Abstract:

Objective: To explore the diagnostic value of urinary lipoarabinomannan (LAM) antigen detection in patients with extrapulmonary tuberculosis. Methods: Urine samples of 92 suspected patients with extra pulmonary tuberculosis treated in Hangzhou Red Cross Hospital from April 2023 to June 2024 were continuously collected for LAM antigen detection, and GeneXpert MTB/RIF (Xpert) test detection was performed on the corresponding lesion site samples. Taking the clinical comprehensive diagnosis as the reference standard, the diagnostic efficiency of the two methods alone and in combination for extrapulmonary tuberculosis was compared. Results: Based on the comprehensive clinical diagnosis results, the sensitivity, specificity and area under curve (AUC) of urine LAM antigen and Xpert for the test of extrapulmonary tuberculosis were 49.3% (95%CI: 36.8%-61.8%), 92.0% (95%CI: 74.0%-99.0%), 0.706 (95%CI: 0.602-0.797) and 49.3% (95%CI: 36.8%-61.8%), 100.0% (95%CI: 86.3%-100.0%), 0.746 (95%CI: 0.645-0.831), respectively. The sensitivity of urine LAM antigen combined with Xpert to detect extrapulmonary tuberculosis was 73.1% (95%CI: 60.9%-83.2%), which was higher than that of urine LAM antigen (χ²=27.672, P<0.001) and Xpert (χ²=17.576, P<0.001). The AUC was 0.826 (95%CI: 0.733-0.897), which was higher than that of urine LAM antigen and Xpert detection; and the differences were statistically significant (Z=1.602, P<0.001; Z=4.175, P=0.037). Conclusion: Urine LAM antigen detection has a certain application prospect in the diagnosis of extrapulmonary tuberculosis, and the combination with Xpert can improve the sensitivity of detection and enhance the application value in the diagnosis of extrapulmonary tuberculosis.

Key words: Tuberculosis, extrapulmonary, Urine, Mannans, Nucleic acid amplification techniques, Diagnosis