Role of the Fibrinogen Degradation Products and D-Dimer in the Differential Diagnosis of Pulmonary Tuberculosis and Community-Acquired Pneumonia.

Background: Differential diagnosis between pulmonary tuberculosis (TB) and community acquired pneumonia (CAP) is often difficult. Pulmonary TB could induce a systemic hypercoagulable state. The present study aims to investigate whether fibrinogen degradation products (FDP) and D-dimer play a diagnostic role for pulmonary TB. Methods: We retrospectively analyzed the clinical and laboratory characteristics of 192 patients with activated pulmonary TB and 110 patients with CAP. The serum levels of FDP and D-dimer were detected and the diagnostic ability was evaluated. Results: The serum levels of FDP and D-dimer were significantly higher in patients with pulmonary TB compared to CAP (both p < 0.05). ROC curve analyses showed that the diagnostic value of FDP in pulmonary TB was noticeably higher than that of D-dimer (p = 0.0197). Combined detection of FDP and D-dimer may slightly improve the sensitivity of diagnosis for pulmonary TB from CAP. However, the AUC showed no significant differences from FDP alone (p = 0.416). Conclusions: The serum level of FDP and D-dimer are useful laboratory markers that can be used to distinguish patients with pulmonary TB from patients with CAP.