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Factor VIII (FVIII) inhibitor formation is a major clinical concern during replacement therapy in patients with hemophilia A. Immune tolerance induction (ITI) is the only therapeutic approach to attempt inhibitor eradication and establishment of long-term immune tolerance to FVIII. Hemophilia Inhibitor Previously Untreated Patient (PUP) Study (HIPS) was a prospective clinical trial to investigate changes in the immune system of PUPs with severe hemophilia A. Five patients who developed persistent FVIII inhibitors during HIPS entered an ITI extension arm (HIPS-ITI). During HIPS-ITI, inhibitor patients received ITI with the same FVIII product (a single source of recombinant, human full-length FVIII) used in HIPS until successful tolerance, declared failure, or a maximum of 2 years after HIPS-ITI enrollment, whichever came first. Blood samples and clinical data were collected monthly. Longitudinal FVIII-binding antibody signatures, associated binding specificities, and apparent affinities were determined for each patient at each sampling time point. ITI was successful or partially successful in 2 patients and failed in 3. Both groups presented with distinct FVIII-specific antibody signatures. ITI success required the disappearance of FVIII inhibitors, which was associated with the eradication or sustained titer minimization of high-affinity FVIII-specific antibodies, particularly of the immunoglobulin G1 (IgG1) and IgG4 subclasses. In contrast, ITI failure, as reflected by FVIII inhibitor persistence, was associated with persistent high-affinity FVIII-specific antibodies. Interestingly, 1 patient with partial ITI success and 1 patient with ITI failure developed apparent oligoreactive FVIII-binding antibodies during ITI. The explanation of the true nature of these antibodies requires more comprehensive follow-ups in future studies. This trial was registered at www.clinicaltrials.gov as #NCT01652027.

Haemophilia B (HB) is less well studied than haemophilia A (HA); despite similarities between the two inherited bleeding disorders, important differences remain that require further research.B-Natural is a multi-centre, prospective, observational study of HB, designed to increase understanding of clinical manifestations, treatment, quality-of-life (QoL), inhibitor development, immune tolerance induction (ITI) outcome, renal function and create a biorepository for future investigations.Participants include sibling pairs/groups without a current/history of inhibitors and singletons or siblings with a current/history of inhibitors followed for six months. Demographics, medical, social history and treatment were recorded. A physical examination including joint range of motion (ROM) was performed; QoL was assessed. Samples were collected for F9 gene mutation, HLA typing, non-inhibitory antibodies and renal function testing.Twenty-four centres enrolled 224 individuals from 107 families including 29 with current/history of inhibitors. Of these, 68, 30.4%, had severe (1% FIX level of normal); 114, 50.9%, moderate (1%-5%); and 42, 18.8%, mild (5-40%) disease. At enrolment, 53.1% had 50 + exposure days to exogenous FIX. Comparison of joint scores showed significant (P .05) differences between those with severe (with/without inhibitors), and those with moderate/mild disease. The majority with severe disease, 80.0% with current/history of inhibitors and 64.3% of those without, were treated with prophylaxis.B-Natural provides data supporting an increased understanding of HB and its impact throughout life. The need for optimal disease control to normalize physical and psychosocial outcomes is underscored, and further analyses will contribute to an increased understanding of critical issues in HB.

