALT and CK(r=0. 865, P<0. 01);3 cases were misdiagnosed as drug-induced liver injury, 22 cases as unexplained liver injury. 25 cases were confirmed by clinical manifestations, autoanti-bodies, EMG, chest HRCT examination and were treated with corticosteroids and immunosuppressive agents after misdiagnosis for 3~11 months. During (0. 5~5)-year-follow-up, 20(80%) patients achieved persistent remission, 2(8%) patients had a relapse when corticosteroids were tapered,3 patients(12%) died of ILD with infection. Conclusion With specific clinical manifestations in IIM, AST and ALT elevation was positively correlated with increased CK. The main cause of misdiagnosis is due to lack of awareness of IIM. Improved awareness of the disease by clinicians in local hospitals will help to prevent misdiag-nosis of IIM.