Novel Test Can Detect Latent HIV-Infected Cells

The TZA test is faster, more cost-effective, and less labor-intensive than the current test for finding dormant HIV cells.

Although antiretrovirals can suppress HIV viral loads to undetectable levels, the virus can still lay dormant in immune cells, preventing patients from truly being cured.

The HIV community has been working tirelessly to rid the body of these dormant HIV-infected cells to develop a cure, and scientists from the University of Pittsburg Graduate School of Public Health is no different. They have developed a new test that can detect these latent HIV cells.

The investigators also reported in Nature Medicine that the amount of the dormant virus in individuals who appear to be nearly cured of HIV is approximately 70-fold larger than prior estimates.

“Globally there are substantial efforts to cure people of HIV by finding ways to eradicate this latent reservoir of virus that stubbornly persists in patients, despite our best therapies,” said senior author Phalguni Gupta, PhD. “But those efforts aren’t going to progress if we don’t have tests that are sensitive and practical enough to tell doctors if someone is truly cured.”

The TZA test is faster and less labor-intensive than the current gold standard test quantitative viral outgrowth assay (Q-VOA), according to the study authors. Furthermore, it is one-third of the cost and produces results in 1 week compared with the 2 weeks it takes the Q-VOA.

The novel test is designed to detect a gene that is only turned on when replicating HIV is present, enabling technicians to quantify the virus. It requires a significantly smaller volume of blood than Q-VOA.

“Using this test, we demonstrated that asymptomatic patients on antiretroviral therapy carry a much larger HIV reservoir than previous estimates—–as much as 70 times what the Q-VOA test was detecting,” Gupta said. “Because these tests have different ways to measure HIV that is capable of replicating, it is likely beneficial to have both available as scientists strive toward a cure.”

The authors noted that the TZA may also be helpful in quantifying replication-competent HIV in the pediatric population, as well as in the lymph nodes and tissues where the virus tends to hide.