Low risk of nevirapine resistance mutations in the prevention of mother-to-child transmission of HIV-1: Agence Nationale de Recherches sur le SIDA Ditrame Plus, Abidjan, Cote d'Ivoire

The frequency of resistance mutations was estimated in the cohort of Agence Nationale de Recherches sur le SIDA Ditrame Plus, a study that evaluated the combination of short-course zidovudine (ZDV) plus lamivudine (3TC) and single-dose nevirapine (SD-NVP) followed by 3 days of postpartum ZDV plus 3TC for the prevention of mother-to-child transmission of human immunodeficiency virus type 1 (HIV-1). The frequency with which resistance mutations were detected in mothers at week 4 postpartum was 1.14% (95% confidence interval [CI], 0.03%-6.17%) for NVP and 8.33% (95% CI, 3.66%-15.76%) for 3TC. In multivariate analysis, 3TC resistance was associated with a longer duration of ZDV plus 3TC prepartum prophylaxis (P=.009). This regimen, which is feasible in resource-limited settings, prevents most peripartum HIV-1 transmission and minimizes the development of NVP resistance.     

Maternal plasma viral load, zidovudine and mother-to-child transmission of HIV-1 in Africa: DITRAME ANRS 049a trial

OBJECTIVE: To study the relationship between maternal plasma RNA levels and mother-to-child transmission (MTCT) of HIV-1 in African breastfed children. DESIGN: Nested case-control study within a randomized trial assessing the efficacy of a short maternal zidovudine (ZDV) regimen to reduce MTCT. METHODS: Eligible women received either 300 mg of ZDV twice a day until labour, 600 mg at the beginning of labour and 300 mg twice a day for 7 days post-partum or a placebo. The diagnosis of paediatric HIV-1 infection was based on PCR tests at days 1--8, 45, 90 and 180 then on serology performed at 3 monthl intervals. Plasma HIV-1 RNA was measured at inclusion and on day 8 after delivery for all women who did transmit HIV to their children (cases) using a Chiron branched DNA assay (sensitivity 50 copies/ml) and compared with women who did not transmit (two per case) matched for phase trial, treatment allocation and site. RESULTS: At inclusion, mean log10 viral load was 4.6 among 55 transmitting mothers and 3.7 among 117 non transmitters (P = 0.0001). Among transmitters, the mean difference in log10 viral load between day 8 post-partum and inclusion was -0.13 in the ZDV group (n = 23) versus 0.27 in the placebo group (n = 32; P = 0.01); among non transmitters it was -0.35 for the ZDV group (n = 47) versus 0.27 in the placebo group (n = 70; P < 10(-4)). In multivariate logistic regression analysis, odds ratios for MTCT were 8.7 (95% confidence interval, 3.7-20.6) for 1 log(10) increase of maternal RNA at inclusion and 4.2 (95% confidence interval, 1.7--10.3) for 1 log(10) increase difference from inclusion to day 8 post-partum. CONCLUSION: High maternal viral load at inclusion strongly predicts MTCT of HIV in Africa. A short ZDV treatment regimen decreases significantly maternal viral load from its pretreatment level.     

Incorporation of zidovudine into leukocyte DNA from HIV-1-positive adults and pregnant women, and cord blood from infants exposed in utero.

