NFκB1 inhibits memory formation and supports effector function of ILC2s in memory-driven asthma

Background

ILC2s are capable of generating memory. The mechanism of memory induction and memory-driven effector function (trained immunity) in ILC2s is unknown.

Objective

NFκB1 is preferentially expressed at a high level in ILC2s. We examined the role of NFkB1 in memory induction and memory-driven effector function in a mouse model of asthma.

Methods

Intranasal administration of Alternaria, flexivent, ELISA, histology, real-time PCR, western blot, flow cytometry and immunofluorescence staining.

Results

NFκB1 was essential for the effector phase of memory-driven asthma. NFκB1 was critical for IL33 production, ILC2 generation, and production of type-2 cytokines, which resulted in eosinophilic inflammation and other features of asthma. NFκB1 induction of type-2 cytokines in ILC2s was independent of GATA3. NFκB1 was important for allergen induction of ILC3s and FoxP3+ Tregs. NFκB1 did not affect Th2 cells or their cytokine production. In contrast to its protagonistic role in the effector phase, NFκB1 had an antagonistic role in the memory phase. NFκB1 inhibited allergen-induced upregulation of memory-associated repressor and preparedness genes in ILC2s. NFκB1 upregulated RUNX1. NFκB1 formed a heterodimer with RUNX1 in ILC2s.

Conclusions

NFκB1 positively regulated the effector phase but inhibited the induction phase of memory. The foregoing pointed to an interdependent antagonism between the memory induction and the memory effector processes. The NFκB1-RUNX1 heterodimer represented a non-canonical transcriptional activator of type-2 cytokines in ILC2s.

Bacterial DNA amplifies neutrophilic inflammation in IL-17-exposed airways

Background

Neutrophilic asthma (NA) is associated with increased airway interleukin (IL)-17 and abnormal bacterial community such as dominance of nontypeable Haemophilus influenzae (NTHi), particularly during asthma exacerbations. Bacteria release various products including DNA, but whether they cooperate with IL-17 in exaggerating neutrophilic inflammation is unclear. We sought to investigate the role of bacteria-derived DNA in airway neutrophilic inflammation related to IL-17-high asthma and underlying mechanisms (e.g. Toll-like receptor 9 (TLR9)/IL-36γ signalling axis).

Methods

Bacterial DNA, IL-8 and IL-36γ were measured in bronchoalveolar lavage fluid (BALF) of people with asthma and healthy subjects. The role of co-exposure to IL-17 and bacterial DNA or live bacteria in neutrophilic inflammation, and the contribution of the TLR9/IL-36γ signalling axis, were determined in cultured primary human airway epithelial cells and alveolar macrophages, and mouse models.

Results

Bacterial DNA levels were increased in asthma BALF, which positively correlated with IL-8 and neutrophil levels. Moreover, IL-36γ increased in BALF of NA patients. Bacterial DNA or NTHi infection under an IL-17-high setting amplified IL-8 production and mouse lung neutrophilic inflammation. DNase I treatment in IL-17-exposed and NTHi-infected mouse lungs reduced neutrophilic inflammation. Mechanistically, bacterial DNA-mediated amplification of neutrophilic inflammation is in part dependent on the TLR9/IL-36γ signalling axis.

Conclusions

Bacterial DNA amplifies airway neutrophilic inflammation in an IL-17-high setting partly through the TLR9 and IL-36γ signalling axis. Our novel findings may offer several potential therapeutic targets including TLR9 antagonists, IL-36γ neutralising antibodies and DNase I to reduce asthma severity associated with exaggerated airway neutrophilic inflammation.

Role of type-2 innate lymphoid cells (ILC2s) in type-2 asthma

PURPOSE OF REVIEW

The purpose of this review is to provide a synthesis of recent discoveries about type-2 innate lymphoid cells, especially, as they relate to the pathogenesis of asthma.

RECENT FINDINGS

We focused on features and characteristics of type-2 innate lymphoid cells (ILC2s) that distinguish them from other type-2 cells, especially Th2 cells. We collected and reviewed data related to human asthma and airway ILC2s. We examined the concept of ILC2 memory and trained immunity. We also analyzed steroid resistance of ILC2s, which is relevant for steroid-resistant asthma.

SUMMARY

The implications of the findings include an understanding of ILC2 inflammation, and pathways and molecules that can be targeted by biologics and other therapeutic agents for management severe and steroid-resistant asthma.

Refractory neutrophilic asthma and ciliary genes

BACKGROUND

Refractory asthma (RA) remains poorly controlled, resulting in high health care utilization despite guideline-based therapies. Patients with RA manifest higher neutrophilia as a result of increased airway inflammation and subclinical infection, the underlying mechanisms of which remain unclear.

OBJECTIVE

We sought to characterize and clinically correlate gene expression differences between refractory and nonrefractory (NR) asthma to uncover molecular mechanisms driving group distinctions.

METHODS

Microarray gene expression of paired airway epithelial brush and endobronchial biopsy samples was compared between 60 RA and 30 NR subjects. Subjects were hierarchically clustered to identify subgroups of RA, and biochemical and clinical traits (airway inflammatory molecules, respiratory pathogens, chest imaging) were compared between groups. Weighted gene correlation network analysis was used to identify coexpressed gene modules. Module expression scores were compared between groups using linear regression, controlling for age, sex, and body mass index.

