Diagnostic value of determining the pleural and serum lysozyme levels in pleural effusions with special reference to tuberculous type

ABSTRACT

The present study was undertaken in order to examine the value of the simultaneous pleural fluid and serum lyzozyme determination in the diagnosis of tuberculous pleural effusion. Lysozyme was measured in the pleural fluid and serum of 51 patients with pleural effusions 15 patients with tuberculous effusion [TB], 15 with malignant effusion [CA], 11 with transudates [TS] and +/- 10 with empyemas [EM]. Serum lysozyme did not show significant differences between different groups. The mean level of pleural fluid lysozymes was statistically significantly increased in tuberculous effusions and empyemas compared to malignant effusions and transudates [P lysozyme pleural fluid/serum ratio [PL/SL ratio] but without overlap between the studied groups. The existance of a raised PL/SL ratio suggested important local synthesis of lysozyme and it come up in empyema and tuberculosis unlike the other groups. This work showed that PL/SL ratio at or above 1.5 always denoted tuberculous effusion or empyema. The conclusion, this work shows that the determination of lysozyme level in pleural effusion and serum and calculation of PL/SL ratio provide a simple and least invasive method for obtaining corroborative information in the differential diagnosis of tuberculous pleurisy