RAPID EVOLUTION OF HUMAN-IMMUNODEFICIENCY-VIRUS STRAINS WITH INCREASED REPLICATIVE CAPACITY DURING THE SERONEGATIVE WINDOW OF PRIMARY INFECTION

The relationship between host and virus was examined during the initia l stages of human immunodeficiency virus type 1 (HIV) infection in a v olunteer from the Multicenter AIDS Cohort Study (MACS). The individual was asymptomatic and unaware of his infection during an initial donat ion of blood and inguinal lymphoid tissue. Proviral DNA, however, was present in cells from both sources; HIV RNA was detected in the plasma , and CD4(+) cell levels were reduced by approximately 50% compared wi th previous donations in the MACS. In a second blood donation 12 days later, plasma HIV RNA increased 200-fold in tandem with viral isolates with an increased growth phenotype in vitro, HN burden was ultimately suppressed upon seroconversion and the emergence of HIV-specific CD8( +) cytotoxic T lymphocytes. These observations provide further evidenc e that the potential benefits of early treatment may be maximized duri ng the early stages of infection, when viral fitness may be low but is unopposed by immune responses.