Benefits and Risks of Antiretroviral Therapy for Perinatal HIV Prevention.

BACKGROUND: Randomized-trial data on the risks and benefits of antiretroviral therapy (ART) as compared with zidovudine and single-dose nevirapine to prevent transmission of the human immunodeficiency virus (HIV) in HIV-infected pregnant women with high CD4 counts are lacking. METHODS: We randomly assigned HIV-infected women at 14 or more weeks of gestation with CD4 counts of at least 350 cells per cubic millimeter to zidovudine and single-dose nevirapine plus a 1-to-2-week postpartum "tail" of tenofovir and emtricitabine (zidovudine alone); zidovudine, lamivudine, and lopinavir-ritonavir (zidovudine-based ART); or tenofovir, emtricitabine, and lopinavir-ritonavir (tenofovir-based ART). The primary outcomes were HIV transmission at 1 week of age in the infant and maternal and infant safety. RESULTS: The median CD4 count was 530 cells per cubic millimeter among 3490 primarily black African HIV-infected women enrolled at a median of 26 weeks of gestation (interquartile range, 21 to 30). The rate of transmission was significantly lower with ART than with zidovudine alone (0.5% in the combined ART groups vs. 1.8%; difference, -1.3 percentage points; repeated confidence interval, -2.1 to -0.4). However, the rate of maternal grade 2 to 4 adverse events was significantly higher with zidovudine-based ART than with zidovudine alone (21.1% vs. 17.3%, P=0.008), and the rate of grade 2 to 4 abnormal blood chemical values was higher with tenofovir-based ART than with zidovudine alone (2.9% vs. 0.8%, P=0.03). Adverse events did not differ significantly between the ART groups (P>0.99). A birth weight of less than 2500 g was more frequent with zidovudine-based ART than with zidovudine alone (23.0% vs. 12.0%, P<0.001) and was more frequent with tenofovir-based ART than with zidovudine alone (16.9% vs. 8.9%, P=0.004); preterm delivery before 37 weeks was more frequent with zidovudine-based ART than with zidovudine alone (20.5% vs. 13.1%, P<0.001). Tenofovir-based ART was associated with higher rates than zidovudine-based ART of very preterm delivery before 34 weeks (6.0% vs. 2.6%, P=0.04) and early infant death (4.4% vs. 0.6%, P=0.001), but there were no significant differences between tenofovir-based ART and zidovudine alone (P=0.10 and P=0.43). The rate of HIV-free survival was highest among infants whose mothers received zidovudine-based ART. CONCLUSIONS: Antenatal ART resulted in significantly lower rates of early HIV transmission than zidovudine alone but a higher risk of adverse maternal and neonatal outcomes. (Funded by the National Institutes of Health; PROMISE ClinicalTrials.gov numbers, NCT01061151 and NCT01253538 .).

Pharmacokinetic Modeling of Lamivudine and Zidovudine Triphosphates Predicts Differential Pharmacokinetics in Seminal Mononuclear Cells and Peripheral Blood Mononuclear Cells.

The male genital tract is a potential site of viral persistence. Therefore, adequate concentrations of antiretrovirals are required to eliminate HIV replication in the genital tract. Despite higher zidovudine (ZDV) and lamivudine (3TC) concentrations in seminal plasma (SP) than in blood plasma (BP) (SP/BP drug concentration ratios of 2.3 and 6.7, respectively), we have previously reported lower relative intracellular concentrations of their active metabolites, zidovudine triphosphate (ZDV-TP) and lamivudine triphosphate (3TC-TP), in seminal mononuclear cells (SMCs) than in peripheral blood mononuclear cells (PBMCs) (SMC/PBMC drug concentration ratios of 0.36 and 1.0, respectively). Here, we use population pharmacokinetic (PK) modeling-based methods to simultaneously describe parent and intracellular metabolite PK in blood, semen, and PBMCs and SMCs. From this model, the time to steady state in each matrix was estimated, and the results indicate that the PK of 3TC-TP and ZDV-TP in PBMCs are different from the PK of the two in SMCs and different for the two triphosphates. We found that steady-state conditions in PBMCs were achieved within 2 days for ZDV-TP and 3 days for 3TC-TP. However, steady-state conditions in SMCs were achieved within 2 days for ZDV-TP and 2 weeks for 3TC-TP. Despite this, or perhaps because of it, ZDV-TP in SMCs does not achieve the surrogate 50% inhibitory concentration (IC50) (as established for PBMCs, assuming SMC IC50 = PBMC IC50) at the standard 300-mg twice-daily dosing. Mechanistic studies are needed to understand these differences and to explore intracellular metabolite behavior in SMCs for other nucleoside analogues used in HIV prevention, treatment, and cure.