OBJECTIVE: The nucleoside analog 3'-azido-3'-deoxythymidine (ZDV) has widespread clinical use but also is carcinogenic in newborn mice exposed to the drug in utero and becomes incorporated into newborn mouse DNA. This pilot study was designed to determine ZDV incorporation into human blood cell DNA from adults and newborn infants. DESIGN: In this prospective cohort study, peripheral blood mononuclear cells (PBMC) were obtained from 28 non-pregnant adults and 12 pregnant women given ZDV therapy, six non-pregnant adults with no exposure to ZDV, and six non-pregnant adults who last received ZDV > or = 6 months previously. In addition, cord blood leukocytes were obtained from 22 infants of HIV-1-positive, ZDV-exposed women and from 12 infants unexposed to ZDV. There were 11 mother-infant pairs involving HIV-1 -positive women. METHODS: DNA was extracted from PBMC obtained from non-pregnant HIV-1-positive adults taking ZDV, pregnant HIV-1-positive women given ZDV during pregnancy, and from adults not taking ZDV. Cord blood leukocytes were examined from infants exposed to ZDV in utero and from unexposed controls. DNA samples were assayed for ZDV incorporation by anti-ZDV radioimmunoassay (RIA). RESULTS: The majority (76%) of samples from ZDV-exposed individuals, pregnant women (8 of 12), non-pregnant adults (24 of 28), or infants at delivery (15 of 22), had detectable ZDV-DNA levels. The range of positive values for ZDV-treated adults and infants was 25-544 and 22-452 molecules ZDV/10(6) nucleotides, respectively. Analysis of 11 mother-infant pairs showed variable ZDV-DNA incorporation in both, with no correlation by pair or by duration of drug treatment during pregnancy. Two of the 24 samples from individuals designated as controls were positive by anti-ZDV RIA. The 20-fold range for ZDV-DNA values in both adults and infants suggested large interindividual differences in ZDV phosphorylation. CONCLUSIONS: Incorporation of ZDV into DNA was detected in most of the samples from ZDV-exposed adults and infants. Therefore, the biologic significance of ZDV-DNA damage and potential subsequent events, such as mutagenicity, should be     

A randomized trial of two postexposure prophylaxis regimens to reduce mother-to-child HIV-1 transmission in infants of untreated mothers

BACKGROUND: Single-dose nevirapine (NVP) prophylaxis to mother and infant is widely used in resource-constrained settings for preventing mother-to-child transmission (MTCT) of HIV-1. Where women do not access antenatal care or HIV testing, postexposure prophylaxis to the infant may be an important preventative strategy. METHODS: This multicentre, randomized, open-label clinical trial (October 2000 to September 2002) in South Africa compared single-dose NVP with 6 weeks of zidovudine (ZDV), commenced within 24 h of delivery among 1051 infants whose mothers had no prior antiretroviral therapy. HIV-1 infection rates were ascertained at birth, and at 6 and 12 weeks of age. Kaplan-Meier survival methods were used to estimate HIV-1 infection rates in an intention-to-treat analysis. RESULTS: Overall, 6 week and 12 week MTCT probability was 12.8% [95% confidence interval (CI),10.5-15.0] and 16.3% (95% CI,13.4-19.2), respectively. At 12 weeks, among infants who were not infected at birth, 24 (7.9%) infections occurred in the NVP arm and 41 (13.1%) in the ZDV arm (log rank P = 0.06). Using multivariate analysis, factors associated with infection following birth were ZDV use [odds ratio (OR), 1.8; 95% CI,1.1-3.2; P = 0.032), maternal CD4 cell count < 500 x 10(6) cells/l (OR, 2.5; 95% CI,1.3-5.0; P = 0.007), maternal viral load > 50 000 copies/ml (OR, 3.6; 95% CI,2.0-6.2; P < 0.0001) and breastfeeding (OR, 2.2; 95% CI,1.3-3.8; P = 0.006). CONCLUSION: A single-dose of NVP given to infants offers protection against HIV-1 infection and should be a strategy used in infants of mothers with untreated HIV infection.     

Breast milk HIV-1 suppression and decreased transmission: a randomized trial comparing HIVNET 012 nevirapine versus short-course zidovudine

