Inclusion body myositis: series of 30 cases from a Brazilian tertiary center

Objectives: To describe a series of 30 consecutive patients with inclusion body myositis (IBM) from our tertiary center, from 1982 to 2012. Materials and Methods: All patients fulfilled the criteria of Griggs et al. (1995) for IBM. Results: The mean age of patients at disease onset was 60.8 � 11.9 years with disease duration of 8.0 � 5.2 years. Eighty % of patients were Caucasian, with similar distribution between genders. Weight loss in early disease was present in less than a quarter of cases. The main symptom was proximal weakness of the lower limbs followed by weakness of the upper (proximal and/or distal) limbs. One third of patients had dysphagia, whereas dysphonia was present in 16.7%, arthralgias in 6.7%, moderate dyspnea symptoms in 3.3% of cases. All patients received prednisone (1mg/kg/day). Several immunosuppressives were used as corticosteroid-sparing according to tolerance, side effects and/or refractoriness. Half of the patients still in follow-up remained stable according to clinical and laboratory data during the study. There were four cases of cancer, four cases associated with viral infections (HIV and hepatitis C virus) and three deaths (two because of sepsis secondary to community bronchopneumonia, and one because of congestive heart failure). Conclusions: This is the first Brazilian series of cases involving large sample of IBM. The profile of the patients analyzed in this study was comparable to those profiles described in literature, except that of IBM cases of our population are equally distributed in both genders and the interval between symptoms onset and diagnosis of the disease was relatively short. It is relevant to note the high frequency of neoplastic diseases and chronic viral infections in our population, reinforcing the need for specific epidemiological studies to verify these associations, once it is poorly described in the literature.