Early detection of reverse transcriptase activity in plasma of neonates infected with HIV-1: a comparative analysis with RNA-based and DNA-based testing using polymerase chain reaction.

Plasma viral load from 71 HIV-1-infected neonates was measured by using Amp-RT, an ultrasensitive quantitative reverse transcriptase (RT) assay and by nucleic acid sequence-based amplification (NASBA), an RNA-based quantitative assay. Results were then compared with those obtained from detection of proviral DNA in peripheral blood mononuclear cells (PBMCs) by polymerase chain reaction (PCR) using Turnbull analysis. At 5 days of life, 50% of neonates were positive by Amp-RT, 30% were NASBA positive, and 20% were DNA-PCR positive. Through the first 12 days of life, Amp-RT was more sensitive than either NASBA or DNA-PCR in detecting HIV-1 infection. Amp-RT values correlated well with NASBA RNA values, with an overall Pearson's r = 0.63 (95% confidence interval [CI], 0.40-0.78). In proportional hazards analysis of infants aged 14 to 61 days (N = 31), a one-log increase in RNA-based viral load was associated with a > fivefold risk of disease progression when using the U.S. Centers for Disease Control and Prevention (CDC) clinical Category C (CDC-C) or death as an endpoint (p =.014). Kaplan-Meier analysis of these data found that RNA viral loads were able to predict disease progression using CDC-C/death as an endpoint (p = .013). Early quantitative viral load measurements may assist clinicians in diagnosing HIV-1 infection, stratifying risk of disease progression, and implementing a treatment plan using highly active antiretroviral therapy for infants within the first few weeks of life.