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Novel point-of-care TB test for patients with HIV superior to current test

Study findings showed that a novel point-of-care tuberculosis test for patients with HIV offers superior diagnostic sensitivity to the currently available test while maintaining specificity, researchers reported.

The researchers said the test, the SILVAMP TB LAM (FujiLAM, Fujifilm), could transform rapid point-of-care TB diagnosis for patients with HIV.

“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, Abbott)] — has suboptimal sensitivity, which restricts its use in clinical practice,” Tobias Broger, MSc, of the Foundation for Innovative New Diagnostics (FIND) in Geneva, and colleagues wrote in The Lancet Infectious Diseases. “The novel FujiLAM assay has been developed to improve the sensitivity of AlereLAM.”

To determine the diagnostic accuracy of the new assay, Broger and colleagues assessed urine samples collected from adult hospital inpatients with HIV during three independent prospective cohort studies in South Africa. According to the study, 968 urine samples were tested between April 18 and May 3, 2018, using both the FujiLAM and AlereLAM assays.

Using the microbiological reference standard, Broger and colleagues estimated the FujiLAM assay to have a higher sensitivity compared with the AlereLAM assay — 70.4% (95%, CI = 53 to 83.1) vs. 42.3% (95%, CI = 31.7 to 51.8). Additionally, they found the estimated specificity of FujiLAM to be 90.8% (95% CI, 86 to 94.4), compared with 95% (95% CI, 87.7 to 98.8) for AlereLAM.

“Considering the substantially improved sensitivity of FujiLAM compared with AlereLAM and the high diagnostic yield compared with sputum-based diagnostics, the FujiLAM assay has the potential to substantially improve rapid diagnosis of tuberculosis in patients with HIV who are admitted to hospital and potentially people with HIV in the general population,” they concluded. “Since AlereLAM has demonstrated survival benefit, FujiLAM might potentially further reduce tuberculosis-related mortality in people with HIV. These findings will inform a WHO policy review for lipoarabinomannan-based diagnostic tests of active tuberculosis.” – by Caitlyn Stulpin

Disclosures: Broger is employed by the Foundation for Innovative New Diagnostics. Please see the study for all other authors’ relevant financial disclosures.