Factors associated with vertical transmission of HIV in the Western Cape, South Africa: a retrospective cohort analysis.

INTRODUCTION: Monitoring mother-infant pairs with HIV exposure is needed to assess the effectiveness of vertical transmission (VT) prevention programmes and progress towards VT elimination. METHODS: We used routinely collected data on infants with HIV exposure, born May 2018-April 2021 in the Western Cape, South Africa, with follow-up through mid-2022. We assessed the proportion of infants diagnosed with HIV at birth (≤7 days), 10 weeks (>1 to 14 weeks) and >14 weeks as proxies for intrauterine, intrapartum/early breastfeeding and late breastfeeding transmission, respectively. We used mixed-effects Poisson regression to assess factors associated with VT in mothers known with HIV by delivery. RESULTS: We included 50,461 infants born to mothers known with HIV by delivery. HIV was diagnosed in 894 (1.8%) infants. Among mothers, 51% started antiretroviral treatment (ART) before and 27% during pregnancy; 17% restarted during pregnancy after ≥6 months interruption; and 6% had no recorded ART during pregnancy. Most pregnancy ART regimens included non-nucleoside reverse transcriptase inhibitors (83%). Of mothers with available results (90% with viral load [VL]; 70% with CD4), VL nearest delivery was <100 copies/ml in 78% and CD4 count ≥350 cells/µl in 62%. HIV-PCR results were available for 86%, 67% and 48% of eligible infants at birth, 10 weeks and >14 weeks. Among these infants, 0.9%, 0.4% and 1.5% were diagnosed positive at birth, 10 weeks and >14 weeks, respectively. Among infants diagnosed with HIV, 43%, 16% and 41% were diagnosed at these respective time periods. Among mothers with VL<100, 100-999, 1000-99,000 and ≥100,000 copies/ml nearest delivery, infant HIV diagnosis incidence was 0.4%, 2.3%, 6.6% and 18.4%, respectively. Increased VT was strongly associated with recent elevated maternal VL with a seven-fold increased rate with even modestly elevated VL (100-999 vs. <100 copies/ml). VT was also associated with unknown/low maternal CD4, maternal age <20 years, no antenatal ART, later maternal ART start/restart in pregnancy and ART gaps. CONCLUSIONS: Despite high maternal ART coverage and routine postnatal prophylaxis, ongoing VT remains a concern. Timing of infant HIV diagnoses suggests intrapartum and/or breastfeeding transmission in nearly 60%. Interventions to ensure retention on ART and sustained maternal viral suppression are needed to reduce VT.

Hypersensitivity reactions, hepatotoxicity, and other discontinuations in persons receiving integrase strand transfer inhibitors: results from the EuroSIDA study.

Background: Hypersensitivity reaction (HSR) and hepatotoxicity are rare, but potentially serious side-effects of antiretroviral use.Objective: To investigate discontinuations due to HSR, hepatotoxicity or other reasons among users of dolutegravir (DTG) vs. raltegravir (RAL) or elvitegravir (EVG) in the EuroSIDA cohort.Methods: We compared individuals ≥18 years and starting combination antiretroviral therapy (ART, ≥3 drugs) with DTG vs. RAL or EVG, with or without abacavir (ABC), between January 16, 2014 and January 23, 2019. Discontinuations due to serious adverse events (SAEs) were independently reviewed.Results: Altogether 4366 individuals started 5116 ART regimens including DTG, RAL, or EVG, contributing 9180 person-years of follow-up (PYFU), with median follow-up 1.6 (interquartile range 0.7-2.8) years per treatment episode. Of these, 3074 (60.1%) used DTG (1738 with ABC, 1336 without) and 2042 (39.9%) RAL or EVG (286 with ABC, 1756 without). 1261 (24.6%) INSTI episodes were discontinued, 649 of the DTG-containing regimens (discontinuation rate 115, 95% CI 106-124/1000 PYFU) and 612 RAL or EVG-containing regimens (173, CI 160-188/1000 PYFU). After independent review, there were five HSR discontinuations, two for DTG (one with and one without ABC, discontinuation rate 0.35, CI 0.04-1.28/1000 PYFU), and three for RAL or EVG without ABC (0.85, CI 0.18-2.48/1000 PYFU). There was one hepatotoxicity discontinuation on DTG with ABC (discontinuation rate 0.18, CI 0.00-0.99/1000 PYFU).Conclusion: During 5 years of observations in the EuroSIDA cohort independently reviewed discontinuations due to HSR or hepatotoxicity were very rare, indicating a low rate of SAEs.

To dose-adjust or not to dose-adjust: lamivudine dose in kidney impairment.