RESULTS

Differential gene expression analysis showed upregulation of proneutrophilic and downregulation of ciliary function genes/pathways in RA compared to NR. A subgroup of RA with downregulated ciliary gene expression had increased levels of subclinical infections, airway neutrophilia, and eosinophilia as well as higher chest imaging mucus burden compared to other RA, the dominant differences between RA and NR. Weighted gene correlation network analysis identified gene modules related to ciliary function, which were downregulated in RA and were associated with lower pulmonary function and higher airway wall thickness/inflammation, markers of poorer asthma control.

CONCLUSIONS

Identification of a novel ciliary-deficient subgroup of RA suggests that diminished mucociliary clearance may underlie repeated asthma exacerbations despite adequate treatment, necessitating further exploration of function, mechanism, and therapeutics.

Efficacy of Different Diagnostic Test for Identifying Wilson's Disease

Wilson disease is an autosomal recessive disorder in which copper pathologically accumulates primarily within the liver, brain and other tissues. It can presents clinically as liver disease, as a progressive neurological disorder or as psychiatric illness. The wide array of clinical manifestations of WD can lead to misdiagnosis with subsequent greater risk of irreversible damage to liver and brain. Many tests can be used to investigate patients of Wilson disease, including serum free copper, 24 hours urine copper estimation, hepatic copper estimation and genetic mutation testing. But there is no single ideal diagnostic test that can exclude or confirm the disease with certainty. The aim of the study was to find out the efficacy of different diagnostic test for the diagnosis of Wilson disease. This cross-sectional analytical study was conducted at department of Paediatric Gastroenterology and Nutrition of Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh from January 2016 through January 2018. A total of 56 cases of Wilson disease and 39 patients with a liver disease other than WD were studied. Wilson disease was diagnosed by Leipzig score. Along with other physical findings and laboratory investigations slit lamp eye examination for KF ring, serum ceruloplasmin and 24 hour urinary copper excretion were done. The mean age of WD patients was 9.69±2.37 years, male female ratio was 1:1. Serum ceruloplasmin level was significantly lower in WD patient (p<0.001). Median of 24 hour urinary copper in WD was 702.75μg/ 24 hr (range119-11210μg/24 hour) and in non WD group it was 77.41μg/24 hour (range 20.0-478μg/24 hour) and the difference between them is statistically significant (p=0.001). The sensitivity of KF ring was 82.1% and specificity was 100%. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of serum ceruloplasmin were 98.2%, 92.3%, 94.8%, 97.2% and 95.7% respectively. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 24 hour urinary copper were 100%, 63%, 80% and 85.1% respectively. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of KF ring, serum ceruloplasmin and basal 24 hour urinary copper excretion when combined together came out to be 70.4%, 100%, 100%, 59.3% and 79.3% respectively. This study result showed that serum ceruloplasmin and 24 hour urinary copper can be used as a screening test for the diagnosis of Wilson disease.

Isolation and Characterization of Conventional and Non-conventional Type 2 Innate Lymphoid Cells (ILC2s) from Human Peripheral Blood Mononuclear Cells (PBMCs)

Innate lymphoid cells (ILCs) are a relatively new family of lymphoid cells that lack lineage cell surface markers but produce various effector cytokines. Based on phenotype and function, the group 2 ILCs (ILC2s) mirror the features of the adaptive CD4⁺ Th2 cell subset. In humans, they are traditionally characterized as the Lin^-IL7Rα⁺CRΤΗ2⁺CD161⁺ cell population that produces type 2 cytokines - IL-5 and IL-13. However, the commonly used surface markers for human ILC2s leave a majority of type 2 cytokine-producing ILC2s unaccounted for. Recently, we characterized a distinct type 2 cytokine-producing Lin^- population that lacks surface expression of canonical CRTH2 but expresses CD30 and TNFR2. Herein, we describe a detailed protocol for isolation, staining, and analysis of the conventional Lin^-CRTH2⁺IL7Ra⁺ and the non-conventional Lin^-CD30⁺TNFR2⁺ ILC2 populations.

Management Strategies to Reduce Exacerbations in non-T2 Asthma

There have been considerable advances in our understanding of asthmatic airway inflammation, resulting in a paradigm shift of classifying individuals on the basis of either the presence or the absence of type 2 (T2) inflammatory markers. Several novel monoclonal antibody therapies targeting T2 cytokines have demonstrated significant clinical effects including reductions in acute exacerbations and improvements in asthma-related quality of life and lung function for individuals with T2-high asthma. However, there have been fewer advancements in developing therapies for those without evidence of T2 airway inflammation (so-called non-T2 asthma). Here, we review the heterogeneity of molecular mechanisms responsible for initiation and regulation of non-T2 inflammation and discuss both current and potential future therapeutic options for individuals with non-T2 asthma.

