Tuberculous
pleural effusions occur in up to 30% of patients with
tuberculosis. It appears that the percentage of patients with
pleural effusion is comparable in human immunodeficiency virus (HIV)-positive and HIV-negative individuals, although there is some evidence that HIV-positive patients with CD4+ counts <200 cells x mL(-1) are less likely to have a tuberculous
pleural effusion. There has recently been a considerable amount of research dealing with the immunology of
tuberculous pleurisy. At present, we have more evidence that activated cells produce
cytokines in a complex pleural response to mycobacteria. Intramacrophage elimination of mycobacterial
antigens,
granuloma formation, direct neutralization of mycobacteria and
fibrosis are the main facets of this reaction. With respect to diagnosis,
adenosine deaminase and
interferon gamma in pleural fluid have proved to be useful tests. Detection of mycobacterial
deoxyribonucleic acid (
DNA) by the polymerase chain reaction is an interesting test, but its usefulness in the diagnosis of
tuberculous pleurisy needs further confirmation. The recommended treatment for
tuberculous pleurisy is a 6 month regimen of
isoniazid and
rifampicin, with the addition of
pyrazinamide in the first 2 months. HIV patients may require a longer treatment. The general use of
corticosteroids is not recommended at this time, but they can be used in individuals who are markedly symptomatic.