Biological effect of active anti-IFN alpha immunization in HIV-infected patients

Circulating interferon (IFN) was investigated in HIV-1 seropositive patients by measuring the IFN alpha antiviral effect in the serum. While serum of healthy seronegative individuals exhibits an antiviral effect, not due to IFNs, considered as background, serum of seropositive patients showed an additional antiviral effect due to the abnormal presence of IFN alpha. Increased titers of IFN alpha were found in the course of the HIV infection and seemed to correlate with the evolution of AIDS disease. Furthermore, patients immunized against IFN alpha had both stabilized CD4 cell count and decreased IFN alpha in their serum. HIV-1-infected patients also exhibited higher titers of natural anti-IFN antibodies than seronegative controls and the level of specific antibodies (Abs) markedly increased in immunized patients. Finally, serum from immunized patients, when compared to seronegative controls, exhibits an interferon neutralizing capacity.