Stanford profs help HIV patients

Researchers at the Stanford University Medical Center may have found a way of helping patients suffering with the human immunodeficiency virus live longer. Stanford Genetics professors Leonard and Leonore Herzenberg discovered a relationship between the number of glutathione molecules HIV patients carry in their CD4 T cells -- the primary cells targeted by HIV -- and the length of time the patients live. Glutathione is normally found throughout the body and plays a role in many routine biological processes, ranging from cell division to cleansing the body of oxidents and other toxic molecules. Doctors commonly trace the progression of HIV by measuring the total number of CD4 T cells in a blood sample. A low CD4 count indicates a weakened immune system and patients with such numbers are considered to be at risk for early death. But Leonard Herzenberg stressed that "total CD4 counts don't reliably predict how how long an individual patient is likely to live or how rapidly the person's disease will progress," adding that "some patients with low CD4 counts unexpectedly survive for a very long time." The Herzenbergs' results -- which were presented at the annual meeting of the American Association of Immunologists in February -- are based on a study of 204 patients who tested HIV positive but showed no outward signs of illness when the research began. Over the next three years, the researchers found that patients who maintained high glutathione levels outlived those with less glutathione -- regardless of the number of CD4 T cells in their blood. "What we show for the first time in this work is that people with HIV who have lower glutathione levels have a much lower probability of surviving over the course of three years than do people with normal glutathione levels," Leonard Herzenberg said. The findings could help doctors treat HIV more effectively with drugs that raise glutathione levels or prevent further loss of the molecule. The Herzenbergs demonstrated that taking daily tablets of a drug called N-acetylcysteine (NAC) -- which is commonly used to treat overdose of the painkiller acetaminophin -- increased the glutathione in patients' blood to a normal level. "We know low glutathione indicates a bad prognosis for survival for HIV patients, and we know that NAC will raise glutathione levels in patients," Leonard Herzenberg explained. "Therefore, it'd be logical to suggest that NAC will help HIV patients live longer." The study also raises questions about whether it is safe for HIV patients to take acetaminophin, which is found in common painkillers such as Tylenol and has been shown to deplete glutathione levels. The Herzenbergs are asking the Food and Drug Administration to label glutathione-depleting drugs such as acetaminophen with a warning stating their potential danger to people with HIV or other conditions that affect the immune system.