Background Atopic dermatitis (AD) and food allergy (FA) are associated with skin barrier dysfunction. Objective Skin biomarkers are needed for skin barrier interventions studies. Methods In this study, skin tape strip (STS) samples were collected from nonlesional skin of 62 children in AD FA+, AD FA−, and nonatopic groups for mass spectrometry proteomic analysis. transepidermal water loss and allergic sensitization were assessed. STS proteomic analysis results were validated in an independent cohort of 41 adults with AD with and without FA versus nonatopic controls. Results A group of 45 proteins was identified as a principal component 1 (PC1) with the highest expression in AD FA+ STSs. This novel set of STS proteins was highly correlative to skin transepidermal water loss and allergic sensitization. PC1 proteins included keratin intermediate filaments; proteins associated with inflammatory responses (S100 proteins, alarmins, protease inhibitors); and glycolysis and antioxidant defense enzymes. Analysis of PC1 proteins expression in an independent adult AD cohort validated differential expression of STS PC1 proteins in the skin of adult patients with AD with the history of clinical reactions to peanut. Conclusions STS analysis of nonlesional skin of AD children identified a cluster of proteins with the highest expression in AD FA+ children. The differential expression of STS PC1 proteins was confirmed in a replicate cohort of adult AD patients with FA to peanut, suggesting a unique STS proteomic endotype for AD FA+ that persists into adulthood. Collectively, PC1 proteins are associated with abnormalities in skin barrier integrity and may increase the risk of epicutaneous sensitization to food allergens.

Asthma prevalence and severity have markedly increased with urbanisation, and children in low-income urban centres have among the greatest asthma morbidity. Outdoor air pollution has been associated with adverse respiratory effects in children with asthma. However, the mechanisms by which air pollution exposure exacerbates asthma, and how these mechanisms compare with exacerbations induced by respiratory viruses, are poorly understood. We aimed to investigate the associations between regional air pollutant concentrations, respiratory illnesses, lung function, and upper airway transcriptional signatures in children with asthma, with particular focus on asthma exacerbations occurring in the absence of respiratory virus.We performed a retrospective analysis of data from the MUPPITS1 cohort and validated our findings in the ICATA cohort. The MUPPITS1 cohort recruited 208 children aged 6-17 years living in urban areas across nine US cities with exacerbation-prone asthma between Oct 7, 2015, and Oct 18, 2016, and monitored them during reported respiratory illnesses. The last MUPPITS1 study visit occurred on Jan 6, 2017. The ICATA cohort recruited 419 participants aged 6-20 years with persistent allergic asthma living in urban sites across eight US cities between Oct 23, 2006, and March 25, 2008, and the last study visit occurred on Dec 30, 2009. We included participants from the MUPPITS1 cohort who reported a respiratory illness at some point during the follow-up and participants from the ICATA cohort who had nasal samples collected during respiratory illness or at a scheduled visit. We used air quality index values and air pollutant concentrations for PMOf the 208 participants from the MUPPITS1 cohort and 419 participants from the ICATA cohort, 168 participants in the MUPPITS1 cohort (98 male participants and 70 female participants) and 189 participants in the ICATA cohort (115 male participants and 74 female participants) were included in our analysis. We identified that increased air quality index values, driven predominantly by increased PMOur findings suggest that air pollution is an important independent risk factor for asthma exacerbations in children living in urban areas and is potentially linked to exacerbations through specific inflammatory pathways in the airway. Further investigation of these potential mechanistic pathways could inform asthma prevention and management approaches.National Institutes of Health, National Institute of Allergy and Infectious Diseases.

Introduction: The B-Natural study is a multicentre, multinational, observational study of haemophilia B (HB) designed to increase understanding of clinical manifestations, treatment and quality of life (QoL). Aim: To characterise and compare QoL in HB across disease severity groups and individuals with inhibitors to identify gaps in treatment. Methods: A total of 224 individuals from 107 families were enrolled from a total of 24 centres in North America (n = 16), Europe (n = 7) and Asia (n = 1). Of these, 68 (30.4%) subjects had severe (5–

