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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.

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.

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.

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.

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.