IMMUNOLOGICAL UNDERSTANDING OF PHOTOPHERESIS AND CYTOKINE THERAPY OF AIDS

Abstract

BACKGROUND: Clinical syndrome of AIDS-related complex (ARC) develops when CD4+ and CD8+ T cells decrease. Extracorporeal photopheresis(ECP) using photoactivator 8-methoxypsoralen (8-MOP) combined with interferons(IFN's) and interleukin-2 (IL-2) given monthly produced excellent response. METHODS: The 7 patients in our study satisfied the following eligibility criteria: CD4+ cells less than 50 mm3; IFN inhibitor factor more than 80 IU/ml; and the absence of gamma IFN production. RESULTS: Therapy initiated a cascade of immunological events: 1) skin associated lymphoid tissue (langerhans cells, T and non-T lymphocytes) met antigenic challenges; 2) antibody titers to: gp120 and 41 (envelope glycoprotein antigen), gp66/31 and 55 (reverse transcriptase enzymes antigen) and p24 (core protein antigen) increased after ECP; 7) ECP tended to kill white blood cells expressing IL-2 receptors and/or HLA-DR antigen. IL-2 prevented this damage when added in BC; 8) CD8+ T cells increased after ECP; 9) specimen of BC taken before reinfusion (after exposure to UV light and addition of IL-2/IFN) inactivated HIV in the culture. CONCLUSIONS: ECP combined with IFNs and IL-2 in ARC patients increased antigenic properties of skin associated lymphoid tissue to HIV present antigens, increased the number of lymphocytes in peripheral blood, skin and lymphoid tissue, improved the ability of lymphocytes to respond to mitogens or antigens, activated cytokine production and included the anti-HIV and ani-infection disease activity. These results will be used as a model to find less expensive methods of therapy.