LOS ANGELES, Feb. 28 -- Like the traditional HIV-associated opportunistic infections, the toll of conditions such as heart and liver disease is also affected by the immune status of a patient, researchers reported here.
Most of us have previously assumed that prolonged survival and advancing age explain much of the increase in these common end-organ diseases" among HIV patients, said Jason Baker, M.D., of the University of Minnesota at the Conference on Retroviruses and Opportunistic Infections here.
But in fact, he told an oral abstract session, the increase is related to a patient's CD4 count.
The finding comes from an analysis of data from the FIRST trial, a large randomized study of 1,397 patients -- who had never been treated for HIV -- that evaluated different treatment strategies, Dr. Baker said.
The study was used because it collected CD4 and HIV RNA levels at the start and every four months during 60 months of follow-up, as well as collecting data on both the traditional opportunistic infections and "non-opportunistic" illnesses, Dr. Baker said.
The non-opportunistic diseases included:
- Liver -- cirrhosis, grade 4 elevations in liver enzymes, and death from liver failure.
- Cardiovascular -- myocardial infarction, stroke, coronary intervention, death from chronic atherosclerotic disease.
- Renal -- end-stage renal disease, insufficiency, or death.
- Cancer -- and malignancy other than Kaposi's sarcoma or non-Hodgkin's lymphoma.
Across all the treatment groups, therapy was effective, Dr. Baker said, in that the median CD4 count rose from 163 cells per microliter of serum to 399.
Over the course of the study, Dr. Baker said, there were 226 opportunistic infections and 86 deaths, compared with 166 non-opportunistic events and 25 deaths.
A multivariate Cox proportional hazards analysis showed that every increase of 100 CD4 cells reduced the risk of an opportunistic infection by 53%, which was significant at P<0.01.
At the same time, every 100-cell increase reduced the risk of a non-opportunistic event by 16%, he said, which was also significant at P<0.01.
In other words, he said, as the CD4 count rises, the rates of non-opportunistic diseases decline -- but not as quickly as the traditional opportunistic infections.
"The fact that it's associated with CD4 levels starts to build the case that it's not just that people aren't dying from other causes," Dr. Baker said.
"Traditionally, we've looked at the benefits of therapy in terms of AIDS-defining illnesses," he said, "and now we may have to include other outcomes" in treatment decisions.
The study didn't have enough power to reliably estimate the risk for individual non-opportunistic diseases, Dr. Baker said. Judith Currier, M.D., of the University of California at Los Angeles, commented that the study starts to "help define what's AIDS-related and what's not." Dr. Currier, who was not involved in the FIRST study, said a key message is that it's better to treat HIV patients than not.
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