Background Patient with rheumatic disease: systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), systemic sclerosis (SSc) and vasculitis often have pleurisy. In the case of immunosuppressed pleuritic patients, it is hard to determine whether the cause of pleural effusion is the primary disease or infection, especially tuberculosis. Many studies investigated the usefulness of adenosine deaminase (ADA) in pleural fluid for the diagnosis of tuberculous pleuritis. Levels of ADA in pleural fluid >50 U/L can indicate pleural tuberculosis with sensitivity 91 (%) and specificity 81 (%).It has been reported that the pleural effusions by rheumatoid arthritis tend to be high ADA activity. To our best knowledge, there is no report about the level of pleural effusion ADA with rheumatic diseases other than rheumatoid arthritis. So, we analyzed ADA activity in pleural effusion of rheumatic disease patients.
Objectives To analysis for ADA value of pleural effusion associated with rheumatic diseases.
Methods We extracted all the patients with diagnoses of rheumatic disease (SLE, RA, SSc, and Vasculitis) who had pleural effusion ADA examination from our electronic medical record between 2007 and 2014. We selected the case of pleural fluid associated with rheumatic diseases by exclusion of the case by other causes. We analyzed the chemistry profile (glucose, protein, lactic dehydrogenase (LDH) and ADA activity), the ratio of lymphocytes to polymorphonuclear leucocytes in pleural effusion.
Results The number of rheumatic pleural fluid in 2007-2014 was 54 patients (SLE 15, RA29, SSc 3, and Vasculitis 7). Pleural effusion ADA value (U/L) (mean, median, range) was SLE (42.4, 32.9, 3.3-98.0), RA (26.2, 22.1, 4.7-65.3), SSc (15.8, 10.9, 6.6-29.9) and Vasculitis (14.9, 15.2, 2.9-29.3). The number of the case which exceed ADA cut-off value of tuberculous pleural effusion (>50U/L) were 5/15 (33.3%) in SLE, 2/29 (6.9%) in RA, 0/3 in SSc and 0/7 in Vasculitis.
Conclusions Pleural effusion ADA value of SLE patient was often higher than tuberculosis ADA cut-off point. Clinical course, cultivation test, and histopathological examination need to be taken into account when interpreting SLE patient's pleural effusion ADA values.
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Disclosure of Interest None declared