The CD4 lymphocyte count rose from 210 (10%) to 304 cells/μl (16%) by 29 days after commencing therapy (Fig. 1). Three months after the initiation of therapy plasma and CSF viral loads were both 50 copies/ml or less and his CD4 cell count had risen to 384 cells/μl.
This is the first study on the in-vivo replication kinetics of an attenuated strain of HIV-1, in this instance caused by deletions in the nef gene and deletions and rearrangements in the long-terminal repeat . The first-phase slope of decline of HIV RNA in this SBBC member was 0.18/day (T1/2 of 3.7 days), slower than that seen in all previously studied individuals infected with wild-type HIV-1 after the commencement of antiretroviral therapy [4–7].
The 24 h delay before the viral load began to decrease was surprising because nevirapine should inhibit HIV replication more rapidly in vivo than nucleoside reverse transcriptase inhibitors (which require intracellular phosphorylation) or protease inhibitors (which act late in the virus life cycle). However, a similar delay in viral load decline was also seen in all individuals infected with wild-type HIV and treated with a protease inhibitor .
This study was approved by the Human Ethics Committee of the State of Victoria, and written informed consent was obtained from D36, who is thanked for his willingness to participate. A. Dunne is thanked for her assistance in performing the viral load assays.
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