OBJECTIVE: To compare the effect of perinatal regimens of short-course nevirapine (HIVNET 012) and zidovudine [Thai-Centers for Disease Control and Prevention (CDC) regimen] on breast milk viral shedding and perinatal transmission during the first 6 weeks postpartum in a randomized clinical trial. DESIGN: Randomized clinical trial. METHODS: Pregnant HIV-1 seropositive women in Nairobi, Kenya who planned to breastfeed were randomized to HIVNET 012 or Thai-CDC regimens. Two to four breast milk samples were collected each week between delivery and 6 weeks postpartum. Breast milk HIV-1 RNA was quantified using the Gen-Probe TMA assay. Infants were tested for HIV-1 DNA at birth and 6 weeks. RESULTS: From March to October 2003, 76 women were enrolled and 795 breast milk samples were collected from 60 women who were randomized and followed after delivery. Between 3 and 21 days postpartum, nevirapine was associated with significantly greater suppression of breast milk log10 HIV-1 RNA: days 3 to 7 (1.98 versus 2.42, P = 0.1); days 8 to 14 (1.78 versus 2.48, P = 0.005); days 15 to 21 (1.90 versus 2.97, P = 0.003). At 6 weeks, the HIV-1 perinatal transmission rate was significantly lower among those who took nevirapine than zidovudine (6.8% versus 30.3%, P = 0.02). CONCLUSIONS: Compared to a peripartum zidovudine regimen, nevirapine was significantly more likely to decrease HIV-1 RNA in breast milk during the first week and through the third week postpartum following single-dose administration, and corresponded with decreased transmission risk at 6 weeks. Sustained breast milk HIV-1 suppression may contribute to the ability of nevirapine to decrease perinatal transmission of HIV-1.     

Efavirenz-based combination antiretroviral therapy after peripartum single-dose nevirapine

Single-dose nevirapine (sdNVP) reduces mother-to-child HIV transmission, but induces NVP resistance and subsequent NVP-based combination antiretroviral therapy (cART) may fail. Some resistance mutations affect NVP more than efavirenz (EFV). We evaluated virological suppression of EFV-based cART in women after sdNVP. A retrospective analysis matched 107 women who had received sdNVP within the 24 months before cART (cases) with women who had never received sdNVP (controls). By total cohort (intention-to-continue treatment) at week 96, 65% of cases and 73% of controls had a viral load (VL) <400 copies/mL and 63% of cases and 64% of controls had VL <25 copies/mL. At weeks 48 and 96, women starting cART less than six months after sdNVP (n = 20) had VL <400 copies/mL of 90% and 75%, respectively compared with 90% and 70%, respectively, for controls. Overall 172 (80%) women reached week 96. EFV-based cART, in field conditions, was effective for women after sdNVP, even within six months of sdNVP.     

Maternal 12-month response to antiretroviral therapy following prevention of mother-to-child transmission of HIV type 1, Ivory Coast, 2003-2006.

OBJECTIVE: Our aim was to study the response to antiretroviral treatment among women exposed to single-dose nevirapine (NVP) and/or short-course zidovudine (ZDV; with or without lamivudine [3TC]) for the prevention of mother-to-child transmission of human immunodeficiency virus (HIV) infection. METHODS: All HIV type 1-infected women who initiated antiretroviral treatment with stavudine or ZDV, 3TC, and NVP or efavirenz were eligible for the MTCT-Plus program in Abidjan, Ivory Coast. Exposed women had received either single-dose NVP alone or short-course ZDV (with or without 3TC) plus single-dose NVP during previous pregnancy. Genotypic resistance testing was performed at week 4 after delivery. Virologic failure was defined as a plasma HIV RNA level >500 copies/mL 12 months after initiation of antiretroviral treatment. RESULTS: Among 247 women who received antiretroviral treatment, 109 (44%) were unexposed; 81 had received short-course ZDV with 3TC, as well as single-dose NVP; 5 had received short-course ZDV plus 3TC; 50 had received short-course ZDV plus single-dose NVP; and 2 had received single-dose NVP alone. No ZDV mutation was detected in the 115 women whose specimens were available for genotypic testing; 11 (15.1%) of 73 women with 3TC exposure who were tested after delivery had 3TC resistance mutations. Three (4.3%) of 69 women exposed to short-course ZDV and 3TC plus single-dose NVP and 16 (38.1%) of 42 women exposed to short-course ZDV plus single-dose NVP had NVP resistance mutations. Antiretroviral treatment was initiated a median of 21 months after the intervention to prevent mother-to-child HIV transmission (median CD4(+) T lymphocyte count, 188 cells/mm(3)). Month 12 virologic failure was identified in 42 (19.2%) of 219 women for whom data were available, and multivariate analysis revealed that it was associated with poor adherence to treatment (adjusted odds ratio [aOR], 12.7; 95% confidence interval [CI], 3.0-53.9), postpartum 3TC resistance mutations (aOR, 6.9; 95% CI, 1.1-42.9), and a baseline CD4(+) T lymphocyte count <200 cells/mm(3) (aOR, 0.3; 95% CI, 0.2-0.8). NVP resistance was not associated with virological failure (aOR, 1.8; 95% CI, 0.5-6.5). CONCLUSIONS: Our study found that poor adherence and 3TC resistance acquired after the intervention to prevent mother-to-child transmission of HIV infection were associated with virologic failure in women who initiated antiretroviral treatment.     

