OBJECTIVE. In this study, we tested the hypothesis that the CD4+/CD8+ T cell ratio could predict HIV infection status in HIV-exposed infants. METHODS. CD4+/CD8+ T cell ratios were determined from data for live-born singleton infants who had been prospectively enrolled in the Women and Infants Transmission Study. Data for 2208 infants with known HIV infection status (179 HIV-infected and 2029 uninfected infants) were analyzed. RESULTS. Receiver operating characteristic curves indicated that the CD4+/CD8+ T cell ratio performed better than the proportion of CD4+ T cells for diagnosis of HIV infection as early as 2 months of age, and this relationship was unaffected by adjustment for maternal race/ethnicity, infant birth weight, gestational age, and gender. At 4 months of age, 90% specificity for HIV diagnosis was associated with 60% sensitivity. For ease of use, graphical estimates based on cubic splines for the time-dependent parameters in a Box-Cox transformation (L), the median (M), and the coefficient of variation (S) were used to create LMS centile curves to show the sensitivity and specificity of CD4+/CD8+ T cell ratios in HIV-infected and uninfected infants until 12 months of age. At 6 months of age, a simplified equation that incorporated sequential CD4+/CD8+ T cell ratios and hematocrit values resulted in improved receiver operating characteristic curves, with 94% positive predictive value and 98% negative predictive value. The positive and negative predictive values remained above 90% in simulated infant populations over a wide range of HIV infection prevalence values. CONCLUSIONS. In the absence of virological diagnosis, a presumptive diagnosis of HIV infection status can be made on the basis of CD4+/CD8+ T cell ratios in HIV-1-exposed infants after 2 months of age; sensitivity and specificity can be improved at 6 months by using a discriminant analysis equation.
OBJECTIVE. We examined the effect of HIV, in combination with other important health and social factors, on the development of cognitive abilities of children perinatally exposed to HIV. METHODS. Serial cognitive assessments were performed for 117 children who were infected vertically and 422 children who were exposed to but not infected with HIV, in a multicenter, natural history, longitudinal study. Repeated-measures analyses were used to evaluate the neurocognitive development of children between the ages of 3 and 7 years, as measured by the McCarthy Scales of Children’s Abilities (MSCA). RESULTS. Children with HIV infection and class C status scored significantly lower in all domains of cognitive development, across all time points, than did those who were HIV infected without an AIDS-defining illness and those who were HIV exposed but not infected. There were no significant differences between the 2 latter groups in General Cognitive Index or specific domain scores. Rates of change in cognitive development were comparable (parallel) among all 3 groups over a period of 4 years. Factors that were associated consistently and significantly with lower mean scores were HIV status, number of times an examination had been completed previously, primary language, maternal education, and gender. No factors were related to rate of change of any mean domain score. CONCLUSIONS. An early AIDS-defining illness increased the risk of chronic static encephalopathy during the preschool and early school age years. Children with HIV infection but no class C event performed as well as noninfected children in measures of general cognitive ability. No significantly different profiles of strengths and weaknesses for verbal, perceptual-performance, quantitative, or memory functioning were observed among children with or without HIV infection. A number of factors were found to have significant effects on the mean scores of children in all 3 groups; however, they were not related to the rate at which learning occurred.
Objective. To examine the association of maternal hard drug use (injection drugs, cocaine, and opiates) on lymphocyte subsets and clinical morbidity in uninfected infants who are born to human immunodeficiency virus-infected mothers who were enrolled in the Women and Infants Transmission Study (1990–2000). Methods. Maternal hard drug use was identified by self-report and/or urine toxicology. Infant evaluations occurred at birth and at 1, 2, 4, 6, 9, 12, 18, and 24 months of age. Results. A total of 401 (28%) of the 1436 uninfected infants were born to drug-using mothers. Maternal CD4 lymphocyte percentage and RNA at delivery were not significantly different between drug users and nonusers. Infants who were born to drug-using mothers had lower mean gestational age (37.8 vs 38.5 weeks) and birth weight (2.9 vs 3.1 kg). Infants with intrauterine drug exposure had lower CD4 lymphocyte percentage over the first 4 months of life after adjusting for covariates and higher natural killer lymphocyte percentage. When the analysis was stratified by time period of entry, the incidence of clinical events was not different between infants who were born to drug users versus nonusers. Conclusion. Maternal hard drug use is associated with immunologic changes in infants early in life, although these changes did not seem to be associated with increased risk of infections.