OBJECTIVES: To assess the risk of adverse diagnoses and laboratory abnormalities associated with a 300 or 150 mg daily dose of lamivudine (3TC) initiated by people with HIV (PWH) with an estimated glomerular filtration rate (eGFR) between at least 30 and 49 ml/min per 1.73 m2 or less. DESIGN: Longitudinal study based on electronic health records of 539 PWH with eGFR between at least 30 and 49 ml/min per 1.73 m2 or less from the Observational Pharmaco-Epidemiology Research and Analysis (OPERA) cohort. METHODS: Common unintended effects of 3TC were evaluated as composite outcomes. We estimated the incidence (univariate Poisson regression) and association between dose and incident composite outcomes (multivariate Poisson regression) among PWH without the relevant diagnoses or laboratory abnormalities at 3TC initiation. RESULTS: PWH initiating 150 mg 3TC had higher HIV RNA, lower eGFR, and more comorbidities than those initiating 300 mg 3TC. The prevalence of relevant diagnoses and laboratory abnormalities was similar in both groups. The most common lab abnormality was low hemoglobin. There was no statistically significant difference in incident adverse diagnoses/severe lab abnormalities with 300 mg versus 150 mg [incidence rate ratio (IRR): 1.51; 95% confidence interval (CI) 0.59--3.92). However, a statistically significant association was observed when gastrointestinal symptoms/moderate lab abnormalities were included in the outcome (IRR: 3.07, 95% CI 1.12--8.40). CONCLUSION: As 3TC is a well tolerated drug with a wide therapeutic window, dose adjustment may be unnecessary among PWH with eGFR between at least 30 and 49 ml/min per 1.73 m2 or less. Clinical judgement is key when weighing the risks and benefits of 3TC dose adjustment for PWH experiencing gastrointestinal symptoms or moderate lab abnormalities.

Two-drug antiretroviral regimens: an assessment of virologic response and durability among treatment-experienced persons living with HIV in the OPERA® Observational Database.

INTRODUCTION: Two-drug regimens (2-DR) have the potential to be a viable solution to the challenges of treatment complexity, cost, adverse effects and contraindications. We sought to describe the real-world use and effectiveness of 2-DR among persons living with HIV (PLHIV) in the United States. METHODS: We analysed data for 10,190 treatment-experienced patients from the OPERA® Observational Database initiating a new 2-DR or three-drug regimen (3-DR) between 1 January 2010 and 30 June 2016. Multivariate Cox Proportional Hazards models were used to estimate the association among 2-DR or 3-DR initiation and virologic suppression (viral load (VL) <50 copies/mL), virologic failure (2 VLs > 200 copies/mL or 1 VL > 200 copies/mL + discontinuation) or regimen discontinuation. RESULTS: Patients initiating a 2-DR (n = 1337, 13%) were older, and more likely to have a lower CD4 count, a history of AIDS and comorbid conditions than patients initiating a 3-DR. There was no difference between groups in time to virologic suppression (aHR: 1.00 (95% CI: 0.88, 1.13)) among viraemic patients (baseline VL ≥ 50 copies/mL, n = 4180), or time to virologic failure (aHR: 1.15 (95% CI: 0.90, 1.48)) among virologically stable patients (baseline VL < 50 copies/mL, n = 6010). However, time to discontinuation was shorter following 2-DR than 3-DR initiation (aHR: 1.51 (95% CI: 1.41, 1.61)). CONCLUSIONS: In this large cohort of treatment-experienced patients, 2-DR prescriptions were common and more frequent among patients with significant comorbidity. Virologic response was similar, but duration of use was shorter with a 2-DR than a 3-DR, suggesting that 2-DRs may be a virologically effective treatment strategy for treatment-experienced PLHIV with existing comorbidities.

Prevalence of pretreatment and acquired HIV-1 mutations associated with resistance to lamivudine or rilpivirine: a systematic review.

BACKGROUND: Pretreatment and acquired drug resistance mutations (DRMs) can limit antiretroviral therapy effectiveness. METHODS: We review prevalence of DRMs with resistance to nucleoside reverse transcriptase inhibitors (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs), focusing on lamivudine and rilpivirine, from 127 articles with >100,000 individuals with HIV-1 infection. RESULTS: Estimated global prevalence of pretreatment resistance to any NRTI was 4% and to any NNRTI was 6%. Most prevalent DRMs resistant to lamivudine or rilpivirine were at positions E138 (4%), V179 (1%) and M184 (1%). Estimated acquired DRM prevalence was 58% for any NRTIs and 67% for any NNRTIs, most frequently at positions M184 (58%) and Y181 (21%). CONCLUSIONS: This review suggests low risk of lamivudine- or rilpivirine-resistant mutations in treatment-naive, HIV-1-infected individuals.

Uptake and effectiveness of two-drug compared with three-drug antiretroviral regimens among HIV-positive individuals in Europe.

