Treating TB, HIV at same time found to save lives

Diane Havlir, MD poses for a portriat on the hallways of the AIDS ward at San Francisco General Hospital on Nov. 25, 2008.

Treating tuberculosis and HIV infections at the same time can be a challenge for patients and their doctors, but attacking both diseases early and aggressively isn’t harmful and could save the lives of those who are sickest, according to a global study led by UCSF researchers.

Tuberculosis is the main cause of death among people with HIV and AIDS worldwide, killing about 400,000 people every year. But how to best treat both conditions has been unclear, because of worries about how the drugs will interact and the burden that dual treatment puts on patients, who must take dozens of pills every day with some gruelling side effects.

The study, published last month in the New England Journal of Medicine, found that patients whose immune systems have been most damaged by HIV benefited by beginning antiretroviral drugs two weeks after starting TB treatment, instead of waiting eight to 12 weeks, as is commonly done now. Those patients were 40 percent less likely to die or develop AIDS.

“Clinicians have been completely unsure of the best time to start HIV therapy in these patients. It was important to know whether we should start HIV therapy early, and now we know it’s worth it,” said Dr. Diane Havlir, chief of the UCSF HIV/AIDS division at San Francisco General Hospital and lead author of the study.

“It’s a tough treatment, but it gives significant medical benefits and it’s lifesaving,” Havlir said.

Tuberculosis is a global epidemic, with more than 9.4 million new cases worldwide every year. HIV-positive people, whose weakened immune systems leave them vulnerable to secondary infections, are especially at risk for contracting the disease.

Almost a quarter of people with HIV infections have tuberculosis, and they are more than 20 times more likely to contract active forms of tuberculosis – meaning they’re symptomatic, and not just harbouring the latent bacteria – than healthy individuals.

TB isn’t nearly as common in the United States as it is in other parts of the world, but it’s enough of a concern that HIV-positive people are tested regularly for tuberculosis, and people diagnosed with TB always get tested for HIV right away.

Tuberculosis is curable, but the regimen used to treat it requires strict adherence to several different medications for at least six months. Patients who don’t stick to the treatment plan run the risk of developing drug-resistant TB, which is far more difficult to cure and can be spread to others. They also remain infectious for a longer period of time.

Treating multiple infections

Meanwhile, antiretroviral drugs, while very effective at suppressing HIV infections and allowing the immune system to rebuild and strengthen, can also be brutal to take. Doctors have worried about the two drug therapies counteracting each other or causing serious side effects in combination.

Plus, if it’s difficult for patients to stick with the drug regimen for one disease, it would be even more challenging for two diseases, public health experts say. So health care providers have been reluctant to tackle both HIV and TB at the same time, usually opting to treat the TB first – because it’s so infectious – and add the antiretroviral drugs several weeks or months later.

The UCSF study, along with two similar studies also published in the New England Journal of Medicine on Wednesday, makes it clear that patients are better off aggressively treating their HIV infection soon after starting TB therapy.

“The default position has been ‘let’s get the active infection under control and worry about HIV later,’ and that’s the wrong answer,” said Dr. Andrew Zolopa, director of the Stanford Positive Care Clinic. He has studied how best to treat HIV and other infections, although not tuberculosis, and found similar results.

The UCSF study followed 809 patients on five continents, mostly in Africa, for 48 weeks. Each of the patients was newly diagnosed with HIV and had not yet started antiretroviral therapy, and had either a confirmed or suspected case of tuberculosis.

Similar side effects

Patients were randomly assigned to start antiretroviral therapy either two weeks after beginning TB treatment or eight to 12 weeks after. Patients aren’t started on both therapies at the same time because the side effects of TB treatment can be severe, although they usually fade after one to two weeks.

Study subjects who started therapy earlier were more likely to develop an inflammatory condition that required additional treatment, but otherwise they had roughly the same number and types of side effects as patients who received the later therapy.

At the end of the study, healthier patients who started HIV treatment earlier were no better off than those who started later. But among the sickest patients, 16 percent of those who were treated earlier had died or developed AIDS within a year, compared with 27 percent of those who got the later treatment.

The sickest patients had T-cell counts – a measure of the strength of the immune system – below 50 at the start of the study; a healthy individual will have a T-cell count of at least 600.

“It might be safe to wait for treatment in some cases,” said Dr. Warner Greene, director of the Gladstone Institute of Virology and Immunology. “But if the (T-cell) count is too low, you’re obligated to treat early now.”

Original Article by Erin Allday via SFGate.com

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