Diagnostic Accuracy and Yield of Determine Urine TB LF-LAM for Detecting Tuberculosis Among Adults and Children with Advanced HIV Disease in Nigeria.

Introduction Tuberculosis (TB) diagnosis remains the weakest link in the care cascade, particularly among people living with HIV and AIDS (PLHIV) with advanced HIV disease (AHD) who often cannot produce quality sputum for standard tests. Urine-based assays such as Determine Urine TB LF-LAM offer a non-invasive, easy-to-collect alternative that can detect lipoarabinomannan antigen even in extrapulmonary TB, making them especially useful in severely immunocompromised individuals. Methods We conducted a cross-sectional study to assess the diagnostic accuracy and yield of Determine Urine TB LF-LAM against GeneXpert MTB/RIF as the reference standard among adults and children (<5 years) with AHD enrolled across 334 selected HIV treatment facilities in Nigeria between July 2022 and July 2025. We calculated the diagnostic yield (DY) for LF-LAM among all AHD patients tested and, in the paired-testing cohort, determined its incremental diagnostic yield (IDY). Test proportions are presented with 95% CI using the Wilson score method. Discordance in paired results was assessed with the McNemar test. Results Of the 17155 AHD patients tested with LF-LAM on first urine samples, 5212 were TB LF LAM positive, giving a diagnostic yield of 30.4%. Among 5212 LF LAM positive, 2,074 (41%) of them were not presumptive through the WHO four-symptom screening and would have been missed without LF-LAM. Among 3,138 patients tested with both GeneXpert and LF-LAM, GeneXpert detected 1914 TB cases. The remaining 1224 GeneXpert-negative cases tested positive through TB LF-LAM, giving an incremental yield of 39% for LF-LAM over GeneXpert (1224/ (1,914+1224) Wilson 95% CI) with significant discordance (McNemar p<0.001). Conclusion Determine Urine TB LF-LAM substantially improved TB case detection among PLHIV with AHD in routine Nigerian HIV programs, including pediatric and severely immunocompromised patients who are unable to produce sputum or with extrapulmonary TB. Its high incremental yield and simplicity underscore the need for programmatic integration of LF-LAM with molecular testing to close diagnostic gaps and reduce TB-related mortality.