Bulletin of Experimental Treatments for AIDS, No. 3, June 1989
Rick Davis

** Jackson GG, et al. Passive immunization of human immunodeficiency virus in patients with advanced AIDS. Lancet , ii:647 652, September 17, 1988.

For several weeks following the infusion, the researchers could only rarely find HIV in the recipients' blood. There were no apparent adverse side effects to donors or recipients.

p24 antibody versus p24 antigen

The p24 antigen test detects a protein (p24) fragment of HIV.

The p24 antibody test measures the amount of antibody against the p24 antigen. Individuals with high levels of p24 antibody and undetectable levels of p24 antigen usually remain healthy. Over time, most HIV positive individuals will have a decline in the amount of detectable p24 antibodies and within a short time may become p24 antigen positive. People who are p24 antigen positive are more likely to develop ARC or AIDS, although at least 1/3 of those who develop AIDS never become p24 antigen positive.

** Moss, AR. Remarks to the 73 annual meeting of the Federation of American Societies for Experimental Biology, New Orleans, March, 1989. Reported by CDC Weekly , April 3, 1989, p.7.

Almost all the PWA in the Jackson trial showed improvement during treatment: higher T helper and T suppressor cell counts (50% average increase), weight gain, and a significant decline in new opportunistic infections. These improvements continued for 11 weeks, and appeared to depend on the amount of plasma infused (55 500 ml). When treatment stopped, symptoms returned, cell counts fell to pre treatment levels, and p24 antigen again became positive. One of the trial participants who was severely ill at the beginning of the trial showed no improvement and died two months later. Three individuals who did show improvement during the treatment period also subsequently died.

In another study (still ongoing) at London's St. Stephen's Hospital, researchers infused 10 PWA and PWARC with 250 500 ml of p24 antibody rich plasma monthly.

** Karpas A, et al. Effects of passive immunization in patients with the AIDS related complex and immune deficiency syndrome. Proceedings of the National Academy of Sciences December, 1988.

In this study, researchers selected donors for high amounts of HIV neutralizing antibody rather than high amounts of p24 antibody. As in the Jackson study, p24 antigen became negative almost immediately, and stayed negative in all but one individual who later developed CMV retinitis, lymphoma and PCP. Unlike the results of the Jackson trial, T helper and T suppressor cell counts did not increase.

The researchers have noted no toxic side effects and have continued to give trial participants monthly infusions. Dr. Michael Youle of St. Stephen's Hospital told Treatment Issues plans to continue adding individuals to the London study.

** Nott V. Passive Immunotherapy. Treatment Issues December 12, 1988.

He emphasized that the trial was being conducted primarily "to assess toxicity," and it had produced "encouraging but inconclusive results." Dr. Youle plans a controlled trial comparing p24 antibody rich plasma to AZT.

** Ibid

More complete results of the St. Stephen's Hospital team's ongoing trial will be presented at the Montreal International AIDS Conference in June 1989.

These preliminary uncontrolled trials have encouraged other researchers to begin or plan controlled studies of passive immunotherapy. A double blind study is currently under way at New York's Bronx V.A. Hospital with 50 participants.

Two companies, Medicorp and Immunotech, have applied to the California Food and Drug Bureau for approval of open and double blind studies. Medicorp, sponsor of the London and New York trials, is applying to the FDA for IND* status.

Passive immunotherapy costs $700 - $1,000 per treatment. An Immunotech spokesperson told BETA the company will charge study participants for treatment costs. Medicorp says it will not charge participants who enroll in its forthcoming trials.

The PATH Project in San Francisco is a community based organization that closely follows developments in passive immunotherapy. Call (415) 549 9137 for further information.

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Copyright © 1989 - Bulletin of Experimental Treatments for AIDS (BETA). Reproduced with permission. BETA is published four times a year by the San Francisco AIDS Foundation. All rights reserved. Noncommercial reproduction is encouraged. Subscription lists are kept confidential. Call 415.487.8060; FAX: 415.487.8069. Mailing Address: P.O. Box 426182, San Francisco, CA 94142-6182.  beta@sfaf.org  http://www.sfaf.org/beta.html