New TB test could mean quicker, more reliable diagnosis

July 9, 2014

A new test for tuberculosis that is undergoing clinical trials could eventually improve the speed and accuracy of diagnosis for the disease, enabling healthcare providers to report results to patients within minutes. So says a study published last week in the journal Angewandte Chemie.

Jeffrey Cirillo, PhD, professor at the Texas A&M Health Science Center College of Medicine, in collaboration with GBDbio, and investigators at Stanford University have identified a new chemical compound to spot the bacteria that cause TB, and results of the first human trial data are promising. Findings show the test can determine that a patient has tuberculosis with 86% sensitivity and 73% specificity. Smear microscopy, the most widely used test in the world, has a significantly lower ability to detect TB, ranging between 50% and 60% sensitivity.

Cirillo’s breakthrough perfects the technology behind the test—a battery-powered, portable tabletop device called the TB REaD. Using a fluorescent substrate, the device targets BlaC—an enzyme produced by the bacteria that cause TB—as an indicator of the bacteria’s presence. Until now, it has not been possible to target a specific TB enzyme for diagnosis.

“It's simple. Take a sputum sample, treat it with the solution, and put it inside the reader,” Cirillo says. “A camera inside looks for a reaction between the sample and solution that produces light. No light, no infection.” Once sputum samples are combined with the reactive substance, the TB REaD is used to detect any fluorescence and deliver the diagnosis in as little as 10 minutes. The test is currently in the later stages of clinical trials with plans to go to market in the next 18 months. Read the study abstract.

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