OBJECTIVE: To assess the use of two-drug antiretroviral regimens (2DR) and virologic and immunologic outcomes compared with three-drug regimens (3DR) in the EuroSIDA cohort. DESIGN: Multicentre, prospective cohort study. METHODS: Logistic regression was used to analyse the uptake and outcomes among HIV-positive individuals who started or switched to a 2DR compared with those on a 3DR. Virologic outcomes were assessed on-treatment as the proportion of individuals with controlled viral load (<400 copies/ml), or with a composite modified FDA snapshot endpoint (mFDA), with mFDA success defined as controlled viral load at 6 months or 12 months for individuals with a known viral load, no regimen changes, AIDS or death. Immunologic response was defined as a 100 cells/µl or a 25% increase in CD4 cell counts from baseline. RESULTS: Between 1 July 2010 and 31 December 2016, 423 individuals started or switched to a 2DR (eight antiretroviral-naive) and 4347 started a 3DR (566 naive). Individuals on 2DR tended to have suppressed viral load, higher CD4 cell counts and more comorbidities at baseline compared with those on 3DR. There were no differences in the proportions of individuals who obtained on-treatment or mFDA success, and no significant differences in the adjusted odds ratios for mFDA success or immunologic responses between the 2DR and 3DR groups at 6 months or 12 months. CONCLUSION: In routine clinical practice, 2DR were largely used for virologically suppressed individuals with higher cumulative exposure to antiretrovirals and comorbidities. Virologic and immunologic outcomes were similar among those on 2DR or 3DR, although confounding by indication cannot be fully excluded due to the observational nature of the study.

HLA-B*57:01 screening and hypersensitivity reaction to abacavir between 1999 and 2016 in the OPERA® observational database: a cohort study.

BACKGROUND: HLA-B*57:01 screening was added to clinical care guidelines in 2008 to reduce the risk of hypersensitivity reaction from abacavir. The uptake of HLA-B*57:01 screening and incidence of hypersensitivity reaction were assessed in a prospective clinical cohort in the United States to evaluate the effectiveness of this intervention. METHODS: We included all patients initiating an abacavir-containing regimen for the first time in the pre-HLA-B*57:01 screening period (January 1, 1999 to June 14, 2008) or the post-HLA-B*57:01 screening period (June 15, 2008 to January 1, 2016). Yearly incidence of both HLA-B*57:01 screening and physician panel-adjudicated hypersensitivity reactions were calculated and compared. RESULTS: Of the 9619 patients eligible for the study, 33% initiated abacavir in the pre-screening period and 67% in the post-screening period. Incidence of HLA-B*57:01 screening prior to abacavir initiation increased from 43% in 2009 to 84% in 2015. The incidence of definite or probable hypersensitivity reactions decreased from 1.3% in the pre-screening period to 0.8% in 2009 and further to 0.2% in 2015 in the post-screening period. CONCLUSIONS: Frequency of HLA-B*57:01 screening increased steadily since its first inclusion in treatment guidelines in the United States. This increase in screening was accompanied by a decreasing incidence of definite or probable hypersensitivity reactions over the same period. However, a considerable proportion of patients initiating abacavir were not screened, representing a failed opportunity to prevent hypersensitivity reactions. Where HLA-B*57:01 screening is standard of care, patients should be confirmed negative for this allele before starting abacavir treatment.

Abacavir Use and Risk for Myocardial Infarction and Cardiovascular Events: Pooled Analysis of Data From Clinical Trials.

BACKGROUND: Some observational studies and randomized controlled trials (RCTs) have suggested an association between abacavir (ABC) use and myocardial infarction (MI), whereas others have not. METHODS: This pooled analysis of 66 phase II-IV RCTs estimates exposure-adjusted incidence rates (IRs) and relative rates (RRs) of MI and cardiovascular events (CVEs) in participants receiving ABC- and non-ABC-containing combination antiretroviral therapy (cART). The primary analysis of MI included ABC-randomized trials with ≥48-week follow-up. Sensitivity analyses of MI and CVEs included non-ABC-randomized and <48-week follow-up trials. RESULTS: In 66 clinical trials, 13 119 adults (75% male, aged 18-85 years) were on ABC-containing cART and 7350 were not. Exposure-adjusted IR for MI was 1.5 per 1000 person-years (PY; 95% confidence interval [CI], 0.67-3.34) in the ABC-exposed group and 2.18 per 1000 PY (95% CI, 1.09-4.40) in the unexposed group. The IR for CVEs was 2.9 per 1000 PY (95% CI, 2.09-4.02) in the exposed group and 4.69 per 1000 PY (95% CI, 3.40-6.47) in the unexposed group with studies of ≥48 weeks of follow-up, with an RR of 0.62 (95% CI, 0.39-0.98). The inclusion of nonrandomized and shorter-duration trials did not significantly change the RR for MI or coronary artery disease. CONCLUSIONS: This pooled analysis found comparable IRs for MI and CVEs among ABC-exposed and -unexposed participants, suggesting no increased risk for MI or CVEs following ABC exposure in a clinical trial population. Modifiable risk factors for MI and CVEs should be addressed when prescribing ART.

