Meeting Report: Early Phases of HIV Type 1 Infection1,2,3

A workshop entitled "Early Phases of HIV-1 Infection" was held to review current research on the immunological and virological aspects of early phases of HIV infection in humans and in animal models, to identify studies for future research, and to foster collaborations among investigators in the biomedical community, In infections of adults, the appearance of cytotoxic T lymphocyte activity, when present, coincides with a decrease in viral load as measured by plasma viremia, In neonatal infections, however, an initial decrease in viral load has been observed months before cytotoxic T lymphocytes are detected, Immunological data, from a limited number of patients, indicated that CD8(+) cytotoxic T lymphocytes detected early after HIV-1 infection may recognize epitopes in any of several HIV-1 proteins: Env, Gag, Pol, Tat, and Nef, With regard to the humoral antibody response, anti-Env binding antibodies appear before neutralizing antibodies and do not predict the appearance of neutralizing activity, The time at which neutralizing antibody appears is variable and unpredictable, Preliminary data indicate that early viral peak load does not predict disease progression in many cases, and the phenotype or virulence of the virus appears to be a critical variable, However, the quantity of HIV-I RNA in plasma is a strong CD4(+) T cell-independent predictor of outcome following HIV-1 seroconversion in homosexual men, Early, high virus load with sustained viremia is often accompanied, in both adults and infants, by the inability to mount an effective immune response, resulting in rapid disease progression.