Objective. To examine the frequency, timing, and factors associated with abnormal cognitive and motor development during the first 30 months of life in infants born to women infected with human immunodeficiency virus type 1 (HIV-1). Methods. Serial neurodevelopmental assessment was performed with 595 infants born to women infected with HIV-1 in a multicenter, prospective, natural history cohort study. Survival analysis methods were used to evaluate 6 outcome events related to abnormal cognitive and motor growth (time to confirmed drop of 1 SD, time to first score <69, and time to confirmed drop of 2 SD) in Bayley Scales of Infant Development Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI) scores among infected (n = 114) and uninfected (n = 481) infants. Proportional hazards modeling was used to evaluate the effects of HIV infection status, prematurity, prenatal exposure to illicit drugs, maternal educational attainment, and primary language. Results. HIV-1 infection was significantly associated with increased risk for all outcome events related to abnormal mental and motor growth. Differences between infected and uninfected infants were apparent by 4 months of age. Prematurity was associated with increased risk for MDI <69 and PDI <69. Maternal education of <9 completed years was associated with increased risk for MDI <69. Neither prenatal exposure to illicit drugs nor primary language other than English was associated with abnormal development. Conclusion. A significant proportion of infants with HIV-1 infection show early and marked cognitive and motor delays or declines that may be important early indicators of HIV disease progression. These abnormalities are independent of other risk factors for developmental delay.
Background. Infants with perinatally acquired human immunodeficiency virus type 1 (HIV-1) infection have widely variable courses. Previous studies showed that a number of maternal and infant factors, when analyzed separately, are associated with infant HIV-1 disease progression. In this study, clincal, virologic, and immunologic characteristics in the mothers and infants were examined together to determine the predictors of disease progression by 18 months of age and the associations with rapid progression during the first 6 months of life. Methods. One hundred twenty-two HIV-1-infected women whose infants were HIV-1 infected were identified from the Women and Infants Transmission Study (WITS) cohort. WITS is a longitudinal natural history study of perinatal HIV-1 infection carried out in 6 sites in the continental United States and in Puerto Rico. The women were enrolled during pregnancy and their infants were enrolled at the time of delivery and followed prospectively by a standardized protocol. Virologic and immunologic studies were performed in laboratories certified by National Institutes of Health-sponsored quality assurance programs. Maternal factors in pregnancy were used as potential predictors of infant disease progression (progression to Centers for Disease Control and Prevention [CDC] Clinical Class C disease or death by 18 months of age) or as correlates of progression at <6 months of age. Infant factors defined during the first 6 months of life were used as potential predictors of progression during 6 to 18 months of age and as correlates of progression at <6 months of age. Results. Progression by 18 months of age occurred in 32% of infants and by 6 months of age in 15%. Maternal characteristics that, by univariate analysis, were significant predictors of infant disease progression by 18 months of age were elevated viral load, depressed CD4+%, and depressed vitamin A. CD8+%, CD8+ activation markers, zidovudine (ZDV) use, hard drug use, and gestational age at delivery were not. When examined in a combined multivariate analysis of maternal characteristics, only vitamin A concentration independently predicted infant progression. Infant characteristics during the first 6 months of life that, by univariate analysis, were associated with disease progression included elevated mean viral load at 1 to 6 months of age, depressed CD4+%, CDC Clinical Disease Category B, and growth delay. Early HIV-1 culture positivity (<48 hours), CD8+%, CD8+ activation markers, and ZDV use during the first month of life did not predict progression. Multivariate analysis of infant characteristics showed that the only independent predictors were progression to CDC Category B by 6 months of age (odds ratio [OR], 5.80) and mean viral load from 1 to 6 months of age (OR, 1.99). The final combined maternal and infant analysis included the significant maternal and infant characteristics in a multivariate analysis. It showed that factors independently predicting infant progression by 18 months of age were progression to CDC Category B by 6 months of age (OR, 5.80) and elevated mean HIV-1 RNA copy number at 1 to 6 months of age (OR, 1.99). The characteristics associated with rapid progression to CDC Category C disease or death by 6 months of age were also examined. The only maternal characteristic associated with progression by 6 months in multivariate analysis was low maternal CD4+%. The infant characteristics associated with progression by 6 months of age in multivariate analysis were depressed mean CD4+% from birth through 2 months and the presence of lymphadenopathy, hepatomegaly, or splenomegaly by 3 months. Infant ZDV use was not assocciated with rapid progression. Conclusion. The strongest predictors of progression by 18 months are the presence of moderate clinical symptoms and elevated RNA copy number in the infants in the first 6 months of life. In contrast, progression by 6 months is associated with maternal and infant immune suppression, and the presence of infant clinical symptoms. The difference suggests that the key pathogenetic mechanisms responsible for progression may vary with age. These observations help provide direction for future pathogenesis research and assist in clinical care.