Brief but Efficient: Acute HIV Infection and the Sexual Transmission of HIV

Background. We examined whether viral dynamics in the genital tract during the natural history of acute human immunodeficiency virus type 1 (HIV-1) infection could explain efficient heterosexual transmission of HIV. Methods. We measured HIV-1 concentration in blood and semen samples from patients with acute and long-term HIV-1 infection. We explored the effect of changes in viral dynamics in semen on the probability of transmission per coital act, using a probabilistic model published elsewhere. Results. Considered over time from infection, semen HIV-1 concentrations, in men with acute infection, increase and decrease in approximate parallel with changes occurring in blood. Modeling suggests that these acute dynamics alone are sufficient to increase probability of heterosexual transmission by 8-10-fold between peak (day 20 after infection, based on the model) and virologic set points (day 54 and later after infection). Depending on the frequency of coitus, men with average semen HIV-1 loads and without sexually transmitted diseases (STDs) would be expected to infect 7%-24% of susceptible female sex partners during the first 2 months of infection. The predicted infection rate would be much higher when either partner has an STD. Conclusions. Empirical biological data strongly support the hypothesis that sexual transmission by acutely infected individuals has a disproportionate effect on the spread of HIV-1 infection. Acute hyperinfectiousness may, in part, explain the current pandemic in heterosexual individual

Low Levels of Perforin Expression in CD8+ T Lymphocyte Granules in Lymphoid Tissue during Acute Human Immunodeficiency Virus Type 1 Infection

Human immunodeficiency virus (HIV)-specific cytotoxic T lymphocyte (CTL) responses are detectable shortly after the acute phase of HIV infection, but they cannot control viral replication and prevent development of chronic immune suppression. This article describes a defect in the coexpression of perforin in granzyme A-positive CD8+ T cells in lymphoid tissue from patients with acute HIV infection and a reduction in the perforin-dependent nuclear translocation of granzyme A. Furthermore, intracellular levels of HIV DNA and RNA found in lymphoid tissue were higher (10-100 times) than those found in blood, and blood samples showed more-coordinated cellular perforin/granzyme A expression. This suggests that mechanisms inhibiting CTL-mediated cytotoxicity are operative in lymphoid tissue early in the course of HIV infectio

Predictors of Virological Outcome and Safety in Primary HIV Type 1-Infected Patients Initiating Quadruple Antiretroviral Therapy: QUEST GW PROB3005

Background. Initiation of antiretroviral therapy during primary human immunodeficiency virus (HIV)-1 infection may confer long-term benefit. Methods. After initiation of zidovudine, lamivudine, abacavir, and amprenavir therapy in patients in the QUEST cohort, predictors of virological outcome, virological and immunological changes, and adverse events were evaluated over 48 weeks. Results. One hundred forty-eight patients started antiretroviral therapy during primary HIV-1 infection with ⩽3 bands on Western Blot (median plasma HIV-1 RNA load, 5.4 log copies/mL; median CD4 cell count, 517 cells/mm3). By week 48, 36% of patients had stopped treatment or were lost to follow-up. Among the 115 patients receiving follow-up care at week 48 (102 of whom were receiving antiretroviral therapy), the median viral load decrease was -5.4 log copies/mL (interquartile range [IQR], -6.4 to -3.9 log copies/mL), and the median increase in CD4 cell count was 147 cells/mm3 (IQR, -1 to 283 cells/mm3); 84.2% of patients had a viral load ⩽50 copies/mL, and 44.7% of patients had a viral load ⩽3 copies/mL. The median cell-associated RNA level decreased from 3.4 log copies/million PBMCs (IQR, 2.9-4.1 log copies/million PBMCs) to 0.8 log copies/million PBMCs (IQR, 0.5-1.4 log copies/million PBMCs), and the median cell-associated DNA level decreased from 2.8 log copies/million PBMCs (IQR, 2.4-3.0 log copies/million PBMCs) to 1.6 log copies/million PBMCs (IQR, 1.2-1.9 log copies/million PBMCs); 33.3% of patients had an undetectable RNA level, and 9.5% of patients had an undetectable cell-associated DNA level. The median CD8+/CD38++ T cell count decreased from 459 cells/mm3 (IQR, 208-974 cells/mm3) to 33 cells/mm3 (IQR, 19-75 cells/mm3). Baseline CD8+/CD38++ T cell count and cell-associated DNA level were independent inverse predictors for reaching a viral load ⩽3 copies/mL. Eighty-three patients experienced a serious adverse event (median duration of an adverse event, 15 days). Conclusions. Initiation of antiretroviral therapy during primary HIV-1 infection was associated with very significant antiretroviral activity and a decrease in immune activation. Lower baseline CD8+/CD38++ T cell count and cell-associated DNA level were predictive of achieving a viral load ⩽3 copies/m