Tuberculosis as aetiology of so-called idiopathic pericarditis

Dear Editor, we read the review article about idiopathic pericarditis by Lorbar and Spodick (1) with great interest. We are thankful to the authors who are reknown by their invaluable contributions to the literature in pericardial diseases. They reported review of the literature between 1978 and 2005 – on comparative incidence of pericarditis. In their article the most common cause assigned to pericarditis was ‘idiopathic’ pericarditis (26.1%), followed by neoplastic disease (25.6%) and iatrogenic pericarditis (16.3%). Living agents constituted 9.4% of pericarditis in their article. Authors stress that sometimes, the diagnosis of ‘idiopathic pericarditis’ is due to an uncomprehensive or inadequate search for aetiological identification of pericarditis. Although they excluded constrictive and chronic forms of pericarditis in their aetiological classification, we think that tuberculosis deserves special attention in aetiological identification of pericarditis. Despite there has been a significant decrease in the incidence of tuberculosis in western countries over the past 100 years, the estimated number of new cases worldwide was increased again from 8.0 million in 1997 to 8.3 million in 2000 (2). Under developed and developing countries constitute more than three quarter of the world's population and are home to 95% of all cases of active tuberculosis and 98% of the nearly 2 million deaths resulting from tuberculosis each year (2). Pericardium is involved in 1–2 % of subjects with pulmonary tuberculosis (3). As human immunodeficiency virus (HIV) infection is continuously becoming more frequent, increase in the incidence of tuberculosis with various organ involvement has recently become one of the major concerns of healthcare professionals. In Turkey where tuberculosis is endemic (4,5), tuberculous pericarditis constitutes at least one-third of identifiable causes. Moreover in our clinical experience more than half of the patients with probable diagnosis of tuberculous pericarditis response to empirical antituberculosis chemotherapy. Therefore, in our view substantial proportion of the pericarditis which are classified as idiopathic might in fact be tuberculous in origin. Difficulties in identifying Mycobacterium tuberculosis is probably the most challenging issue in classification and treatment of pericarditis (6). Tuberculosis should always be kept in mind as aetiology of pericarditis especially in populations were pulmonary tuberculosis is prevalent, in intravenous drug users, immunosuppressed subjects and those infected with HIV, recurrent pericarditis and pericarditis with large pericardial effusions.