Prolidase activity in serum and pleural fluids in patients with tuberculous pleural effusion [correction of effussion].

OBJECTIVES: Pleural tuberculosis, which is present in around 4% of all tuberculosis cases may resolve spontaneously or associated with progressive disease and a high recurrence rate. Recently upon exposed to cytokines and bacterial products, mesothelium has been shown to produce collagen that may be involved in pleural inflammatory responses. Prolidase is involved in the final stage of degradation in collagen catabolism. In this study we aimed to evaluate pleural fluid and serum prolidase activities in patients with tuberculous (TB) pleurisy and compared with those in non-tuberculous (non-TB) pleural effusions.

DESIGN AND METHODS: 21 patients with tuberculous (TB) pleurisy (11 F/10 M), ages 35-52 (median 44) and 22 patients (10 F/12 M), ages 41-63 (median 52) with non-tuberculous pleurisy included as non-tuberculous (non-TB) pleurisy group consecutively referred to our pulmonary clinic for evaluation. Serum and pleural prolidase activities in 21 TB and 22 non-TB pleurisy patients were analyzed by photometric method.

RESULTS: Prolidase enzyme activities in serum and pleural fluids of TB group (1072+/-171 and 1392+/-215 U/L, respectively) were significantly higher than those values in non-TB group (787+/-144 and 943+/-174 U/L, respectively). Prolidase activities in pleural fluid were significantly higher than those in serum in both groups. There was a significant positive correlation between pleural and serum prolidase activities in TB group (r=0.579 and p=0.006) and in non-TB group (r=0.858 and p<0.001). In Receiver Operating Characteristic (ROC) analysis, sensitivity and specificity values were 86% and 82% for a cut-off value of 1130 U/L for pleural prolidase activity and were 81% and 82% for a cut-off value of 952 U/L for serum prolidase activity, respectively.

CONCLUSION: In conclusion, there is an elevated pleural fluid and serum prolidase enzyme activity in patients with TB pleurisy compared with non-TB pleurisy group. The higher enzyme activities in TB group might reflect increased collagen turnover in those patients.