Evaluating virological outcomes in people with HIV on stable antiretroviral therapy with reduced frequency of HIV viral load monitoring during the COVID-19 pandemic.

OBJECTIVES: In response to the COVID-19 pandemic, HIV outpatient attendances were restricted from March 2020, resulting in reduced frequency of HIV viral load (VL) monitoring (previously 6-monthly) in clinically stable and virologically suppressed people living with HIV (PLWH). We investigated virological outcomes during this period of reduced monitoring and compared with the previous year, prior to the COVID-19 pandemic. METHODS: People living with HIV with undetectable VL (<200 HIV RNA copies /mL) on antiretroviral therapy (ART) were identified from March 2018 to February 2019. We determined VL outcomes during the pre-COVD-19 period (March 2019-February 2020) and the COVID-19 period (March 2020-February 2021) when monitoring was restricted. Frequency and longest durations between VL tests in each period were evaluated, and virological sequelae in those with detectable VL were determined. RESULTS: Of 2677 PLWH virologically suppressed on ART (March 2018-February 2019), VLs were measured and undetectable in 2571 (96.0%) and 2003 (77.9%) in the pre-COVID and COVID periods, respectively. Mean (SD) numbers of VL tests were 2.3 (1.08) and 1.1 (0.83) and mean longest duration between VL tests was 29.5 weeks (SD 8.25, 3.1% were ≥12 months) and 43.7 weeks (12.64, 28.4% were ≥12 months), in the pre-COVID and COVID periods, respectively. Of 45 individuals with one or more detectable VL during the COVID-19 period, two developed new drug resistance mutations. CONCLUSION: Reduced VL monitoring was not associated with poorer virological outcomes in the majority of stable individuals receiving ART. One in 20 individuals had not returned for VL testing after ≥31 months and the risk of harm in these individuals is unknown.

Fear, anxiety, and production in laying hens with healed keel bone fractures.

For laying hens, the immediate aftermath and healing period of a keel fracture (KF) is characterized by reduced ability to perform species-specific behavior, access resources, and pain. However, the longer-term impacts, once the fracture is completely healed, are less clear. As well as acute pain and behavioral changes, a negative experience can shape future responses to putatively threatening stimuli, raising future fear, and anxiety levels during husbandry-related events. We aimed to determine whether hens that had previously sustained keel bone fractures, but were now outside of the peak age range for new fractures, showed higher fear and anxiety levels compared to intact hens. We also determined if healed keel bone fractures were associated with reduced production, changes in behavior and resource use. One hundred and fifty hens with a palpation score of 1 ( "KF") and 150 hens with a palpation score of 0 (keel fracture free, "KFF") were selected from a commercial farm at 63 wk of age and housed in 6 groups (3 × KF and 3 × KFF). We compared production (hen weight and feed consumption, egg quantity, quality and weight, floor eggs, shell thickness, and weight) and home pen behavior (behaviors and transitional movements) in both groups. Finally, we measured the responses of KF (n = 75) and KFF (n = 75) during tonic immobility, novel arena, and novel object tests. KF and KFF hens did not differ in their responses to the tonic immobility, novel arena, and novel object tests, nor were there differences between the 2 groups in home pen behavior and transitional movements. KFF birds were lighter and laid eggs with less eggshell membrane compared KF birds, but no differences were found between KF and KFF in any other production measures. We found no evidence that healed KFs were associated with detrimental welfare effects in laying hens, but further work is required to determine the mechanisms and implications of the lower body weight and egg shell membrane.

Objective and subjective rapid frailty screening tools in people with HIV.

