Clinical and Laboratory Discriminators for Tuberculosis and Lymphoma in Adults Presenting with Fever of Unknown Origin: A Prospective Cohort Study

Background: Tuberculosis and lymphoma are the common causes of fever of unknown origin (FUO) and show some similar clinical symptoms. The purpose of this study was to analyze the clinical characteristics of tuberculosis and lymphoma to find effective methods to distinguish them. Methods: A cohort including 100 tuberculosis and 81 lymphoma patients in FUO was prospectively enrolled. A predictive model of tuberculosis based on clinical parameters was established by using logistic regression equation, and its efficacy was evaluated by Receiving operating curve (ROC). Results: Both lymphoma and tuberculosis were more common in middle-aged and elderly males (P=0.043), and the total fever duration was relatively long (P=0.086). Muscle pain (P=0.017) and chills (P=0.045) were more common in tuberculosis patients, while hepatosplenomegaly (P<0.001) and lymphadenopathy (P<0.001) were more prevalent in lymphoma patients. The positive rate of T-SPOT.TB in the tuberculosis group was significantly higher than that in the lymphoma group (P<0.001). In the lymphoma group, LDH and SF were all significantly increased (P<0.001), while ALB and PLT were significantly decreased (P<0.001). The AUC of the diagnostic prediction model for tuberculosis established by combining parameters was 0.96 (95% CI, 0.935-0.986), with a sensitivity of 90.9% and a specificity of 87.1%. A validation cohort consisted of 42 patients with FUO from other departments during the same period, the AUC of the validation cohort was 0.948 (95% CI, 0.886-0.999), with a sensitivity of 90% and a specificity of 90.9%. Conclusion: The integration of clinical parameters facilitates enhanced discriminative capacity between tuberculosis and lymphoma.