INTERLEUKIN-1-BETA IN PLEURAL FLUIDS OF DIFFERENT ETIOLOGIES - ITS ROLE AS INFLAMMATORY MEDIATOR IN EMPYEMA

Study objectives: To measure interleukin-1 beta (IL-1 beta levels in pleural effusions of different etiologies and their relationship with several pleural inflammatory parameters, and to verify whether IL-1 beta can be used as diagnostic marker in the differential diagnosis of pleural diseases. Material and method: One hundred two pleural effusions were analyzed using a monoclonal antibody enzyme-linked immunosorbent assay, Pleural fluids were classified as follows: transudates (n=28), empyema (n=14), parapneumonic (n=13), tuberculous (n=19), neoplastic (n=17), and miscellaneous effusions (n=11). Results: IL-1 beta was above 200 pg/mL in all the patients with empyema but only in three patients with other etiologies, Two of those three bad parapneumonic effusions and the remaining one had a tuberculous pleurisy with a previous bacterial empyema, No significant relationships were found between pleural effusion IL-1 beta levels and the different inflammatory parameters analyzed, As a diagnostic criterion for empyema, pleural IL-1 beta concentration greater than 200 pg/mL, had a sensitivity of 100%, a specificity of 96%, and a positive and negative predictive value of 0.82 and 1, respectively. Conclusions: Our data suggest that IL-1 beta has a significant role in pyogenic infections of the pleural space but not in effusions of other etiologies. It could be used as a diagnostic marker of empyema.