Improving urine-based tuberculosis diagnosis in people living with HIV

Award amount: 50,000.00

Tuberculosis (TB) is the leading cause of mortality in people living with HIV. To reduce the burden of disease, a non-sputum biomarker-based diagnostic for tuberculosis (TB) is urgently needed. Urine-based testing is promising, but current assays that detect the Mycobacterium tuberculosis (MTB) antigen lipoarabinomannan (LAM) have poor performance and are only recommended in HIV-infected individuals who are severely ill or have advanced AIDS. There is a need to improve the sensitivity of these assays, and for approaches to detect other low abundant TB biomarkers in urine. Hydrogel nanocages have been developed that can tightly bind to LAM, and have been shown to purify, protect and concentrate urine LAM to improve analytical sensitivity. Nanocages can also be used with mass spectrometry to identify low abundant protein biomarkers in urine. We propose the first application of hydrogel nanocages for people living with HIV, through pre-analytic concentration of urine for LAM testing and detection of a urine TB protein signature for TB diagnosis. In Aim 1, we will conduct a nested case-control study with urine samples from a cohort of HIV-infected adults in Kampala, Uganda who were evaluated for TB with standard sputum Xpert MTB/RIF testing and culture. We will compare the diagnostic accuracy (sensitivity and specificity) and added yield of lateral flow LAM testing with and without use of LAM-specific nanocages. In Aim 2, we will use nanoparticle mass spectrometry to detect other low abundant MTB-specific proteins in urine samples, and use machine learning approaches to identify a panel of proteins that can discriminate TB disease. In the one year of the study, I will gain experience, mentorship and preliminary data to support a career as an independent investigator who advances TB diagnosis in populations with paucibacillary disease.