Management of Atopy with Dupilumab and Omalizumab in CADINS Disease.

The caspase activation and recruitment domain 11 (CARD11) gene encodes a scaffold protein required for lymphocyte antigen receptor signaling. Dominant-negative, loss-of-function (LOF) pathogenic variants in CARD11 result in CARD11-associated atopy with dominant interference of NF-κB signaling (CADINS) disease. Patients with CADINS suffer with severe atopic manifestations including atopic dermatitis, food allergy, and chronic spontaneous urticaria in addition to recurrent infections and autoimmunity. We assessed the response of dupilumab in five patients and omalizumab in one patient with CADINS for the treatment of severe atopic symptoms. CARD11 mutations were validated for pathogenicity using a T cell transfection assay to assess the impact on activation-induced signaling to NF-κB. Three children and three adults with dominant-negative CARD11 LOF mutations were included. All developed atopic disease in infancy or early childhood. In five patients, atopic dermatitis was severe and recalcitrant to standard topical and systemic medications; one adult suffered from chronic spontaneous urticaria. Subcutaneous dupilumab was initiated to treat atopic dermatitis and omalizumab to treat chronic spontaneous urticaria. All six patients had rapid and sustained improvement in atopic symptoms with no complications during the follow-up period. Previous medications used to treat atopy were able to be decreased or discontinued. In conclusion, treatment with dupilumab and omalizumab for severe, refractory atopic disease in patients with CADINS appears to be effective and well tolerated in patients with CADINS with severe atopy.

Investigating age and ethnicity as novel high-risk phenotypes in mucinous ovarian cancer: retrospective study in a multi-ethnic population.

OBJECTIVES: Primary mucinous ovarian carcinoma represents 3% of ovarian cancers and is typically diagnosed early, yielding favorable outcomes. This study aims to identify risk factors, focussing on the impact of age and ethnicity on survival from primary mucinous ovarian cancer. METHODS: A retrospective observational study of patients treated at Sandwell and West Birmingham Hospitals NHS Trust and University Hospital Coventry and Warwickshire. Patients included were women aged ≥16 years, with primary mucinous ovarian cancer confirmed by specialist gynecological histopathologist and tumor immunohistochemistry, including cytokeratin-7, cytokeratin-20, and CDX2. Statistical analyses were performed using R integrated development environment, with survival assessed by Cox proportional hazards models and Kaplan-Meier plots. RESULTS: A total of 163 patients were analyzed; median age at diagnosis was 58 years (range 16-92), 145 (89%) were International Federation of Gynecology and Obstetrics stage I and 43 (26%) patients had infiltrative invasion. Women aged ≤45 years were more likely to have infiltrative invasion (RR=1.38, 95% CI 0.78 to 2.46), with increased risk of death associated with infiltrative invasion (HR=2.29, 95% CI 1.37 to 5.83). Compared with White counterparts, South Asian women were more likely to undergo fertility-sparing surgery (RR=3.52, 95% CI 1.48 to 8.32), and have infiltrative invasion (RR=1.25, 95% CI 0.60 to 2.58). South Asian women undergoing fertility-sparing surgery had worse prognosis than those undergoing traditional staging surgery (HR=2.20, 95% CI 0.39 to 13.14). In FIGO stage I disease, 59% South Asian and 37% White women received adjuvant chemotherapy (p=0.06). South Asian women exhibited a worse overall prognosis than White women (HR=2.07, 95% CI 0.86 to 4.36), particularly pronounced in those aged ≤45 years (HR=8.75, 95% CI 1.22 to 76.38). CONCLUSION: This study identified young age as a risk factor for diagnosis of infiltrative invasion. Fertility-sparing surgery in South Asian women is a risk factor for poorer prognosis. South Asian women exhibit poorer overall survival than their White counterparts.

Nonsquamous Malignancies of Vagina and Vulva: 23-Year Experience at a Tertiary Center in the United Kingdom.