Changes in HIV-1 subtypes B and C genital tract RNA in women and men after initiation of antiretroviral therapy.

BACKGROUND: Combination antiretroviral therapy (cART) reduces genital tract human immunodeficiency virus type 1 (HIV-1) load and reduces the risk of sexual transmission, but little is known about the efficacy of cART for decreasing genital tract viral load (GTVL) and differences in sex or HIV-1 subtype. METHODS: HIV-1 RNA from blood plasma, seminal plasma, or cervical wicks was quantified at baseline and at weeks 48 and 96 after entry in a randomized clinical trial of 3 cART regimens. RESULTS: One hundred fifty-eight men and 170 women from 7 countries were studied (men: 55% subtype B and 45% subtype C; women: 24% subtype B and 76% subtype C). Despite similar baseline CD4(+) cell counts and blood plasma viral loads, women with subtype C had the highest GTVL (median, 5.1 log10 copies/mL) compared to women with subtype B and men with subtype C or B (4.0, 4.0, and 3.8 log10 copies/mL, respectively; P < .001). The proportion of participants with a GTVL below the lower limit of quantification (LLQ) at week 48 (90%) and week 96 (90%) was increased compared to baseline (16%; P < .001 at both times). Women were significantly less likely to have GTVL below the LLQ compared to men (84% vs 94% at week 48, P = .006; 84% vs 97% at week 96, P = .002), despite a more sensitive assay for seminal plasma than for cervical wicks. No difference in GTVL response across the 3 cART regimens was detected. CONCLUSIONS: The female genital tract may serve as a reservoir of persistent HIV-1 replication during cART and affect the use of cART to prevent sexual and perinatal transmission of HIV-1.

Maternal and infant antiretroviral regimens to prevent postnatal HIV-1 transmission: 48-week follow-up of the BAN randomised controlled trial.

BACKGROUND: In resource-limited settings where no safe alternative to breastfeeding exists, WHO recommends that antiretroviral prophylaxis be given to either HIV-infected mothers or infants throughout breastfeeding. We assessed the effect of 28 weeks of maternal or infant antiretroviral prophylaxis on postnatal HIV infection at 48 weeks. METHODS: The Breastfeeding, Antiretrovirals, and Nutrition (BAN) Study was undertaken in Lilongwe, Malawi, between April 21, 2004, and Jan 28, 2010. 2369 HIV-infected breastfeeding mothers with a CD4 count of 250 cells per µL or more and their newborn babies were randomly assigned with a variable-block design to one of three, 28-week regimens: maternal triple antiretroviral (n=849); daily infant nevirapine (n=852); or control (n=668). Patients and local clinical staff were not masked to treatment allocation, but other study investigators were. All mothers and infants received one dose of nevirapine (mother 200 mg; infant 2 mg/kg) and 7 days of zidovudine (mother 300 mg; infants 2 mg/kg) and lamivudine (mothers 150 mg; infants 4 mg/kg) twice a day. Mothers were advised to wean between 24 weeks and 28 weeks after birth. The primary endpoint was HIV infection by 48 weeks in infants who were not infected at 2 weeks and in all infants randomly assigned with censoring at loss to follow-up. This trial is registered with ClinicalTrials.gov, number NCT00164736. FINDINGS: 676 mother-infant pairs completed follow-up to 48 weeks or reached an endpoint in the maternal-antiretroviral group, 680 in the infant-nevirapine group, and 542 in the control group. By 32 weeks post partum, 96% of women in the intervention groups and 88% of those in the control group reported no breastfeeding since their 28-week visit. 30 infants in the maternal-antiretroviral group, 25 in the infant-nevirapine group, and 38 in the control group became HIV infected between 2 weeks and 48 weeks of life; 28 (30%) infections occurred after 28 weeks (nine in maternal-antiretroviral, 13 in infant-nevirapine, and six in control groups). The cumulative risk of HIV-1 transmission by 48 weeks was significantly higher in the control group (7%, 95% CI 5-9) than in the maternal-antiretroviral (4%, 3-6; p=0·0273) or the infant-nevirapine (4%, 2-5; p=0·0027) groups. The rate of serious adverse events in infants was significantly higher during 29-48 weeks than during the intervention phase (1·1 [95% CI 1·0-1·2] vs 0·7 [0·7-0·8] per 100 person-weeks; p<0·0001), with increased risk of diarrhoea, malaria, growth faltering, tuberculosis, and death. Nine women died between 2 weeks and 48 weeks post partum (one in maternal-antiretroviral group, two in infant-nevirapine group, six in control group). INTERPRETATION: In resource-limited settings where no suitable alternative to breastfeeding is available, antiretroviral prophylaxis given to mothers or infants might decrease HIV transmission. Weaning at 6 months might increase infant morbidity. FUNDING: US Centers for Disease Control and Prevention.