The molecular and epigenetic mechanisms of innate lymphoid cell (ILC) memory and its relevance for asthma

Repetitive exposure of Rag1^−/− mice to the Alternaria allergen extract generated a form of memory that elicited an asthma-like response upon a subthreshold recall challenge 3–15 wk later. This memory was associated with lung ICOS⁺ST2⁺ ILC2s. Genetic, pharmacologic, and antibody-mediated inhibition and adoptive transfer established an essential role for ILC2s in memory-driven asthma. ATAC-seq demonstrated a distinct epigenetic landscape of memory ILC2s and identified Bach2 and AP1 (JunD and Fosl2) motifs as major drivers of altered gene accessibility. scRNA-seq, gene knockout, and signaling studies suggest that repetitive allergenic stress induces a gene repression program involving Nr4a2, Zeb1, Bach2, and JunD and a preparedness program involving Fhl2, FosB, Stat6, Srebf2, and MPP7 in memory ILC2s. A mutually regulated balance between these two programs establishes and maintains memory. The preparedness program (e.g., Fhl2) can be activated with a subthreshold cognate stimulation, which down-regulates repressors and activates effector pathways to elicit the memory-driven phenotype.

170 Primary Breast Lymphoma-Mimicking Inflammatory Breast Disease: A Case Report

Primary breast lymphoma (PBL) is an unusual clinical entity accounting for 0.4–0.5% of all breast neoplasms. The usual presentation includes a painless palpable mass similar to that of breast carcinoma. Diffuse large B-cell lymphoma (DLBCL) is the most common identifiable type of PBL based on the histopathological examination.

We report an unusual case of 22 years old Bangladeshi woman presented with a 6-month history of a lump on left breast. Although the lump was initially small, it began a rapid growth after 4 months. The swelling was localized and did not show any skin involvement or discharge and as she didn’t have any positive familial history of breast carcinoma her primary attending physician diagnosed it as a case of breast abscess. When local incision and drainage proved ineffective, she was referred to us. After doing an immunohistochemistry from incisional biopsy the diagnosis was confirmed as Diffuse Large B-cell Lymphoma. The patient was treated initially by chemotherapy with CHOP therapy followed by wide local excision.

Early and accurate diagnosis of PBL is crucial for selecting the appropriate MDT treatment strategies to avert potentially harmful surgical interventions.

Sprouty2 positively regulates T cell function and airway inflammation through regulation of CSK and LCK kinases

The function of Sprouty2 (Spry2) in T cells is unknown. Using 2 different (inducible and T cell-targeted) knockout mouse strains, we found that Spry2 positively regulated extracellular signal-regulated kinase 1/2 (ERK1/2) signaling by modulating the activity of LCK. Spry2-/- CD4+ T cells were unable to activate LCK, proliferate, differentiate into T helper cells, or produce cytokines. Spry2 deficiency abrogated type 2 inflammation and airway hyperreactivity in a murine model of asthma. Spry2 expression was higher in blood and airway CD4+ T cells from patients with asthma, and Spry2 knockdown impaired human T cell proliferation and cytokine production. Spry2 deficiency up-regulated the lipid raft protein caveolin-1, enhanced its interaction with CSK, and increased CSK interaction with LCK, culminating in augmented inhibitory phosphorylation of LCK. Knockdown of CSK or dislodgment of caveolin-1-bound CSK restored ERK1/2 activation in Spry2-/- T cells, suggesting an essential role for Spry2 in LCK activation and T cell function.

Maternal diesel particle exposure promotes offspring asthma through NK cell-derived granzyme B

Mothers living near high-traffic roads before or during pregnancy are more likely to have children with asthma. Mechanisms are unknown. Using a mouse model, here we showed that maternal exposure to diesel exhaust particles (DEP) predisposed offspring to allergic airway disease (AAD, murine counterpart of human asthma) through programming of their NK cells; predisposition to AAD did not develop in DEP pups that lacked NK cells and was induced in normal pups receiving NK cells from WT DEP pups. DEP NK cells expressed GATA3 and cosecreted IL-13 and the killer protease granzyme B in response to allergen challenge. Extracellular granzyme B did not kill, but instead stimulated protease-activated receptor 2 (PAR2) to cooperate with IL-13 in the induction of IL-25 in airway epithelial cells. Through loss-of-function and reconstitution experiments in pups, we showed that NK cells and granzyme B were required for IL-25 induction and activation of the type 2 immune response and that IL-25 mediated NK cell effects on type 2 response and AAD. Finally, experiments using human cord blood and airway epithelial cells suggested that DEP might induce an identical pathway in humans. Collectively, we describe an NK cell-dependent endotype of AAD that emerged in early life as a result of maternal exposure to DEP.

