Boulassel MR, Routy JP, Smith GH, Klein M, MacLeod J, Gilmore N, Bruce S, Sekaly PR, Lalonde RG; International Conference on AIDS.

Int Conf AIDS. 2002 Jul 7-12; 14: abstract no. ThPeA7145.

Immunodeficiency Service, McGill University Health Centre, Royal Victoria Hospital, McGill University, Montreal, Canada

BACKGROUND: IL-7 contributes to the regulation of the T-cell pool. Recent reports have shown an inverse correlation between IL-7 and T-lymphopenia in advanced HIV-patients. IL-7, like IL-2, has been shown to increase viral replication in vitro. We hypothesize the increased IL-7 levels are caused by T-lymphopenia and not HIV viremia. To answer this, we analyzed changes in IL-7 levels longitudinally and correlated these changes with CD4, CD8 counts and viremia in advanced and in primary/early phase HIV patients. METHODS: Plasma IL-7 levels were measured at baseline, week 4, 12 and 24 in 25 advanced HIV-patients with severe lymphopenia (at baseline, median CD4=46 cells/ml; range 1-247) and elevated viremia (median 4.9 log10 copies/ml; range 3.5-5.5) and in 31 patients with primary/early phase HIV-infection most with a preserved T-lymphocyte pool (at baseline, median CD4=520 cells/ml; range 68-1137) and elevated viremia (median 4.0 log10 copies/ml; range 1.7-6.3). Sera from 30 healthy adults were used as controls. RESULTS: Throughout the study, IL-7 remained significantly higher in both advanced and early HIV infection (medians 10.8 pg/ml, range 2.7-33 and 15.9 pg/ml, range 2.2-36.8 respectively) than in controls (median 1.8 pg/ml, range 0.4-3.6; P< 0.0001). There was a strong negative correlation between IL-7 and CD4 and CD8 counts at baseline (r=-0.70 and r=-0.67, P<0.0004, respectively), and a weak positive correlation with viremia (r= 0.5, P<0.01) in advanced HIV infection. Interestingly, these relationships were lost from week 4 to week 24, when CD4 counts increased (median CD4=161 cells/ml, range 1-372 at week 24). In early HIV infection IL-7 and CD4, CD8 or viremia were not correlated over 24 weeks of study. CONCLUSIONS: These data suggest that viremia may increase IL-7 and may be related to the loss of CD4 cells, but not in the absence of lymphopenia (early disease) or when therapy increases CD4 counts (advanced disease).

Publication Types:

• Meeting Abstracts

Keywords:

• AIDS Vaccines
• Acquired Immunodeficiency Syndrome
• Adult
• Anti-HIV Agents
• Antiretroviral Therapy, Highly Active
• CD4 Lymphocyte Count
• CD4-Positive T-Lymphocytes
• HIV
• HIV Infections
• HIV Protease Inhibitors
• HIV Seropositivity
• Humans
• In Vitro
• Interleukin-2
• Interleukin-7
• Lymphopenia
• Viremia
• drug therapy
• therapy

Other ID:

• GWAIDS0014144

UI: 102251642

From Meeting Abstracts