Maternal or infant antiretroviral drugs to reduce HIV-1 transmission.

BACKGROUND: We evaluated the efficacy of a maternal triple-drug antiretroviral regimen or infant nevirapine prophylaxis for 28 weeks during breast-feeding to reduce postnatal transmission of human immunodeficiency virus type 1 (HIV-1) in Malawi. METHODS: We randomly assigned 2369 HIV-1-positive, breast-feeding mothers with a CD4+ lymphocyte count of at least 250 cells per cubic millimeter and their infants to receive a maternal antiretroviral regimen, infant nevirapine, or no extended postnatal antiretroviral regimen (control group). All mothers and infants received perinatal prophylaxis with single-dose nevirapine and 1 week of zidovudine plus lamivudine. We used the Kaplan-Meier method to estimate the cumulative risk of HIV-1 transmission or death by 28 weeks among infants who were HIV-1-negative 2 weeks after birth. Rates were compared with the use of the log-rank test. RESULTS: Among mother-infant pairs, 5.0% of infants were HIV-1-positive at 2 weeks of life. The estimated risk of HIV-1 transmission between 2 and 28 weeks was higher in the control group (5.7%) than in either the maternal-regimen group (2.9%, P=0.009) or the infant-regimen group (1.7%, P<0.001). The estimated risk of infant HIV-1 infection or death between 2 and 28 weeks was 7.0% in the control group, 4.1% in the maternal-regimen group (P=0.02), and 2.6% in the infant-regimen group (P<0.001). The proportion of women with neutropenia was higher among those receiving the antiretroviral regimen (6.2%) than among those in either the nevirapine group (2.6%) or the control group (2.3%). Among infants receiving nevirapine, 1.9% had a hypersensitivity reaction. CONCLUSIONS: The use of either a maternal antiretroviral regimen or infant nevirapine for 28 weeks was effective in reducing HIV-1 transmission during breast-feeding. (ClinicalTrials.gov number, NCT00164736.)

Validation of the Gen-Probe Aptima qualitative HIV-1 RNA assay for diagnosis of human immunodeficiency virus infection in infants.