Effect of immediate neonatal zidovudine on prevention of vertical transmission of human immunodeficiency virus type 1.

OBJECTIVE: To describe the effects of various short zidovudine (ZDV) prophylactic regimens on vertical transmission of human immunodeficiency virus type 1 (HIV-I) infection, especially the effect of immediate neonatal ZDV prophylaxis. MATERIALS AND METHODS: The study included children of HIV-1-infected mothers who were born at a teaching hospital in Bangkok. The ZDV prophylaxis regimens varied by time periods that included: (1) no ZDV (1991-1996); (2) antenatal oral ZDV, 250 mg given twice a day starting at 34 to 36 weeks gestation and continued until labor (1995-1998); (3) antenatal oral ZDV plus immediate neonatal oral ZDV, 6 mg/0.6 mL/dose started within the first 2 hours after birth and continued at 6-hour intervals for 4 to 6 weeks (1997-1998); and (4) intrapartum intravenous ZDV given in addition to regimen 3 (1998-1999). Neonatal ZDV was administered within 2 hours after birth in 95% of the neonates. RESULTS: In a cohort of 136 children born at least 9 months before the analysis date, the HIV-1 vertical infection rates were: (1) no ZDV, 11 of 48 (22.9%, 95% confidence interval [CI] = 12.0-37.3); (2) late antenatal ZDV, 10 of 47 (21.3%, 95% CI = 10.7-35.7); (3) late antenatal ZDV plus immediate neonatal ZDV, 0 of 28 (0%, 95% CI = 0-12.3); (4) late antenatal, intrapartum intravenous ZDV, plus immediate neonatal ZDV, 0 of 13 (0%, 95% CI = 0-24.7). An estimated 0% (95% CI = 0-8.6) of the infants who received immediate neonatal ZDV with or without intrapartum ZDV were infected, as compared with 22.1% (95% CI = 14.2-31.8 ) of those who received no ZDV or only late antenatal ZDV (P < 0.001). CONCLUSIONS: The results of this study suggests high protective effect of immediate administration of neonatal ZDV. Perinatal components of antiretroviral prophylaxis provided the best results for protecting against vertical HIV-1 transmission.     

Randomized study of didanosine monotherapy and combination therapy with zidovudine in hemophilic and nonhemophilic subjects with asymptomatic human immunodeficiency virus-1 infection. AIDS Clinical Trial Groups

To evaluate the safety and efficacy of didanosine (ddl) monotherapy and three different combinations of zidovudine (ZDV) and ddl in asymptomatic human immunodeficiency virus-1 (HIV-1) infection, we conducted an open-label, phase I/II study in 126 asymptomatic HIV-1- infected hemophilic and nonhemophilic subjects with a CD4 count of 200 to 500/mm3 stratified for prior zidovudine treatment and baseline CD4 count. Study arms included arm A, low-dose combination (ZDV 150 mg and ddl 134 mg, daily); arm B, moderate-dose combination (ZDV 300 mg and ddI 334 mg, daily); arm C, high-dose combination (ZDV 600 mg and ddl 500 mg, daily), and arm D, ddl monotherapy (ddl 500 mg, daily). Earlier, more frequent hepatotoxicity was experienced by hemophilic subjects (P = .008), but there were no differences in toxicity between treatment arms (P = .51), nor were there any differences in the rate of development of clinical endpoints by treatment (P = .41). Smaller median CD4 increases occurred over the first 12 weeks for arms A and D, 44/mm3 and 42/mm3, than arms B and C, 105/mm3 and 114/mm3, respectively, (P = .015). Hemophilia status (P = .0004) and prior ZDV experience (P = .044) independently predicted weaker CD4 responses during the first 12 weeks of treatment. Using a regression model and adjusting for hemophilia status, prior ZDV treatment, and baseline CD4, there was a significant reduction in quantitative viral load from baseline by week 12 for all treatment arms combined (P = .0001), with significantly lower median percent reduction for arm A (56.3%) than arms B, C, and D (94.6%, 98.5%, and 91.9%, respectively, P = .015). Although greater hepatoxicity and weaker CD4 responses occur in hemophilic subjects, didanosine monotherapy and combination therapy with zidovudine are safe and effective in asymptomatic HIV-1-infected patients.     

