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BACKGROUND: Quantifying pediatric immunologic recovery by highly active antiretroviral therapy (HAART) initiation at different CD4 percentage (CD4%) and age thresholds may inform decisions about timing of treatment initiation. METHODS: HIV-1-infected, HAART-naive children in Europe and the Americas were followed from 2002 through 2009 in PENPACT-1. Data from 162 vertically infected children, with at least World Health Organization “mild” immunosuppression and CD4% RESULTS: Seventy-two percent of baseline immunosuppressed children recovered to normal within 4 years. Compared with “severe” immunosuppression, more children with “mild” immunosuppression (difference 36%, 95% confidence interval [CI]: 22% to 49%) or “advanced” immunosuppression (difference 20.8%, 95% CI: 5.8% to 35.9%) recovered a normal CD4%. For each 5-year increase in baseline age, the proportion of children achieving a normal CD4% declined by 19% (95% CI: 11% to 27%). Combining baseline CD4% and age effects resulted in >90% recovery when initiating HAART with “mild” immunosuppression at any age or “advanced” immunosuppression at age CONCLUSIONS: Initiating HAART at higher CD4% and younger ages maximizes potential for immunologic recovery. Guidelines should weigh immunologic benefits against long-term risks.

Quantifying pediatric immunologic recovery by highly active antiretroviral therapy (HAART) initiation at different CD4 percentage (CD4%) and age thresholds may inform decisions about timing of treatment initiation.

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.

Understanding human immunodeficiency virus type 1 (HIV-1) transmission is central to developing effective prevention strategies, including a vaccine. We compared phenotypic and genetic variation in HIV-1 env genes from subjects in acute/early infection and subjects with chronic infections in the context of subtype C heterosexual transmission. We found that the transmitted viruses all used CCR5 and required high levels of CD4 to infect target cells, suggesting selection for replication in T cells and not macrophages after transmission. In addition, the transmitted viruses were more likely to use a maraviroc-sensitive conformation of CCR5, perhaps identifying a feature of the target T cell. We confirmed an earlier observation that the transmitted viruses were, on average, modestly underglycosylated relative to the viruses from chronically infected subjects. This difference was most pronounced in comparing the viruses in acutely infected men to those in chronically infected women. These features of the transmitted virus point to selective pressures during the transmission event. We did not observe a consistent difference either in heterologous neutralization sensitivity or in sensitivity to soluble CD4 between the two groups, suggesting similar conformations between viruses from acute and chronic infection. However, the presence or absence of glycosylation sites had differential effects on neutralization sensitivity for different antibodies. We suggest that the occasional absence of glycosylation sites encoded in the conserved regions of env, further reduced in transmitted viruses, could expose specific surface structures on the protein as antibody targets.

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 log10 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 log10 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.

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 (≥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 ≥100%, nevirapine exposure was 53%, and lopinavir and ritonavir exposures were ≤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.

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 ≤20 months old; DBS older than 30 months demonstrated only 72.2% sensitivity (39/54) (P < 0.001) but displayed 100% specificity (61/61).

Dried blood spots that had been stored ambiently for 3 to 6 years lost approximately 1 log10 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.

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.

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.

We evaluated an ultrasensitive p24 antigen enzyme immunosorbent assay on 802 plasma specimens from 582 infants and children of 0 to 180 days of age. Overall sensitivity and specificity were 91.7% and 98.5%, respectively. After exclusion of infants of less than 7 days of age, the sensitivity and specificity were 93.7% and 98.3%, respectively.

The human immunodeficiency virus type 1 (HIV-1) surface Env protein has been implicated in the development of HIV-1-associated dementia (HAD). HIV-1 env diversity was analyzed by heteroduplex tracking assay in 27 infected subjects with various neurological statuses. env compartmentalization between the blood and cerebral spinal fluid (CSF) was apparent with all neurological categories. However, in subjects with HAD, significantly more CSF virus was represented by CNS-unique env variants. Variants specialized for replication in the CNS may play a larger role in the development of HAD. Alternatively, HAD may be associated with a more pronounced state of immunosuppression that permits more extensive replication and independent evolution within the CNS compartment.

