There are a few studies that have shown low levels of complement components in pleural fluid in patients with rheumatoid arthritis,’ and on the other hand, a high level of complement breakdown products in patients with rheumatoid arthritis and in tuberculosis. There is also evidence that synovial fluid of patients with rheumatoid arthritis contains complement activation products measured by novel methods. The aim of this study was to determine the role of complement components in pleural effusion, measured with novel markers of complement activation, to assess which pathway of activation predominates in different diseases, and to find out whether the analysis of complement components and their activation products could help in diagnostic procedure differentiating the etiologies of pleural effusion.
Materials and Methods
The study population consisted of 71 patients who had pleural effusion secondary to tuberculosis (n=23), rheumatic disease (n=10), or malignancy (n=38), diagnosed at the Department of Pulmonary Diseases of Turku University Hospital during 1990 to 1992. In the group of patients with tuberculosis, there were 16 men and 7 women, and their mean age was 56 years (range, 26 to 88 years); in the group of patients with rheumatic pleurisy, there were 8 men and 2 women, and their mean age was 54 years (range, 39 to 70 years); and in the group of patients with malignant pleural effusion, there were 22 men and 16 women, and their mean age was 65 years (range, 46 to 90 years).
The criteria used for determining the etiology were as follows. Malignant effusion: an effusion associated with previously or simultaneously diagnosed breast or lung malignancy, independent of the cytologic or histologic status, if no obvious alternative diagnosis was evident. In our study group, there were 12 patients with breast cancer and 26 patients with lung cancer. In both groups, in eight cases, malignancy in the pleural cavity was either cytologically or histologically confirmed. Buy proventil Here Tuberculous effusion: an effusion that met at least one of the following criteria: positive culture for Mycobacterium tuberculosis in the pleural fluid or sputum (n=3), or pleural biopsy specimen showing a granulomatous lesion typical of tuberculosis (n=5), or both (n=4), or a positive response for tuberculous chemotherapy when clinically suspected (n=ll). Rheumatoid effusion: an effusion that occurred in a patient with rheumatoid arthritis, was neither transudate nor parapneumonic, and could not be classified to any of the above-mentioned groups.