Kinetics of productive and latent HIV infection in lymphatic tissue and peripheral blood during triple-drug combination therapy with or without additional interleukin-2.

OBJECTIVE

To study decay rates of productively and latently infected cells in peripheral blood and lymph nodes during triple antiretroviral therapy and the possible impact of interleukin-2 (IL-2) on viral kinetics.

METHODS

In this non-randomized study, nine antiretroviral-naive HIV-positive patients received either saquinavir hard gel capsules 2400 mg three times daily (group I; four patients) or saquinavir soft gel capsules 1200 mg three times daily and IL-2 (group II), in both cases together with two nucleoside analogues. Plasma viraemia and lymphocyte subsets were analysed. Axillary lymph nodes were excised before and after 12 weeks of therapy. Lymph node sections were examined by in situ hybridization for HIV RNA, and productively infected cells were counted. Infection rates of FACS-sorted CD3, CD4 lymph node and peripheral blood mononuclear cells were determined by nested DNA PCR.

RESULTS

Baseline plasma HIV RNA levels ranged from < 25 to > 1 x 10(6) copies/ml and remained undetectable throughout the study in one patient in group I. Plasma viraemia became undetectable after 3 months in four patients (three in group I). Productively infected cells were markedly reduced in the follow-up lymph node specimens. HIV DNA-positive CD4 T cells were reduced in lymphoid tissue and peripheral blood in all six evaluable patients. There were no significant differences between the groups in the clearance rates of plasma virus and of HIV DNA-positive cells.

CONCLUSIONS

Combined antiretroviral therapy rapidly suppressed active HIV replication in plasma and lymphoid tissue. Latently infected cells were cleared at a slower rate. Viral clearance did not appear to be markedly affected by additional IL-2 therapy.