Newly Recognized, Treatable Organism May Mimic KS -- or Other AIDS Diagnoses

A newly described micro-organism has been found to cause opportunistic infections in persons with HIV -- infections which can mimic symptoms of Kaposi's sarcoma (KS) and Mycobacterium avium complex (MAC, also called MAI). The infectious agent is a previously unknown bacillus which is believed to be related to Rochalimaea quintana. The bacillus was thoroughly discussed last December 6 in a group of reports in The New England Journal of Medicine.

Infection with this organism can lead to bacillary angiomatosis, hepatic peliosis, bacteremia, and possibly cat- scratch disease. Last month, Colin Blakeney, a friend of AIDS TREATMENT NEWS and a member of ACT UP/San Francisco, called us to share first hand experience with this infection. We want in turn to share with readers what he learned, as well as some observations of a national expert on the new bacillus, Philip E. LeBoit, M. D., a pathologist at the University of California San Francisco School of Medicine.

Since January of this year, Colin had been experiencing symptoms suggestive of infections of Mycobacterium avium complex (MAC, or MAI): intermittent chills, very high fevers, anemia and loss of appetite. Several months earlier he had been diagnosed with Kaposi's sarcoma, based on a biopsy of a single lesion.

After more than 100 various tests failed to explain Colin's constitutional symptoms, doctors removed one of his lymph nodes. An analysis of the node revealed the same infection described above. He was started on 1500 mg daily doses of the antibiotic ciprofloxacin, and the symptoms responded within several days. Unfortunately, the ciprofloxacin seemed to stop working after two weeks, and he was switched to doxycycline, which has apparently worked for the last four weeks.

His doctors are now suspicious of the lab report that identified the KS lesion. Because of the nature of angiomatosis, they are re-evaluating the biopsy to rule out the possibility that the lesion was misidentified as KS. Colin feels that it is now very important for everyone with HIV, and their primary physicians, to be aware of the possibility of this bacillus posing as other opportunistic infections or as KS.

Although the particular species of this bacillus has not been named or categorized yet, its discovery might have some very important consequences. For example, how many people who have been diagnosed and treated for symptoms of KS, or MAC, actually are dealing with this bacillus? Could this explain why some people do not respond to the current KS and MAC therapies? Could this explain why the empirical use of antibiotics like doxycycline seems to help symptoms which have eluded diagnosis? What is the potential for this bacillus to operate as a cofactor in the progression of HIV, as mycoplasma and herpes infections have been alleged to do? We are eager for answers to such questions, answers which might go a long way toward solving the puzzle of HIV disease.

Dr. LeBoit has been working toward those answers. He told us that this bacillus has no doubt existed since before the AIDS epidemic, but probably does not cause disease in persons without immune deficiency. Unfortunately, nearly all of the symptoms associated with the bacillus -- fevers, profound anemia, lymphadenopathy, splenomegaly and skin lesions -- can easily be attributed to other opportunistic conditions.

In view of the skin lesions and the prevalence of KS in the epidemic, Dr. LeBoit estimates that potentially one of every fifty KS diagnoses is actually angiomas caused by this bacillus. This could explain why some people's lesions never respond to chemotherapeutic agents, as well as why some "MAC-type" symptoms persist during MAC treatment.

However, the bacillus does respond effectively to some antibiotics; Dr. LeBoit's first choice is erythromycin, 2 grams daily. He feels that doxycycline is an effective choice as well, only more expensive. Treatment in this case is simpler than diagnosis, which must be done by a knowledgeable pathologist. Pathologists and clinicians alike who are interested in the criteria for identifying this infection, which may include a liver biopsy, can obtain them in an early article describing the bacillus -- volume 13 of the American Journal of Surgical Pathology, 1989, pages 909 to 920. Dr. LeBoit emphasized that non-dermatologists working without a biopsy cannot definitively diagnose the infection.