Interferon-alpha in patients with asymptomatic human immunodeficiency virus (HIV) infection. A randomized,...

To evaluate the toxicity and clinical efficacy of interferon-alpha 2b (IFN-alpha) in patients with asymptomatic human immunodeficiency virus (HIV) infection.

Randomized, placebo-controlled, and double-blind study.

Outpatient clinic of a government referral-based research hospital.

Volunteer sample of 34 patients with asymptomatic HIV infection who had CD4 counts of 400 cells/mm3 or more, positive peripheral blood mononuclear cell cultures for HIV, or p24 antigenemia.

Patients were randomly assigned to receive either IFN-alpha or placebo, 35 x 10(6) units per day subcutaneously. Doses of IFN-alpha or placebo were modified according to predefined laboratory and clinical criteria. Therapy lasted at least 12 weeks.

Seventeen patients were randomly assigned to each group. The two groups had similar mean CD4 counts at study entry. Thirty-five percent of patients assigned to receive IFN-alpha withdrew from the study because of toxicity. The average daily dose of IFN-alpha was 17.5 x 10(6) units. All patients receiving IFN-alpha reported flu-like symptoms; other toxicities included granulocytopenia (55%) and elevated liver enzyme levels (45%). While receiving IFN-alpha, 7 patients (41%) became HIV culture negative (three or more consecutive negative peripheral blood mononuclear cell cultures taken at least 2 weeks apart). In contrast, 2 patients in the placebo group (13%) became culture negative while on study (P = 0.05). During the treatment period, CD4 lymphocyte percentages were sustained at or above the baseline level in patients receiving IFN-alpha and declined slightly in patients receiving placebo. Of the 32 study patients followed after study (range, 5 to 33 months), no patients in the IFN-alpha group developed an acquired immunodeficiency syndrome (AIDS)-defining opportunistic infection, compared with 5 patients in the placebo group (P = 0.02).

Treatment of early-stage HIV infection with IFN-alpha can result in a decrease in frequency of viral isolation. Although its use may be accompanied by dose-dependent toxicities, IFN-alpha may have a role in slowing progression of HIV disease.