Are soluble IL-2 receptor and IL-12p40 levels useful markers for diagnosis of tuberculous pleurisy?

BACKGROUND

The differential diagnostic utilities of the levels of soluble interleukin (IL)-12p40 and the IL-2 receptor in sera and pleural effusions were evaluated in patients with exudative pleural effusions.

METHODS

We enrolled a total of 120 patients with exudative pleural effusions. The clinical, radiological, and histopathological diagnoses were tuberculous pleurisy in 52, malignant pleurisy in 39, and parapneumonic effusions in 29 patients.

RESULTS

We measured serum IL-12p40 and adenosine deaminase (ADA) levels in patients with tuberculous pleurisy and in a control group treated for pleural effusion to determine if such levels were useful in the diagnosis of pleural effusion (p < 0.005). Definite microbiological or histopathological diagnoses of tuberculous pleurisy or pleural effusion were recorded, and we found that ADA and serum soluble IL-2 receptor levels aided in diagnosis (p < 0.001). The levels of ADA and soluble IL-2 in pleural effusions afforded sensitivities and specificities of 84.62% and 82.69% and of 70.59% and 80.88%, respectively. The soluble IL-2 receptor level afforded a sensitivity and specificity of 82.69% and 52.9%. IL-12p40 levels in pleural effusions and sera afforded sensitivities and specificities of 80.77% and 80.77% and of 60.29% and 39.71%, respectively.

CONCLUSION

Soluble IL-2 receptor levels in patients with tuberculous pleurisy serve as markers of disease in non-endemic countries, similarly to ADA levels.