The clinical utility of serum procalcitonin in immunocompetent patients with pleural tuberculosis

Introduction: Serum procalcitonin (PCT) is associated with the severity and prognosis in pulmonary tuberculosis. However, previous studies on its clinical association in pleural tuberculosis are lacking. The aim of study is to investigate the association between serum PCT and clinical parameters and define its utility, in patients with pleural tuberculosis. Materials and methods: We retrospectively analyzed 71 immuocompetence patients (median age, 44 years; PCT < 0.05 ng/mL, n = 40 vs. PCT ≥ 0.05 ng/mL, n = 31), with pleural tuberculosis Results: There were 44 males. The median serum PCT level was 0.025ng/mL (interquartile range (IQR): 0.025 - 0.110). Forty patients (56%) had pulmonary tuberculosis by radiologic or microbiological criteria. One patient died, and two patients had drugresistance. At the end of treatment, the incidence of residual pleural opacity (RPO) was 62% on chest radiography (CXR). Male, pleuro-pulmonary tuberculosis, high pleural lactate dehydrogenase (LDH), RPO on CXR and mycobacterial identification in pleural fluid were associated with abnormal serum PCT level, in univariable logistic analysis. However, only pleuro-pulmonary tuberculosis (OR: 5.099, 95% CI, 1.044 - 24.908, P = 0.044) and high pleural LDH (OR: 12.874, 95% CI, 2.885 - 57.453, P = 0.001) were still significantly related to serum PCT above normal value, by multivariable logistic analysis. Conclusions: Serum PCT level can be associated with concomitant pulmonary tuberculosis and the degree of pleural inflammation in pleural tuberculosis. Therefore, serum PCT can aid physicians in selecting patients that require early isolation and greater attention.