OBJECTIVES: As people with HIV (PWH) age, the prevalence of frailty increases. Rapid screening tests to identify frailty within HIV outpatient settings are required to identify at-risk individuals. We undertook a service evaluation to assess three short frailty assessments in PWH. METHODS: We assessed two objective [gait speed (GS), timed-up-and-go test (TUGT)] and one subjective [the self-reported health questionnaire (SRH)] frailty screening tools in PWH aged > 40 years attending a single HIV outpatient department. Factors associated with positive frailty screening tests (defined as GS < 0.8 m/s, TUGT ≥ 10 s and SRH score < 6) were assessed using logistic regression models. ETHICAL CONSIDERATIONS: This was a service evaluation and was approved as a service evaluation by the Imperial College Healthcare NHS trust HIV clinical research committee (February 2020). All participants were given verbal information and were able to terminate the screening tests at any time. RESULTS: Of 84 PWH approached, 80 individuals completed all screening tests (median age = 56 years, range: 40-80) with a positive frailty screening prevalence in 19%, 33% and 20% for GS, TUGT and SRH, respectively. All tests were considered acceptable to participants. Factors statistically significantly associated with frailty included age (GS and TUGT), detectable HIV RNA (TUGT), number of comorbidities (GS and TUGT), presence of polypharmacy (GS and TUGT) and total number of concomitant medication (GS and SRH). CONCLUSIONS: Rates of positive screening tests for frailty are dependent on screening tool used, with all three tools being acceptable to participants. Objective measures of frailty screening (GS and TUGT) are more closely associated with clinical parameters than is a subjective measure of frailty screening (SRH).

Continuation of emtricitabine/lamivudine within combination antiretroviral therapy following detection of the M184V/I HIV-1 resistance mutation.

OBJECTIVES: The aim of the study was to investigate whether lamivudine (3TC) or emtricitabine (FTC) use following detection of M184V/I is associated with better virological outcomes. METHODS: We identified people with viruses harbouring the M184V/I mutation in UK multicentre data sets who had treatment change/initiation within 1 year. We analysed outcomes of viral suppression (< 200 HIV-1 RNA copies/mL) and appearance of new major drug resistance mutations (DRMs) using Cox and Poisson models, with stratification by new drug regimen (excluding 3TC/FTC) and Bayesian implementation, and estimated the effect of 3TC/FTC adjusted for individual and viral characteristics. RESULTS: We included 2597 people with the M184V/I resistance mutation, of whom 665 (25.6%) were on 3TC and 458 (17.6%) on FTC. We found a negative adjusted association between 3TC/FTC use and viral suppression [hazard ratio (HR) 0.84; 95% credibility interval (CrI) 0.71-0.98]. On subgroup analysis of individual drugs, there was no evidence of an association with viral suppression for 3TC (n = 184; HR 0.94; 95% CrI 0.73-1.15) or FTC (n = 454; HR 0.99; 95% CrI 0.80-1.19) amongst those on tenofovir-containing regimens, but we estimated a reduced rate of viral suppression for people on 3TC amongst those without tenofovir use (n = 481; HR 0.71; 95% CrI 0.54-0.90). We found no association between 3TC/FTC and detection of any new DRM (overall HR 0.92; 95% CrI 0.64-1.18), but found inconclusive evidence of a lower incidence rate of new DRMs (overall incidence rate ratio 0.69; 95% CrI 0.34-1.11). CONCLUSIONS: We did not find evidence that 3TC or FTC use is associated with an increase in viral suppression, but it may reduce the appearance of additional DRMs in people with M184V/I. 3TC was associated with reduced viral suppression amongst people on regimens without tenofovir.

Compromised CD4:CD8 ratio recovery in people living with HIV aged over 50 years: an observational study.

OBJECTIVES: Persistent CD4:CD8 ratio inversion (< 1) is associated with mortality in older people. We investigated the interaction of the effects of baseline CD8 count and age at HIV diagnosis on CD4:CD8 ratio recovery with antiretroviral therapy (ART). METHODS: An observational study (1 January 2007 to 31 December 2016) was carried out using routinely collected data from the HIV outpatient services at Imperial College Healthcare NHS Trust, London, UK. CD4 and CD8 counts, prior to and during ART, treatment during primary HIV infection (PHI) and HIV-1 viral load were included in univariate and multivariate analyses using Cox proportional hazard regression. RESULTS: Data were included for 876 patients starting ART, where HIV suppression was achieved. Of these patients, 741 of 876 (84.6%) were male and 507 of 876 (57.9%) were Caucasian. The median time on ART was 38 [interquartile range (IQR) 17-66] months. CD8 count change on ART was bidirectional; low CD8 counts (≤ 600 cells/µL) increased and high CD8 counts (> 900 cells/µL) decreased. The median pre-ART CD4:CD8 ratio was 0.41 (IQR 0.24-0.63), and recovery (≥ 1) occurred in 274 of 876 patients (31.3%). Pre- and post-ART CD4:CD8 ratios were lower in those aged > 50 years compared with young adults aged 18-30 years (P < 0.001 and P = 0.002, respectively). After adjustment, younger age at HIV diagnosis (P < 0.001) and treatment during PHI (P < 0.001) were favourable for CD4:CD8 ratio normalization. CONCLUSIONS: Older age (> 50 years) at HIV diagnosis was associated with persistent CD4:CD8 ratio inversion, whereas treatment of PHI was protective. These findings confirm the need for testing and early treatment of people aged > 50 years, and could be used in a risk management algorithm for enhanced surveillance.

