Rhoda S. Sperling

Maternal Viral Load, Zidovudine Treatment, and the Risk of Transmission of Human Immunodeficiency Virus Type 1 from Mother to Infant

BACKGROUND AND METHODS A placebo-controlled trial has shown that treatment with zidovudine reduces the rate at which human immunodeficiency virus type 1 (HIV-1) is transmitted from mother to infant. We present data from that trial showing the number of infected infants at 18 months of age and the relation between the maternal viral load, the risk of HIV-1 transmission, and the efficacy of zidovudine treatment. Viral cultures were obtained, and HIV-1 RNA was measured by two assays in samples of maternal blood obtained at study entry and at delivery. RESULTS In 402 mother-infant pairs, the rate of transmission of HIV-1 was 7.6 percent (95 percent confidence interval, 4.3 to 12.3 percent) with zidovudine treatment and 22.6 percent (95 percent confidence interval, 17.0 to 29.0 percent) with placebo (P<0.001). In the placebo group, a large viral burden at entry or delivery or a positive culture was associated with an increased risk of transmission (the transmission rate was greater than 40 percent in the highest quartile of the RNA level). In both groups, transmission occurred at a wide range of maternal plasma HIV-1 RNA levels. Zidovudine reduced plasma RNA levels somewhat (median reduction, 0.24 log). Zidovudine was effective regardless of the HIV-1 RNA level or the CD4+ count at entry. In the zidovudine group, however, after we adjusted for the base-line HIV-1 RNA level and CD4+ count, the reduction in viral RNA from base line to delivery was not significantly associated with the risk of transmission of HIV-1. CONCLUSIONS A high maternal plasma concentration of virus is a risk factor for the transmission of HIV-1 from an untreated mother to her infant. The reduction in such transmission after zidovudine treatment is only partly explained by the reduction in plasma levels of viral RNA. To prevent HIV-1 transmission, initiating maternal treatment with zidovudine is recommended regardless of the plasma level of HIV-1 RNA or the CD4+ count.

Maternal viral load, zidovudine treatment, and the risk of transmission of human immunodeficiency virus type 1 from mother to infant

BACKGROUND AND METHODS A placebo-controlled trial has shown that treatment with zidovudine reduces the rate at which human immunodeficiency virus type 1 (HIV-1) is transmitted from mother to infant. We present data from that trial showing the number of infected infants at 18 months of age and the relation between the maternal viral load, the risk of HIV-1 transmission, and the efficacy of zidovudine treatment. Viral cultures were obtained, and HIV-1 RNA was measured by two assays in samples of maternal blood obtained at study entry and at delivery. RESULTS In 402 mother-infant pairs, the rate of transmission of HIV-1 was 7.6 percent (95 percent confidence interval, 4.3 to 12.3 percent) with zidovudine treatment and 22.6 percent (95 percent confidence interval, 17.0 to 29.0 percent) with placebo (P<0.001). In the placebo group, a large viral burden at entry or delivery or a positive culture was associated with an increased risk of transmission (the transmission rate was greater than 40 percent in the highest quartile of the RNA level). In both groups, transmission occurred at a wide range of maternal plasma HIV-1 RNA levels. Zidovudine reduced plasma RNA levels somewhat (median reduction, 0.24 log). Zidovudine was effective regardless of the HIV-1 RNA level or the CD4+ count at entry. In the zidovudine group, however, after we adjusted for the base-line HIV-1 RNA level and CD4+ count, the reduction in viral RNA from base line to delivery was not significantly associated with the risk of transmission of HIV-1. CONCLUSIONS A high maternal plasma concentration of virus is a risk factor for the transmission of HIV-1 from an untreated mother to her infant. The reduction in such transmission after zidovudine treatment is only partly explained by the reduction in plasma levels of viral RNA. To prevent HIV-1 transmission, initiating maternal treatment with zidovudine is recommended regardless of the plasma level of HIV-1 RNA or the CD4+ count.

Pharmacokinetics of Nevirapine in Human Immunodeficiency Virus Type 1-Infected Pregnant Women and Their Neonates

The safety, toxicity, and pharmacokinetics of intrapartum and early newborn nevirapine were evaluated in 17 human immunodeficiency virus type 1-infected women in labor and their newborns. No adverse effects of nevirapine were noted in any study mothers or infants. Following maternal dosing with 200 mg during labor, concentrations exceeding 100 ng/mL (10 times the in vitro IC50) were achieved in the newborns. Nevirapine elimination was prolonged in both mothers and infants, with median half-lives ranging from 36.8 to 65.7 h. Administration of 200 mg orally to the mothers in labor and of a single 2-mg/kg oral dose to the infants at 48-72 h after birth maintained serum concentrations in the infants > 100 ng/mL through 7 days of life.

