Cytokine network and acute primary HIV-1 infection.

OBJECTIVE: To investigate the relationship between cytokine serum levels, peripheral blood lymphocyte subsets and clinical picture in acute primary HIV-1 infection. PATIENTS AND METHODS: Absolute number/microliters total lymphocytes, CD4+, CD8+ and natural killer (NK) cells, as well as serum levels of soluble CD8 receptor, interleukin (IL)-1 beta, IL-2, IL-4, IL-6, tumour necrosis factor (TNF)-alpha, interferon (IFN)-gamma, beta 2-microglobulin and 5'-neopterin were determined in 15 patients with acute primary HIV-1 infection, 16 asymptomatic HIV-1-seropositive individuals and 18 HIV-1-seronegative individuals at risk for HIV-1 infection. RESULTS: Acute primary HIV-1 infection was characterized by significant CD4+ lymphocytopenia with low IL-2 serum concentrations, and by high absolute number of circulating CD8+ and NK cells, with elevated serum levels of soluble CD8 receptor, IL-1 beta, IFN-gamma and 5'-neopterin. Follow-up of acute seroconverters showed a significant decrease in NK cell counts and IL-1 beta levels, with an increase of IL-6. CONCLUSIONS: In acute primary HIV-1 infection, significant alteration of cytokine release, possibly induced by viral antigens, could be responsible for both clinical picture and activation of cytotoxic cells through abnormal mechanisms.