Virtual support for paediatric HIV treatment decision making.

OBJECTIVE: The objective of this study is to review clinical outcomes of recommendations made by a multidisciplinary paediatric virtual clinic (PVC) for complex case management of paediatric HIV as a model of care within a tertiary network. DESIGN: A retrospective review of the clinical outcomes of paediatric and adolescent (0-21 years) referrals to the PVC at St. Mary's Hospital, Imperial College Healthcare NHS Trust, London was performed between October 2009 and November 2013. RESULTS: 234 referrals were made for 182 children from 37 centres, discussed in 42 meetings (median age 13 years, IQR 10-15 years). Reasons for referral included virological failure (44%), simplification of the current regimen (24%) and antiretroviral drug complications (24%). At latest follow-up, PVC advice had been instituted in 80% of referrals. Suppression following virological failure was achieved in 48% following first referral and 57% following subsequent discussions and was maintained in 95% of children referred for regimen simplification. Following advice, dyslipidaemia resolved in 42% and liver function normalised in 73% with biochemical hepatitis. Adherence support aided resolution of viraemia in nine children and 12% of referrals resulted in additional support, including psychology, social services and mental health input. CONCLUSIONS: Combined multidisciplinary virtual input with adult expertise in resistance and newer agents, paediatric knowledge of pill swallowing, childhood formulations/weight banding and parental support, assists complex treatment decision making in paediatric HIV infection. The Virtual Clinic model could be applied to the management of other rare complex diseases of childhood within a clinical network.

HIV-1 co-receptor tropism and disease progression in children and young adults with perinatally acquired HIV-1 infection. The HICCUP Study.

OBJECTIVES: Retrospective analysis of evolution of HIV tropism and association with disease progression in perinatal HIV-1 infection (PaHIV). METHODOLOGY: Eligible patients with PaHIV were grouped as slow, rapid or long-term non-progressors (LTNP). The V3 region of gp120 was sequenced from stored plasma samples and tropism determined by geno2pheno algorithm (FPR 5.75%). Logistic regression with generalised estimating equations assessed factors associated with R5 virus. Time to tropism change was assessed using standard survival methods. RESULTS: At baseline (n=48) median age was 12 years (IQR 9.3-14.8), 52% were female, 79% were Black African, 96% were non-B subtypes and 81% (39/48) had R5-using virus. Median follow-up was 7.7 years (308.6 person-years), with a median of five (range 1-14) samples per subject (total 252). Analysing all samples, R5 virus was associated with higher current CD4 cell count (median 520 cells/mm(3) R5 vs 202 for X4, P=0.0005), LTNP (35% vs 11%, P=0.05), non-Black ethnicity (74% vs 89%, P=0.05) and female gender (55% vs 28%, P=0.005). Twelve of 38 (31%) with R5 virus at baseline switched to X4/dual-using virus, with an estimated 5-year risk of switch of 24.4% (95% CI 9.7-39.2%) predicted by lower current CD4 cell count (unadjusted HR 0.62/50 cells higher, 95% CI 0.47-0.81, P=0.0006). Eleven of 19 (58%) with X4/dual-using virus subsequently had R5 virus at one or more time points. CONCLUSION: Maraviroc was a treatment option for 81% at 12 years, falling to 56% at 18 years, with lower CD4 cell count predictive of co-receptor switching. Paediatric studies of CCR5 antagonists should be expedited to ensure they are an early treatment option before tropism switching occurs.

Raltegravir resistance in the cerebrospinal fluid.

We report the first published case of integrase inhibitor resistance in the central nervous system compartment in the absence of evidence of integrase inhibitor resistance in the plasma of a patient without human immunodeficiency virus (HIV)-encephalitis in the context of other HIV-associated central nervous system infections.

Tape transfer sectioning of tissue microarrays introduces nonspecific immunohistochemical staining artifacts.

