Tuberculosis (TB) kills more people than any other infectious disease. Most people who die of TB were never diagnosed, either because they could not access a test, or because the test returned a false negative result. TB needs diagnostic tests that are smaller, less expensive, and more sensitive. We have developed single-molecule immunoassays for lipoarabinomannan (LAM) and tuberculosis antigen 85B (Ag85B) in urine with limits of detection of 5.9 pg/mL and 0.015 pg/mL, respectively. Using these two antigens, we developed a test and validated it on a blinded cohort of 258 patients. Our test was 89% sensitive and 91% specific in HIV-positive patients, and 87% sensitive and 83% specific in HIV-negative patients. Currently, this assay is carried out using the Quanterix HD-X. We are in the process of developing a small, portable device to carry out this assay and others, including a blood cytokine panel we published in 2019, in a point-of-care format.
Funding: Bill and Melinda Gates Foundation