The qualitative Roche HIV-1 DNA Amplicor assay has been used for the past 20 years to diagnose HIV infection in infants and young children but is being phased out; hence, alternative assays must be found. The Gen-Probe Aptima qualitative HIV-1 RNA assay is currently the only FDA-cleared HIV-1 nucleic acid assay approved for diagnosis, but data on the use of this assay with infant plasma are limited. We assessed Aptima's performance using control material for reproducibility and limit of detection and 394 plasma samples (0.2 to 0.5 ml) from HIV-exposed infected and uninfected infants and children for analytical sensitivity and specificity. Assays to assess within-run repeatability and between-run reproducibility indicated that the controls with 10,000 (5 of 5), 200 (5 of 5), 100 (16 of 16), 50 (12 of 12), and 25 (20 of 20) HIV-1 RNA copies/ml (cp/ml) were always positive, and negatives were always negative (20 of 20). The limit of detection was 14 cp/ml, as determined by probit analysis. The analytic sensitivity of the assay was 99.5% (189/190 samples; 95% confidence interval [CI], 97.1 to 99.9%) and specificity was 99.5% (199/200 samples; 95% CI, 97.2 to 99.9%). These results suggest that the assay is suitable for early infant diagnosis of HIV-1.

Detection of acute HIV infection: a field evaluation of the determine® HIV-1/2 Ag/Ab combo test.

BACKGROUND: Most human immunodeficiency virus (HIV) point-of-care tests detect antibodies (Ab) but not p24 antigen (Ag) or RNA. In the absence of antibodies, p24 antigen and RNA typically indicate acute HIV infection. We conducted a field evaluation of the Determine® HIV-1/2 Ag/Ab Combo rapid test (Combo RT). METHODS: The antigen portion of the Combo RT (for acute HIV infection) was compared with a Roche Monitor HIV RNA polymerase chain reaction assay. The antibody portion of Combo RT (for established HIV infection) was compared with rapid test algorithms. Participants were enrolled at a sexually transmitted infection clinic and HIV testing and counseling center in Lilongwe, Malawi. Rapid testing was conducted with parallel testing in the clinic and serial testing in the center. The Combo RT was performed in clinic participants with negative or discordant antibody results and in all center participants. RESULTS: Of the participants 838 were HIV negative, 163 had established HIV infection, and 8 had acute HIV infection. For detecting acute HIV infection, the antigen portion had a sensitivity of 0.000 and a specificity of 0.983. For detecting established HIV infection, the antibody portion had a sensitivity of 0.994 and a specificity of 0.992. CONCLUSIONS: Combo RT displayed excellent performance for detecting established HIV infection and poor performance for detecting acute HIV infection. In this setting, Combo RT is no more useful than current algorithms.

The setpoint study (ACTG A5217): effect of immediate versus deferred antiretroviral therapy on virologic set point in recently HIV-1-infected individuals.

BACKGROUND: The benefits of antiretroviral therapy during early human immunodeficiency virus type 1 (HIV-1) infection remain unproved. METHODS: A5217 study team randomized patients within 6 months of HIV-1 seroconversion to receive either 36 weeks of antiretrovirals (immediate treatment [IT]) or no treatment (deferred treatment [DT]). Patients were to start or restart antiretroviral therapy if they met predefined criteria. The primary end point was a composite of requiring treatment or retreatment and the log(10) HIV-1 RNA level at week 72 (both groups) and 36 (DT group). RESULTS: At the June 2009 Data Safety Monitoring Board (DSMB) review, 130 of 150 targeted participants had enrolled. Efficacy analysis included 79 individuals randomized ≥72 weeks previously. For the primary end point, the IT group at week 72 had a better outcome than the DT group at week 72 (P = .005) and the DT group at week 36 (P = .002). The differences were primarily due to the higher rate of progression to needing treatment in the DT group (50%) versus the IT (10%) group. The DSMB recommended stopping the study because further follow-up was unlikely to change these findings. CONCLUSIONS: Progression to meeting criteria for antiretroviral initiation in the DT group occurred more frequently than anticipated, limiting the ability to evaluate virologic set point. Antiretrovirals during early HIV-1 infection modestly delayed the need for subsequent treatment. CLINICAL TRIALS REGISTRATION: NCT00090779.

Cross-platform analysis of HIV-1 RNA data generated by a multicenter assay validation study with wide geographic representation.