Background In infants, distinct nasopharyngeal bacterial microbiotas differentially associate with the incidence and severity of acute respiratory tract infection and childhood asthma development. Objective We hypothesized that distinct nasal airway microbiota structures also exist in children with asthma and relate to clinical outcomes. Methods Nasal secretion samples (n = 3122) collected after randomization during the fall season from children with asthma (6-17 years, n = 413) enrolled in a trial of omalizumab (anti-IgE) underwent 16S rRNA profiling. Statistical analyses with exacerbation as the primary outcome and rhinovirus infection and respiratory illnesses as secondary outcomes were performed. Using A549 epithelial cells, we assessed nasal isolates of Moraxella, Staphylococcus, and Corynebacterium species for their capacity to induce epithelial damage and inflammatory responses. Results Six nasal airway microbiota assemblages, each dominated by Moraxella, Staphylococcus, Corynebacterium, Streptococcus, Alloiococcus, or Haemophilus species, were observed. Moraxella and Staphylococcus species–dominated microbiotas were most frequently detected and exhibited temporal stability. Nasal microbiotas dominated by Moraxella species were associated with increased exacerbation risk and eosinophil activation. Staphylococcus or Corynebacterium species–dominated microbiotas were associated with reduced respiratory illness and exacerbation events, whereas Streptococcus species–dominated assemblages increased the risk of rhinovirus infection. Nasal microbiota composition remained relatively stable despite viral infection or exacerbation; only a few taxa belonging to the dominant genera exhibited relative abundance fluctuations during these events. In vitro, Moraxella catarrhalis induced significantly greater epithelial damage and inflammatory cytokine expression (IL-33 and IL-8) compared with other dominant nasal bacterial isolates tested. Conclusion Distinct nasal airway microbiotas of children with asthma relate to the likelihood of exacerbation, rhinovirus infection, and respiratory illnesses during the fall season.

Background Mucus plugging can worsen asthma control, lead to reduced lung function and fatal exacerbations. MUC5AC is the secretory mucin implicated in mucus plugging, and MUC5AC gene expression has been associated with development of airway obstruction and asthma exacerbations in urban children with asthma. However, the genetic determinants of MUC5AC expression are not established. Objectives This study sought to assess single-nucleotide polymorphisms (SNPs) that influence MUC5AC expression and relate to pulmonary functions in childhood asthma. Methods This study used RNA-sequencing data from upper airway samples and performed cis-expression quantitative trait loci (eQTL) and allele-specific expression analyses in 2 cohorts of predominantly Black and Hispanic urban children, a high asthma-risk birth cohort, and an exacerbation-prone asthma cohort. Inducible MUC5AC eQTLs were further investigated during incipient asthma exacerbations. Significant eQTLs SNPs were tested for associations with lung function measurements and their functional consequences were investigated in DNA regulatory databases. Results Two independent groups of SNPs in the MUC5AC gene that were significantly associated with MUC5AC expression were identified. Moreover, these SNPs showed stronger eQTL associations with MUC5AC expression during asthma exacerbations, which is consistent with inducible expression. SNPs in 1 group also showed significant association with decreased pulmonary functions. These SNPs included multiple EGR1 transcription factor binding sites, suggesting a mechanism of effect. Conclusions These findings demonstrate the applicability of organ-specific RNA-sequencing data to determine genetic factors contributing to a key disease pathway. Specifically, they suggest important genetic variations that may underlie propensity to mucus plugging in asthma and could be important in targeted asthma phenotyping and disease management strategies.

Introduction: Inhibitors develop less frequently in haemophilia B (HB) than haemophilia A (HA). However, when present, the success of tolerization by immune tolerance induction (ITI) therapy is lower and the risk of complications higher. Aim: To evaluate the use and outcome of ITI in patients with HB and inhibitors. Methods: Subjects include singletons or siblings with a current/history of inhibitors enrolled in B-Natural—an observational study designed to increase understanding of clinical management of patients with HB. Patients were followed for 6 months and information on demographics, medical and social history, and treatment were recorded. Results: Twenty-nine patients with severe HB and inhibitors were enrolled in 24 centres. Twenty-two underwent one or more courses of ITI with or without immune suppression. Eight patients (36.4%) were successfully tolerized after the first course of ITI. One of these successes (12.5%) experienced allergic manifestations, whereas the corresponding number for the 10 treatment failures was five (50%). One of seven (14.2%) patients with large deletions and three of eight (37.5%) with nonsense mutations were tolerized at the first attempt, and all patients experiencing nephrosis either failed or were on-going. At study end, 11 (50%) were considered successfully tolerized after one or more ITI courses, three were unsuccessful, and eight were still undergoing treatment. Conclusion: Our data underscore the possibilities and difficulties of achieving tolerization in patients with HB with inhibitors. The type of mutation and complications appear to correlate with ITI outcome, but more accurate definitions of successful ITI are warranted.