IL-33/ST2 signaling modulates Afghanistan particulate matter induced airway hyperresponsiveness in mice

Increased symptoms of asthma-like respiratory illnesses have been reported in soldiers returning from tours of duty in Afghanistan. Inhalation of desert particulate matter (PM) may contribute to this deployment-related lung disease (DRLD), but little is known about disease mechanisms. The IL-33 signaling pathway, including its receptor ST2, has been implicated in the pathogenesis of lung diseases including asthma, but its role in PM-mediated airway dysfunction has not been studied. The goal of this study was to investigate whether IL-33/ST2 signaling contributes to airway dysfunction in preclinical models of lung exposure to Afghanistan PM (APM). Wild-type (WT) and ST2 knockout (KO) mice on the BALB/C background were oropharyngeally instilled with a single dose of saline or 50 μg of APM in saline. Airway hyperresponsiveness (AHR) and inflammation were assessed after 24 h. In WT mice, a single APM exposure induced AHR and neutrophilic inflammation. Unlike the WT mice, ST2 KO mice that lack the receptor for IL-33 did not demonstrate AHR although airway neutrophilic inflammation was comparable to the WT mice. Oropharyngeal delivery of a soluble ST2 decoy receptor in APM-exposed WT mice significantly blocked AHR. Additional data in mouse tracheal epithelial cell and lung macrophage cultures demonstrated a role of APM-induced IL-33/ST2 signaling in suppression of regulator of G protein signaling 2 (RGS2), a gene known to protect against bronchoconstriction. We present for the first time that APM may increase AHR, one of the features of asthma, in part through the IL-33/ST2/RGS2 pathway.

Exploring health risk of people living near the Secondary Transfer Stations and Landfills in Dhaka

Background

Proper management of increasing solid waste is a major challenge for Dhaka city. Hence, the consequences on health are numerous and depend on the nature of the waste, individuals exposed, duration of exposure and availability of interventions for those exposed. This study seeks to identify the potential health risk associated with contamination from STSs and landfills in Dhaka city.

Methods

This study has adopted a multi-method approach that includes qualitative data collection and analysis of secondary spatial data. Thematic analysis was performed for analysing the qualitative data and. Spatial data were collected from the Survey of Bangladesh and analysed to show the spatial distribution of 68 STSs out of 81 STSs in Dhaka City.

Results

Qualitative study suggests that the leachate migration from the landfill and STSs make the surrounding environment worse and causes health sufferings to the people living near the STS or landfill along with the people directly working. Furthermore, findings from the spatial data reveal that, 12 STSs within 50-100 meters and 54 STSs within 100 meters radius of an education institute and round 75 STSs are also located within 100 meters radius of the health facilities. Numerous settlements and natural features are also located within 500 meters of buffer zone from the both landfills. Flies and mosquitoes are breeding at a greater pace in and around the landfills where high quantities of solid waste are being dumped. Again, waterlogging is very common due to the dumping of waste which in turn is causing the spread of dengue and other water borne diseases in the surrounding area.

Conclusions

Poor management and incautious allocation of the STSs and landfills have adverse effects on the people's health residing nearby. Managing waste in the landfill and STS with a proper manner, and engaging more manpower with adequate safety equipment could be a great help to reduce the health sufferings of the people living nearby.

Key messages

Improper solid waste management practice effects on the health of people residing near the STSs and landfills. To manage the waste of the STSs and landfills in an efficient way and not cause daily nuisance to the nearby residents.

Abdominal Tuberculosis in Children: Is It Really Uncommon?

Now a day's tuberculosis has become a global emergency especially in children and abdomen is the sixth commonest extra-pulmonary site of involvement. Diagnosis of abdominal tuberculosis (TB) in children is still challenging. Non specific constitutional symptoms and long lasting abdominal manifestations cause unnecessary delay in diagnosis in children. Abdominal TB can be of various types like peritoneal TB, gastrointestinal TB, tubercular lymphadenopathy and visceral TB. Diagnosis can be confirmed by histopathology, culture or PCR and imaging technique also play an important role in diagnosis. Morbidity and mortality can be reduced in significant number by early recognition and effective aggressive treatment. In TB endemic areas, it could be strongly considered in children with vague complaints like chronic abdominal pain, low grade fever and weight loss. Response to anti-tubercular therapy may indirectly help the physicians to come to a diagnosis.

Volumetric assessment of paranasal sinus opacification on computed tomography can be automated using a convolutional neural network

BACKGROUND

Computed tomography (CT) plays a key role in evaluation of paranasal sinus inflammation, but improved, and standardized, objective assessment is needed. Computerized volumetric analysis has benefits over visual scoring, but typically relies on manual image segmentation, which is difficult and time-consuming, limiting practical applicability. We hypothesized that a convolutional neural network (CNN) algorithm could perform automatic, volumetric segmentation of the paranasal sinuses on CT, enabling efficient, objective measurement of sinus opacification. In this study we performed initial clinical testing of a CNN for fully automatic quantitation of paranasal sinus opacification in the diagnostic workup of patients with chronic upper and lower airway disease.

METHODS

Sinus CT scans were collected on 690 patients who underwent imaging as part of multidisciplinary clinical workup at a tertiary care respiratory hospital between April 2016 and November 2017. A CNN was trained to perform automatic segmentation using a subset of CTs (n = 180) that were segmented manually. A nonoverlapping set (n = 510) was used for testing. CNN opacification scores were compared with Lund-MacKay (LM) visual scores, pulmonary function test results, and other clinical variables using Spearman correlation and linear regression.

RESULTS

CNN scores were correlated with LM scores (rho = 0.82, p < 0.001) and with forced expiratory volume in 1 second (FEV₁ ) percent predicted (rho = -0.21, p < 0.001), FEV₁ /forced vital capacity ratio (rho = -0.27, p < 0.001), immunoglobulin E (rho = 0.20, p < 0.001), eosinophil count (rho = 0.28, p < 0.001), and exhaled nitric oxide (rho = 0.40, p < 0.001).

