Decrease of enhanced interferon alpha levels in sera of HIV-infected and AIDS patients receiving combined antiretroviral therapy.

In the advanced stages of human immunodeficiency virus (HIV) infection the defective interferon (IFN) responses have been observed. Persisting high lebels of the acid-labile interferons (al-IFNs) have been found in sera of the patients with AIDS. The combined antiretroviral therapy, that included the reverse transcriptase and viral protease inhibitors, resulted in a significant improvement of the clinical state of the majority of HIV-infected patients. In this report we describe the levels of IFNs in 41 HIV patients subjected to the combined treatment. High IFN levels (median 84, up to 576 U/ml) were found in sera of patients classified as the stage C2 or C3 of AIDS before the treatment. The combined therapy resulted in the decrease of IFN levels (median 7.5, up to 24 U/ml) that approached the levels of IFNs detected in the HIV+, A1-A3 stage patients (median 4, up to 36 U/ml). In contrast, the unsuccessful therapy connected with the worsening of the clinical state and the decrease of CD4+ cell count had no effect on the IFNs levels (median 48, up to 96 U/ml). Thus, the measurements of IFN activity in sera may be useful for monitoring the effects of the antiretroviral combined therapy. In sera of the AIDS patients, subjected to the antiviral bioassays, the mixture of the acid-labile and acid-stable form of IFN-alpha, with the prevailing al-IFN-alpha, have been detected.