New urine test quickly detects tuberculosis in HIV-positive patients

An innovative urine test developed by the scientists can detect tuberculosis in people living with HIV earlier and more quickly than before. This Point-of-care tests could save lives by allowing faster diagnosis and treatment.

The current and most widely available method for diagnosing Mycobacterium tuberculosis uses patients' sputum. However, TB diagnosis presents a challenge, particularly for people living with HIV, as some cannot produce sputum, resulting in untimely and inaccurate diagnoses.

Fujifilm Corporation and FIND's TB-LAM diagnostic tool, however, can overcome these challenges in diagnosing tuberculosis by using a patient's urine instead of their sputum. This breakthrough technology is also inexpensive, highly sensitive, and does not require large equipment or a power supply to operate, so it can be utilized in resource-limited settings in low- and middle-income countries.

Lipoarabinomannan (LAM) is an antigen that has been explored extensively in blood, urine, and sputum as a biomarker for active TB detection. It has the advantage of being very stable and detectable in a wide diagnostic time window.

The new urine test will improve the speed and accuracy of diagnosis, providing earlier treatment and improving health outcomes.

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"The test works by using an antibody to detect the presence of a carbohydrate produced by the organism that causes tuberculosis," explained Todd Lowary, who is a collaborator on the project. "Point-of-care tests are important as they can be done in areas where the access to health care is low and comparatively unsophisticated."

Lowary, an expert in carbohydrate synthesis and the Raymond Lemieux Professor of Carbohydrate Chemistry, was part of an international team, including the Foundation for Innovative New Diagnostics and Fujifilm, that developed the test, called Fujifilm SILVAMP TB LAM.

"Our contribution was to screen the specificity of a selection of possible antibodies against a panel of different carbohydrates to identify the best one antibody," explained Lowary. "That led to the increased sensitivity of the diagnostic."

The group has issued a call for trial partners for those who wish to pilot the test in clinical settings. Studies to test the new test's efficacy with HIV-negative patients and new antibodies are being developed to enhance the test's performance.

According to the World Health Organization (WHO), tuberculosis is the 10th leading cause of death worldwide—1.7 million people died of tuberculosis worldwide in 2016, 95 percent of which were in low- and middle-income countries.