CONCLUSION

Segmentation of the paranasal sinuses on CT can be automated using a CNN, providing truly objective, volumetric quantitation of sinonasal inflammation.

Optimal identification of human conventional and nonconventional (CRTH2-IL7Rα-) ILC2s using additional surface markers

BACKGROUND

Human type 2 innate lymphoid cells (ILC2s) are identified by coupled detection of CRTH2 and IL7Rα on lineage negative (Lin^-) cells. Type 2 cytokine production by CRTH2^-IL7Rα^- innate lymphoid cells (ILCs) is unknown.

OBJECTIVE

We sought to identify CRTH2^-IL7Rα^- type 2 cytokine-producing ILCs and their disease relevance.

METHODS

We studied human blood and lung ILCs from asthmatic and control subjects by flow cytometry, ELISA, RNA sequencing, quantitative PCR, adoptive transfer to mice, and measurement of airway hyperreactivity by Flexivent.

RESULTS

We found that IL-5 and IL-13 were expressed not only by CRTH2⁺ but also by CRTH2^-IL7Rα⁺ and CRTH2^-IL7Rα^- (double-negative [DN]) human blood and lung cells. All 3 ILC populations expressed type 2 genes and induced airway hyperreactivity when adoptively transferred to mice. The frequency of type 2 cytokine-positive IL7Rα and DN ILCs were similar to that of CRTH2 ILCs in the blood and lung. Their frequency was higher in asthmatic patients than in disease controls. Transcriptomic analysis of CRTH2, IL7Rα, and DN ILCs confirmed the expression of mRNA for type 2 transcription factors in all 3 populations. Unexpectedly, the mRNA for GATA3 and IL-5 correlated better with mRNA for CD30, TNFR2, ICOS, CCR4, and CD200R1 than for CRTH2. By using a combination of these surface markers, especially CD30/TNFR2, we identified a previously unrecognized ILC2 population.

CONCLUSIONS

The commonly used surface markers for human ILC2s leave a majority of type 2 cytokine-producing ILC2s unaccounted for. We identified top GATA3-correlated cell surface-expressed genes in human ILCs by RNA sequencing. These new surface markers, such as CD30 and TNFR2, identified a previously unrecognized human ILC2 population. This ILC2 population is likely to contribute to asthma.

Mucinous Carcinoma of The Breast: Report of Two Cases

Mucinous carcinoma of the breast is one of 16 rare varieties of malignant lesions of epithelial origin Inbreast. They account for 1-6% of all breast cancer. Variations Inpresentation, cllnlcal course and prognosis has been observed in these patients. In this communication we report two cases of pure mucinous carcinoma of the breast .Both the cases were unusual, first one of them having early presentation with pulmonary and bone metastasis less commonly seen In this type of breast carcinoma and the second case had lymph node involvement that is seen in less than one fifth of the cases of mucinous carcinoma of breast. A brief review about mucinous carcinoma is supplemented with the report. Journal of Surgical Sciences (2013) Vol. 17 (1) : 45-49

Variation between hospitals in outcomes following cardiac surgery in the UK

INTRODUCTION

We examine the influence of variations in provision of cardiac surgery in the UK at hospital level on patient outcomes and also to assess whether there is an inequality of access and delivery of healthcare. Cardiothoracic surgery has pioneered the reporting of surgeon-specific outcomes, which other specialties have followed. We set out to identify factors other than the individual surgeon, which can affect outcomes and enable other surgical specialties to adopt a similar model.

MATERIALS AND METHODS

A retrospective analysis of prospectively collected data of patient and hospital level factors between 2013 and 2016 from 16 cardiac surgical units in the UK were analysed through the Society for Cardiothoracic Surgery of Great Britain and Ireland and the Royal College of Surgeons Research Collaborative. Patient demographic data, risks factors, postoperative complications and in-hospital mortality, as well as hospital-level factors such as number of beds and operating theatres, were collected. Correlation between outcome measures was assessed using Pearson's correlation coefficient. Associations between hospital-level factors and outcomes were assessed using univariable and multivariable regression models.

RESULTS

Of 50,871 patients (60.5% of UK caseload), 25% were older than 75 years and 29% were female. There was considerable variation between units in patient comorbidities, bed distribution and staffing. All hospitals had dedicated cardiothoracic intensive care beds and consultants. Median survival was 97.9% (range 96.3-98.6%). Postoperative complications included re-sternotomy for bleeding (median 4.8%; range 3.5-6.9%) and mediastinitis (0.4%; 0.1-1.0%), transient ischaemic attack/cerebrovascular accident (1.7%; range 0.3-3.0%), haemofiltration (3.7%; range 0.8-6.8%), intra-aortic balloon pump use (3.3%; range 0.4-7.4%), tracheostomy (1.6%; range 1.3-2.6%) and laparotomy (0.3%; range 0.2-0.6%). There was variation in outcomes between hospitals. Univariable analysis showed a small number of positive associations between hospital-level factors and outcomes but none remained significant in multivariable models.