Prenatal Maternal Stress and Cord Blood Innate and Adaptive Cytokine Responses in an Inner-City Cohort

RATIONALE Stress-elicited disruption of immunity begins in utero. OBJECTIVES Associations among prenatal maternal stress and cord blood mononuclear cell (CBMC) cytokine responses were prospectively examined in the Urban Environment and Childhood Asthma Study (n = 557 families). METHODS Prenatal maternal stress included financial hardship, difficult life circumstances, community violence, and neighborhood/block and housing conditions. Factor analysis produced latent variables representing three contexts: individual stressors and ecological-level strains (housing problems and neighborhood problems), which were combined to create a composite cumulative stress indicator. CBMCs were incubated with innate (lipopolysaccharide, polyinosinic-polycytidylic acid, cytosine-phosphate-guanine dinucleotides, peptidoglycan) and adaptive (tetanus, dust mite, cockroach) stimuli, respiratory syncytial virus, phytohemagglutinin, or medium alone. Cytokines were measured using multiplex ELISAs. Using linear regression, associations among increasing cumulative stress and cytokine responses were examined, adjusting for sociodemographic factors, parity, season of birth, maternal asthma and steroid use, and potential pathway variables (prenatal smoking, birth weight for gestational age). MEASUREMENTS AND MAIN RESULTS Mothers were primarily minorities (Black [71%], Latino [19%]) with an income less than

Differential expression of imprinted genes in normal and IUGR human placentas.

15,000 (69%). Mothers with the highest cumulative stress were older and more likely to have asthma and deliver lower birth weight infants. Higher prenatal stress was related to increased IL-8 production after microbial (CpG, PIC, peptidoglycan) stimuli and increased tumor necrosis factor-alpha to microbial stimuli (CpG, PIC). In the adaptive panel, higher stress was associated with increased IL-13 after dust mite stimulation and reduced phytohemagglutinin-induced IFN-gamma. CONCLUSIONS Prenatal stress was associated with altered innate and adaptive immune responses in CBMCs. Stress-induced perinatal immunomodulation may impact the expression of allergic disease in these children.

Safety of the maternal–infant zidovudine regimen utilized in the Pediatric Aids Clinical Trial Group 076 Study

Genomic imprinting refers to silencing of one parental allele in the zygotes of gametes depending upon the parent of origin. Loss of imprinting (LOI) is the gain of function from the silent allele that can have a maximum effect of doubling the gene dosage. LOI may play a significant role in the etiology of intrauterine growth restriction (IUGR). Using placental tissue from 10 normal and 7 IUGR pregnancies, we conducted a systematic survey of the expression of a panel of 74 “putatively” imprinted genes using quantitative RT-PCR. We found that 52/74 (~70%) of the genes were expressed in human placentas. Nine of the 52 (17%) expressed genes were significantly differentially expressed between normal and IUGR placentas; 5 were up-regulated (PHLDA2, ILK2, NNAT, CCDC86, PEG10) and 4 down-regulated (PLAGL1, DHCR24, ZNF331, CDKAL1). We also assessed LOI profile of 14 imprinted genes in 14 normal and 24 IUGR placentas using a functional and sensitive assay developed in our laboratory. Little LOI was observed in any placentas for 5 of the genes (PEG10, PHLDA2, MEG3, EPS15, CD44). With the 149 heterozygosities examined, 40 (26.8%) exhibited LOI > 3%. Some genes exhibited frequent LOI in placentas regardless of the disease status (IGF2, TP73, MEST, SLC22A18, PEG3), while others exhibited LOI only in IUGR placentas (PLAGL1, DLK1, H19, SNRPN). Importantly, there was no correlation between gene expression and LOI profile. Our study suggests that genomic imprinting may play a role in IUGR pathogenesis, but mechanisms other than LOI may contribute to dysregulation of imprinted genes.

Maternal Viral Genotypic Zidovudine Resistance and Infrequent Failure of Zidovudine Therapy to Prevent Perinatal Transmission of Human Immunodeficiency Virus Type 1 in Pediatric AIDS Clinical Trials Group Protocol 076

Objective:To determine the safety of the zidovudine (ZDV) regimen utilized in the Pediatric AIDS Clinical Trial Group (ACTG) 076 study. Design:ACTG 076 was a randomized, double-blind, placebo-controlled trial which demonstrated that a ZDV regimen could prevent mother-to-child HIV-1 transmission. Infants were followed through 18 months of age and women were followed through 6 months postpartum. Methods:Maternal complications, pregnancy outcomes, growth and development of the uninfected infants, and HIV-1 disease progression in the women were monitored prospectively. Results:Maternal therapy was well tolerated. There was no serious pattern of adverse pregnancy outcomes associated with ZDV use. Amongst the ZDV-exposed infants, the only recognized toxicity was anemia within the first 6 weeks of life; the risk for anemia was not associated with premature delivery, duration of maternal treatment, degree of maternal immunosuppression, or maternal anemia. ZDV treatment was not associated with an increased incidence of newborn structural abnormalities. At 18 months of age, uninfected infants did not differ in growth parameters or immune function. No childhood neoplasias were reported in either group. In the women, at 6 months postpartum, there were no differences in clinical, immunologic, or virologic disease progression. Conclusion:There were no identified problems that would alter current recommendations for the routine use of ZDV for the prevention of mother–child HIV-1 transmission.

