An HLA-I signature favouring KIR-educated Natural Killer cells mediates immune control of HIV in children and contrasts with the HLA-B-restricted CD8+ T-cell-mediated immune control in adults.

Natural Killer (NK) cells contribute to HIV control in adults, but HLA-B-mediated T-cell activity has a more substantial impact on disease outcome. However, the HLA-B molecules influencing immune control in adults have less impact on paediatric infection. To investigate the contribution NK cells make to immune control, we studied >300 children living with HIV followed over two decades in South Africa. In children, HLA-B alleles associated with adult protection or disease-susceptibility did not have significant effects, whereas Bw4 (p = 0.003) and low HLA-A expression (p = 0.002) alleles were strongly associated with immunological and viral control. In a comparator adult cohort, Bw4 and HLA-A expression contributions to HIV disease outcome were dwarfed by those of protective and disease-susceptible HLA-B molecules. We next investigated the immunophenotype and effector functions of NK cells in a subset of these children using flow cytometry. Slow progression and better plasma viraemic control were also associated with high frequencies of less terminally differentiated NKG2A+NKp46+CD56dim NK cells strongly responsive to cytokine stimulation and linked with the immunogenetic signature identified. Future studies are indicated to determine whether this signature associated with immune control in early life directly facilitates functional cure in children.

Borrowing information across patient subgroups in clinical trials, with application to a paediatric trial.

BACKGROUND: Clinical trial investigators may need to evaluate treatment effects in a specific subgroup (or subgroups) of participants in addition to reporting results of the entire study population. Such subgroups lack power to detect a treatment effect, but there may be strong justification for borrowing information from a larger patient group within the same trial, while allowing for differences between populations. Our aim was to develop methods for eliciting expert opinions about differences in treatment effect between patient populations, and to incorporate these opinions into a Bayesian analysis. METHODS: We used an interaction parameter to model the relationship between underlying treatment effects in two subgroups. Elicitation was used to obtain clinical opinions on the likely values of the interaction parameter, since this parameter is poorly informed by the data. Feedback was provided to experts to communicate how uncertainty about the interaction parameter corresponds with relative weights allocated to subgroups in the Bayesian analysis. The impact on the planned analysis was then determined. RESULTS: The methods were applied to an ongoing non-inferiority trial designed to compare antiretroviral therapy regimens in 707 children living with HIV and weighing ≥ 14 kg, with an additional group of 85 younger children weighing < 14 kg in whom the treatment effect will be estimated separately. Expert clinical opinion was elicited and demonstrated that substantial borrowing is supported. Clinical experts chose on average to allocate a relative weight of 78% (reduced from 90% based on sample size) to data from children weighing ≥ 14 kg in a Bayesian analysis of the children weighing < 14 kg. The total effective sample size in the Bayesian analysis was 386 children, providing 84% predictive power to exclude a difference of more than 10% between arms, whereas the 85 younger children weighing < 14 kg provided only 20% power in a standalone frequentist analysis. CONCLUSIONS: Borrowing information from a larger subgroup or subgroups can facilitate estimation of treatment effects in small subgroups within a clinical trial, leading to improved power and precision. Informative prior distributions for interaction parameters are required to inform the degree of borrowing and can be informed by expert opinion. We demonstrated accessible methods for obtaining opinions.

Excessive Media Consumption About COVID-19 is Associated With Increased State Anxiety: Outcomes of a Large Online Survey in Russia.

