IgA+ memory B-cells are significantly increased in patients with asthma and small airway dysfunction.

BACKGROUND: Comprehensive studies investigated the role of T-cells in asthma which led to personalised treatment options targeting severe eosinophilic asthma. However, little is known about the contribution of B-cells to this chronic inflammatory disease. In this study we investigated the contribution of various B-cell populations to specific clinical features in asthma. METHODS: In the All Age Asthma Cohort (ALLIANCE), a subgroup of 154 adult asthma patients and 28 healthy controls were included for B-cell characterisation by flow cytometry. Questionnaires, lung function measurements, blood differential counts and allergy testing of participants were analysed together with comprehensive data on B-cells using association studies and multivariate linear models. RESULTS: Patients with severe asthma showed decreased immature B-cell populations while memory B-cells were significantly increased compared with both mild-moderate asthma patients and healthy controls. Furthermore, increased frequencies of IgA+ memory B-cells were associated with impaired lung function and specifically with parameters indicative for augmented resistance in the peripheral airways. Accordingly, asthma patients with small airway dysfunction (SAD) defined by impulse oscillometry showed increased frequencies of IgA+ memory B-cells, particularly in patients with mild-moderate asthma. Additionally, IgA+ memory B-cells significantly correlated with clinical features of SAD such as exacerbations. CONCLUSIONS: With this study we demonstrate for the first time a significant association of increased IgA+ memory B-cells with asthma and SAD, pointing towards future options for B-cell-directed strategies in preventing and treating asthma.

T2-high asthma phenotypes across lifespan.

RATIONALE: In adults, personalised asthma treatment targets patients with type 2 (T2)-high and eosinophilic asthma phenotypes. It is unclear whether such classification is achievable in children. OBJECTIVES: To define T2-high asthma with easily accessible biomarkers and compare resulting phenotypes across all ages. METHODS: In the multicentre clinical All Age Asthma Cohort (ALLIANCE), 1125 participants (n=776 asthmatics, n=349 controls) were recruited and followed for 2 years (1 year in adults). Extensive clinical characterisation (questionnaires, blood differential count, allergy testing, lung function and sputum induction (in adults)) was performed at baseline and follow-ups. Interleukin (IL)-4, IL-5 and IL-13 were measured after stimulation of whole blood with lipopolysaccharide (LPS) or anti-CD3/CD28. MEASUREMENTS AND MAIN RESULTS: Based on blood eosinophil counts and allergen-specific serum IgE antibodies, patients were categorised into four mutually exclusive phenotypes: "atopy-only", "eosinophils-only", "T2-high" (eosinophilia + atopy) and "T2-low" (neither eosinophilia nor atopy). The T2-high phenotype was found across all ages, even in very young children in whom it persisted to a large degree even after 2 years of follow-up. T2-high asthma in adults was associated with childhood onset, suggesting early origins of this asthma phenotype. In both children and adults, the T2-high phenotype was characterised by excessive production of specific IgE to allergens (p<0.0001) and, from school age onwards, by increased production of IL-5 after anti-CD3/CD28 stimulation of whole blood. CONCLUSIONS: Using easily accessible biomarkers, patients with T2-high asthma can be identified across all ages delineating a distinct phenotype. These patients may benefit from therapy with biologicals even at a younger age.

Patient Outcomes of an International Telepediatric Cardiac Critical Care Program.

BACKGROUND: An optimal model for telemedicine use in the international care setting has not been established. Our objective was to describe variables associated with patient outcome during the implementation of an international pediatric cardiac critical care (PCCC) telemedicine program. MATERIALS AND METHODS: A retrospective review was performed of clinical records and a telemedicine database of patients admitted to the cardiac intensive care unit (CICU) at the Fundacion Cardiovascular de Colombia, Bucaramanga, Colombia, during the initial 10 months of our program, compared with patients admitted during a previous period. Information collected included demographic data, cardiac diagnosis and associated factors, Risk Adjustment for Congenital Heart Surgery (RACHS)-1 classification, and perioperative events. Primary outcome was composed of CICU and hospital mortality. Secondary outcomes were CICU and hospital length of stay (LOS). RESULTS: Of the 553 patients who were included, teleconsultation was done for 71 (12.4%), with a total of 156 encounters, including 19 for patients on extracorporeal membrane oxygenation. Three hundred twenty-one recommendations were given, and 42 real-time interventions were documented. RACHS-1 distribution was similar between study periods (p=0.427). Teleconsulted patients were significantly younger (44 versus 24 months; p=0.03) and had higher surgical complexity than nonteleconsulted patients (p=0.01). RACHS-1 adjusted hospital survival was similar between study periods. CICU and hospital LOS intervals were significantly shorter in the telemedicine period (10 versus 17 days [p=0.02] and 22 versus 28 days [p<0.001]). In surgical cases, preoperative CICU LOS was significantly shorter (3 versus 6 days; p<0.001). Variables associated with hospital mortality were higher RACHS-1 categories, lower weight, bypass time longer than 150 min, and use of circulatory arrest, as well as the presence of sepsis or necrotizing enterocolitis. Those associated with increased LOS were lower weight, extracorporeal membrane oxygenation, and cross-clamp time longer than 60 min. CONCLUSIONS: An international telemedicine service in PCCC was associated with lower CICU and hospital LOS. Prospective telemedicine interventions aimed to decrease mortality and LOS should focus on patients with higher RACHS-1 categories, lower-weight infants, and those with prolonged operative time and selective perioperative complications.

Dexmedetomidine and fentanyl exhibit temperature dependent effects on human respiratory cilia.

BACKGROUND: Dexmedetomidine (dex) is commonly used in intensive care due to its effective sedation and analgesia with few adverse effects and minimal respiratory depression. However, we recently observed that exposing mouse epithelial respiratory cells to dex decreased ciliary beat frequency (CBF), suggesting dex may pose pulmonary risk. OBJECTIVE: The purpose of this study is to determine the effects of dex at clinically relevant doses on CBF in human respiratory epithelia. METHODS: Human nasal epithelial cilia were obtained from the inferior nasal turbinate with a rhinoprobe and placed in culture medium at 15°C and 37°C. At 5 and 30 min, video-microscopy was used to assess CBF, either without (control) or with different concentrations (1, 5, and 10 nM) of dex, fentanyl (fen), and dex + fen combination. RESULTS: At 15°C, CBF was lower in the dex group compared to controls at 5 and 30 min. At 37°C, there was a significant increase in CBF with dex at 5 and 30 min, except for dex at 5 nM after 5 min, which showed a significant decrease. At 15°C the combination of dex + fen showed a positive interaction, causing less ciliary inhibition as expected. In contrast, no interaction between drugs was seen between dex and fen at 37°C. CONCLUSION: At low temperatures, dex reduces CBF in human respiratory epithelia, whereas dex increases CBF at physiologic temperature in vitro. Whether these effects translate into clinical consequences during hypothermia, as with cardiopulmonary bypass surgery will require further studies.