HIV-1 RNA quantitation continues to be extremely important for monitoring patients infected with HIV-1, and a number of assays have been utilized for this purpose. Differences in assay performance with respect to log(10) recovery and HIV-1 subtype specificity have been well documented for commercially available assays, although comparisons are usually limited to one or two assay platforms. Two new FDA-approved assays, the Roche Cobas AmpliPrep/Cobas TaqMan HIV-1 test (RT) and the Abbott RealTime HIV-1 assay (AR), that utilize real-time PCR have replaced previous HIV-1 RNA platforms. Inadequate detection of some strains of HIV-1 resulted in the addition of a new primer/probe set and the introduction of a second version of the RT assay. In this study, comparisons of assay performance between the different FDA-approved HIV-1 RNA assay platforms (both new and existing) were performed by using validation data that included both well-characterized virus stock and locally collected clinical samples. Laboratories across diverse geographical regions performed the validation testing and submitted data to the Virology Quality Assurance program (VQA) for analysis. Correlation values for clinical sample testing varied across the assay platforms (r = 0.832 to 0.986), and average log(10) recoveries for HIV-1 RNA controls (compared to the nominal value) ranged from -0.215 to 0.181. These data demonstrate the need for use of one assay platform for longitudinal patient monitoring, but the data also reinforce the notion that no one assay is superior and that testing across platforms may be required for discordance reconciliation.

Pharmacokinetics and safety of single-dose tenofovir disoproxil fumarate and emtricitabine in HIV-1-infected pregnant women and their infants.

Tenofovir (TFV) is effective in preventing simian immunodeficiency virus (SIV) transmission in a macaque model, is available as the oral agent tenofovir disoproxil fumarate (TDF), and may be useful in the prevention of mother-to-child transmission of human immunodeficiency virus (HIV). We conducted a trial of TDF and TDF-emtricitabine (FTC) in HIV-infected pregnant women and their infants. Women received a single dose of either 600 mg TDF, 900 mg TDF, or 900 mg TDF-600 mg FTC at labor onset or prior to a cesarean section. Infants received no drug or a single dose of TDF at 4 mg/kg of body weight or of TDF at 4 mg/kg plus FTC at 3 mg/kg as soon as possible after birth. All regimens were safe and well tolerated. Maternal areas under the serum concentration-time curve (AUC) and concentrations at the end of sampling after 24 h (C(24)) were similar between the two doses of TDF; the maximum concentrations of the drugs in serum (C(max)) and cord blood concentrations were higher in women delivering via cesarean section than in those who delivered vaginally (P = 0.04 and 0.046, respectively). The median ratio of the TFV concentration in cord blood to that in the maternal plasma at delivery was 0.73 (range, 0.26 to 1.95). Without TDF administration, infants had a median TFV concentration of 12 ng/ml 12 h after birth. Following administration of a single dose of TDF at 4 mg/kg, infant TFV concentrations fell below the targeted level, 50 ng/ml, by 24 h postdose. In HIV-infected pregnant women and their infants, 600 mg of TDF is acceptable as a single dose during labor. Low concentrations at birth support infant dosing as soon after birth as possible. Rapidly decreasing TFV levels in infants suggest that multiple or higher doses of TDF will be necessary to maintain concentrations that are effective for viral suppression.

Pre-existing minority drug-resistant HIV-1 variants, adherence, and risk of antiretroviral treatment failure.

BACKGROUND: The clinical relevance of detecting minority drug-resistant human immunodeficiency virus type 1 (HIV-1) variants is uncertain. METHODS: To determine the effect of pre-existing minority nonnucleoside reverse-transcriptase inhibitor (NNRTI)-resistant variants on the risk of virologic failure, we reanalyzed a case-cohort substudy of efavirenz recipients in AIDS Clinical Trials Group protocol A5095. Minority K103N or Y181C populations were determined by allele-specific polymerase chain reaction in subjects without NNRTI resistance by population sequencing. Weighted Cox proportional hazards models adjusted for recent treatment adherence estimated the relative risk of virologic failure in the presence of NNRTI-resistant minority variants. RESULTS: The evaluable case-cohort sample included 195 subjects from the randomly selected subcohort (51 with virologic failure, 144 without virologic failure), plus 127 of the remaining subjects who experienced virologic failure. Presence of minority K103N or Y181C mutations, or both, was detected in 8 (4.4%), 54 (29.5%), and 11 (6%), respectively, of 183 evaluable subjects in the random subcohort. Detection of minority Y181C mutants was associated with an increased risk of virologic failure in the setting of recent treatment adherence (hazard ratio, 3.45 [95% confidence interval, 1.90-6.26]) but not in nonadherent subjects (hazard ratio, 1.39 [95% confidence interval, 0.58-3.29]). Of note, 70% of subjects with minority Y181C variants achieved long-term viral suppression. CONCLUSIONS: In adherent patients, pre-existing minority Y181C mutants more than tripled the risk of virologic failure of first-line efavirenz-based antiretroviral therapy. CLINICAL TRIALS REGISTRATION: NCT00013520.

