Immunologic function and virologic suppression among children with perinatally acquired HIV infection on highly active antiretroviral therapy

Background: The goal of highly active antiretroviral therapy (HAART) has been to stabilize and reconstitute immune function and suppress viral replication to the greatest degree possible. Suppression of HIV viral replication has been associated with improved long-term and short-term prognosis. Limited data are available on the level of virologic suppression and immune function of pediatric patients followed in clinical settings in the HAART era. Objective: The objective of this study was to assess the level of virologic suppression and immune function in a cohort of children with perinatally acquired HIV infection followed at dedicated HIV specialty care sites. Research Design: This study comprised a cohort study of HIV-infected children and adolescents. Subjects: Study subjects consisted of 263 HIV-positive children (≤17 years old), on HAART, with at least one outpatient visit and CD4 test recorded in 2001 seen at 4 U.S. HIV primary pediatrics and specialty care sites (2 eastern, 1 southern, and 1 western). Measures: Measures consisted of all plasma HIV-1 RNA levels ≤400 during calendar year 2001. Results: Two hundred sixty-three patients received HIV-related treatment during 2001, with a mean age of 8.5 years. Sixty-eight percent were black, 54% were females, and the majority (85%) was insured by Medicaid. A total of 28.6% had a class C AIDS diagnosis. A total of 23.5% and 34% of patients maintained viral suppression at <50 copies per milliliter (cpm), or <400 cpm, respectively, for the calendar year; 32.5% and 38.8%, respectively, fulfilled the criteria if one "blip" to <5000 cpm was allowed. Forty-eight percent maintained all viral loads <5000 cpm, and 74.9% overall had HIV-1 RNAs ≤15,000 cpm. Eighty-seven percent of patients had CD4% >25; only 4.2% had CD4 <15%. Overall, 12.5% of patients had either CD4% <15 or severely decreased absolute CD4 counts (adjusted for age). A total of 4.6% of patients had HIV-1 RNAs > 100,000 cpm and severe immunosuppression. Patients who were less likely to achieve virologic suppression to <400 cpm included those with CD4 count <200 cells/mm³ (odds ratio [OR], 0.06; 95% confidence interval [CI], 0.007-0.46), those with AIDS (OR, 0.5; 95% CI, 0.28-0.94), and those with moderate (OR, 0.42; 95% CI, 0.22-0.79), or severe immunologic suppression (OR, 0.14; 95% CI, 0.046-0.43) based on CD4%. Conclusion: In this multisite, pediatric cohort, the rate of near-complete virologic suppression (<50 or <400 cpm) was low. However, the majority of patients have near-normal CD4 counts and viral loads <15,000 cpm. Follow up will be critical to assess the implications of ongoing low-level viral replication with near-normal CD4 values.