AL-721 is a lipid mixture extracted from hen egg yolks by a special process. In the mid-to-late 1980s there were high hopes that it had significant anti-HIV effects. It was thought to act by removing cholesterol from the surface membranes of HIV particles and making them more fluid, thus making it impossible for them to bind to and infect human cells.

AL-721 refers to the mixture of yolk ingredients in the substance: 7 parts neutral glycerines, 2 parts phosphatidyl choline (lecithin) and 1 part phosphatidylethanolamine. It is manufactured by the Ethigen Corporation and marketed under the name Ovithin 120.

Current use

Early laboratory tests suggested AL-721 could reduce reverse transcriptase activity, and phase I and II studies suggested some improvements in the immune functions of HIV-positive people, although no effects on p24 antigenaemia or CD4 count were seen.

Three clinical trials of AL-721 have been reported in full in the medical literature. One of these was inconclusive (Yust); the others (Grieco and Mildvan) found no benefits with the possible exception of weight gain, which may have been due to AL-721s calorific value as a food. Small-scale studies also failed to establish any beneficial effects.

In addition, some batches of AL-721 were contaminated with salmonella. AL-721 has also been shown to trigger allergy in some cases. Other side-effects seen in studies included diarrhoea, abdominal pain and nausea.

Despite being a very popular `underground' treatment in the 1980s, in the light of these studies interest in AL-721 has now all but disappeared. No trials are known to be under way anywhere in the world.

Getting it

Several lipid compounds very similar to AL-721 are available through health food shops. There is no evidence that these compounds have any beneficial effects. AL-721 can be prescribed on the NHS as a food supplement.

Key research

Yust treated 16 HIV-positive people (10 asymptomatic, 3 ARC, 3 AIDS) in an open trial of AL-721 (10 g/day in a fat-free breakfast for up to 16 months). 5/9 antigen-positive participants had a significant reduction in the serum level of HIV antigens following approximately 3 months AL-721 treatment, which remained suppressed throughout the trial period. In 2 of the other 4 antigen-positive people, combination of AZT and AL-721 resulted in a marked decrease in antigen levels. No consistent effect on T-lymphocyte subpopulations was seen. Clinical parameters were not studied.

Grieco evaluated the effects of AL-721 in an 8-week open trial in which 10 g twice daily was administered on a low fat diet to 8 HIV-infected men with lymphadenopathy. There appeared to be a detectable effect on reverse transcriptase level culture positivity during the 8-week period which may be suggestive of diminished HIV recoverability and reduction of viral load; however, this technique has not been standardised and is not a direct measure of viral load. Augmentation of mitogen-induced lymphoproliferative responses was suggested in 4/8 participants; however, there were no evident effects on CD4 counts or circulating serum p24 antigen values.

Peters treated 14 HIV p24 antigenaemic people with AIDS or ARC in a study of AL-721 (15g twice daily for 12 weeks) or placebo in a study in which a change in p24 antigenaemia was the primary end-point, with secondary clinical end-points. There was no fall in p24 antigen concentrations and all had higher values at the end of their treatment period. All 6 treated AIDS patients had at least one major opportunistic infection during treatment, with a mean of 1.1 infections per 12 weeks.

Mildvan enrolled 40 men with lymphadenopathy or ARC and CD4 counts above 200 in a multicentre dose-ranging study of oral AL-721, with an escalating dose schedule over 8 weeks. No patients progressed to AIDS during the study. There were no significant changes in weight associated with any dose tested. CD4 counts remained stable, and no statistically significant differences in counts were detected across dose groups. Levels of p24 antigen did not change consistently in the 3 patients with measurable antigen at entry. The study concludes that AL721's lack of effect on surrogate markers does not support its use as an antiretroviral agent.

References

Grieco MH et al. Open study of AL-721 treatment of HIV-infected subjects with generalised lymphadenopathy syndrome: an eight week open trial and follow-up. Antiviral Res 9: 177-190, 1988.

Mildvan D et al. An open-label, dose-ranging trial of AL721 in patients with persistent generalised lymphadenopathy and AIDS-related complex. JAIDS 4(10): 945-951, 1991.

Peters B et al. Ineffectiveness of AL-721 in HIV disease. Lancet 335: 545-546, 1990.

Shinitsky M et al. Suppression of HIV antigenaemia by AL-721. Lancet 335: 1281-1282, 1990.

Wolf et al. Atopic dermatitis provoked by AL 721 in a patient with AIDS. Ann Allergy 66(5): 421-423, 1991.

Yust I et al. Reduction of circulating HIV antigens in seropositive patients after treatment with AL-721. Israel J Med Sci 26: 20-26, 1990.