Impact of aciclovir on ulcer healing, lesional, genital and plasma HIV-1 RNA among patients with genital ulcer disease in Malawi.

OBJECTIVE: By a randomised, double-blind, placebo-controlled trial of aciclovir 800 mg twice daily for 5 days added to the syndromic management of genital ulcer disease (GUD) to determine the impact on ulcer healing and HIV outcomes. METHODS: Patients presenting with GUD in Malawi were evaluated for HIV and herpes simplex virus type-2 (HSV-2) serologies, ulcer aetiology, lesional, genital and plasma HIV-1 RNA and CD4+ count. Patients were followed up at days 2, 4, 7, 14 and 28. The primary study outcome was ulcer healing at day 14, with secondary outcomes being lesional and genital HIV-1 shedding at day 14 and HIV-1 plasma viral load at day 28 among HIV-1/HSV-2 co-infected individuals. RESULTS: Four hundred and twenty-two patients (74% male) were randomised (208 to aciclovir, 214 to placebo), of whom 61% were HIV-1 seropositive and 72% HSV-2 seropositive; 67% (267/398) had HSV-2 ulcers. 85% of ulcers were healed at day 14 with no difference between treatment arms (risk ratio (RR)=1.02, 95% CI 0.93 to 1.11). Among 244 HIV-1/HSV-2 co-infected individuals, aciclovir reduced lesional HIV-1 RNA (adjusted RR=0.64, 95% CI 0.41 to 0.99) and seminal HIV-1 RNA (adjusted RR=0.59, 95% CI 0.40 to 0.88), but not cervical HIV-1 RNA or plasma HIV-1 RNA. CONCLUSIONS: Episodic HSV treatment with aciclovir added to syndromic management did not produce a significant clinical benefit in this African population.

Efficacy, pharmacokinetics and neurocognitive performance of dual, NRTI-sparing antiretroviral therapy in acute HIV-infection.

OBJECTIVES: The aim of this study was to evaluate penetration of antiretrovirals into compartments and efficacy of a dual, NRTI-sparing regimen in acute HIV infection (AHI). DESIGN: Single-arm, open-label pilot study of participants with AHI initiating ritonavir-boosted darunavir 800 mg once daily and etravirine 400 mg once daily or 200 mg twice daily within 30 days of AHI diagnosis. METHODS: Efficacy was defined as HIV RNA less than 200 copies/ml by week 24. Optional sub-studies included pharmacokinetics analysis from genital fluids (weeks 0-4, 12, 48), cerebrospinal fluid (CSF) (weeks 2-4, 24 and 48) and endoscopic biopsies (weeks 4-12 and 36-48). Neuropsychological performance was assessed at weeks 0, 24 and 48. RESULTS: Fifteen AHI participants were enrolled. Twelve (80%) participants achieved HIV RNA less than 200 copies/ml by week 24. Among 12 participants retained through week 48, nine (75%) remained suppressed to less than 50 copies/ml. The median time from ART initiation to suppression less than 200 and less than 50 copies/ml was 59 and 86 days, respectively. The penetration ratios for etravirine and darunavir in gut associated lymphoid tissue were 19.2 and 3.05, respectively. Most AHI participants achieving viral suppression experienced neurocognitive improvement. Of the three participants without overall improvement in neurocognitive functioning as measured by impairment ratings (more than two tests below 1 SD), two had virologic failure. CONCLUSION: NRTI-sparing ART started during AHI resulted in rapid viral suppression similar to NRTI-based regimens. More novel and compact two-drug treatments for AHI should be considered. Early institution of ART during AHI appears to improve overall neurocognitive function and may reduce the risk of subsequent neurocognitive impairment. CLINICALTRIALS.GOV:: NCT00855413.

