Comparative analysis of GeneXpert MTB/RIF and lipoarabinomannan testing in tuberculosis diagnosis among HIV-positive and HIV-negative patients attending the University Teaching Hospital of Kigali

INTRODUCTION: Tuberculosis (TB) is a major health burden in the world, and particularly in individuals living with HIV. This study evaluated the comparative performance of GeneXpert MTB/ RIF and Lipoarabinomannan tests against TB culture, in HIV-positive and HIV-negative patients in the University Teaching Hospital of Kigali. METHODS: A total of 124 participants (37 HIV-positive and 87 HIV-negative) were enrolled. Sputum, urine, and other specimens were tested using GeneXpert MTB/RIF and urinary LF-LAM, with results compared against TB culture on Lowenstein–Jensen media as the diagnostic gold standard. RESULTS: In HIV-positive patients, LF-LAM had a sensitivity of 75% (95% CI: 47%-91%) and a specificity of 84% (95% CI: 65%-94%), whereas GeneXpert had a sensitivity of 67% (95% CI: 39%-86%) and a higher specificity of 96% (95% CI: 80%-99%). All tests performed better in HIV-positive patients (p-value = 0.0008 for LAM; p-value = 0.0001 for GeneXpert). In the HIV-negative group, GeneXpert's sensitivity was 65% (95% CI: 41%- 83%), significantly outperforming LF-LAM's sensitivity of 35% (95% CI: 17%- 59%). These findings underscore the importance of tailored diagnostic approaches based on patient immune status to optimize TB detection accuracy. The study elucidated the disparities between the LAM test and GeneXpert in diagnosing tuberculosis among patients with or without HIV, paving the way for more targeted and effective diagnostic interventions. CONCLUSION: The study findings showed a complementary role of both GeneXpert and LF-LAM. LF-LAM is strongly effective as a quick screening test in TB detection and an early intervention tool in HIV-positive patients because it has a much greater diagnostic sensitivity in this population. Integration of the LAM test into TB diagnostic algorithms for immunocompromised populations could improve early detection and treatment initiation, thus reducing TB morbidity and mortality.