Diagnostic Yield Of Urine Xpert MTB/RIF Ultra To Detect Mycobacterium Tuberculosis Among Severely Immunosuppressed Inpatients With HIV: A Prospective Cohort Study In Ghana

Abstract

Objectives: Due to the higher prevalence of sputum scarce pulmonary tuberculosis (TB) and extrapul monary TB among people with HIV compared to HIV-negative people, diagnosis of HIV-associated TB can not rely solely on sputum-based methods. We estimated the TB diagnostic yield of urine Xpert MTB/RIF Ultra (Ultra) and its prognostic significance among inpatients with HIV. Methods: Adults admitted with HIV in Ghana between October 2019 and November 2021 were enrolled if they had a positive WHO 4-symptom screen, advanced HIV, or severe illness according to WHO criteria for people with HIV. Urine samples were frozen and later analyzed using Ultra. Two TB reference stan dards were used: an extended microbiological reference (eMRS) including culture, Xpert/Ultra on non urine samples, or urine LF-LAM; and a composite reference (CRS) including eMRS or TB diagnosis by microscopy, recommended TB treatment, or TB at death. Patients were followed for 8 weeks. Results: Of 141 participants, 118 (83.7%) provided urine samples for storage. TB prevalence was 25.0% by eMRS and 37.3% by CRS. Urine Ultra was positive in 34/118 (28.8%) patients. Ultra-positive patients had lower median CD4 count compared to Ultra-negative patients (31 vs 78 cells/mm3, P = 0.025). If urine Ultra had been used to guide TB diagnosis, it would have identified an additional 20 patients not detected by CRS. No difference in 8-week mortality was observed between Ultra-positive and negative patients. Conclusion: Urine Ultra shows promise as a supplementary point-of-care TB test among inpatients with HIV.