Background The idiopathic inflammatory myopathies (IIM) are systemic autoimmune disease characterised with proximal muscle weakness. The epidemiology of these multifactorial diseases is partially known. These are rare diseases and Immunological or Rheumatological centres or international collaborations are required to carry the majority or all of these patients. Nowadays there are studies for establishing national or international registry of IIM patient. The Myositis study group of Division of Clinical Immunology, Institution of Internal Medicine, University of Debrecen Medical and Health Science Centre have been found in 1975. Most of the Hungarian patients are carried in this department since then. So we have preliminary epidemiological data of Hungarian IIM patients. The database is under continuous development.
Objectives The aim of this report is to show our epidemiological findings. Sex and age were analysed in each IIM subgroup. Standardized incidence rates were calculated as new cases/million population/year with 95% confidence interval (CI).
Results Between 1999 and 2010 1119 patients were hospitalized due to IIM in Hungary. We selected the data of these years because we have less information about the patients before 1999 (no computerized data before this date). 288 patients were carried in our department. 61,93% suffered from polymyositis (PM), 32,17 % had dermatomyositis (DM), 4,15% had juvenile dermatomyositis (JDM), 0,69% was diagnosed with amyopathic dermatomyositis (ADM) and we found other myositis (OTM) in 1,03% of the patients. The mean age of patients was 47,73 years (ys), respectively 48,46 ys (PM) – 52,19 ys (DM) -9,66 ys (JDM) – 34 ys (ADM) – 32 ys (OTM) in the subgroups. 67,82% of the patients were adult woman (mean age: 50,07 ys), we found 27,68 % of adult man (mean age:49,11 ys) and 4,5% children (9,6 ys).
Cancer associated myositis was found in 31 cases (10,72%), the mean age of patients were 53,51 years. The most frequent tumor types were breast and lung cancer but gastrointestinal, reproductive and hematological malignancies were also presented.
Overlap syndromes, preciously the association of IIM with other autoimmune diseases have been found in 14 cases (4,84%), the mean age of these patients were 44,64 years. The mainly presented overlap syndrome was Systhemic sclerosis and Sjögren’s syndrome. The average incidence rate was 0.95 cases per 100.000 persons per year.
Conclusions Our results represented that the epidemiological data of Hungarian IIM population correlate with the former publicised findings. IIM commonly developed in middle-aged woman. The male/female ratio is 1/2. Dermatomyositis can occur in children and in adults as well, however PM is mainly the disease of adults. These are rare diseases with incidence of 0.1-1 /100.000/year. Our next goal is to develop a National Registry for IIM patients to have more information about epidemiological, clinical and serological characteristics of Hungarian patients.
Disclosure of Interest None Declared