HIV-1 VIRAL LOAD AND CD4 CELL COUNT IN UNTREATED CHILDREN WITH VERTICALLY ACQUIRED ASYMPTOMATIC OR MILD DISEASE

Background: Plasma HIV-1 RNA levels are high in vertically infected in fants. Information in older children is limited, particularly in those who have not received antiretroviral therapy. Objectives: To describe the relationships between HIV-1 RNA, age and CD4 cell count in untrea ted vertically infected children. Design: HIV-1 RNA was measured in 70 children [median age, 3.5 years (range, 0.4-11.9 years); median CD4 c ell count, 881 x 10(6)/l (interquartile range, 576-1347 x 10(6) cells/ l)] enrolled in a randomized placebo-controlled trial comparing immedi ate with deferred zidovudine in asymptomatic or mildly symptomatic ver tically infected children (PENTA-1 trial). Short-term variability was assessed by comparing HIV-1 RNA at -2 and 0 weeks (prior to randomizat ion). The relationship between age and HIV-1 RNA, and CD4 cell count w as analysed using data from all children prior to randomization and se quential samples from 35 remaining on placebo for up to 105 weeks, by fitting mixed linear models. Results: The within-individual SD in vira l load was 0.26 log(10) copies/ml. The median plasma HIV-1 RNA at enro lment was 4.61 log(10) (range, 2.3-6.56 log(10) copies/ml), significan tly higher in children aged less than or equal to 2 years (median, 5.2 3 log(10) copies/ml) than in those aged > 2 years (4.51 log(10) copies /ml; P < 0.0001). Mean HIV-1 RNA fell by 0.38 log(10) copies/ml per ye ar up to 2 years of age, by 0.21 log(10) copies/ml per year from 2 to 4 years of age, and by 0.03 log(10) copies/ml per year from 4 to 6 yea rs of age reaching a nadir of 4.25 log(10) copies/ml at 6 years. Mean log(10) CD4 cell count declined steadily with age and was not signific antly correlated with HIV-1 RNA, although there was some evidence that the rate of log(10) CD4 cell decline was negatively correlated with t he initial rate of HIV-1 RNA decline. No mutations associated with res istance to zidovudine were observed. Conclusions: Age is a key factor in the interpretation of both viral load and CD4 cell count in vertica lly infected children. (C) 1998 Rapid Science Ltd.