Rationale: Rhinovirus (RV) C can cause asymptomatic infection and respiratory illnesses ranging from the common cold to severe wheezing. Objectives: To identify how age and other individual-level factors are associated with susceptibility to RV-C illnesses. Methods: Longitudinal data from the COAST (Childhood Origins of Asthma) birth cohort study were analyzed to determine relationships between age and RV-C infections. Neutralizing antibodies specific for RV-A and RV-C (three types each) were determined using a novel PCR-based assay. Data were pooled from 14 study cohorts in the United States, Finland, and Australia, and mixed-effects logistic regression was used to identify factors related to the proportion of RV-C versus RV-A detection. Measurements and Main Results: In COAST, RV-A and RV-C infections were similarly common in infancy, whereas RV-C was detected much less often than RV-A during both respiratory illnesses and scheduled surveillance visits (P

Urban children who develop allergic sensitization and asthma have persistently elevated gene expression of the type 2 cytokines IL9, IL13, and IL31 in cockroach allergen stimulated PBMCs from age 2 through 7 years old.

Skin barrier dysfunction has been reported in both atopic dermatitis (AD) and food allergy (FA). However, only one-third of patients with AD have FA. The purpose of this study was to use a minimally invasive skin tape strip sampling method and a multiomics approach to determine whether children with AD and FA (AD FA+) have stratum corneum (SC) abnormalities that distinguish them from AD without FA (AD FA−) and nonatopic (NA) controls. Transepidermal water loss was found to be increased in AD FA+. Filaggrin and the proportion of ω-hydroxy fatty acid sphingosine ceramide content in nonlesional skin of children with AD FA+ were substantially lower than in AD FA− and NA skin. These abnormalities correlated with morphologic changes in epidermal lamellar bilayer architecture responsible for barrier homeostasis. Shotgun metagenomic studies revealed that the nonlesional skin of AD FA+ had increased abundance of Staphylococcus aureus compared to NA. Increased expression of keratins 5, 14, and 16 indicative of hyperproliferative keratinocytes was observed in the SC of AD FA+. The skin transcriptome of AD FA+ had increased gene expression for dendritic cells and type 2 immune pathways. A network analysis revealed keratins 5, 14, and 16 were positively correlated with AD FA+, whereas filaggrin breakdown products were negatively correlated with AD FA+. These data suggest that the most superficial compartment of nonlesional skin in AD FA+ has unique properties associated with an immature skin barrier and type 2 immune activation.

Background Childhood asthma in inner-city populations is a major public health burden, and understanding early-life immune mechanisms that promote asthma onset is key to disease prevention. Children with asthma demonstrate a high prevalence of aeroallergen sensitization and T H 2-type inflammation; however, the early-life immune events that lead to T H 2 skewing and disease development are unknown. Objective We sought to use RNA sequencing of PBMCs collected at age 2 years to determine networks of immune responses that occur in children with allergy and asthma. Methods In an inner-city birth cohort with high asthma risk, we compared gene expression using RNA sequencing in PBMCs collected at age 2 years between children with 2 or more aeroallergen sensitizations, including dust mite, cockroach, or both, by age 3 years and asthma by age 7 years (cases) and matched control subjects who did not have any aeroallergen sensitization or asthma by age 7 years. Results PBMCs from the cases showed higher levels of expression of natural killer (NK) cell–related genes. After cockroach or dust mite allergen but not tetanus antigen stimulation, PBMCs from the cases compared with the control subjects showed differential expression of 244 genes. This gene set included upregulation of a densely interconnected NK cell–like gene network reflecting a pattern of cell activation and induction of inflammatory signaling molecules, including the key T H 2-type cytokines IL9 , IL13 , and CCL17 , as well as a dendritic cell–like gene network, including upregulation of CD1 lipid antigen presentation molecules. The NK cell–like response was reproducible in an independent group of children with later-onset allergic sensitization and asthma and was found to be specific to only those children with both aeroallergen sensitization and asthma. Conclusion These findings provide important mechanistic insight into an early-life immune pathway involved in T H 2 polarization, leading to the development of allergic asthma.