CONCLUSIONS

Variations among hospital level factors exists in both delivery of, and outcomes, following cardiac surgery in the UK. However, there was no clear association between these factors and patient outcomes. This negative finding could be explained by differences in outcome definition, differences in risk factors between centres that are not captured by standard risk stratification scores or individual surgeon/team performance.

Toll-Interacting Protein, Tollip, Inhibits IL-13-Mediated Pulmonary Eosinophilic Inflammation in Mice

Toll-interacting protein (Tollip) is a key negative regulator of innate immunity by preventing excessive proinflammatory responses. Tollip genetic variation has been associated with airflow limitation in asthma subjects and Tollip expression. Whether Tollip regulates lung inflammation in a type 2 cytokine milieu (e.g., IL-13) is unclear. Our goal was to determine the in vivo role of Tollip in IL-13-mediated lung eosinophilic inflammation and the underlying mechanisms. Tollip-knockout (KO) and wild-type (WT) mice were inoculated intranasally with recombinant mouse IL-13 protein to examine lung inflammation. To determine how Tollip regulates inflammation, alveolar macrophages and bone marrow-derived macrophages from Tollip KO and WT mice were cultured with or without IL-13 and/or IL-33. IL-13-treated Tollip KO mice significantly increased lung eosinophilic inflammation and eotaxin-2 (CCL24) levels compared with the WT mice. IL-13- treated Tollip KO (vs. WT) macrophages, in the absence and particularly in the presence of IL-33, increased expression of the IL-33 receptor ST2L and CCL24, which was in part dependent on enhanced activation of interleukin (IL)-1 receptor-associated kinase 1 (IRAK1) and signal transducer and activator of transcription 6 (STAT6). Our results suggest that Tollip downregulates IL-13-mediated pulmonary eosinophilia in part through inhibiting the activity of the ST2L/IL-33/IRAK1 axis and STAT6.

Experimental asthma persists in IL-33 receptor knockout mice because of the emergence of thymic stromal lymphopoietin-driven IL-9+ and IL-13+ type 2 innate lymphoid cell subpopulations

BACKGROUND

IL-33 plays an important role in the development of experimental asthma.

OBJECTIVE

We sought to study the role of the IL-33 receptor suppressor of tumorigenicity 2 (ST2) in the persistence of asthma in a mouse model.

METHODS

We studied allergen-induced experimental asthma in ST2 knockout (KO) and wild-type control mice. We measured airway hyperresponsiveness by using flexiVent; inflammatory indices by using ELISA, histology, and real-time PCR; and type 2 innate lymphoid cells (ILC2s) in lung single-cell preparations by using flow cytometry.

RESULTS

Airway hyperresponsiveness was increased in allergen-treated ST2 KO mice and comparable with that in allergen-treated wild-type control mice. Peribronchial and perivascular inflammation and mucus production were largely similar in both groups. Persistence of experimental asthma in ST2 KO mice was associated with an increase in levels of thymic stromal lymphopoietin (TSLP), IL-9, and IL-13, but not IL-5, in bronchoalveolar lavage fluid. Expectedly, ST2 deletion caused a reduction in IL-13⁺ CD4 T cells, forkhead box P3-positive regulatory T cells, and IL-5⁺ ILC2s. Unexpectedly, ST2 deletion led to an overall increase in innate lymphoid cells (CD45⁺lin^-CD25⁺ cells) and IL-13⁺ ILC2s, emergence of a TSLP receptor-positive IL-9⁺ ILC2 population, and an increase in intraepithelial mast cell numbers in the lung. An anti-TSLP antibody abrogated airway hyperresponsiveness, inflammation, and mucus production in allergen-treated ST2 KO mice. It also caused a reduction in innate lymphoid cell, ILC2, and IL-9⁺ and IL-13⁺ ILC2 numbers in the lung.

CONCLUSIONS

Genetic deletion of the IL-33 receptor paradoxically increases TSLP production, which stimulates the emergence of IL-9⁺ and IL-13⁺ ILC2s and mast cells and leads to development of chronic experimental asthma. An anti-TSLP antibody abrogates all pathologic features of asthma in this model.

The R213G polymorphism in SOD3 protects against allergic airway inflammation

Oxidative stress is important in the pathogenesis of allergic asthma. Extracellular superoxide dismutase (EC-SOD; SOD3) is the major antioxidant in lungs, but its role in allergic asthma is unknown. Here we report that asthmatics have increased SOD3 transcript levels in sputum and that a single nucleotide polymorphism (SNP) in SOD3 (R213G; rs1799895) changes lung distribution of EC-SOD, and decreases likelihood of asthma-related symptoms. Knockin mice analogous to the human R213G SNP had lower airway hyperresponsiveness, inflammation, and mucus hypersecretion with decreased interleukin-33 (IL-33) in bronchoalveolar lavage fluid and reduced type II innate lymphoid cells (ILC2s) in lungs. SOD mimetic (Mn (III) tetrakis (N-ethylpyridinium-2-yl) porphyrin) attenuated Alternaria-induced expression of IL-33 and IL-8 release in BEAS-2B cells. These results suggest that R213G SNP potentially benefits its carriers by resulting in high EC-SOD in airway-lining fluid, which ameliorates allergic airway inflammation by dampening the innate immune response, including IL-33/ST2-mediated changes in ILC2s.

