Faculty Opinions recommendation of Novel lipoarabinomannan point-of-care tuberculosis test for people with HIV: a diagnostic accuracy study.

Background Most tuberculosis-related deaths in people with HIV could be prevented with earlier diagnosis and treatment. The only commercially available tuberculosis point-of-care test (Alere Determine TB LAM Ag [AlereLAM]) has suboptimal sensitivity, which restricts its use in clinical practice. The novel Fujifilm SILVAMP TB LAM (FujiLAM) assay has been developed to improve the sensitivity of AlereLAM. We assessed the diagnostic accuracy of the FujiLAM assay for the detection of tuberculosis in hospital inpatients with HIV compared with the AlereLAM assay. Methods For this diagnostic accuracy study, we assessed biobanked urine samples obtained from the FIND Specimen Bank and the University of Cape Town Biobank, which had been collected from hospital inpatients (aged 18 years) with HIV during three independent prospective cohort studies done at two South African hospitals. Urine samples were tested using FujiLAM and AlereLAM assays. The conduct and reporting of each test was done blind to other test results. The primary objective was to assess the diagnostic accuracy of FujiLAM compared with AlereLAM, against microbiological and composite reference standards (including clinical diagnoses). Findings Between April 18, 2018, and May 3, 2018, urine samples from 968 hospital inpatients with HIV were evaluated. The prevalence of microbiologically-confirmed tuberculosis was 62% and the median CD4 count was 86 cells per L. Using the microbiological reference standard, the estimated sensitivity of FujiLAM was 704% (95% CI 530 to 831) compared with 423% (317 to 518) for AlereLAM (difference 281%) and the estimated specificity of FujiLAM was 908% (860 to 944) and 950% (877-988) for AlereLAM (difference -42%). Against the composite reference standard, the specificity of both assays was higher (957% [920 to 980] for FujiLAM vs 982% [957 to 996] for AlereLAM; difference -25%), but the sensitivity of both assays was lower (649% [501 to 767] for FujiLAM vs 382% [281 to 473] for AlereLAM; difference 267%). Interpretation In comparison to AlereLAM, FujiLAM offers superior diagnostic sensitivity, while maintaining specificity, and could transform rapid point-of-care tuberculosis diagnosis for hospital inpatients with HIV. The applicability of FujiLAM for settings of intended use requires prospective assessment.