Genital tract, cord blood, and amniotic fluid exposures of seven antiretroviral drugs during and after pregnancy in human immunodeficiency virus type 1-infected women.

The objective of the study was to measure antiretroviral exposures in four physiological compartments during pregnancy, delivery, and postpartum. This prospective, open-label, longitudinal study collected paired blood plasma (BP) and genital tract (GT) aspirates antepartum, at delivery, and up to 12 weeks postpartum. Antiretroviral cord BP and amniotic fluid concentrations were also measured. Drug concentrations were analyzed by validated high-performance liquid chromatography/UV and liquid chromatography/tandem mass spectrometry methods, with secondary compartment concentrations presented as the percentage of BP. Fourteen women taking lamivudine plus zidovudine and either lopinavir-ritonavir (n = 7), nelfinavir (n = 6), or nevirapine (n = 1) were enrolled; four also received tenofovir. GT penetration relative to BP was highest for the nucleoside reverse transcriptase inhibitors compared to the protease inhibitors and nevirapine. Only antepartum nelfinavir GT penetration was significantly higher than in the second trimester (geometric mean ratio [GMR], 179.3) or third trimester (GMR, 41.9). Compared to nonpregnant historical controls, antepartum GT penetration was significantly lower (P < 0.05) for zidovudine (GMR, 0.25) and lopinavir (GMR, 0.03); postpartum lopinavir GT penetration continued to be significantly lower (GMR, 0.27). Cord BP exposures were highest for lamivudine and tenofovir (> or = 100%), with cord BP levels of the remaining drugs ranging from 49 to 86% of that of the respective BP level. Amniotic exposures for lamivudine, zidovudine, tenofovir, and nelfinavir were > or = 100%, nevirapine exposure was 53%, and lopinavir and ritonavir exposures were < or = 6% that of BP. We conclude that GT, cord BP, and amniotic fluid exposures vary within and between antiretroviral drug classes and biologic sites. Measurement of antiretroviral exposure in maternal genital secretions, cord BP, and amniotic fluid may be needed to identify signals of subtherapeutic or supratherapeutic drug exposure.

Diagnosis of human immunodeficiency virus type 1 infection in infants by use of dried blood spots and an ultrasensitive p24 antigen assay.

We tested 617 dried blood spots (DBS) from human immunodeficiency virus-exposed infants from five countries using an ultrasensitive p24 antigen assay (Up24). The sensitivity was 94.4% (67/71) and the specificity was 100% (431/431) for infants with DBS specimens

Qualitative human immunodeficiency virus RNA analysis of dried blood spots for diagnosis of infections in infants.

The Gen-Probe Aptima human immunodeficiency virus type 1 (HIV-1) RNA assay was adapted for the diagnosis of HIV infection in infants by using dried blood spots. The assay was 99% sensitive (128/129) and 100% specific (162/162). This may prove useful in resource-limited settings, since it precludes the need for a phlebotomist and maintenance of a cold chain.

Nevirapine resistance in human immunodeficiency virus type 1-positive infants determined using dried blood spots stored for up to six years at room temperature.

Dried blood spots that had been stored ambiently for 3 to 6 years lost approximately 1 log(10) of human immunodeficiency virus type 1 (HIV-1) RNA, but the majority could still be genotyped for resistance. Nevirapine resistance was found in 7/16 (43.5%) HIV-1-positive HIVNET 024 infants at 4 to 6 weeks, but no resistance was found at other time points.

Detection of acute infections during HIV testing in North Carolina.