BACKGROUND: The COVID-19 pandemic has potentially had a negative impact on the mental health and well-being of individuals and families. Anxiety levels and risk factors within particular populations are poorly described. OBJECTIVE: This study aims to evaluate confidence, understanding, trust, concerns, and levels of anxiety during the COVID-19 pandemic in the general population and assess risk factors for increased anxiety. METHODS: We launched a cross-sectional online survey of a large Russian population between April 6 and 15, 2020, using multiple social media platforms. A set of questions targeted confidence, understanding, trust, and concerns in respondents. The State-Trait Anxiety Inventory was used to measure anxiety. Multiple linear regressions were used to model predictors of COVID-19-related anxiety. RESULTS: The survey was completed by 23,756 out of 53,966 (44.0% response rate) unique visitors; of which, 21,364 were residing in 62 areas of Russia. State Anxiety Scale (S-Anxiety) scores were higher than Trait Anxiety Scale scores across all regions of Russia (median S-Anxiety score 52, IQR 44-60), exceeding published norms. Time spent following news on COVID-19 was strongly associated with an increased S-Anxiety adjusted for baseline anxiety level. One to two hours spent reading COVID-19 news was associated with a 5.46 (95% CI 5.03-5.90) point difference, 2-3 hours with a 7.06 (95% CI 6.37-7.74) point difference, and more than three hours with an 8.65 (95% CI 7.82-9.47) point difference, all compared to less than 30 minutes per day. Job loss during the pandemic was another important factor associated with higher S-Anxiety scores (3.95, 95% CI 3.31-4.58). Despite survey respondents reporting high confidence in information regarding COVID-19 as well as an understanding of health care guidance, they reported low overall trust in state and local authorities, and perception of country readiness. CONCLUSIONS: Among Russian respondents from multiple social media platforms, there was evidence of higher levels of state anxiety associated with recent job loss and increased news consumption, as well as lower than expected trust in government agencies. These findings can help inform the development of key public health messages to help reduce anxiety and raise perceived trust in governmental response to this current national emergency. Using a similar methodology, comparative surveys are ongoing in other national populations.

Differential Immunodominance Hierarchy of CD8+ T-Cell Responses in HLA-B*27:05- and -B*27:02-Mediated Control of HIV-1 Infection.

The well-characterized association between HLA-B*27:05 and protection against HIV disease progression has been linked to immunodominant HLA-B*27:05-restricted CD8+ T-cell responses toward the conserved Gag KK10 (residues 263 to 272) and polymerase (Pol) KY9 (residues 901 to 909) epitopes. We studied the impact of the 3 amino acid differences between HLA-B*27:05 and the closely related HLA-B*27:02 on the HIV-specific CD8+ T-cell response hierarchy and on immune control of HIV. Genetic epidemiological data indicate that both HLA-B*27:02 and HLA-B*27:05 are associated with slower disease progression and lower viral loads. The effect of HLA-B*27:02 appeared to be consistently stronger than that of HLA-B*27:05. In contrast to HLA-B*27:05, the immunodominant HIV-specific HLA-B*27:02-restricted CD8+ T-cell response is to a Nef epitope (residues 142 to 150 [VW9]), with Pol KY9 subdominant and Gag KK10 further subdominant. This selection was driven by structural differences in the F pocket, mediated by a polymorphism between these two HLA alleles at position 81. Analysis of autologous virus sequences showed that in HLA-B*27:02-positive subjects, all three of these CD8+ T-cell responses impose selection pressure on the virus, whereas in HLA-B*27:05-positive subjects, there is no Nef VW9-mediated selection pressure. These studies demonstrate that HLA-B*27:02 mediates protection against HIV disease progression that is at least as strong as or stronger than that mediated by HLA-B*27:05. In combination with the protective Gag KK10 and Pol KY9 CD8+ T-cell responses that dominate HIV-specific CD8+ T-cell activity in HLA-B*27:05-positive subjects, a Nef VW9-specific response is additionally present and immunodominant in HLA-B*27:02-positive subjects, mediated through a polymorphism at residue 81 in the F pocket, that contributes to selection pressure against HIV.IMPORTANCE CD8+ T cells play a central role in successful control of HIV infection and have the potential also to mediate the eradication of viral reservoirs of infection. The principal means by which protective HLA class I molecules, such as HLA-B*27:05 and HLA-B*57:01, slow HIV disease progression is believed to be via the particular HIV-specific CD8+ T cell responses restricted by those alleles. We focus here on HLA-B*27:05, one of the best-characterized protective HLA molecules, and the closely related HLA-B*27:02, which differs by only 3 amino acids and which has not been well studied in relation to control of HIV infection. We show that HLA-B*27:02 is also protective against HIV disease progression, but the CD8+ T-cell immunodominance hierarchy of HLA-B*27:02 differs strikingly from that of HLA-B*27:05. These findings indicate that the immunodominant HLA-B*27:02-restricted Nef response adds to protection mediated by the Gag and Pol specificities that dominate anti-HIV CD8+ T-cell activity in HLA-B*27:05-positive subjects.

Identifying central tenets needed in our education systems: Results from a pilot integrated clinical apprenticeship.

