Clinical importance of serum neopterin level in patients with pulmonary tuberculosis.

OBJECTIVE: Neopterin is a sensitive marker for cell-mediated immune response. Because of this, the neopterin levels of body fluids show cell-mediated immune response in different infectious diseases which involve T cells and macrophages. The aim of this study was to determine the clinical importance of neopterin levels in patients with tuberculosis and compare with those levels of healthy subjects.

METHODS: Seventy patients with tuberculosis (46 newly diagnosed cases, 15 relapse cases, and 9 multidrug-resistant tuberculosis cases) and 18 healthy adult individuals were included in the study. Neopterin concentrations were measured by the ELISA method according to the protocol of the manufacturer. Chi-square test was used in statistical analysis; p⩽0.05 was considered statistically significant.

RESULTS: Serum mean neopterin levels were 23.74±21.8nmol/L (median: 18.3) in newly diagnosed patients with pulmonary tuberculosis; 28.69±21.2nmol/L (median: 21.2) in relapse patients and 31.28±14nmol/L (median: 25.4) in multidrug-resistant tuberculosis cases, respectively. Serum mean neopterin levels were 4.03±5.12nmol/L (median: 5.1) in healthy subjects. The serum neopterin levels were found to be significantly higher in patients with tuberculosis than the control group. There was a statistically significant correlation between neopterin positivity (neopterin level ⩾10nmol/L was accepted to be positive) and clinical symptoms of hemoptysis and weight loss. Besides statistically significant correlations between neopterin positivity and hemoglobin level, sedimentation rate, mean leukocyte count and radiological involvement (localized or diffuse) were determined.

CONCLUSION: Serum neopterin levels can be used as a helper laboratory finding for the diagnosis of patients with tuberculosis. For this aim, further controlled studies are needed.