Under 10% of gynaecological cancers are diagnosed in the vulva and vagina, mostly squamous cell carcinomas. Melanoma, Paget disease, basal cell carcinomas, and other cancers can present with vulval/vaginal symptoms. The pathology information system of a tertiary referral center for vulvo-vaginal cancers was searched for cancers of the vulva and vagina from 1996 to 2019. Squamous carcinomas were excluded, and the remaining entities were catalogued. A total of 221 nonsquamous cancers were found, including 135 vaginal and 86 vulval cases. One hundred eight cases of metastatic carcinomas from the endometrium, cervix, ovary, bowel, bladder, kidney, and breast formed the largest category. Basal cell carcinomas constituted the second largest category. Others included melanomas, Paget disease, and adenoid cystic carcinomas. Primary adenocarcinomas included porocarcinoma, mammary type carcinoma, enteric type carcinoma, clear cell carcinoma, Bartholin gland adenocarcinoma and malignant transformation of hidradenoma papilliferum. The vulva and vagina can harbor a wide range of nonsquamous malignancies. The most challenging of these are adenocarcinomas which can be metastatic from other sites. The dominance of metastatic carcinomas in this series is likely to reflect consultation practice of specialist pathologists.

First-in-class humanized FSH blocking antibody targets bone and fat.

Blocking the action of FSH genetically or pharmacologically in mice reduces body fat, lowers serum cholesterol, and increases bone mass, making an anti-FSH agent a potential therapeutic for three global epidemics: obesity, osteoporosis, and hypercholesterolemia. Here, we report the generation, structure, and function of a first-in-class, fully humanized, epitope-specific FSH blocking antibody with a KD of 7 nM. Protein thermal shift, molecular dynamics, and fine mapping of the FSH-FSH receptor interface confirm stable binding of the Fab domain to two of five receptor-interacting residues of the FSHß subunit, which is sufficient to block its interaction with the FSH receptor. In doing so, the humanized antibody profoundly inhibited FSH action in cell-based assays, a prelude to further preclinical and clinical testing.

Gastrointestinal Stromal Tumors (GISTs) as Incidental Findings in Gynecological Surgery.

Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors of the gastrointestinal tract that may be diagnosed incidentally as a part of intra-abdominal surgery for other diseases. This is a single center review to document the incidental finding of GIST at surgery for gynecological malignancies during a 10-yr period. Sixteen cases of incidental GISTs were identified in women ranging in age from 39 to 82 yr. GISTs presented as incidental secondary lesions in women undergoing surgery for other indications, typically primary debulking surgery for tubo-ovarian high-grade serous carcinoma. The GIST was located in the stomach wall in 9 cases. Other sites were cecum, omentum, and mesentery. Diagnosis of GIST was supported by immunohistochemistry in all cases and by molecular studies in 3 cases. Seventy-five percent of cases were micro-GISTs, measuring <2 cm in diameter and, where Miettinen and Lasota criteria could be applied, fitted into "no risk," "very low risk" or "low risk" prognostic groups. Seventy-five percent of women for whom survival data was available, showed disease-free survival at follow-up. The 2 women who died had concurrent high stage or high-grade gynecological malignancy at initial diagnosis.

Mutations in RPSA and NKX2-3 link development of the spleen and intestinal vasculature.

Idiopathic intestinal varicosis is a developmental disorder defined by dilated and convoluted submucosal veins in the colon or small bowel. A limited number of families with idiopathic intestinal varices has been reported, but the genetic cause has not yet been identified. We performed whole-exome and targeted Sanger sequencing of candidate genes in five intestinal varicosis families. In four families, mutations in the RPSA gene were found, a gene previously linked to congenital asplenia. Individuals in these pedigrees had intestinal varicose veins and angiodysplasia, often in combination with asplenia. In a further four-generation pedigree that only showed intestinal varicosities, the RPSA gene was normal. Instead, a nonsense mutation in the homeobox gene NKX2-3 was detected which cosegregated with the disease in this large family with a LOD (logarithm of the odds) score of 3.3. NKX2-3 is a component of a molecular pathway underlying spleen and gut vasculature development in mice. Our results provide a molecular basis for familial idiopathic intestinal varices. We provide evidence for a relationship between the molecular pathways underlying the development of the spleen and intestinal mucosal vasculature that is conserved between humans and mice. We propose that clinical management of intestinal varices, should include assessment of a functional spleen.

Role of the pathologist in assessing response to treatment of ovarian and endometrial cancers.