Purpose: The ability of healthcare systems to deliver world-class compassionate care depends on the quality of training and education of staff. Matching student-centered learning with patient-centered care is the focus for much curricula reform. This study explores the effect a novel longitudinal curriculum had on medical students' attitudes and experiences to better identify central tenets needed in our education system. Methods: Single-center, qualitative focus-group study conducted in 2017 of medical students in a longitudinally integrated clinical apprenticeship at a large UK medical school. Students were randomly assigned to focus groups to describe their educational journey and explore how longitudinal learning prepared them for a medical career, valuing their unique position as student participants in the healthcare system. Results: Four themes emerged from students' experiences: navigating the patient journey, their professional development, their learning journey, and the healthcare system. Conclusions: Listening to student voices lends insights for educators refining educational models to produce doctors of tomorrow. This project identified the educational value of students having authentic roles in helping patients navigate the healthcare system and the benefits of consistent mentorship and greater autonomy. The gulf between gaining skills as a future doctor and gaining skills to pass summative exams calls into question assessment methods.

When water is thicker than blood: recognising a systemic cause of haemoptysis.

The case of an 11-year-old child presenting with acute haemoptysis and breathlessness is described. The girl was Malaysian and had recently arrived in the UK. She subsequently deteriorated, developing respiratory failure. The course of the illness is described, with reference to the diagnostic process at each stage. The case demonstrates the importance of having a broad investigatory approach in acute haemoptysis.

Is antenatal screening for hepatitis C virus cost-effective? A decade's experience at a London centre.

BACKGROUND & AIMS: This study aims to assess the cost-effectiveness of a routine universal antenatal hepatitis C virus (HCV) screening programme at a London centre. METHODS: Ten years' retrospective antenatal screening and outcome data informed a cost-effectiveness analysis using the previously validated MONARCH model. The cost and quality of life outcomes associated with the screening and treatment of newly identified hepatitis C cases were used to generate cost-effectiveness estimates for the screening programme. RESULTS: A total of 35,355 women were screened between 1st November 2003 and 1st March 2013; 136 women (0.38%) were found to be HCV antibody positive. Of 78 (0.22%) viraemic cases, 44 (0.12%) were newly diagnosed. In addition, the screening programme identified three (6.8%) vertical transmissions in children of newly diagnosed mothers. Of 16 newly diagnosed mothers biopsied, all were in the F0-F2 METAVIR disease stages, and 50% had HCV genotype 1. Postnatal treatment with pegylated interferon and ribavirin was initiated in 19 women, with 14 (74%) achieving sustained virologic response. The total cost of screening and confirmation of diagnoses was estimated to be £240,641. This translates to £5469 per newly diagnosed individual. The incremental cost-effectiveness ratio of this screening and treatment strategy was £2400 per QALY gained. Treatment with newer direct-acting antiviral regimens would have a projected cost of £9139 per QALY gained, well below the £20,000-30,000/QALY gained willingness-to-pay threshold applied by policy advisory bodies. CONCLUSIONS: This study demonstrates that an antenatal screening and treatment programme is feasible and effective, at a cost considered acceptable.

Slow progression of pediatric HIV associates with early CD8+ T cell PD-1 expression and a stem-like phenotype.

HIV nonprogression despite persistent viremia is rare among adults who are naive to antiretroviral therapy (ART) but relatively common among ART-naive children. Previous studies indicate that ART-naive pediatric slow progressors (PSPs) adopt immune evasion strategies similar to those described in natural hosts of SIV. However, the mechanisms underlying this immunophenotype are not well understood. In a cohort of early-treated infants who underwent analytical treatment interruption (ATI) after 12 months of ART, expression of PD-1 on CD8+ T cells immediately before ATI was the main predictor of slow progression during ATI. PD-1+CD8+ T cell frequency was also negatively correlated with CCR5 and HLA-DR expression on CD4+ T cells and predicted stronger HIV-specific T lymphocyte responses. In the CD8+ T cell compartment of PSPs, we identified an enrichment of stem-like TCF-1+PD-1+ memory cells, whereas pediatric progressors and viremic adults had a terminally exhausted PD-1+CD39+ population. TCF-1+PD-1+ expression on CD8+ T cells was associated with higher proliferative activity and stronger Gag-specific effector functionality. These data prompted the hypothesis that the proliferative burst potential of stem-like HIV-specific cytotoxic cells could be exploited in therapeutic strategies to boost the antiviral response and facilitate remission in infants who received early ART with a preserved and nonexhausted T cell compartment.

