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.

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.

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.

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.

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.

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.

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.

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. RESULT: 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 CD4þ 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 5­10-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

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.

Recovery of effective HIV-specific CD4+ T-cell activity following antiretroviral therapy in paediatric infection requires sustained suppression of viraemia.

BACKGROUND: The success of increasing access to antiretroviral therapy (ART) in paediatric HIV infection prompts the question of the potential for eradication of HIV infection in this age group. 'Shock-and-kill' HIV cure approaches, currently in development, may depend upon an effective antiviral T-cell response to eradicate virus-infected cells. METHOD: We here investigate the ability of HIV-infected children receiving ART from early childhood (median 24 months' age) to generate effective HIV-specific CD4 and CD8 T-cell immune responses that would facilitate future immune-based cure therapies. RESULTS: Initial analysis of ART-naive HIV-infected children demonstrated that maintenance of normal-for-age absolute CD4 T-cell counts was strongly linked to high IL-2 production and polyfunctional HIV-specific CD4 T-cell responses (P < 0.0001 in each case). Low viral load was, similarly, strongly associated with markedly low IFN-γ and high IL-2 HIV-specific CD4 T-cell responses (P < 0.0001). In children receiving ART, establishment of this immune profile (high IL-2 and low IFN-γ HIV-specific T-cell production) was strongly related to the duration of viraemic suppression. Failure to suppress viraemia on ART, and even the successful suppression of viraemia interrupted by the occurrence of transient viraemia of more than 1000 HIV copies/ml, was associated with an immune profile of high IFN-γ and low IL-2 HIV-specific T-cell responses and low polyfunctionality. CONCLUSION: These data are consistent with recovery of functional CD4 T-cell responses in ART-treated children, in contrast to relative lack of CD4 T-cell function recovery described in ART-treated adults. However, the challenges of achieving long-term suppression of viraemia in ART-treated children through adolescence remain daunting.

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.

Discontinuation of Efavirenz in Paediatric Patients: Why do Children Switch?

BACKGROUND: Efavirenz, a non-nucleoside reverse transcriptase inhibitor (NNRTI) is used globally as first-line antiretroviral therapy (ART) in combination with a dual nucleoside backbone in adults and children from 3 years of age. Up to 40% of adults taking efavirenz report central nervous system (CNS) adverse effects, and the rates of discontinuation of efavirenz-based treatment are higher than other first-line regimens. Data on efavirenz discontinuation are more limited for children and adolescents. OBJECTIVE: In this study, we aimed to describe our single-centre paediatric experience of efavirenz. METHODS: Retrospective case-note audit of children and adolescents with perinatally acquired HIV who ever received efavirenz. RESULTS: From 1998 and 2014, 51 children and adolescents aged ≤ 18 years received efavirenz-based treatment. Median age at efavirenz initiation was 9.4 years (interquartile range [IQR] 7-13). More than half (30/51; 59%) subsequently switched off efavirenz-15 (29%) following virological failure with NNRTI-associated resistance mutations, and 16 (30%) after reporting adverse effects. Of those who experienced adverse effects, one-fifth (19.6%) described CNS adverse effects, including sleep disturbance, reduced concentration, headaches, mood change and psychosis. Four children (three males) developed gynaecomastia, two developed hypercholesterolaemia, and one child developed Stevens-Johnson syndrome. Comparison between those reporting side effects and the rest of the cohort showed no difference in age, sex, initial CD4 cell count, viral suppression, length of efavirenz-based treatment, weight, or efavirenz dose per kilogram. Median time to switch was 25 months (IQR 10-71) in those who experienced side effects and 22 months (IQR 12-50) for virological failure. One individual experienced both virological failure and adverse effects. CONCLUSION: Almost two-thirds of this paediatric cohort switched from efavirenz-based treatment to an alternative regimen, due in equal proportions to both virological failure and toxicity. The majority of side effects involved the CNS. First-line regimens with improved tolerability and a higher genetic barrier to resistance should be the preferred option for children.

Role of HIV-specific CD8+ T cells in pediatric HIV cure strategies after widespread early viral escape.