Tissue microarrays place tens to hundreds of formalin fixed, paraffin embedded tissue cores into a paraffin block in a systematic grid pattern that permits their simultaneous evaluation in a single section. The fragmented nature of the tissue cores often makes sectioning of tissue microarrays difficult so that the resulting disks of tissue lose their shape, fracture or fall out of the paraffin section altogether. We have evaluated an alternative sectioning protocol for stabilizing the tissue microarray surface by placing an adhesive tape "window" over the face of the paraffin block prior to sectioning. Once sectioned, the tape/sections are transferred directly onto coated microscope slides, thereby avoiding routine floating of sections on a water bath. After sectioning with either the tape transfer or standard protocols, slides were stained either using hematoxylin and eosin or immunohistochemistry using antibodies to S-100 protein and the tissue specific antigens, keratin (AE1/3) and the leukocyte common antigen CD45. We found that the tape method produced thicker sections that were darker and more densely packed with loss of tissue definition compared to sections prepared using water bath flotation. Quantitative image analysis of immunohistochemical staining demonstrated that the tape method produced a higher incidence of nonspecific staining, which raised the potential for false positive staining.

The associations between age and the development of laboratory abnormalities and treatment discontinuation for reasons other than virological failure in the first year of highly active antiretroviral therapy.

OBJECTIVE: The aim of this study was to describe the relationship between age and the time to treatment discontinuation in the absence of virological failure as well as the development of specific laboratory abnormalities, in patients starting highly active antiretroviral therapy (HAART) for the first time. METHODS: Analyses included 8708 antiretroviral-naïve patients from the UK Collaborative HIV Cohort (CHIC) study who started HAART from 1998 onwards. We considered time to the first discontinuation of any drug in the initial HAART regimen for reasons other than virological failure; the association between this and age at the start of HAART was determined using proportional hazards regression after adjustment for potential confounders. The incidence of specific laboratory abnormalities in the first year after starting HAART was compared in those of different ages using multiple logistic regression. RESULTS: A total of 2650 patients discontinued at least one drug in their HAART regimen in the first year for reasons other than virological failure; after controlling for confounders, those aged < 30 years at the time of starting HAART were more likely to discontinue than those aged 30-39 years [relative hazard (RH) 1.12; 95% confidence interval (CI) 1.01, 1.24] as were those aged > or = 50 years (RH 1.14; 95% CI 1.00, 1.31). There were strong associations between greater age and raised total cholesterol, decreased haemoglobin and raised triglycerides over the first year, although the latter disappeared after adjustment for pre-HAART levels, suggesting that this finding reflected higher pre-HAART triglyceride levels in older individuals. CONCLUSIONS: Continued attempts to improve the tolerability of HAART regimens may help to sustain the good outcomes in all age groups over the longer term.

Lessons from IAVI-006, a phase I clinical trial to evaluate the safety and immunogenicity of the pTHr.HIVA DNA and MVA.HIVA vaccines in a prime-boost strategy to induce HIV-1 specific T-cell responses in healthy volunteers.

IAVI-006 was the first large randomised, double-blinded, placebo-controlled Phase I clinical trial to systematically investigate the prime-boost strategy for induction of HIV-1 specific CD8+ cytotoxic T-lymphocytes (CTL) in a factorial trial design using (i) priming with 0.5 mg or 2 mg of pTHr.HIVA DNA vaccine, followed by (ii) two booster vaccinations with 5 x 10(7) MVA.HIVA at weeks 8 and 12 (early boost) or weeks 20 and 24 (late boost). This study set the basis for later clinical trials and demonstrated the safety of these candidate HIV vaccines. The safety and immunogenicity results are presented and the lessons derived from this clinical trial are discussed.

Participation in two phase II prophylactic HIV vaccine trials in the UK.

There will be a continued imperative to recruit large numbers of healthy volunteers to early phase prophylactic HIV vaccine (PHV) trials. We studied mechanisms associated with participation in two related phase II PHV trials. The most cited reasons for volunteering were altruism and a personal connection to HIV. The most successful recruiting strategies targeted organisations dealing with HIV, health or social issues, or were directed to large audiences through the mass media. However, circulated emails and word of mouth were the most resource-effective approaches. Group discussions and the collection of a pool of potential volunteers were much less effective than one-to-one discussions and immediate screening after recruitment. We utilised our findings to devise key recommendations to assist PHV trial teams who are planning future studies.