Intrauterine herpes simplex virus infection presenting with hypopigmented lesions.

Genital herpes simplex virus (HSV) is a sexually transmitted infection that can be transmitted from mother to child in utero, perinatally, or postnatally. Cutaneous infection with HSV commonly presents as vesicles affecting the skin, eyes, or mouth. In our case, we report a well child with cutaneous hypopigmented patches at birth that preceded typical blistering.

Robust HIV-specific CD4+ and CD8+ T-cell responses distinguish elite control in adolescents living with HIV from viremic nonprogressors.

BACKGROUND: Elite controllers are therapy-naive individuals living with HIV capable of spontaneous control of plasma viraemia for at least a year. Although viremic nonprogressors are more common in vertical HIV-infection than in adults' infection, elite control has been rarely characterized in the pediatric population. DESIGN: We analyzed the T-cell immunophenotype and the HIV-specific response by flow cytometry in four pediatric elite controllers (PECs) compared with age-matched nonprogressors (PNPs), progressors and HIV-exposed uninfected (HEUs) adolescents. RESULTS: PECs T-cell populations had lower immune activation and exhaustion levels when compared with progressors, reflected by a more sustained and preserved effector function. The HIV-specific T-cell responses among PECs were characterized by high-frequency Gag-specific CD4+ T-cell activity, and markedly more polyfunctional Gag-specific CD8+ activity, compared with PNPs and progressors. These findings were consistently observed even in the absence of protective HLA-I molecules such as HLA-B∗27/57/81. CONCLUSION: Pediatric elite control is normally achieved after years of infection, and low immune activation in PNPs precedes the increasing ability of CD8+ T-cell responses to achieve immune control of viraemia over the course of childhood, whereas in adults, high immune activation in acute infection predicts subsequent CD8+ T-cell mediated immune control of viremia, and in adult elite controllers, low immune activation is therefore the consequence of the rapid CD8+ T-cell mediated immune control generated after acute infection. This distinct strategy adopted by PECs may help identify pathways that facilitate remission in posttreatment controllers, in whom protective HLA-I molecules are not the main factor.

Replicative capacity of human immunodeficiency virus type 1 transmitted from mother to child is associated with pediatric disease progression rate.

Human immunodeficiency virus (HIV)-infected infants in the developing world typically progress to AIDS or death within the first 2 years of life. However, a minority progress relatively slowly. This study addresses the potential contribution of viral factors to HIV disease progression in eight infants selected from a well-characterized cohort of C clade HIV-infected infants, monitored prospectively from birth in Durban, South Africa. Three infants were defined as "progressors," and five were defined as "slow progressors." We observed that slow-progressor infants carry HIV isolates with significantly lower replicative capacity compared to virus from progressors. Furthermore, our data suggest a link between the attenuated viral phenotype and HLA-B* 57/5801 epitope-specific Gag mutational patterns of the transmitted virus and not to coreceptor usage or to the presence of Nef deletions or insertions. These data underline the importance of virus-host interactions and highlight the contribution of viral attenuation through Gag-specific CD8(+) T-cell escape mutations, among other factors, in the control of pediatric HIV infection.

HLA-Cw*03-restricted CD8+ T-cell responses targeting the HIV-1 gag major homology region drive virus immune escape and fitness constraints compensated for by intracodon variation.

The potential importance of HLA-C-restricted CD8+ cytotoxic T lymphocytes (CTL) in HIV infection remains undetermined. We studied the dominant HLA-Cw*03-restricted CTL response to YVDRFFKTL(296-304) (YL9), within the conserved major homology region (MHR) of the Gag protein, in 80 HLA-Cw*03-positive individuals with chronic HIV infection to better define the efficacy of the YL9 HLA-C-restricted response. The HLA-Cw*03 allele is strongly associated with HIV sequence changes from Thr-303 to Val, Ile, or Ala at position 8 within the YL9 epitope (P=1.62×10(-10)). In vitro studies revealed that introduction of the changes T303I and T303A into the YL9 epitope both significantly reduced CTL recognition and substantially reduced the viral replicative capacity. However, subsequent selection of the Val-303 variant, via intracodon variation from Ile-303 (I303V) or Ala-303 (A303V), restored both viral fitness and CTL recognition, as supported by our in vivo data. These results illustrate that HLA-C-restricted CTL responses are capable of driving viral immune escape within Gag, but in contrast to what was previously described for HLA-B-restricted Gag escape mutants, the common Cw*03-Gag-303V variant selected resulted in no detectable benefit to the host.

