AL-721 is a lipid compound composed of neutral lipids, phosphatidylcholine and phosphatidylethanolamine in a 7:2:1 ratio. The objective of this open study was to evaluate the effects of AL-721 in vivo in an 8-week open trial in which 10 g twice daily was administered on a low fat diet to eight HIV-infected subjects with lymphadenopathy syndrome (LAS). Serial lymphocyte cocultivation studies in 7 patients with initial culture positivity appeared to demonstrate reduction of reverse transcriptase peak counts in 5 with the trough noted in 4 at 8 weeks and in one at 4 weeks following termination of therapy. The mean values for all 7 patients revealed a baseline value of 73,419 with decrease to a low of 27418 at 8 weeks. Mean levels of total lymphocytes, T-4, T-8 and T-11 cells were not altered but lymphoproliferative responses to concanavalin A and pokeweed mitogens appeared to be augmented in 4 of the 8 subjects in association with AL-721 treatment. No side effects were noted. In a subsequent follow-up study using a normal diet in the same subjects lymphocyte cocultivation and mitogen-induced responses were less consistently affected when 15 g twice daily AL-721 was readministered. In addition, serum HIV p24 antigen and CD4 levels were not altered during both the 8-week open and subsequent AL-721 readministration. Four of the 8 patients have progressed to AIDS over the subsequent 14 months.