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Background:  Current treatment recommendations for HIV-infected children suggest using a combination of reverse transcriptase (RTI) and protease inhibitors (PI). Adherence to these treatments is often suboptimal due to poor PI palatability, toxicity, dosing schedule and psychosocial factors. For patients with adherence problems or failing PI-containing regimens, therapy simplification consisting primarily of RTI combinations, termed partial treatment interruption, may be an option. This retrospective study describes the short and long-term follow-up of a cohort of pediatric patients undergoing partial treatment interruption.

Methods:  The cohort included 15 perinatally HIV-infected children who had failed or were not adherent to one or more PI-containing regimens. Their treatments were simplified to include 2 or 3 RTI. Gender and race distribution was 10 males and 5 females, 3 caucasians, 5 African Americans, and 7 Hispanics. Data collection included clinical information, viral load, and CD4% at baseline (averages of all values within 4 months before partial treatment interruption), and at 24, 48, and 96 weeks while on partial treatment interruption. At 48 and 96 weeks, 15 and 8 subjects, respectively, were evaluable for study. 

Results:  At baseline the median age, CD4%, and absolute T-cell count were 10.9 years (range 4 to 16 years), 25.8 (range 15 to 49.5%) and 596.2 cells/mm³ (range 221.5 to 1804.7 cells/mm³), respectively. All patients had detectable viral load (median 4.66 log₁₀ copies/mL, range 2.92 to 5.22 log₁₀ copies/mL). Over the first 24 weeks 14/15 children maintained a CD4 % within 5% of their baseline. At week 48, 4/15 subjects had a CD4% decrease of ³5% (6.7 to 9.5%), and by week 96, 4/8 patients (including 2/4 evaluated at week 48) had a decline in their CD4% of ³5% (7.5 to 9.5%). Persistent elevation in viral load were not observed. During their partial treatment interruption, no child had CDC-defined clinical disease progression. Statistical comparisons of CD4% and viral load at different time points were not significant. No specific baseline features were identified as lead factors for better outcome or longer stability on a simplified partial treatment interruption regimen.

Conclusions:  No significant immunologic, virologic or clinical deterioration was observed in our cohort of patients undergoing partial treatment interruption. Simplification of therapy by partial treatment interruption may provide a safe, effective and durable option in patients intolerant of PI-based HAART.

Keywords: treatment interruption; antiretroviral therapy; pediatrics