Serum neopterin level in cases of pulmonary tuberculosis and pneumonia

Background: Pulmonary tuberculosis (TB) sometimes has diagnostic difficulties and a lot of differential diagnosis such as pneumonia. The aim of this work was to assess the role of serum neopterin in differentiating between pulmonary TB and pneumonia and to estimate the effect of antituberculous drugs for 2 months on serum levels of neopterin in patients with pulmonary TB. Patients and methods: We measured serum neopterin in patients with TB, pneumonia patients, and controls. Serum neopterin was measured again after 2 months of antituberculous therapy in patients with pulmonary TB. Results: Serum neopterin was significantly higher in tuberculous patients than in pneumonia patients, with a sensitivity of 90% and a specificity of 80% at an optimal cut-off value of 20.5 nmol/l. It decreased significantly after 2 months of antituberculous therapy in tuberculous patients. Conclusion: Serum neopterin levels significantly increase in pulmonary TB and correlate with the radiological extent of the disease. Combined anti-TB treatment decreases the levels of serum neopterin. Measurement of the serum neopterin levels may be useful in following up the drug response in pulmonary TB. Serum neopterin levels may also be helpful in discriminating pulmonary TB from pneumonia.