BACKGROUND: North Carolina has added nucleic acid amplification testing for the human immunodeficiency virus (HIV) to standard HIV antibody tests to detect persons with acute HIV infection who are viremic but antibody-negative. METHODS: To determine the effect of nucleic acid amplification testing on the yield and accuracy of HIV detection in public health practice, we conducted a 12-month observational study of methods for state-funded HIV testing. We compared the diagnostic performance of standard HIV antibody tests (i.e., enzyme immunoassay and Western blot analysis) with an algorithm whereby serum samples that yielded negative results on standard antibody tests were tested again with the use of nucleic acid amplification. A surveillance algorithm with repeated sensitive-less-sensitive enzyme immunoassay tests was also evaluated. HIV infection was defined as a confirmed positive result on a nucleic acid amplification test or as HIV antibody seroconversion. RESULTS: Between November 1, 2002, and October 31, 2003, 109,250 persons at risk for HIV infection who had consented to HIV testing presented at state-funded sites. There were 606 HIV-positive results. Established infection, as identified by standard enzyme immunoassay or Western blot analysis, appeared in 583 participants; of these, 107 were identified, with the use of sensitive-less-sensitive enzyme immunoassay tests, as recent infections. A total of 23 acutely infected persons were identified only with the use of the nucleic acid amplification algorithm. With all detectable infections taken into account, the sensitivity of standard antibody testing was 0.962 (95 percent confidence interval, 0.944 to 0.976). There were two false positive results on nucleic acid amplification tests. The specificity and positive predictive value of the algorithm that included nucleic acid amplification testing were greater than 0.999 (95 percent confidence interval, 0.999 to >0.999) and 0.997 (95 percent confidence interval, 0.988 to >0.999), respectively. Of the 23 acute HIV infections, 16 were detected at sexually transmitted disease clinics. Emergency measures for HIV prevention protected 48 sex partners and one fetus from high-risk exposure to HIV. CONCLUSIONS: The addition of nucleic acid amplification testing to an HIV testing algorithm significantly increases the identification of cases of infection without impairing the performance of diagnostic testing. The detection of highly contagious, acutely infected persons creates new opportunities for HIV surveillance and prevention.

Optimizing screening for acute human immunodeficiency virus infection with pooled nucleic acid amplification tests.

Recent studies have shown the public health importance of identifying individuals with acute human immunodeficiency virus infection (AHI); however, the cost of nucleic acid amplification testing (NAAT) makes individual testing of at-risk individuals prohibitively expensive in many settings. Pooled NAAT (or group testing) can improve efficiency and test performance of testing for AHI, but optimizing the pooling algorithm can be difficult. We developed simple, flexible biostatistical models of specimen pooling with NAAT for the identification of AHI cases; these models incorporate group testing theory, operating characteristics of biological assays, and a model of viral dynamics during AHI. Pooling algorithm sensitivity, efficiency (test kits used per individual specimen evaluated), and positive predictive value (PPV) were modeled and compared for three simple pooling algorithms: two-stage minipools (D2), three-stage hierarchical pools (D3), and square arrays with master pools (A2m). We confirmed the results by stochastic simulation and produced reference tables and a Web calculator to facilitate pooling by investigators without specific biostatistical expertise. All three pooling strategies demonstrated improved efficiency and PPV for AHI case detection compared to individual NAAT. D3 and A2m algorithms generally provided better efficiency and PPV than D2; additionally, A2m generally exhibited better PPV than D3. Used selectively and carefully, the simple models developed here can guide the selection of a pooling algorithm for the detection of AHI cases in a wide variety of settings.

Comparison of two rapid human immunodeficiency virus (HIV) assays, Determine HIV-1/2 and OraQuick Advance Rapid HIV-1/2, for detection of recent HIV seroconversion.

Modified protocols of two rapid tests were compared with a less sensitive (LS) (detuned) enzyme immunoassay (EIA) for their abilities to distinguish recent human immunodeficiency virus (HIV) seroconversion from long-term infections. The results for samples from 100 HIV-positive patient that had previously been tested by the Vironostika LS EIA had a 97% concordance with the results of the Determine HIV 1/2 assay and 93% concordance with those of the OraQuick HIV 1/2 assay.