Impact of HLA in mother and child on disease progression of pediatric human immunodeficiency virus type 1 infection.

A broad Gag-specific CD8(+) T-cell response is associated with effective control of adult human immunodeficiency virus (HIV) infection. The association of certain HLA class I molecules, such as HLA-B*57, -B*5801, and -B*8101, with immune control is linked to mutations within Gag epitopes presented by these alleles that allow HIV to evade the immune response but that also reduce viral replicative capacity. Transmission of such viruses containing mutations within Gag epitopes results in lower viral loads in adult recipients. In this study of pediatric infection, we tested the hypothesis that children may tend to progress relatively slowly if either they themselves possess one of the protective HLA-B alleles or the mother possesses one of these alleles, thereby transmitting a low-fitness virus to the child. We analyzed HLA type, CD8(+) T-cell responses, and viral sequence changes for 61 mother-child pairs from Durban, South Africa, who were monitored from birth. Slow progression was significantly associated with the mother or child possessing one of the protective HLA-B alleles, and more significantly so when the protective allele was not shared by mother and child (P = 0.007). Slow progressors tended to make CD8(+) T-cell responses to Gag epitopes presented by the protective HLA-B alleles, in contrast to progressors expressing the same alleles (P = 0.07; Fisher's exact test). Mothers expressing the protective alleles were significantly more likely to transmit escape variants within the Gag epitopes presented by those alleles than mothers not expressing those alleles (75% versus 21%; P = 0.001). Reversion of transmitted escape mutations was observed in all slow-progressing children whose mothers possessed protective HLA-B alleles. These data show that HLA class I alleles influence disease progression in pediatric as well as adult infection, both as a result of the CD8(+) T-cell responses generated in the child and through the transmission of low-fitness viruses by the mother.

Self-Perceived Confidence of Medical Students Communicating with Pediatric Patients in a 7-Week Pediatric Placement: A Pilot Survey.

BACKGROUND: Pediatrics is a specialty reserved until later stages of the medical curriculum, with many students receiving early exposure via volunteering opportunities. Self-perceived confidence across the pediatric curriculum is crucial, due to limited clinical exposure before qualification. We aimed to assess the impact of a 7-week pediatric placement on medical students' self-perceived confidence and factors that influenced self-perceived confidence. METHODS: We conducted a prospective pilot survey on three cohorts of fifth-year students undertaking pediatric placements in 2018. A two-part questionnaire was distributed before and after the placement, evaluating the level of self-confidence in clinical skills using a 10-point scale. RESULTS: Of 103 students, 62 (60%) students completed both questionnaires. Of these, 34 (55%) students reported previous professional experiences with children. There was a significant increase in self-reported confidence scores across ten questions before (mean 5.4 [IQR 4.1-6.1]) and after the placement (7.6 [6.6-8.5], p<0.0001). Subgroup analyses between students with prior professional experience with children and those without revealed a significant difference in preplacement confidence in four pediatric practices: verbal communication, physical engagement, asking sensitive or probing questions, and explaining medical management (p<0.05). There was no significant difference in postplacement confidence between these two groups. CONCLUSION: Medical students with prior professional experience with children reported higher self-confidence in interacting with pediatric patients prior to placement. However, a large and consistent increase in confidence across the cohort was such that there were no measurable differences at exit. This study supports the value of undergraduate pediatric training in promoting student self-confidence in managing pediatric clinical issues.

PENTA 2009 guidelines for the use of antiretroviral therapy in paediatric HIV-1 infection.

