Researchers at Columbia University have found evidence of a previously unknown herpesvirus in KS lesions of persons with AIDS. This virus has not been found in tissues of persons without AIDS and without KS -- including those with lymphoma and other diseases. It is occasionally present in non-KS tissue from persons with AIDS.

This association does not necessarily mean that the virus causes KS -- since it could be a normally-occurring virus which preferentially grows in KS tissue. But if the virus does cause KS, the finding will be very important for developing treatments, for diagnostic tests to tell who is at risk, and for epidemiological studies to prevent the spread of the virus. It is not known whether or not the new virus is sensitive to any existing drugs.

Researchers have long believed that KS is not a true cancer -- and that it is probably caused by an infectious agent other than HIV, but is unlikely to become a serious problem except in those who are immune compromised. It is 20 times more likely to be found in gay men with AIDS than in hemophiliacs with AIDS, and may be transmitted (separately from HIV) by unsafe sexual practices.

The new research used an advanced biotechnology technique called representational difference analysis (RDA). In RDA, two different tissues are taken from the same patient -- in this case from a KS lesions, vs. tissue without KS. RDA uses gene amplification (PCR) in a special way, in order to find genetic sequences which are uniquely present in the tissue of interest. (Once such a sequence is identified, more conventional techniques can be used to identify it in other tissue samples.) The paper describing the research appeared in SCIENCE, December 16. The NEW YORK TIMES reported that the editors of SCIENCE took five months to examine the data, to be especially careful to make sure the results were valid. There is skepticism about the reasons for the delay.

This research was funded by Columbia University's Department of Pathology, and School of Public Health.

Comment: Foscarnet, Call for Information At the Second International Congress on Drug Therapy in HIV Infection, last month in Glasgow, Scotland, a physician in the audience reported that several KS patients had improved when treated with foscarnet (Foscavir), an approved drug usually used for treating CMV infection. According to NURSING 94 DRUG HANDBOOK, foscarnet inhibits all known herpesviruses in laboratory tests. Unfortunately foscarnet must be given intravenously, and it can cause serious toxicities.

We heard that some KS experts scoffed at these case reports, because the information was not from a controlled trial. They probably did know about the Columbia findings, which were not public at the time of the Glasgow meeting but were discussed privately there.

If you know of any case in which a person with KS has used foscarnet, regardless of whether or not there seemed to be any effect on the KS, please contact John S. James at AIDS TREATMENT NEWS, 415/255-0588, or fax to 415/255-4659.

References Chang Y, Cesarman E, Pessin MS, Lee F, Culpepper J, Knowles DM, and Moore PS. Identification of herpesvirus-like DNA sequences in AIDS-associated Kaposi's sarcoma. SCIENCE. 1994; volume 266, pages 1865-1869.

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