Cervicovaginal HIV-1 and herpes simplex virus type 2 shedding during genital ulcer disease episodes

OBJECTIVE: To investigate correlates of herpes simplex virus type 2 (HSV-2) DNA and HIV-1 RNA among women with genital ulcer disease (GUD). DESIGN: Baseline data from a randomized placebo-controlled trial of episodic herpes treatment in Ghana and the Central African Republic. METHODS: GUD aetiology was determined by polymerase chain reaction (PCR) from a lesional swab. Real-time PCR was used to quantify HIV-1 RNA, and HSV-2 DNA in cervicovaginal lavages (CVL) and HIV-1 RNA in plasma. Genital infection was defined as the presence of virus in the lesion or CVL. RESULTS: Of 441 women enrolled, 79.0% were HSV-2 seropositive, 46.6% were HIV-1 seropositive, and 50.0% had an HSV-2 ulcer. Among 180 HSV-2/HIV-1 co-infected women, cervicovaginal HIV-1 RNA was detected more frequently in women with HSV-2 ulcers (67.9%) or cervicovaginal HSV-2 DNA only (72.3%) compared with women without genital HSV-2 infection (42.4%) (P = 0.004). Women with genital HSV-2 infection had higher median cervicovaginal HIV-1-RNA loads (3.14 log10 copies/mL versus 2.10 log10 copies/mL; P = 0.003), higher plasma HIV-1-RNA loads (median 5.10 versus 4.65 log10 copies/mL; P = 0.07), and lower median CD4 cell counts) (198 versus 409 cells/mm, P = 0.03). Cervicovaginal HIV-1 RNA and HSV-2 DNA were significantly correlated after adjusting for plasma HIV-1 RNA and CD4 cell counts (P < 0.001) and a 10-fold increase in cervicovaginal HSV-2 DNA was associated with a 1.7-fold increase in plasma HIV-1 RNA (P = 0.003). CONCLUSION: Genital HSV-2 infection is associated with increased cervicovaginal and plasma HIV-1 RNA among co-infected women with genital ulcers, independently of the level of immunodeficiency, highlighting the close interaction between these two viruses and the role of HSV-2 as a co-factor for the sexual transmission of HIV-1.     

Oral zidovudine during labor to prevent perinatal HIV transmission, Bangkok: tolerance and zidovudine concentration in cord blood. Bangkok Collaborative Perinatal HIV Transmission Study Group

OBJECTIVES: To evaluate tolerance for the oral administration of zidovudine (ZDV) during labor and measure the resulting ZDV concentrations in umbilical cord blood. DESIGN: A cross-sectional study of women in a placebo-controlled trial of short-course ZDV (twice a day from 36 weeks' gestation until labor and every 3 h during labor) to prevent perinatal HIV transmission in Bangkok. METHODS: Umbilical cord blood was collected. Sixty control specimens and specimens from 372 women (182 in the ZDV group, 190 in the placebo group) were tested for ZDV by radioimmunoassay (lower detection limit < 1 ng/ml). RESULTS: All women in the ZDV group took one or more labor dose, 170 (93%) took their last dose within 3 h of delivery, and only five (3%) experienced nausea or vomiting, a proportion similar to the placebo group. The median concentration of ZDV in the cord blood in the ZDV group was 252 ng/ml (range, < 1-1133 ng/ml); 31 (17%) specimens were less than 130 ng/ml (0.5 microM), the concentration thought to be active against HIV in vitro. Median concentrations were 189 ng/ml in specimens from women taking one or two labor doses, 290 ng/ml in those taking three or four doses, and 293 ng/ml in those taking more than four doses (P < 0.01). The ZDV concentration was not associated with time since the last dose, body weight, or perinatal transmission. CONCLUSION: Oral intrapartum ZDV was feasible and well tolerated. Most ZDV concentrations in the cord blood after oral dosing during labor were at therapeutic concentrations but were lower than those reported after continuous intravenous administration. Although concentrations were not associated with perinatal transmission, these data do not exclude the possibility that intrapartum and neonatal chemoprophylaxis is effective.     