PENTA Guidelines aim to provide practical recommendations for treating children with HIV infection in Europe. Changes to guidance since 2004 have been informed by new evidence and by expectations of better outcomes following the ongoing success of antiretroviral therapy (ART). Participation in PENTA trials of simplifying treatment is encouraged. The main changes are in the following sections: 'When to start ART': Treatment is recommended for all infants, and at higher CD4 cell counts and percentages in older children, in line with changes to adult guidelines. The number of age bands has been reduced to simplify and harmonize with other paediatric guidelines. Greater emphasis is placed on CD4 cell count in children over 5 years, and guidance is provided where CD4% and CD4 criteria differ. 'What to start with': A three-drug regimen of two nucleoside reverse transcriptase inhibitors (NRTIs) with either a nonnucleoside reverse transcriptase inhibitor (NNRTI) or a boosted protease inhibitor (PI) remains the first choice combination. Lamivudine and abacavir are the NRTI backbone of choice for most children, based on long-term follow-up in the PENTA 5 trial. Stavudine is no longer recommended. Whether to start with an NNRTI or PI remains unclear, but PENPACT 1 trial results in 2009 may help to inform this. All PIs should be ritonavir boosted. Recommendations on use of resistance testing, therapeutic drug monitoring and HLA testing draw from data in adults and from European paediatric cohort studies. Recently updated US and WHO paediatric guidelines provide more detailed review of the evidence base. Differences between guidelines are highlighted and explained.

Paediatric Integrase Inhibitor Use in a Real-Life Setting: A Single-Centre Cohort Experience 2009-2018.

BACKGROUND AND OBJECTIVE: Integrase strand transfer inhibitors (INSTIs) have become the preferred first-line antiretroviral therapy in adults. There is paucity of published data on their use in children outside of clinical trials, particularly long-term safety and tolerability. This study aimed to describe INSTI use including the number of, and reasons for INSTI discontinuation. METHODS: We conducted a retrospective cohort analysis by database and electronic record review of children aged under 18 years with perinatally acquired human immunodeficiency virus who started INSTI-based antiretroviral therapy between May 2009 and March 2018, in a single tertiary centre. RESULTS: Fifty-six INSTI-based regimens were prescribed in 54 children, 64.9% from 2015 onwards. Twenty-one of 56 (37.5%) regimens commenced with raltegravir, 29 (51.8%) with dolutegravir and six (10.7%) with elvitegravir. The median age at the start of treatment was 15 years (interquartile range 13.5-16.4) with a median duration of INSTI-antiretroviral therapy of 1.65 years (range 0.01-8.8). Twenty-four children had a detectable viral load at the start INSTI therapy; 20 (83%) achieving viral suppression in a median of 26 days (interquartile range 19.5-34.5). There were 26 discontinuations of INSTI-based antiretroviral therapy after a median of 183 days; 9/26 because of adverse events. Four of nine adverse events were attributed to INSTI use, all in patients taking dolutegravir and the adverse events were neuropsychiatric and gastrointestinal in nature. CONCLUSIONS: INSTI-based regimens were generally efficacious and well tolerated in this paediatric cohort, with 4/26 discontinuations due to INSTI-attributed adverse events. Further post-marketing surveillance of INSTI use in children is warranted.

Strong sex bias in elite control of paediatric HIV infection.

BACKGROUND: Reports of posttreatment control following antiretroviral therapy (ART) have prompted the question of how common immune control of HIV infection is in the absence of ART. In contrast to adult infection, where elite controllers have been very well characterized and constitute approximately 0.5% of infections, very few data exist to address this question in paediatric infection. METHODS: We describe 11 ART-naive elite controllers from 10 cohorts of HIV-infected children being followed in South Africa, Brazil, Thailand, and Europe. RESULTS: All but one of the elite controllers (91%) are females. The median age at which control of viraemia was achieved was 6.5 years. Five of these 11 (46%) children lost control of viraemia at a median age of 12.9 years. Children who maintained control of viraemia had significantly higher absolute CD4 cell counts in the period of elite control than those who lost viraemic control. On the basis of data available from these cohorts, the prevalence of elite controllers in paediatric infection is estimated to be 5-10-fold lower than in adults. CONCLUSION: Although conclusions are limited by the study design, these data suggest that, whilst paediatric elite control can be achieved, compared with adult elite controllers, this occurs rarely, and takes some years after infection to achieve. Also, loss of immune control arises in a high proportion of children and often relatively rapidly. These findings are consistent with the more potent antiviral immune responses observed in adults and in females.