Regulation and characterization of the interferon-α present in patients with advanced human immunodeficiency virus type 1 disease

To examine a possible association between plasma viremia and interferon- α (IFN-α) in patients with the acquired immunodeficiency syndrome (AIDS), we performed IFN plasma immunoadsorption by apheresis (IFN-α apheresis) in four volunteers with AIDS who had sustained levels of endogenous plasma IFN- α. IFN-α apheresis with two plasma volume exchanges was performed daily for 5 days. Clinical signs and symptoms and hematologic, virologic, and immunologic parameters were monitored. Two subjects developed anemia from phlebotomy, and one had a catheter-associated bacteremia. The IFN-α apheresis was effective only in transiently removing IFN-α: depletion of IFN-α led only to its rapid reconstitution. Cell-associated HIV-1 was unchanged, but three of four subjects had a modest decrease in culturable plasma virus burden following the procedures. The recovery of in vivo HIV-1- related IFN-α by apheresis allowed its biologic and biochemical characterization. The HIV-1 IFN-α showed characteristics on ELISA, western blot, and biologic assays similar to two subspecies of the natural protein. The natural, recombinant, and HIV-1-induced IFN-αs demonstrated nearly identical antiviral activities. The HIV-1 IFN-α eluted from the column was not acid labile. The inability of large amounts of plasma IFN-α found in some patients with AIDS to affect viral burden likely reflects properties of the virus or of host factors independent of IFN-α.