Effect of zidovudine on serum human immunodeficiency virus antigen levels in symptom-free subjects.

18 men with longstanding human immunodeficiency virus (HIV) antigenaemia but no symptoms received zidovudine in low-dose regimens (250 mg 6-hourly, 500 mg 6-hourly, or 500 mg 12-hourly) with or without acyclovir. Serum HIV antigen rose in only 1 patient and declined significantly in 13 (to below cut-off values in 9). In the 1 subject from whom HIV antigen positive cerebrospinal fluid was obtained, the fluid was antigen negative after 12 weeks of treatment. Acyclovir treatment alone or in addition did not seem to influence serum antigen levels. In 7 untreated men serum antigen levels rose or remained stable during follow-up. CD4+ cell counts increased in 14/18 treated subjects and 1/7 untreated subjects. No disease progression was observed in either group. Regression of enlarged lymph nodes was seen in the zidovudine-treated subjects. Adverse reactions to the study drugs were infrequent and mild. Anaemia caused symptoms in 2, but serious leucopenia or neutropenia was not observed.