Abstract:

Objective: To assess the utility and concordance of QuantiFERON-TB Gold Plus (QFT-Plus) and QuantiFERON-TB Gold In-Tube (QFT-GIT) assays in the adjunctive diagnosis of osteoarticular tuberculosis. Methods: Between April and September 2023, 88 patients diagnosed with osteoarticular tuberculosis at the Beijing Chest Hospital, affiliated with Capital Medical University, were enrolled as the observation group, while 123 individuals presenting with non-tuberculous osteoarticular conditions comprised the control group. Each participant underwent concurrent peripheral blood assays using both the QFT-Plus and QFT-GIT. This study evaluated the diagnostic utility and result concordance of the two tests in aiding the diagnosis of osteoarticular tuberculosis. Results: Of the 211 initial participants, 4 were excluded due to indeterminate results, leaving 207 subjects for analysis (86 in the observation group and 121 in the control). The QFT-Plus assay demonstrated a sensitivity of 95.3% (95%CI: 87.9%-98.5%), specificity of 70.2% (95%CI: 61.2%-78.0%), positive predictive value of 65.5% (95%CI: 60.2%-77.5%), and negative predictive value of 95.5% (95%CI: 88.3%-98.6%). The QFT-GIT assay recorded a sensitivity of 91.9% (95%CI: 83.4%-96.4%), specificity of 66.9% (95%CI: 57.7%-75.1%), positive predictive value of 66.4% (95%CI: 57.1%-74.6%), and negative predictive value of 92.0% (95%CI: 83.8%-96.5%). The overall concordance between QFT-Plus and QFT-GIT results was 91.8% (95%CI: 88.1%-95.5%), with a positive agreement of 92.4% (95%CI: 87.7%-97.2%) and a negative agreement of 90.9% (95%CI: 84.9%-96.9%). The Kappa coefficient for agreement was 0.832 (95%CI: 0.756-0.908, P<0.001). Conclusion: The QFT-Plus and QFT-GIT assays demonstrated substantial concordance and comparable diagnostic efficacy in the auxiliary evaluation of osteoarticular tuberculosis.

Key words: Tuberculosis, osteoarticular, Diagnosis, differential, Immunologic tests, Evaluation studies