New Delhi, Oct 1 (IANS): In a significant breakthrough to help patients battling both HIV and tuberculosis (TB), a study led by an Indian-origin scientist found a cancer therapy that can help control TB and not interfere with combined antiretroviral therapy (cART).

cART is a treatment that uses a combination of three or more drugs to treat HIV infection.

While many cases of TB can be controlled with months of antibiotics, the infection can return in people who are immunocompromised as a result of HIV. A resurging TB infection -- responsible for more than 1.3 million deaths worldwide -- can often be deadly to these individuals.

“This is an important hurdle that this host-directed therapy had to clear in order to help patients battling both HIV and TB,” said Professor Smriti Mehra, from Texas Biomedical Research Institute (Texas Biomed)

In the study, published in the peer-reviewed journal JCI Insight, the scientist and her team focussed on the protein, called IDO (short for Indoleamine-2,3-dioxygenase) -- a therapy currently used in cancer.

The host-directed therapy, already approved by the US FDA, blocks or inhibits an immune system protein naturally found in the body.

The team showed that IDO normally suppresses the immune system, preventing it from causing excessive inflammation and organ damage.

Blocking IDO for short intervals led to more successful cancer treatments.

Mehra’s team previously showed that the same approach improves control of TB in conjunction with antibiotics.

They experimented with the therapy in the current study in nonhuman primates with both TB and simian immunodeficiency virus -- the nonhuman primate version of HIV.

The results showed the IDO inhibitor does not interfere with cART and is safe for patients with HIV.

Animals given cART and the IDO inhibitor showed no “increase in viral load” compared to those with only cART.

The scientist also called for longer-term studies to confirm there are no unintended side effects.