Passive sexual transmission of human immunodeficiency virus type 1 variants and adaptation in new hosts.

Human immunodeficiency virus type 1 (HIV-1) genetic diversity is a major obstacle for the design of a successful vaccine. Certain viral polymorphisms encode human leukocyte antigen (HLA)-associated immune escape, potentially overcoming limited vaccine protection. Although transmission of immune escape variants has been reported, the overall extent to which this phenomenon occurs in populations and the degree to which it contributes to HIV-1 viral evolution are unknown. Selection on the HIV-1 env gene at transmission favors neutralization-sensitive variants, but it is not known to what degree selection acts on the internal HIV-1 proteins to restrict or enhance the transmission of immune escape variants. Studies have suggested that HLA class I may determine susceptibility to HIV-1 infection, but a definitive role for HLA at transmission remains unproven. Comparing populations of acute seroconverters and chronically infected patients, we found no evidence of selection acting to restrict transmission of HIV-1 variants. We found that statistical associations previously reported in chronic infection between viral polymorphisms and HLA class I alleles are not present in acute infection, suggesting that the majority of viral polymorphisms in these patients are the result of transmission rather than de novo adaptation. Using four episodes of HIV-1 transmission in which the donors and recipients were both sampled very close to the time of infection we found that, despite a transmission bottleneck, genetic variants of HIV-1 infection are transmitted in a frequency-dependent manner. As HIV-1 infections are seeded by unique donor-adapted viral variants, each episode is a highly individual antigenic challenge. Host-specific, idiosyncratic HIV-1 antigenic diversity will seriously tax the efficacy of immunization based on consensus sequences.

Clinical implications of stopping nevirapine-based antiretroviral therapy: relative pharmacokinetics and avoidance of drug resistance.

OBJECTIVE: To determine the pharmacokinetics of cessation of nevirapine (NVP) in order to design clinical protocols which will reduce the risk of resistance to nonnucleoside reverse transcriptase inhibitors (NNRTIs). METHODS: In a case study, NNRTI genotypic resistance was demonstrated in a patient discontinuing therapy for toxicity. Subsequently, nine patients receiving NVP-containing antiretroviral regimens and stopping treatment were recruited. Patients were advised to continue the nucleoside analogue reverse transcriptase inhibitor (NRTI) backbone for 5 days following cessation of NVP. Plasma NVP concentrations were determined over 7-10 days after the last dose. HIV-1 reverse transcriptase genotyping was performed at viral load rebound (approximately day 21 following cessation) to detect mutations associated with reduced NNRTI sensitivity. RESULTS: The median predicted time for plasma NVP concentration to fall below the inhibitory concentration (IC)(50) of wild-type virus was 168 h (range 108-264 h). De novo genotypic mutations conferring resistance to NRTIs or NNRTIs were not demonstrated following cessation of therapy. CONCLUSIONS: The prolonged elimination half-life of NVP compared with NRTIs, which persists even after 20 weeks of therapy, raises concern over the development of NNRTI resistance if all three drugs are stopped together. Continuation of the NRTI backbone for a further 5 days, allowing the elimination of NVP, may avoid the development of drug resistance.

Exchange of organic solvents between the atmosphere and grass--the use of open top chambers.

Volatile organic compounds (VOC) are of increasing environmental significance as a result of continually increasing volumes of traffic on European roads. An open-top chamber fumigation system has been devised to investigate how these contaminants transfer between the atmosphere and the ground, and how they partition between and within air-plant-soil systems. Variation in chamber temperature, solar radiation in the chamber and chamber flow rate were identified as factors that affected final air concentrations. These were assessed and quantified for all individual chambers used--effectively characterising each chamber. The real-life VOC concentrations generated were stable and readily reproducible. Grass exposed to benzene, toluene, 1,1,1-trichloroethane and tetrachloroethene, respectively, equilibrated in response to a change in air concentration within hours. The rate of equilibration in exposed grass in all cases was independent of air temperature. 1,1,1-Trichloroethane and tetrachloroethene appear to be biologically inert demonstrating a simple physico-chemical approach to equilibrium, however, benzene and toluene do not appear independent of plant metabolic activity. Aqueous solubility can account for all of the toluene and benzene in the fumigated plant material.