Steroid resistance of airway type 2 innate lymphoid cells from patients with severe asthma: The role of thymic stromal lymphopoietin

BACKGROUND

Type 2 innate lymphoid cells (ILC2s) represent an important type 2 immune cell. Glucocorticoid regulation of human ILC2s is largely unknown.

OBJECTIVE

We sought to assess steroid resistance of human blood and airway ILC2s from asthmatic patients and to examine its mechanism of induction.

METHODS

We studied human blood and lung ILC2s from asthmatic patients and control subjects using flow cytometry and ELISA.

RESULTS

Dexamethasone inhibited (P = .04) chemoattractant receptor-homologous molecule expressed on T_H2 lymphocytes and type 2 cytokine expression by blood ILC2s stimulated with IL-25 and IL-33. However, it did not do so when ILC2s were stimulated with IL-7 and thymic stromal lymphopoietin (TSLP), 2 ligands of IL-7 receptor α. Unlike blood ILC2s, bronchoalveolar lavage (BAL) fluid ILC2s from asthmatic patients were resistant to dexamethasone. BAL fluid from asthmatic patients had increased TSLP but not IL-7 levels. BAL fluid TSLP levels correlated (r = 0.74) with steroid resistance of ILC2s. TSLP was synergistically induced in epithelial cells by IL-13 and human rhinovirus. Mechanistically, dexamethasone upregulated ILC2 expression of IL-7 receptor α, which augmented and sustained signal transducer and activator of transcription (STAT) 5 signaling by TSLP. TSLP induced mitogen-activated protein kinase kinase (MEK), c-Fos, inhibitor of DNA binding 3, phosphorylated signal transducer and activator of transcription (pSTAT) 3, and pSTAT5, molecules linked to steroid resistance. Dexamethasone inhibited c-Fos, inhibitor of DNA binding 3, and pSTAT3 but not pSTAT5 and MEK. The MEK inhibitor trametinib, the Janus kinase-STAT inhibitor tofacitinib, and the STAT5 inhibitor pimozide reversed steroid resistance of BAL ILC2s.

CONCLUSIONS

Dexamethasone inhibited type 2 cytokine production by blood ILC2s. IL-7 and TSLP abrogated this inhibition and induced steroid resistance of ILC2s in a MEK- and STAT5-dependent manner. BAL fluid ILC2s from asthmatic patients with increased TSLP levels were steroid resistant, which was reversed by clinically available inhibitors of MEK and STAT5.

Airway and serum biochemical correlates of refractory neutrophilic asthma

Background

Despite progress in the diagnosis and management of asthma, many patients have poorly controlled or refractory asthma (RA). The mechanism of this RA is not well understood.

Objective

We sought to explore the relationship between neutrophils and other biomarkers of RA.

Method

Sixty patients with RA, 30 patients with nonrefractory asthma (NRA), and 20 healthy subjects were enrolled. We performed a comprehensive characterization of these study subjects, which included laboratory and pulmonary function studies, chest computed tomography, and bronchoscopy with bronchoalveolar lavage (BAL). We analyzed BAL fluid and serum for a total of 244 biomolecules using a multiplex assay and correlated them with clinical and other laboratory parameters.

Results

RA was significantly different from NRA with regard to pulmonary function indices, bronchial basement membrane thickness, and BAL fluid neutrophil and lymphocyte counts but not eosinophil counts. BAL fluid neutrophil counts negatively and positively correlated with forced vital capacity and age, respectively. Of the 244 biomolecules studied, 52 and 14 biomolecules from BAL fluid and serum, respectively, were significantly different among the study groups. Thirteen of these 52 molecules correlated with BAL fluid neutrophil counts. BAL fluid from 40% of patients with RA was positive for a pathogenic microbe. Infection-negative neutrophilic RA was associated with an increase in levels of select biomarkers of inflammation in the serum, suggesting the presence of systemic inflammation.

Conclusions

RA was associated with increased numbers of neutrophils and proneutrophilic biomolecules in the airways. Subclinical infection was present in 40% of patients with RA, which likely contributed to neutrophilic inflammation. A subgroup of patients with noninfected neutrophilic RA was associated with systemic inflammation.

Unscreened older men diagnosed with prostate cancer are at increased risk of aggressive disease

BACKGROUND

To evaluate the relationship between PSA testing history and high-risk disease among older men diagnosed with prostate cancer.

METHODS

Records from 1993 to 2014 were reviewed for men who underwent radiotherapy for prostate cancer at age 75 years or older. Patients were classified into one of four groups based on PSA-testing history: (1) no PSA testing; (2) incomplete/ineffective PSA testing; (3) PSA testing; or (4) cannot be determined. Outcomes of interest were National Comprehensive Cancer Network (NCCN) risk group (that is, low, intermediate or high risk) and biopsy grade at diagnosis. Multivariable logistic regression was used to determine the association between PSA testing history and high-risk cancer.