Standardisation of pathological evaluation of tissue responses to therapy permits robust stratification of patient outcomes for management decisions and allows comparison of results across clinical trials. In gynaecological pathology there are two major areas where pathological assessment of treatment response is currently used to determine ongoing therapy. High-grade serous carcinoma (HGSC) of tubo-ovarian origin frequently presents as high-stage disease and may be managed by neoadjuvant chemotherapy with debulking surgery. The chemotherapy response score (CRS) is a reproducible, validated three-tiered morphological scoring system to assess the response of HGSC to treatment. Interobserver agreement is shown to be substantial following online training, and women with CRS3 have significantly improved progression-free and overall survival. Low-grade endometrioid endometrial cancer and atypical hyperplasia/endometrioid intraepithelial neoplasia may be managed by progestogenic therapy in women who wish to preserve fertility or for whom medical co-morbidities preclude surgical management. The response to treatment is assessed histologically in successive endometrial biopsies. The histological parameters are well described, but the pathological classification of treatment response is still under development. Pathological assessment of the response to treatment is incorporated into clinical guidelines.

Peripheral immunophenotype in dementia with Lewy bodies and Alzheimer's disease: an observational clinical study.

BACKGROUND: Inflammation plays a key role in the aetiology and progression of Alzheimer's disease (AD). However, the immunophenotype of the second most common neurodegenerative cause of dementia, dementia with Lewy bodies (DLB), remains unclear. To date there have been no studies examining peripheral inflammation in DLB using multiplex immunoassay and flow cytometry concomitantly. We hypothesised that, using blood biomarkers, DLB would show an increased proinflammatory profile compared with controls, and that there would be a distinct profile compared with AD. METHODS: 93 participants (31 with DLB, 31 with AD and 31 healthy older controls) completed a single study visit for neuropsychiatric testing and phlebotomy. Peripheral blood mononuclear cells were quantified for T and B cell subsets using flow cytometry, and serum cytokine concentrations were measured using multiplex immunoassay. RESULTS: We detected reduced relative numbers of helper T cells and reduced activation of B cells in DLB compared with AD. Additionally, interleukin (IL)-1ß was detected more frequently in DLB and the serum concentration of IL-6 was increased compared with controls. CONCLUSIONS: Peripheral inflammation is altered in DLB compared with AD, with T cell subset analysis supporting a possible shift towards senescence of the adaptive immune system in DLB. Furthermore, there is a proinflammatory signature of serum cytokines in DLB. Identification of this unique peripheral immunophenotype in DLB could guide development of an immune-based biomarker and direct future work exploring potential immune modulation as a novel treatment.

Immunological Profiling of Paediatric Inflammatory Bowel Disease Using Unsupervised Machine Learning.

OBJECTIVES: The current classification of inflammatory bowel disease (IBD) is based on clinical phenotypes, which is blind to the molecular basis of the disease. The aim of this study was to stratify a treatment-naïve paediatric IBD cohort through specific innate immunity pathway profiling and application of unsupervised machine learning (UML). METHODS: In order to test the molecular integrity of biological pathways implicated in IBD, innate immune responses were assessed at diagnosis in 22 paediatric patients and 10 age-matched controls. Peripheral blood mononuclear cells (PBMCs) were selectively stimulated for assessing the functionality of upstream activation receptors including NOD2, toll-like receptor (TLR) 1-2 and TLR4, and the downstream cytokine responses (IL-10, IL-1ß, IL-6, and TNF-α) using multiplex assays. Cytokine data generated were subjected to hierarchical clustering to assess for patient stratification. RESULTS: Combined immune responses in patients across 12 effector responses were significantly reduced compared with controls (P = 0.003) and driven primarily by "hypofunctional" TLR responses (P values 0.045, 0.010, and 0.018 for TLR4-mediated IL-10, IL-1ß, and TNF-α, respectively; 0.018 and 0.015 for TLR1-2 -mediated IL-10 and IL-1ß). Hierarchical clustering generated 3 distinct clusters of patients and a fourth group of "unclustered" individuals. No relationship was observed between the observed immune clusters and the clinical disease phenotype. CONCLUSIONS: Although a clinically useful outcome was not observed through hierarchical clustering, our study provides a rationale for using an UML approach to stratify patients. The study also highlights the predominance of hypo-inflammatory innate immune responses as a key mechanism in the pathogenesis of IBD.