Allergic inflammation has been linked to increased susceptibility to viral illnesses, but it is unclear whether this association is causal.To test whether omalizumab treatment to reduce IgE would shorten the frequency and duration of rhinovirus (RV) illnesses in children with allergic asthma.In the PROSE (Preventative Omalizumab or Step-up Therapy for Severe Fall Exacerbations) study, we examined children with allergic asthma (aged 6-17 yr; n = 478) from low-income census tracts in eight U.S. cities, and we analyzed virology for the groups randomized to treatment with guidelines-based asthma care (n = 89) or add-on omalizumab (n = 259). Weekly nasal mucus samples were analyzed for RVs, and respiratory symptoms and asthma exacerbations were recorded over a 90-day period during the fall seasons of 2012 or 2013. Adjusted illness rates (illnesses per sample) by treatment arm were calculated using Poisson regression.RVs were detected in 97 (57%) of 171 exacerbation samples and 2,150 (36%) of 5,959 nonexacerbation samples (OR, 2.32; P 0.001). Exacerbations were significantly associated with detection of rhinovirus C (OR, 2.85; P 0.001) and rhinovirus A (OR, 2.92; P 0.001), as well as, to a lesser extent, rhinovirus B (OR, 1.98; P = 0.019). Omalizumab decreased the duration of RV infection (11.2 d vs. 12.4 d; P = 0.03) and reduced peak RV shedding by 0.4 log units (95% confidence interval, -0.77 to -0.02; P = 0.04). Finally, omalizumab decreased the frequency of RV illnesses (risk ratio, 0.64; 95% confidence interval, 0.49-0.84).In children with allergic asthma, treatment with omalizumab decreased the duration of RV infections, viral shedding, and the risk of RV illnesses. These findings provide direct evidence that blocking IgE decreases susceptibility to RV infections and illness. Clinical trial registered with www.clinicaltrials.gov (NCT01430403).

Pediatric health-related quality of life (HRQOL) questionnaires have been validated in children with sickle cell disease (SCD), but small sample sizes in these studies have limited clinical comparisons. We used the baseline clinical data from the Collaborative Data (C-Data) Project of the Comprehensive Sickle Cell Centers (CSCC) Clinical Trial Consortium to perform a detailed, descriptive study of HRQOL using the PedsQL version 4.0 generic core and fatigue scales.Retrospective clinical data were obtained via medical record abstraction. Staff-administered health history, psychosocial, and health behavior interviews were completed by a parent or guardian. PedsQL forms were completed separately by the child and a parent/guardian.The study enrolled 1,772 subjects (53% boys) with a mean age of 9.6 years (SD 4.7). SS or Sbeta(0) thalassemia occurred in 68% and 32% had SC or Sbeta(+) thalassemia. The occurrences of pain, priapism, avascular necrosis of hips/shoulders (AVN), or asthma were the most common complications/conditions reported. Multiple regression models controlling for hemoglobinopathies, gender, and age suggested that parent reports of physical functioning and sleep/rest fatigue declined in response to pain or AVN, while school functioning scales declined in response to pain or asthma. Sickle pain, and to a lesser extent asthma, negatively influenced child reports on almost all functioning and fatigue scales.While longitudinal studies will be necessary to determine sensitivity to change, the current study suggests the potential utility of several PedsQL HRQOL scales as patient-reported outcome measures for observational or interventional treatment studies of children and adolescents with SCD.