Recent studies have suggested greater HIV cure potential among infected children than adults. A major obstacle to HIV eradication in adults is that the viral reservoir is largely comprised of HIV-specific cytotoxic T lymphocyte (CTL) escape variants. We here evaluate the potential for CTL in HIV-infected slow-progressor children to play an effective role in "shock-and-kill" cure strategies. Two distinct subgroups of children were identified on the basis of viral load. Unexpectedly, in both groups, as in adults, HIV-specific CTL drove the selection of escape variants across a range of epitopes within the first weeks of infection. However, in HIV-infected children, but not adults, de novo autologous variant-specific CTL responses were generated, enabling the pediatric immune system to "corner" the virus. Thus, even when escape variants are selected in early infection, the capacity in children to generate variant-specific anti-HIV CTL responses maintains the potential for CTL to contribute to effective shock-and-kill cure strategies in pediatric HIV infection.

Hepatic, Renal, Hematologic, and Inflammatory Markers in HIV-Infected Children on Long-term Suppressive Antiretroviral Therapy.

BACKGROUND: Data on long-term toxicity of antiretroviral therapy (ART) in HIV-infected children are sparse. PENPACT-1 was an open-label trial in which HIV-infected children were assigned randomly to receive protease inhibitor (PI)- or nonnucleoside reverse-transcriptase inhibitor (NNRTI)-based ART. METHODS: We examined changes in clinical, immunologic, and inflammatory markers from baseline to year 4 in the subset of children in the PENPACT-1 study who experienced viral suppression between week 24 and year 4 of ART. Liver enzyme, creatinine, and cholesterol levels and hematologic parameters were assessed during the trial. Cystatin C, high-sensitivity C-reactive protein (hs-CRP), interleukin 6 (IL-6), d-dimer, and soluble CD14 (sCD14) were assayed from cryopreserved specimens. RESULTS: Ninety-nine children (52 on PI-based and 47 on NNRTI-based ART) met inclusion criteria. The median age at initiation of ART was 6.5 years (interquartile range [IQR], 3.7-13.4 years), and 22% were aged <3 years at ART initiation; 56% of the PI-treated children received lopinavir/ritonavir, and 70% of NNRTI-treated children received efavirenz initially. We found no evidence of significant clinical toxicity in either group; growth, liver, kidney, and hematologic parameters either remained unchanged or improved between baseline and year 4. Total cholesterol levels increased modestly, but no difference between the groups was found. IL-6 and hs-CRP levels decreased more after 4 years in the NNRTI-based ART group. The median change in IL-6 level was -0.35 pg/ml in the PI-based ART group and -1.0 in the NNRTI-based ART group (P = .05), and the median change in hs-CRP level was 0.25 µg/ml in the PI-based ART group and -0.95 µg/ml in the NNRTI-based ART group (P = .005). CONCLUSION: These results support the safety of prolonged ART use in HIV-infected children and suggest that suppressive NNRTI-based regimens can be associated with lower levels of systemic inflammation.

Hepatocellular Carcinoma in Perinatally Acquired HIV and HBV Coinfection: A Case Report.

This report describes a case of hepatocellular carcinoma in an adolescent with perinatally acquired HIV and hepatitis B virus coinfection, arising despite more than a decade of suppressive antiretroviral therapy for both HIV and hepatitis B virus. This case raises important questions regarding optimal hepatocellular carcinoma screening in this high-risk group and the oncogenic potential of even very well-controlled viral infection.

Post-exposure prophylaxis guidelines for children and adolescents potentially exposed to HIV.

UK guidelines for HIV post-exposure prophylaxis (PEP) in adults have recently been updated. Indications for PEP have been modified and there has been a change in the recommended antiretroviral therapy for adults to a combination of raltegravir with tenofovir and emtricitabine (Truvada). Raltegravir and tenofovir are now available in paediatric formulations and offer improved safety and tolerability over previously recommended ritonavir-boosted lopinavir with zidovudine. This guideline provides recommendations for those caring for children potentially exposed to HIV and other bloodborne viruses in primary care, emergency departments, secondary care and specialist paediatric HIV centres.