New Directions in Vulvar Cancer Pathology.

PURPOSE OF REVIEW: The aim of this article is to provide clinicians and pathologists with an understanding of the aetiopathology, pathogenesis and classification of vulval neoplasia and their molecular correlates. RECENT FINDINGS: There is an increased understanding of subcellular changes in vulvar malignancies. These provide the direction for further research and aid personalised treatment for patients. The article explores concepts of the aetiology of vulvar cancer and updates the reader with the equivalence of terminology of preneoplastic vulval disease. The differential diagnosis of squamous neoplasia and their clinicopathological correlation is detailed. The salient findings from recent literature into the understanding of the disease of squamous cell neoplasia and rare vulvar malignancies are summarised.

IL-12 and IL-7 synergize to control mucosal-associated invariant T-cell cytotoxic responses to bacterial infection.

BACKGROUND: Bacterial respiratory tract infections and exacerbations of chronic lung diseases are commonly caused by nontypeable Haemophilus influenzae (NTHi). Cell-mediated cytotoxicity might be key to controlling infection, but the responses of NTHi-specific T-cell populations are not well understood. Mucosal-associated invariant T (MAIT) cells are a recently discovered, innate-like subset of T cells with cytotoxic function, the role of which in lung immunity is unclear. OBJECTIVE: The aim of this study was to determine the mechanisms behind conventional T-cell and MAIT cell cytotoxic responses to NTHi. METHODS: Human ex vivo lung explants were infected with a clinical strain of NTHi. Monocyte-derived macrophages were also infected with NTHi in vitro and cocultured with autologous T cells. Cytotoxic responses of T-cell subsets were measured by using flow cytometry. RESULTS: We found significant upregulation of the cytotoxic markers CD107a and granzyme B in lung CD4+, CD8+, and MAIT cell populations. We show that MAIT cell cytotoxic responses were upregulated by a combination of both time-dependent antigen presentation and a novel mechanism through which IL-12 and IL-7 synergistically control granzyme B through upregulation of the IL-12 receptor. CONCLUSIONS: Overall, our data provide evidence for a cytotoxic role of MAIT cells in the lung and highlight important differences in the control of adaptive and innate-like T-cell responses. Understanding these mechanisms might lead to new therapeutic opportunities to modulate the antibacterial response and improve clinical outcome.

Magnetic Resonance Imaging and Molecular Characterization of a Hormone-Mediated Murine Model of Prostate Enlargement and Bladder Outlet Obstruction.

Urinary complications resulting from benign prostatic hyperplasia and bladder outlet obstruction continue to be a serious health problem. Novel animal model systems and imaging approaches are needed to understand the mechanisms of disease initiation, and to develop novel therapies for benign prostatic hyperplasia. Long-term administration of both estradiol and testosterone in mice can result in prostatic enlargement and recapitulate several clinical components of lower urinary tract symptoms. Herein, we use longitudinal magnetic resonance imaging and histological analyses to quantify changes in prostatic volume, urethral volume, and genitourinary vascularization over time in response to estradiol-induced prostatic enlargement. Our data demonstrate significant prostatic enlargement by 12 weeks after treatment, with no detectable immune infiltration by macrophages or T- or B-cell populations. Importantly, the percentage of cell death, as measured by terminal deoxynucleotidyl transferase dUTP nick-end labeling, was significantly decreased in the prostatic epithelium of treated animals as compared to controls. We found no significant change in prostate cell proliferation in treated mice when compared to controls. These studies highlight the utility of magnetic resonance imaging to quantify changes in prostatic and urethral volumes over time. In conjunction with histological analyses, this approach has the high potential to enable mechanistic studies of initiation and progression of clinically relevant lower urinary tract symptoms. In addition, this model is tractable for investigation and testing of therapeutic interventions to ameliorate or potentially reverse prostatic enlargement.

Impact of radiologically stratified exacerbations: insights into pneumonia aetiology in COPD.