RESULTS

PSA-testing history was available in 274 (94.5%) of 290 subjects meeting study criteria. In total, 148 men (54.0%) underwent PSA testing with follow-up biopsy, 72 (26.3%) underwent PSA testing without appropriate follow-up, and 54 men (19.7%) did not undergo PSA testing. Patients who underwent PSA testing were significantly less likely to be diagnosed with NCCN high-risk cancer (23.0% vs 51.6%, P<0.001). On multivariable analysis, men with no/incomplete PSA testing had more than three-fold increased odds of high-risk disease at diagnosis (odds ratio 3.39, 95% confidence interval 1.96-5.87, P<0.001) as compared to the tested population.

CONCLUSIONS

Older men who underwent no PSA testing or incomplete testing were significantly more likely to be diagnosed with high-risk prostate cancer than those who were previously screened. It is reasonable to consider screening in healthy older men likely to benefit from early detection and treatment.

Mechanism of TH2/TH17-predominant and neutrophilic TH2/TH17-low subtypes of asthma

BACKGROUND

The mechanism of T_H2/T_H17-predominant and T_H2/T_H17-low asthma is unknown.

OBJECTIVE

We sought to study the immune mechanism of T_H2/T_H17-predominant and T_H2/T_H17-low asthma.

METHODS

In a previously reported cohort of 60 asthmatic patients, 16 patients were immunophenotyped with T_H2/T_H17-predominant asthma and 22 patients with T_H2/T_H17-low asthma. We examined bronchoalveolar lavage (BAL) fluid leukocytes, cytokines, mediators, and epithelial cell function for these asthma subgroups.

RESULTS

Patients with T_H2/T_H17-predominant asthma had increased IL-1β, IL-6, IL-23, C3a, and serum amyloid A levels in BAL fluid, and these correlated with IL-1β and C3a levels. T_H2/T_H17 cells expressed higher levels of the IL-1 receptor and phospho-p38 mitogen-activated protein kinase. Anakinra, an IL-1 receptor antagonist protein, inhibited BAL T_H2/T_H17 cell counts. T_H2/T_H17-low asthma had 2 distinct subgroups: neutrophilic asthma (45%) and pauci-inflammatory asthma (55%). This contrasted with patients with T_H2/T_H17-predominant and T_H2-predominant asthma, which included neutrophilic asthma in 6% and 0% of patients, respectively. BAL fluid neutrophils strongly correlated with BAL fluid myeloperoxidase, IL-8, IL-1α, IL-6, granulocyte colony-stimulating factor, and GM-CSF levels. Sixty percent of the patients with neutrophilic asthma had a pathogenic microorganism in BAL culture, which suggested a subclinical infection.

CONCLUSION

We uncovered a critical role for the IL-1β pathway in patients with T_H2/T_H17-predminant asthma. A subgroup of patients with T_H2/T_H17-low asthma had neutrophilic asthma and increased BAL fluid IL-1α, IL-6, IL-8, granulocyte colony-stimulating factor, and GM-CSF levels. IL-1α was directly involved in IL-8 production and likely contributed to neutrophilic asthma. Sixty percent of neutrophilic patients had a subclinical infection.

Nonsteroidal anti-inflammatory-induced inhibition of signal transducer and activator of transcription 6 (STAT-6) phosphorylation in aspirin-exacerbated respiratory disease

BACKGROUND

Aspirin desensitization provides long-term clinical benefits. The exact mechanisms of aspirin desensitization are not clearly understood.

OBJECTIVE

We sought to evaluate the effects of nonsteroidal anti-inflammatory drugs (NSAIDs) on T-cell activation of the IL-4 pathway in aspirin-sensitive patients with asthma and control subjects.

METHODS

A total of 11 aspirin-sensitive patients with asthma, 10 aspirin-tolerant patients with asthma, and 10 controls without asthma were studied. PBMCs were stimulated with an anti-CD3 antibody and IL-4 or IL-12, with and without the presence of NSAIDs. The expression of phosphorylated signal transducers and activators of transcription 6 (pSTAT6), phosphorylated signal transducers and activators of transcription 4, and IL-4 was detected in CD4 T cells by flow cytometry.

RESULTS

Stimulation with a combination of anti-CD3 and IL-4 induced pSTAT6 in CD4 T cells from all subjects. The induction of pSTAT6 was significantly higher in aspirin-sensitive patients with asthma than in controls subjects. The increase in pSTAT6 was inhibited in a dose-dependent manner by aspirin and indomethacin and minimally by sodium salicylate. This inhibition was strongest in aspirin-sensitive patients. Two-group comparisons showed significant differences in pSTAT6 inhibition by all concentrations of indomethacin and aspirin: between aspirin-sensitive and aspirin-tolerant groups and between aspirin-sensitive and control groups. No differences were found between aspirin-tolerant and control groups at all 3 concentrations. The inhibition of pSTAT6 was associated with reduced IL-4 expression.

CONCLUSIONS

NSAIDs inhibited signal transducers and activators of transcription 6 signaling in CD4 T cells. This inhibition was significantly higher in aspirin-sensitive patients than in aspirin-tolerant subjects and was associated with reduced expression of IL-4. These findings have implications for clinical benefits of aspirin desensitization in aspirin-sensitive patients with asthma.