Simon Collins, HIV i-Base
Although treatment guidelines now recognise that patients who started treatment with higher CD4 counts than currently recommended, may safely discontinue therapy, especially if they are experiencing toxicity from treatment, there is still a reluctance from some doctors to suggest this option to their patients. Several studies at Warsaw provided additional support for this option.
Cotte and colleagues from Hôtel-Dieu Hospital in Lyons assessed virological and immunological response in 41 asymptomatic patients who had started treatment with CD4 counts >350 cells/mm3, with a range of treatment histories, all of whom had undetectable viral load <50 copies/mL for the previous 12 months. The protocol recommended that patients restart treatment after two consecutive CD4 counts <350 cells/mm3. 
Mean CD4 count prior antiretroviral treatment (some patients started with mono- and dual-therapy) was 489 +/–132 cells/mm3 and 541 +/–155 cells/mm3 prior to HAART. Mean duration of ARV treatment was 4.3 +/–1.6 years.
Mean duration of treatment interruption is currently 16 +/–14 months with nine patients restarting treatment when their CD4 count dropped below 350 cells/mm3. One patient developed acute seroconversion symptoms three weeks after the interruption and restarted treatment two months later. One patient restarted HAART after a herpes zoster infection at month seven. All patients restarting treatment achieved viral load <50 copies/mL and CD4 count >300 cells/mm3 by three months after the reintroduction of therapy.
Mean viral load was just over 4.5 logs and CD4 count around 650 cells/mm3 (from a baseline of just under 800 cells/mm3) after 24 months off-treatment.
Discontinuation of treatment in any asymptomatic individual is likely to lead to improved quality of life – that could potentially last for several years. Caution should be taken when stopping drugs that have long half-life and low resistance threshold such as 3TC, nevirapine and efavirenz. BHIVA guidelines suggest switching the NNRTI in a regimen to nelfinavir for the last two weeks of therapy.
Ref: Cotte L, Lebouche B, Miailhes P et al. HAART interruption in virologically controlled patients who started treatment at an early stage of HIV-infection. 9th EACS, Warsaw. 25-29 October 2003. Abstract 7.6/5.