Study objective: Identification of predictive factors for the development of residual pleural thickening (RPT).
Design: Retrospective study.
Location: A 1,500-bed tertiary hospital.
Patients: Patients with pleural tuberculosis diagnosed between December 1991 and February 1995 in our Respiratory Disease Service.
Interventions: The clinical and radiologic characteristics, and measurements of microbiological and biochemical parameters and markers in pleural fluid were studied. RPT was defined in a posteroanterior chest radiograph as a pleural space of >2 mm measured in the lower lateral chest at the level of an imaginary line intersecting the diaphragmatic dome.
Measurements and results: In 56 patients studied, 11 (19.6%) had RPT 10 mm and 24 (42.8%) had RPT >2 mm. The pleural fluid of patients with RPT 10 mm had a significantly lower glucose concentration and pH and higher lysozyme and tumor necrosis factor-α levels than the other patients. The pleural fluid of patients with RPT >2 mm showed no significant differences.
Conclusions: The development of RPT 10 mm was related to higher concentrations of lysozyme and tumor necrosis factor-α and lower glucose concentration and pH in pleural fluid compared with development of lower measurements of RPT.