Pazopanib efficacy in renal cell carcinoma: evidence for predictive genetic markers in angiogenesis-related and exposure-related genes.

PURPOSE: Pazopanib, an oral angiogenesis inhibitor, is approved for the treatment of advanced renal cell carcinoma (RCC). Response to pazopanib monotherapy varies between patients, and no validated biomarkers predictive of treatment outcome have been identified. We tested the hypothesis that this variability is partially dependent on germline genetic variants that may affect pazopanib exposure or angiogenesis pathways. PATIENTS AND METHODS: Twenty-seven functional polymorphisms within 13 genes were evaluated in 397 patients with RCC. Genetic association with progression-free survival (PFS) and objective response rate (RR) was analyzed using the Cox proportional hazards model and proportional odds model, respectively. RESULTS: Three polymorphisms in IL8 and HIF1A and five polymorphisms in HIF1A, NR1I2, and VEGFA showed nominally significant association (P ≤ .05) with PFS and RR, respectively. Compared with the wild-type AA genotype (median PFS, 48 weeks), the IL8 2767TT variant genotype showed inferior PFS (27 weeks, P = .009). The HIF1A 1790AG genotype was associated with inferior PFS and reduced RR, compared with the wild-type GG genotype (median PFS, 20 v 44 weeks; P = .03; RR, 30% v 43%, P = .02). Reductions in RR were detected for the NR1I2 -25385TT genotype, compared with the wild-type CC genotype (37% v 50%, P = .03), and for the VEGFA -1498CC genotype compared with the TT genotypes (33% v 51%). CONCLUSION: Germline variants in angiogenesis- and exposure-related genes may predict treatment response to pazopanib monotherapy in patients with RCC. If validated, these markers may explain why certain patients fail antiangiogenesis therapy and they may support the use of alternative strategies to circumvent this issue.

Screening for Lrrk2 G2019S and clinical comparison of Tunisian and North American Caucasian Parkinson's disease families.

Mutations in the leucine-rich repeat kinase-2 gene (LRRK2) are responsible for some forms of familial as well as sporadic Parkinson's disease (PD). The purpose of this study was to examine the frequency of a single pathogenic mutation (6055G > A) in the kinase domain of this gene in United States and Tunisian familial PD and to compare clinical characteristics between patients with and without the mutation. Standardized case report forms were used for clinical and demographic data collection. We investigated the frequency of the most common substitution of LRRK2 (G2019S, 6055G>A) and its impact on epidemiological and phenotypic features. The frequency of mutations in Tunisian families was 42% (38/91) and in U.S. families 2.6% (1/39), with the unique opportunity to compare homozygous (n = 23) and heterozygous (n = 109) Tunisian carriers of G2019S substitutions. Individuals with G2019S substitutions had an older age at onset but few other differences compared with families negative for the substitution. Patients with LRRK2 mutations had typical clinical features of PD. Comparisons between individuals with heterozygous and homozygous LRRK2 mutations suggested that gene dosage was not correlated with phenotypic differences; however, the estimated penetrance was greater in homozygotes across all age groups.

Multiple components of 2,4-dichlorophenoxyacetic acid uptake by rat choroid plexus.

Initial rates of uptake of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D; 20 microM) were measured in intact lateral choroid plexus from rat. Although inhibition of uptake by millimolar concentrations of estrone sulfate (ES) and unlabeled 2,4-D was maximal at 85%, inhibition by p-aminohippurate (PAH) saturated at about 50%. Inhibition by ES plus PAH was no greater than by ES or 2,4-D alone. Thus, inhibition studies indicated three distinct components of uptake; two mediated and one not. The sodium-dependent component of 2,4-D uptake coincided with the PAH-sensitive component, indicating uptake mediated by organic anion transporter subtype (Oat) 3. Consistent with this, efflux of 2,4-D from preloaded tissue was accelerated by all Oat3 substrates tested, and 2,4-D increased the efflux of the Oat3 substrate, PAH. Consistent with the inhibition data, kinetic analysis showed three components of 2,4-D uptake: a nonmediated component (linear kinetics), a high-affinity component, and a low-affinity component. The high-affinity component appeared to coincide with the PAH-sensitive and sodium-dependent component characterized in inhibition studies. The PAH-insensitive, low-affinity component was inhibited by ES, dehydroepiandrosterone sulfate, and taurocholate but not by 5-hydroxyindole acetic acid. Thus, the first step in transport of 2,4-D from cerebrospinal fluid to blood involves two transporters: Oat3 and a PAH-insensitive, sodium-independent transporter. Based on inhibitor profile, the latter may be Oatp3.