Acquired Immunodeficiency Syndrome: Gonzalez C

Essajee SM, Kim M, Gonzalez C, Rigaud M, Kaul A, Chandwani S, Hoover W, Lawrence R, Spiegel H, Pollack H, Krasinski K, Borkowsky W. · Department of Pediatrics, New York University Medical Center/Bellevue Hospital, New York 10016, USA. · AIDS. · Pubmed #10630521 No free full text.

Abstract: OBJECTIVE: To determine the long-term immunologic and virologic effects of highly active antiretroviral therapy (HAART) in children with AIDS. DESIGN: A prospective observational study. SETTING: Two pediatric HIV clinics. PARTICIPANTS: Twenty-five protease-inhibitor naive HIV-infected children (aged 2-18 years) with advanced disease (CD4 < or =6%). INTERVENTION: HAART (one protease inhibitor and one or more nucleoside analogs). Diphtheria and tetanus immunization in six patients after 18 months of therapy. MAIN OUTCOME MEASURES: Changes in percentage of CD4 cells and plasma HIV-1 RNA levels; post-treatment assays of lymphoproliferative responses to recall antigens; CD4 cell memory phenotype. RESULTS: Median duration of follow-up was 18.8 months (range, 7.5-28 months). At baseline the CD4 cell percentage was 2% (range, 0-6%), this increased significantly to 16% (range, 3-48%) above baseline at 12 months (P = 0.002). The mean maximum CD4 cell increase was 20.7% (range 4-48%) which corresponds to 657x10(6) cells/l (range, 30-2240x10(6) cells/l) above baseline. By contrast, the median viral load was not significantly lower at 12 months than at baseline (P = 0.34), and only 25% of the patients had sustained undetectable viral load. Of the reconstituted CD4 cells 70% were naive, and none of the subjects had lymphoproliferative responses to tetanus and diphtheria although 40% did develop responses to Candida, an environmental antigen. A single immunization with diphtheria and tetanus toxoid produced lymphoproliferative responses to tetanus in three out of six patients. CONCLUSIONS: HAART was associated with sustained increases in CD4 cell counts, despite a high incidence of 'virologic failure'. CD4 counts and the proportion of naive cells were higher than have been reported in adults, which may be a reflection of greater thymic activity in children. Memory cell clones for antigens encountered in the past which are not prevalent before therapy could not be expanded without additional antigenic exposure.

Chien PC, Chen D, Chen PD, Tuen M, Cohen S, Migueles SA, Connors M, Rosenberg E, Malhotra U, Gonzalez C, Hioe CE. · Department of Pathology, New York University School of Medicine, and Veterans Affairs New York Harbor Healthcare System, New York, New York 10010, USA. · J Infect Dis. · Pubmed #14976603 No free full text.

Abstract: BACKGROUND: Antibodies to the CD4-binding domain (CD4bd) of human immunodeficiency virus type 1 (HIV-1) glycoprotein 120 (gp120) inhibit gp120 antigen presentation to CD4 T cells. These findings imply that the presence of anti-CD4bd antibodies might contribute to the dearth of envelope-specific T helper responses observed in most HIV-1-positive patients. In the absence of these antibodies, however, anti-envelope T helper responses might be maintained. METHODS: We used ELISA to evaluate the levels of anti-CD4bd antibodies in rare HIV-1-positive patients who exhibit envelope-specific lymphoproliferation. Subsequently, we examined the contribution of anti-CD4bd antibodies to disease progression by comparing anti-CD4bd antibody levels in 3 cohorts of HIV-1-positive patients with distinct rates of disease progression. RESULTS: Although most HIV-1-positive individuals produce anti-CD4bd antibodies, 77% of patients with envelope-specific lymphoproliferation have undetectable anti-CD4bd antibody levels. Moreover, comparison of the 3 HIV-1-positive cohorts revealed that individuals with long-term nonprogression have significantly lower anti-CD4bd antibody titers than do those with rapid or slow progression. Unlike immunoglobulin G (IgG) from rapid progressors, IgG from nonprogressors had no suppressive effects on glycoprotein (gp) 120-specific T cell proliferation. CONCLUSIONS: Low anti-CD4bd antibody levels are associated with the absence of disease progression. A number of HIV-1-positive individuals without these antibodies also appear to sustain gp120-specific T helper responses needed to help control the infection.