Human immunodeficiency virus (HIV) RNA testing is the gold standard for monitoring antiretroviral therapy in HIV-infected patients. However, equipment and reagent costs preclude widespread use of the assay in resource-limited settings. The Perkin-Elmer Ultrasensitive p24 assay and the Cavidi Exavir Load assay both offer potentially simpler, less costly technologies for monitoring viral load. These assays were compared to the Roche Amplicor HIV-1 Monitor Test, v1.5, using panels of clinical samples (subtype B) from HIV-positive subjects and HIV-spiked samples (subtypes A, C, D, CRF_01AE, CRF_02AG, and F). The Ultrasensitive p24 assay detected 100% of the spiked samples with virus loads of >250,000copies/ml and 61% of the clinical samples with virus loads of 219 to 288,850 copies/ml. Detection rates were improved substantially if an external lysis buffer was added to the procedure. The Cavidi assay detected 54 to 100% of spiked samples with virus loads >10,000 copies/ml and 68% of the clinical samples. These detection rates were also greatly improved with a newly implemented version of this kit. Coefficients of variation demonstrate good reproducibility for each of these kits. The results from the Cavidi v1.0, Cavidi v2.0, and Perkin-Elmer, and the Perkin-Elmer Plus external buffers all correlated well with the results from the Roche Monitor Test (r = 0.83 to 0.96, r = 0.84 to 0.99, r = 0.58 to 0.67, and r = 0.59 to 0.95, respectively). Thus, the use of these two assays for monitoring patients, together with less-frequent confirmation testing, offers a feasible alternative to frequent HIV RNA testing in resource-limited settings.

Human immunodeficiency virus type 1 (HIV-1) exists as a complex population of multiple genotypic variants in persons with chronic infection. However, acute HIV-1 infection via sexual transmission is a low-probability event in which there is thought to be low genetic complexity in the initial inoculum. In order to assess the viral complexity present during primary HIV-1 infection, the V1/V2 and V3 variable regions of the env gene were examined by using a heteroduplex tracking assay (HTA) capable of resolving these genotypic variants. Blood plasma samples from 26 primary HIV-1-infected subjects were analyzed for their level of diversity. Half of the subjects had more than one V1/V2 viral variant during primary infection, indicating the frequent transmission of multiple variants. This observation is inconsistent with the idea of infrequent transmission based on a small transmitting inoculum of cell-free virus. In chronically infected subjects, the complexity of the viral populations was even greater in both the V1/V2 and the V3 regions than in acutely infected subjects, indicating that in spite of the presence of multiple variants in acute infection, the virus does pass through a genetic bottleneck during transmission. We also examined how well the infecting virus penetrated different anatomical compartments by using the HTA. Viral variants detected in blood plasma were compared to those detected in seminal plasma and/or cerebral spinal fluid of six individuals. The virus in each of these compartments was to a large extent identical to virus in blood plasma, a finding consistent with rapid penetration of the infecting variant(s). The low-probability transmission of multiple variants could be the result of transient periods of hyperinfectiousness or hypersusceptibility. Alternatively, the inefficient transfer of a multiply infected cell could account for both the low probability of transmission and the transfer of multiple variants.

We compared an assay using signal amplification of a heat-dissociated p24 antigen (HDAg) with the Roche Monitor human immunodeficiency virus (HIV) RNA assay. The two assays gave comparable results when 130 specimens from 130 patients were tested (r = 0.60, P < 0.0001). The HDAg assay was almost as sensitive (85%) as the Roche HIV RNA kit (95%), just as specific (25 negative results from 25 HIV seronegative volunteers [100%]), less variable (mean log standard deviation of 0.07 compared to 0.11 when eight specimens were tested three or four times), and less expensive (reagent and labor costs, $8 versus $75). The assay appeared to be useful for monitoring established patients (n = 17) and identifying seroconverters (n = 4). HIV subtypes A to F were all recognized. This assay should be useful for monitoring patients in resource-poor countries and for monitoring vaccine recipients.

