Initial Adaptation to Develop a Rapid, Sensitive Point-of-care (POC) Assay to Detect the Mycobacterium Tuberculosis (Mtb) Lipoarabinomannan Antigen in Urine from Tuberculosis Patients

Wednesday, March 10, 2021: 9:40 AM - 10:15 AM

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Description

Millions of cases of tuberculosis (TB) go undiagnosed each year. Traditional TB diagnostic methods, such as culture or smear microscopy, are slow or low in sensitivity. Molecular techniques, such as GeneXpert MTB/RIF, are costly and often unavailable in primary-care settings because of their infrastructure needs. These tests are all sputum based and the difficulty of obtaining sputum from children and the inability to detect non-pulmonary or paucibacillary TB confounds the problem. There is a critical need for a sensitive, non-sputum-based POC test for TB diagnosis. We are working towards developing a TBLAM TESTTM, a practical field applicable test of active TB infection in patients with or without HIV co-infection. This presentation will discuss the rigor of previous research in the validity studies performed in the laboratory of Delphi Chatterjee, Ph.D. at Colorado State University who established that: 1) with a sensitive new non-immunoassay urinary LAM can be detected in 96% of confirmed HIV-negative TB patients at levels of 10-40 ng/mL; 2) LAM is sequestered in urine in protein complexes, reducing the sensitivity of antibody-based LAM detection assays; 3) sequestration can be broken by using proteases; and Professor Charles Henry, Ph.D. at Colorado State University with his extensive expertise in microfabrication of paper-based chemical tests, and microfluidics, is developing a small paper based assay for detecting Mtb LAM. This body of work will provide proof of concept data for the development of an assay to detect LAM in the urine of patients with active TB. The presentation will be based on selection of the best combination of mAbs for detection of LAM in lateral flow.; devise a POC-compatible urine processing step to improve assay sensitivity by immobilizing proteases on a solid support and evaluate TBLAM TESTTM performance on the well characterized collection urine specimens from confirmed HIV-positive and -negative Mtb infected subjects.