Johns Hopkins Medicine
Media Relations and Public Affairs
Media contact: David March
August 10, 2006
NEWS TIP FROM JOHNS HOPKINS MEDICINE
XVI INTERNATIONAL CONFERENCE ON AIDS, AUG. 13-18, TORONTO, CANADA
HOPKINS STUDY SHOWS ISONIAZID PLUS ANTIRETROVIRAL THERAPY BEST PREVENTS TB IN PEOPLE WITH HIV
A study by Johns Hopkins and Brazilian scientists shows that pairing a common tuberculosis drug, isoniazid, with highly active antiretroviral therapy (HAART) is more effective than either therapy on its own at preventing full-blown TB disease in people with HIV. TB disease remains the leading cause of death worldwide among those with HIV and AIDS and is epidemic in developing countries with the highest HIV-infection rates.
A team of Hopkins and Brazilian researchers reviewed the medical records of 11,036 HIV-positive men and women in Rio de Janeiro, Brazil, one of 22 countries most affected by TB, and found that among those treated with both drugs, the risk of developing TB disease was reduced by 67 percent. Isoniazid on its own reduced the frequency of disease from the highly contagious tubercle bacillus by 32 percent. Scientists have known for years that HAART on its own reduced the risk of TB, by 51 percent in this survey, but they did not know until now the drugs’ combined effects.
In the Hopkins survey, sicker patients - those with immune cell CD4 counts of less than 350 per cubic milliliter of blood - were found to benefit more, with a 66 percent reduced risk of TB, compared to those with higher CD4 counts, whose risk went down by 56 percent.
Jonathan Golub, Ph.D., an assistant professor of infectious diseases at The Johns Hopkins University School of Medicine, says the results offer the first evidence that combination antiretroviral therapy with isoniazid could confer the best chance of preventing TB disease in people co-infected with HIV and TB. Study senior author Richard Chaisson, M.D., a professor of infectious diseases at Hopkins and founding director of its Center for Tuberculosis Research, notes that while isoniazid treatment is recommended by the World Health Organization to prevent TB in HIV patients, most physicians fail to prescribe the drug, which costs less than $1 for a full course of therapy.
The study team will continue to monitor how well the drugs, both in combination and alone, help reduce the number of new cases of TB disease within the HIV-infected population of Rio de Janeiro. Their research is part of three ongoing studies by the Consortium to Respond Effectively to the AIDS/TB Epidemic, known as CREATE, that is led by Chaisson at Hopkins and funded by the Bill and Melinda Gates Foundation. The goal of researchers in CREATE is to develop novel strategies to detect and treat latent TB infection and active TB disease in patients also infected with HIV. Worldwide, each year, more than 9 million new cases of TB are diagnosed, and more than 2 million people die from the disease, caused by Mycobacterium tuberculosis.
Tuberculosis (TB) incidence by HAART and isoniazid prophylactic therapy (IPT) in HIV-infected patients in Rio de Janeiro, Brazil. Jonathan Golub, V. Saraceni, S. Cavalcante, A. Pacheco, I. Moulton, B. King, R. Moore, Richard Chaisson, and B. Durovni
- JHM -
(Scheduled for presentation at 12:30 p.m. ET, Monday, Aug. 14; poster presentation #MOPE395, Poster Exhibition Area, Level 800, South Building of Metro Toronto Convention Center.)