EFFECTS OF IL-2 THERAPY IN ASYMPTOMATIC HIV-INFECTED INDIVIDUALS ON PROLIFERATIVE RESPONSES TO MITOGENS, RECALL ANTIGENS AND HIV-RELATED ANTIGENS

The effects of IL-2 therapy on lymphoproliferative responses to mitoge ns, recall antigens and HIV epitopes were studied in asymptomatic HIV- infected patients enrolled in a phase II study of intermittent continu ous intravenous (CIV) IL-2 and subcutaneous infusions of polyethylene glycol-modified (PEG) IL-2. Sixteen consecutive patients randomized to receive CIV IL-2 (n = 5), PEG IL-2 (n = 7) or antiviral therapy alone (n = 4) were studied. All patients were vaccinated with tetanus toroi d (TT) before receiving therapy. Proliferative responses to phytohaema gglutinin (PHA), soluble anti-CD3, TT, streptokinase/streptodornase (S K/SD) and 11 previously described HIV-specific T-helper epitopes from gag and env were studied at weeks 0, 16, 30 and 38. Median CD4(+) lymp hocyte increases of 272 and 255CD4(+) cells/mu l were observed in the CIV IL-2 and PEG IL-2 groups at week 48, while decreasing by 104 cells /mu l in the anti-retroviral therapy alone group. At each time point p roliferative responses to PHA, anti-CD3, TT and SK/SD were not differe nt between treatment arms. Similarly, no differences in responses to H IV epitopes were found between the groups and no new responses to HIV epitopes were detected. IL-2 therapy results in a significant increase in peripheral blood CD4(+) lymphocyte count, but this increase is not associated with quantifiable improvements in lymphoproliferative resp onses to mitogens, recall or HN antigens.