We determined the frequency with which human immunodeficiency virus (HIV) peripheral blood mononuclear cell cultures convert from positive to negative in subjects enrolled in a substudy of AIDS Clinical Trials Group (ACTG) 320, which compared the efficacy of treatment with a combination of indinavir, zidovudine, and lamivudine (indinavir arm) to that of a combination of zidovudine and lamivudine (dual-nucleoside arm). All subjects included for study had positive baseline HIV cultures. Cultures were performed in real time with 107 fresh patient peripheral blood mononuclear cells, using the ACTG consensus method. We found lower rates of positive HIV cultures in the indinavir treatment arm than in the dual-nucleoside treatment arm (64 versus 96% at week 24, P < 0.001). Within the indinavir arm of the study, we found that positive cultures were less likely to occur in samples with a plasma HIV type 1 (HIV-1) RNA level of P < 0.001). In addition, HIV cultures from samples with HIV-1 RNA levels of ≥500 copies/ml turned positive 8.5 days earlier, on average, than those from samples with levels of P < 0.001). However, 38% of samples with plasma RNA levels of

The gp120 V3-encoding region of human immunodeficiency virus type 1 (HIV-1) RNA derived from the saliva and blood plasma of 11 individuals was characterized by heteroduplex tracking assay and sequence analyses. R5-like viral variants were identified in both fluids of all subjects. X4-like variants were detected in the plasma and/or saliva of three subjects, indicating that X4-like variants are not excluded from the saliva compartment. Viral subpopulations were similar in both fluids of most subjects, suggesting that HIV-1 in oral fluids and blood may stem from a common source. These findings raise the possibility of using saliva as a noninvasive fluid for evaluating and monitoring viral evolution in infected persons.

We compared Roche MONITOR and Organon Teknika NucliSens assays for human immunodeficiency virus type 1 (HIV-1) RNA in cerebrospinal fluid (CSF). Results of 282 assays were highly correlated (r = 0.826), with MONITOR values being 0.29 ± 0.4 log10 copies/ml (mean ± standard deviation) values. Both assays can reliably quantify HIV-1 RNA in CSF.

Context Although protease inhibitors are used routinely in adults with human immunodeficiency virus (HIV) infection, the role of these drugs in the treatment of clinically stable HIV-infected children is not clear. Objective To evaluate the safety, tolerance, and virologic response produced by a change in antiretroviral therapy in HIV-infected children who were clinically and immunologically stable while receiving previous therapy. Design The Pediatric AIDS Clinical Trials Group 338, a multicenter, phase 2, randomized, open-label controlled trial conducted from February 6 to April 30, 1997 (patient entry period); patients were followed up for 48 weeks. Setting Pediatric HIV research clinics in the United States and Puerto Rico. Patients Two hundred ninety-seven antiretroviral-experienced, protease inhibitor-naive, clinically stable HIV-infected children aged 2 to 17 years. Interventions Children were randomized to receive zidovudine, 160 mg/m(2) 3 times per day, plus lamivudine, 4 mg/kg 2 times per day (n = 100); the same regimen plus ritonavir, 350 mg/m(2) 2 times per day (n = 100); or ritonavir, 350 mg/m(2) 2 times per day, and stavudine, 4 mg/kg 2 times per day (n = 97). Main Outcome Measure Plasma HIV-1 RNA levels at study weeks 12 and 48, compared among the 3 treatment groups. Results At study week 12, 12% of patients in the zidovudine-lamivudine group had undetectable plasma HIV RNA levels ( Conclusions In our study, change in antiretroviral therapy to a ritonavir-containing regimen was associated with superior virologic response at study week 12 compared with change to a dual nucleoside analog regimen. More children receiving ritonavir in combination with 2 compared with 1 nucleoside analog had undetectable HIV RNA levels at study week 48.

To the Editor.Drs. Schmid and Fontanarosa thoroughly discussed the causes and management of nongonococcal urethritis. However, they did not emphasize the link between treatment of sexually transmitted diseases and prevention of human immunodeficiency virus (HIV).