Antiretroviral therapy for HIV-2 infected patients

Objectives: To evaluate clinical and RNA load response to antiretroviral th erapy amongst patients infected with HIV-2 and to study the development of drug resistance. Methods: Seven HIV-2 seropositive patients were monitored with clinical exa mination, CD4 cell count and HIV-2 viral RNA load. Viruses From four subjec ts were genotyped and in vitro recovery of virus by co-cultivation with PBM Cs and HVS T-cells was attempted, Viruses isolated from two subjects were a ssayed for phenotypic antiviral resistance. The main outcome measures were the relationship between disease stage, viral load, CD4 cell count, viral s ubtype and the clinical course of HIV-2 infection and the effect of combina tion antiretroviral therapy on disease progression, CD4 cell count. HIV-2 R NA viral load and drug resistance. Results: The median time of follow-up was 3 years (range 0-8 years). Three patients had AIDS, and one had symptomatic disease, Of the four patients ge notyped, three were infected with HIV-2 subtype B and one with subtype A. V iraemia was detectable only at CD4 counts of less than 300 x 10(6)/ml, Two patients with high viral loads failed to respond to antiretroviral therapy although their treatment may not have been optimal, One developed in vitro phenotypic antiviral resistance, The genotype of this patient's viral rever se transcriptase is being analysed, Conclusions: In contrast to HIV-1,HIV-2 RNA levels were often undetectable despite advanced disease and low CD4 cell counts. However, HIV-2 was dearly capable of causing CD4 cell depletion resulting in symptomatic disease. Th e principles of highly active antiretroviral therapy seem to apply to HIV-2 and suboptimal therapy may lead to drug resistance. The timing of therapy initiation, monitoring of response and the measurement of resistance remain unresolved issues and conclusions cannot be extrapolated from HIV-1. (C) 2 001 The British Infection Society.