The reverse transcriptase 67N 70R 215Y genotype is the predominant TAM pathway associated with virologic failure among HIV type 1C-infected adults treated with ZDV/ddI-containing HAART in southern Africa

HIV-1C has become the dominant HIV-1 subtype in the global AIDS epidemic. Historically, the evolution of drug-resistant mutations was characterized primarily among antiretroviral (ARV)-treated HIV-1B infections. Whereas the non-B viruses are susceptible to the currently used ARVs, some differences between HIV-1 subtypes in response to ARV regimens have been reported. We analyzed the profile of ARV-associated mutations in HIV-1C infection treated with ZDV/ddI-containing regimens in an open-label, randomized 3 x 2 x 2 factorial study comparing ZDV/3TC vs. ZDV/ddI vs. d4T/3TC and EFV vs. NVP regimens in drug-naive adults in Botswana. The overall rate of virologic failure in the ZDV/ddI-containing arms was 14%. We addressed the development of NRTI-associated mutations in 23 virologically failed patients in the ZDV/ddI-containing arms. The 67N 70R 215Y genotype with wild-type amino acids at codon positions 41 and 210 was a dominant pattern of NRTI-associated mutations at the time of virologic failure. The mutation T215Y was the first step in the evolution of the 67N 70R 215Y genotype and was followed by mutations K70R and D67N. Representing a mixture of TAM-1 (41L/210W/215Y) and TAM-2 (67N/70R/215F /219Q) pathways, the 67N 70R 215Y genotype with wild-type amino acids at codon positions 41, 210, and 219 is a unique TAM pathway that is rarely seen in HIV-1B infection. Although limited by relatively small numbers, our data suggest that the 67N 70R 215Y genotype may be the HIV-1C-specific response to the first-line ZDV/ddI-containing regimen at the time of virologic failure. The presence of the 67N 70R 215Y genotype with wild-type amino acids at codon positions 41, 210, and 219 in HIV-1C infection suggests that the evolution of ARV-associated mutations and TAM pathways might be unique in non-B HIV-1 subtypes treated with particular ARV regimens.     

Effect of perinatal zidovudine prophylaxis on the evolution of cell-free HIV-1 RNA in breast milk and on postnatal transmission

Perinatal zidovudine (ZDV) prophylaxis decreases rates of perinatal transmission of human immunodeficiency virus type 1 (HIV-1). Its relationship with levels of HIV-1 RNA in breast milk and postnatal transmission in breast-fed African children is unknown. At day 8 after delivery, levels of HIV-1 RNA in breast milk from 28 women who transmitted HIV-1 (Ts) postnatally and from 130 women who did not transmit HIV-1 (NTs) were lower for women receiving ZDV than for women receiving placebo. Levels of HIV-1 RNA in breast milk remained low over time in NTs but increased by 8-16-fold in Ts treated with ZDV from baseline to days 45/90 after delivery. Levels of HIV-1 RNA in breast milk at day 8 after delivery and the increase in levels of HIV-1 RNA in breast milk from day 8 to days 45/90 after delivery were independently associated with postnatal transmission. An increase in the levels of HIV-1 RNA in breast milk from day 8 to 45 after delivery was associated with maternal ZDV prophylaxis. The rebound in levels of HIV-1 RNA in breast milk after discontinuation of maternal antiretrovirals needs to be further explored--it may justify prolonging antiretroviral prophylaxis during the entire breast-feeding period.