Adults with Sickle Cell Disease (SCD) experience multiple disease-related complications, but few studies have examined relationships between these events and health-related quality of life (HRQOL). We determined the number and type of previous or co-occurring SCD-related complications and their reported HRQOL in a cohort of 1,046 adults from the Comprehensive Sickle Cell Centers (CSCC). Participants had a median age of 28.0 years (48% male, 73% SS or Sβ⁰ thalassemia) and had experienced several SCD-related complications (mean 3.8 ± 2.0), which were influenced by age, gender, and hemoglobinopathy type (P < 0.0001). In multivariate models, increasing age reduced all SF-36 scales scores (P < 0.05) except mental health, while female gender additionally diminished physical function and vitality scale scores (P < 0.01). Of possible complications, only vaso-occlusive crisis, asthma, or avascular necrosis diminished SF-36 scale scores. Chronic antidepressants usage predominantly diminished scores on bodily pain, vitality, social functioning, emotional role, and mental health scales, whereas chronic opioid usage diminished all scale scores (P < 0.01). Our study documents substantial impairment of HRQOL in adults with SCD that was influenced by only a few of many possible medical complications. It suggests that more effective treatments of persistent pain and depression would provide the largest HRQOL benefit.

Nitric oxide (NO) is an important inflammatory mediator produced from arginine. NO has a multitude of functions which could impact favorably on vaso-occlusion in sickle cell disease (SCD) including improvement in endothelial dysfunction, increased blood flow and a decrease in antioxidant stress. SCD patients have low NO and arginine levels. In preliminary animal studies using the sickle mouse model, arginine supplementation decreased the mean corpuscular hemoglobin concentration and the percentage of dense cells via a reduction in Gardos channel activity1. In humans with SCD, oral arginine increased NO levels in patients with vaso-occlusive crisis but not when patients were at well. In an attempt to determine if daily oral arginine would result in an increase in NO and other beneficial effects, the CSCC launched a multi-institution, blinded, phase II study of arginine in SCD. Children and adults were treated for three months with one of two doses of arginine (.05g/kg/day or .1 g/kg/day) or placebo. The pediatric and adult cohorts were analyzed separately. For this phase II study, the following laboratory values were chosen as surrogates for clinical benefit: NOx, RBC Gardos channel activity, RBC density, sVCAM, nitrotyrosine, ektacytometry, endothelin-1, and fetal hemoglobin. To determine the impact of arginine on these laboratory measures, patients had 3 baseline assessments in the 4 weeks prior to starting therapy with arginine. An average of these 3 measurements was used to determine change from baseline during therapy with arginine. Laboratory outcomes after one month and three months of therapy with arginine were compared with the average baseline measurement. This report summarizes the results of the pediatric cohort of patients. Fifty-one children were enrolled in the study and 48 completed at least one month of study drug making them evaluable. Arginine levels did not change significantly during treatment in any of the arms. The average percent change from baseline to 3 months on study drug being +18% for placebo, +35% for low dose arginine, and +19% for high dose arginine). None of the three primary outcome variables (NO, Gardos channel activity, RBC density) changed significantly with arginine therapy after one month or after 3 months of arginine. After 3 months of study drug, the average percentage change from baseline in NO was −33% for low dose arginine, +4% for high dose arginine, and +8% for placebo. Gardos channel activity changes were −1% for low dose, +3% for high dose, and +9% for placebo. RBC density changes were +10% for low dose, +11% for high dose, and −6% for placebo. Similarly, none of the other outcome variables changed with treatment at either one or 3 months. There were no significant differences in adverse events between the three treatment groups. Our data indicate that oral arginine therapy does not seem to provide clinical benefit for pediatric patients with SCD based on assessment of these selected laboratory outcomes. It is possible that the doses of arginine used in this study were not sufficient to produce significant changes in the laboratory measures chosen. It is also possible that children, due to less severe arginine deficiency, did not respond as well as adults with SCD. Supported by NHLBI U54HL070587.