Selective COX-2 inhibition and cardiovascular effects: a review of the rofecoxib development program

Maternal samples were assessed from 96 women enrolled in Pediatric AIDS Clinical Trials Group protocol 076 to determine the prevalence of human immunodeficiency virus type 1 (HIV-1) genotypic zidovudine resistance at entry, if zidovudine resistance developed on study, and the role of zidovudine resistance in vertical transmission of HIV-1 despite zidovudine therapy. Low and high levels of genotypic resistance were assessed by differential hybridization, oligoligation, or direct sequencing of plasma HIV-1 RNA for codons K70R and T215Y/F. None of the women had high-level genotypic resistance to zidovudine at study entry or delivery. For low-level zidovudine resistance, the 95% confidence intervals were 0.3%-6.8% for baseline prevalence and 0.3%-14% for delivery incidence. Low-level zidovudine resistance, adjusted for plasma viral RNA level at delivery, was not strongly associated with an increase in vertical transmission risk (odds ratio, 4.8; 95% confidence interval, 0.2-131; P = .35).

Lack of tumors in infants with perinatal HIV-1 exposure and fetal/neonatal exposure to zidovudine.

See related Editorials on pages 561 and 563. Cyclo-oxygenase-2 (COX-2) inhibitors appear to alter the balance of vasoactive eicosanoids (prostacyclin and thromboxane) and to suppress the inflammatory mediators implicated in the progression of atherogenesis and ischemic myocardial injury. Neutral, harmful, and beneficial cardiovascular (CV) effects have all been postulated to result from these changes. Investigations conducted with rofecoxib, a selective COX-2 inhibitor, have substantially contributed to our understanding of this scientific area. Rofecoxib had little or no effect on platelet aggregation or platelet-derived thromboxane synthesis but reduced systemic prostacyclin synthesis by 50% to 60%. These findings prompted extensive analyses of CV thrombotic events within the rofecoxib development program. Among 5435 osteoarthritis trial participants, similar rates of CV thrombotic events were reported with rofecoxib, placebo, and comparator, nonselective NSAIDs (ibuprofen, diclofenac, and nabumetone). In the VIGOR gastrointestinal outcomes trial of >8000 patients, naproxen (an NSAID with aspirin-like sustained antiplatelet effects throughout its dosing interval) was associated with a significantly lower risk of CV events than was rofecoxib. A subsequent pooled analysis from 23 studies (including VIGOR) encompassing multiple disease states and including more than 14,000 patient-years at risk also demonstrated that rofecoxib was not associated with excess CV thrombotic events compared with either placebo or nonnaproxen NSAIDs. Again, naproxen appeared to be the outlier, suggesting a cardioprotective benefit of naproxen. Finally, among the predominantly elderly, male population participating in Alzheimer trials, both rofecoxib- and placebo-treated patients had similar rates of CV thrombotic events. The totality of data is not consistent with an increased CV risk among patients taking rofecoxib.

Influence of human immunodeficiency virus infection on pelvic inflammatory disease.

Zidovudine (ZDV) therapy during pregnancy and to the neonate reduced perinatal HIV transmission by nearly 70% in Pediatric AIDS Clinical Trials Group (PACTG) protocol 076. ZDV has been reported as positive in several in vitro carcinogenicity screening tests. We evaluated the short-term risk for tumors in 727 children with known ZDV exposure enrolled into the PACTG 076/219 and the Women and Infants Transmission Study (WITS). ZDV exposure in utero (antepartum) occurred in 97% and 99% of infants in PACTG 076/219 or WITS, respectively. Mean follow-up was 38.3 months with 366.9 person years follow-up for PACTG 076/219 and 14.5 months with 743.7 person years follow-up for WITS. No tumors of any nature were observed; relative risk was 0 (95% confidence interval [CI], 0-17.6). These data are reassuring regarding the short-term lack of tumors for ZDV-exposed infants observed to date. Longitudinal, standardized follow-up for infants with in utero antiretroviral exposure is necessary to assess long-term carcinogenicity.