Last week a medical journal, the Lancet, disclosed in an article and letter to the editor that Kaposi’s sarcoma, the symptom most conspicuously identified with acquired immune deficiency syndrome, may not in fact be caused by HIV, the so-called AIDS virus.
The article, from the federal Centers for Disease Control, suggested that Kaposi’s sarcoma--frequently called a cancer although that designation has lately come into question--may rather be caused by an “as yet unidentified infectious agent transmitted mainly by sexual contact.” Although findings received modest coverage, they shake the foundations of accepted orthodoxy about AIDS.
“It is the strangest twist in terms of medical news in the epidemic in years,” says Randy Shilts, author of “And the Band Played On.” “It calls into question everything--the existing paradigm for the epidemic, the direction of research, treatment modalities and even the integrity of the blood supply.”
Kaposi’s sarcoma is said to afflict 15% of all AIDS patients. Yet in a series of autopsy studies, pathologists report that the condition is almost universal in those with AIDS, internally if not dermatologically. “We find the lesions which are generally called KS in about 95% of AIDS patients,” says Dr. George Hensley, professor in the department of pathology at the University of Miami Medical School, who oversaw the studies. This suggests a remarkably high prevalence rate of a second unknown agent in AIDS patients. Until the agent is identified and patients can be tested for it, it is impossible not to wonder how many AIDS patients may also be infected with the agent--and how many of their other symptoms may derive from it rather than HIV.
The studies reported in the Lancet are not the first to suggest that prominent clinical problems in AIDS may be due to something other than HIV. A lengthy review last year in the journal Acta Neuropathologica argued that the central nervous system damage in AIDS cannot currently be explained by HIV infection, and that indeed “cytopathic infection of neural cells by HIV either does not occur or is of little clinical significance.” The primary neurological damage may be due to a second unidentified infectious agent. We simply do not know.
The two reports also raise disturbing therapeutic issues. Many patients with Kaposi’s sarcoma are presumptively diagnosed as having AIDS--without being administered an HIV test--and they are then put on AZT, a toxic anti-viral drug and acknowledged carcinogen. Should this treatment, appropriate only to a virus, prove irrelevant to Kaposi’s sarcoma and perhaps other AIDS symptoms, interesting liability issues arise. Treatment strategies, of course, will be reevaluated.
Researchers at the Centers for Disease Control in Atlanta have offered reassuring explanations for the new findings. Two epidemics must have started simultaneously in the same populations, they contend, and HIV remains the underlying culprit for everything except Kaposi’s sarcoma. This unwieldy hypothesis serves as a kind of damage control: Whatever is afflicting Kaposi’s sarcoma patients has nothing to do with AIDS, and everything else that researchers have said about the role of HIV in the epidemic is still true.
One is driven to wonder whether the researchers might have been correct on the point they have abandoned--that Kaposi’s sarcoma and all the other dismaying symptoms of AIDS do indeed have the same cause--but are wrong in the one that they still cling to: that HIV is the cause of AIDS. To question this has been denounced as heresy. But it was also once heresy to question HIV’s role in Kaposi’s sarcoma.