Progress Toward a Urine Test for Tuberculosis

Lipoarabinomannan (LAM) is a mycobacterial antigen that is shed into the urine in people with active tuberculosis (TB). Enzyme-linked immunosorbent assay and lateral flow assays that detect LAM may be positive in people with HIV who have low CD4 cell counts (WHO Policy Guidance 2015), but they are not sensitive enough to diagnose TB in HIV-negative populations. Now, investigators have developed a technique to detect LAM at lower concentrations.

A high-affinity copper complex dye within a hydrogel nanocage was used to capture LAM in urine; this approach increased the sensitivity of LAM detection 100- to 1000-fold. When the assay was applied to samples from 48 HIV-uninfected people with pulmonary TB and 53 controls, its sensitivity was 96% and…