The authors of a multi center study published in the July 3, 2001 issue of Annals of Internal Medicine calculated the exact reduction in death and opportunistic infections attributable to HAART. Researchers at 11 university medical centers across the country followed 528 advanced AIDS patients for an average of 15 months during the period from August 1995 through June 1999. The researchers found that HAART decreased the HIV death rate to 38 percent of pre-HAART levels, and decreased the rate of most opportunistic infections to 66 percent of pre-HAART levels.
"In general, other studies were based on healthier populations," said Edward Murphy, MD, MPH, professor of laboratory medicine at the University of California, San Francisco and principal investigator for the study at the UCSF site. "This study supports the clinical experience of doctors, that HAART does work in these advanced patients."
Patients entering the study had a median CD4+ lymphocyte count of 15. Healthy adults usually have CD4+ counts between 600 and 1,000. Patients with counts below 200 have severely suppressed immune systems. "Untreated, someone with a count of 10 or 20 has a life expectancy of about a year," said Murphy.
The study analyzed data from the Viral Activation Transfusion Study (VATS) which followed AIDS patients with anemia who also tested positive for cytomegalovirus (CMV), a herpes virus that is a common cause of opportunistic diseases in persons with AIDS. Researchers used VATS data because the study spanned the introduction of HAART. In January of 1996 only 1 percent of study participants were using HAART, but by January of 1999 that number rose to 79 percent. Because of the timing of the study, researchers were able to track the effects of HAART on individual patients. "Our study was able to determine each patient's HAART history," said Murphy. "Therefore, we could figure out more precisely what the benefit of HAART was."
Researchers also found that HAART decreased opportunistic infections (not including CMV) to 66 percent of pre-HAART levels, but HAART did not decrease instances of CMV disease.
HAART suppresses the replication of HIV particles in the blood stream, allowing a patient's immune system to recover. For this study, HAART was defined as use of at least three HIV antiretroviral medications, at least one of which was an HIV protease inhibitor or a non-nucleoside HIV reverse transcriptase inhibitor.
Co-investigators on the study include Edward Murphy, MD, MPH, UCSF; Ann Collier, MD, University of Washington; Leslie Kalish, ScD, New England Research Institute; Susan Assmann, PhD, New England Research Institute; Michael Para, MD, Ohio State University; Timothy Flanigan, MD, Brown University Medical School; Princy Kumar, MD, Georgetown University Medical Center; Letty Mintz, ANP, Mount Sinai Medical Center; Frances Wallach, MD, Mount Sinai Medical Center; and George Nemo, PhD, National Heart, Lung, and Blood Institute.
The study was funded by the National Heart, Lung and Blood Institute.