measurement of nitric oxide in the differential diagnosis of tuberculous pleurisy

Abstract

Introduction: The differential diagnosis of tuberculous pleurisy from malignant pleural effusion is difficult in sometimes even with various laboratory findings, especially in the area with high prevalence of pulmonary tuberculosis. Nitric oxide(NO) is known to be increased in the sputum or exhaled breath of patients with active pulmonary tuberculosis. But, there is no data about pleural fluid NO in the tuberculous pleurisy. Therefore, we tried to investigate the usefulness of pleural fluid NO in the differential diagnosis of tuberculous pleurisy. Methods: We measured serum and pleural fluid NO in the patients with acute lymphocyte-dominant pleural effusion. Results: In the total 23 patients, male was 15 and their age was 55±18 years old. The final diagnosis were tuberculous pleurisy in 13 cases, malignant pleural effusion in 9 cases, and non-specific pleuritis in 1 case. Pleural fluid NO was 795.0± 485.3 mmol in tuberculous pleurisy, 596.1± 103.9 mmol in malignant pleural effusion, and 595.8 mmol in non-specific pleuritis. Serum NO was 839.8± 293.5 mmol in tuberculous pleurisy, 573.5± 231.6 mmol in malignant pleural effusion, and 648.9 mmol in non-specific pleuritis. And, both serum and pleural fluid NO showed no significant difference in the 3 groups. Pleural fluid NO showed significant correlations with pleural fluid neutrophil count, the ratio of pleural fluid/serum protein, and the ratio of pleural fluid/serum albumin (p<0.05 in each). Protein concentration, leukocyte count and lymphocyte count in pleural fluid were significantly higher in the tuberculous pleurisy than malignant pleural effusion (p<0.05 in each). Conclusions: NO showed no definite role in the differential diagnosis of tuberculous pleurisy. And, pleural fluid NO might be associated with neutrophil recruitment and protein leak in the pleural space.