A TB Test that Will Light Up (Your Urine).

Abstract

The DVD may have gone out of style, but it could make fashionable the hottest “new” biomarker for tuberculosis (TB)2 (1). Lipoarabinomannan (LAM), a track from the 80s, is a mycobacterial cell wall component and glycolipid that is produced in abundance by active TB and can be found in the sputum, blood, and urine. A urine-based LAM test would free us of the challenges to collect (and contain) sputum, which is the basis of conventional TB tests. Sounds pretty easy—set up an ELISA or rapid lateral flow assay for the myoglobin-sized LAM and we're done, right? Yes and no. There is a commercial rapid lateral flow assay LAM test, but on review of its data, the World Health Organization has only endorsed its use in HIV, that is, positive patients with low CD4+ counts and active TB (2). This endorsement has a history. The rapid tests were met with enthusiasm but showed poor accuracy until they were applied only to this high-risk population. The rapid tests may perform better in immunosuppressed HIV-positive patients simply because of a higher antigen load in the urine, higher TB burden, greater permeability of the glomeruli, or more chances for TB in the genitourinary tract (2). So, the goal would be to make a test that is more sensitive and applies to HIV-negative patients as well. And that is where the DVD comes in. Dr. Sangho Bok, an assistant professor of engineering at Southern Utah University, and Dr. Shubhra Gangopadhyay, the C.W. LaPierre Endowed Chair in the Electrical Engineering and Computer Science Department at the University of Missouri, are corresponding authors on a clinical validation of a novel technique to detect single molecules of …