14th International AIDS Conference Barcelona, Spain — July 7-12, 2002

Int Conf AIDS. 2002 Jul 7-12;14:Abstract No. ThOrB1439

BACKGROUND: There is growing interest in treatment interruption (TI) after response to HAART. We present data on 75 patients who stopped HAART and assess predictors of reinitiation (RI) and CD4 decline.

METHODS: Patients entered an observational database when the clinician interrupted HAART with the plan to reinitiate based on lab parameters. CD4 count and viral load (VL) were evaluated pre-HAART, on HAART, during TI and following RI.

RESULTS: 75 patients underwent TI. Med. pre-HAART CD4 was 426 and med. VL was 27,000. Med. CD4 at TI was 677 and VL was 263 (<50 in 24 [32%]). Of the 23 (31%) who have resumed therapy (mean TI 30 wks), med. CD4 decline was 258 and med. VL increase was 122,000. Med. CD4 at RI was 258 and med. VL was 160,500. Among the 52 (69%) who remain off therapy (mean TI 69 wks), med. CD4 is 508 with a med. decline of 255 and med. VL is 22,151. 14 (64%) of resumers and 17 (33%) of non-resumers met current DHHS criteria for initiation pre-HAART. By univariate analysis correlates of RI included CD4 pre-HAART (OR 0.6, p=.003) and on HAART (OR 0.73, p=.003). VL and CD4 during TI were also correlated with resumption (p<.01). VL during TI was associated with rate of CD4 decline (p=.042). By multivariate analysis a lower CD4 count at HAART initiation predicted RI (OR=.64, 95% CI .46-0.87). The rate of CD4 decline was 314/yr for resumers and 115/yr for non-resumers (p=.003), with estimated med. times to CD4 <200 assuming continued TI of 0.7 yrs and 3.9 yrs for non-resumers (p<.001).

CONCLUSIONS: 69% of our cohort remain off therapy after a mean TI of 69 weeks. Low pre-HAART CD4 predicted RI and VL rebound was correlated with rate of CD4 decline. Thus the best candidates for prolonged TI are those with higher baseline CD4 counts and lower viral loads, patients who are less likely to be treated based on current guidelines. Randomized trials are needed to assess the safety and durability of prolonged TI and the related strategy of pulse therapy.

Presenting author: J E Gallant

1 Johns Hopkins University School of Medicine, Baltimore, United States

2 Johns Hopkins Bloomberg School of Public Health, Baltimore, United States

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Copyright © 2002 - International AIDS Society (IAS). Reproduction of this abstract (other than one copy for personal reference) must be cleared through the IAS.