BACKGROUND: COPD patients have increased risk of developing pneumonia, which is associated with poor outcomes. It can be symptomatically indistinguishable from exacerbations, making diagnosis challenging. Studies of pneumonia in COPD have focused on hospitalised patients and are not representative of the ambulant COPD population. Therefore, we sought to determine the incidence and aetiology of acute exacerbation events with evidence of pneumonic radiographic infiltrates in an outpatient COPD cohort. METHODS: One hundred twenty-seven patients with moderate to very severe COPD aged 42-85 years underwent blood and sputum sampling over one year, at monthly stable visits and within 72 h of exacerbation symptom onset. 343 exacerbations with chest radiographs were included. RESULTS: 20.1% of exacerbations had pneumonic infiltrates. Presence of infiltrate was highly seasonal (Winter vs summer OR 3.056, p = 0.027). In paired analyses these exacerbation events had greater increases in systemic inflammation. Bacterial detection rate was higher in the pneumonic group, with Haemophilus influenzae the most common bacteria in both radiological groups. Viral detection and sputum microbiota did not differ with chest radiograph appearance. CONCLUSIONS: In an outpatient COPD cohort, pneumonic infiltrates at exacerbation were common, and associated with more intense inflammation. Bacterial pathogen detection and lung microbiota were not distinct, suggesting that exacerbations and pneumonia in COPD share common infectious triggers and represent a continuum of severity rather than distinct aetiological events. TRIAL REGISTRATION: Trial registration Number: NCT01360398 .

Relationship of CT-quantified emphysema, small airways disease and bronchial wall dimensions with physiological, inflammatory and infective measures in COPD.

BACKGROUND: COPD is a complex, heterogeneous disease characterised by progressive development of airflow limitation. Spirometry provides little information about key aspects of pathology and is poorly related to clinical outcome, so other tools are required to investigate the disease. We sought to explore the relationships between quantitative CT analysis with functional, inflammatory and infective assessments of disease to identify the utility of imaging to stratify disease to better predict outcomes and disease response. METHODS: Patients from the AERIS study with moderate-very severe COPD underwent HRCT, with image analysis determining the quantity of emphysema (%LAA<- 950), small airways disease (E/I MLD) and bronchial wall thickening (Pi10). At enrolment subjects underwent lung function testing, six-minute walk testing (6MWT), blood sampling for inflammatory markers and sputum sampling for white cell differential and microbiological culture and PCR. RESULTS: 122 subjects were included in this analysis. Emphysema and small airways disease had independent associations with airflow obstruction (ß = - 0.34, p < 0.001 and ß = - 0.56, p < 0.001). %LAA<- 950 had independent associations with gas transfer (ß = - 0.37, p < 0.001) and E/I MLD with RV/TLC (ß = 0.30, p =0.003). The distance walked during the 6MWT was not associated with CT parameters, but exertional desaturation was independently associated with emphysema (ß = 0.73, p < 0.001). Pi10 did not show any independent associations with lung function or functional parameters. No CT parameters had any associations with sputum inflammatory cells. Greater emphysema was associated with lower levels of systemic inflammation (CRP ß = - 0.34, p < 0.001 and fibrinogen ß = - 0.28, p =0.003). There was no significant difference in any of the CT parameters between subjects where potentially pathogenic bacteria were detected in sputum and those where it was not. CONCLUSIONS: This study provides further validation for the use of quantitative CT measures of emphysema and small airways disease in COPD as they showed strong associations with pulmonary physiology and functional status. In contrast to this quantitative CT measures showed few convincing associations with biological measures of disease, suggesting it is not an effective tool at measuring disease activity.

Synchronization of relativistic particles in the hyperbolic Kuramoto model.

We formulate a noncompact version of the Kuramoto model by replacing the invariance group SO(2) of the plane rotations by the noncompact group SO(1, 1). The N equations of the system are expressed in terms of hyperbolic angles αi and are similar to those of the Kuramoto model, except that the trigonometric functions are replaced by hyperbolic functions. Trajectories are generally unbounded, nevertheless synchronization occurs for any positive couplings κi, arbitrary positive multiplicative parameters λi and arbitrary exponents ωi. There are no critical values for the coupling constants. We measure the onset of synchronization by means of several order and disorder parameters. We show numerically and by means of exact solutions for N = 2 that solutions can develop singularities if the coupling constants are negative, or if the initial values are not suitably restricted. We describe a physical interpretation of the system as a cluster of interacting relativistic particles in 1 + 1 dimensions, subject to linear repulsive forces with space-time trajectories parametrized by the rapidity αi. The trajectories synchronize provided that the particle separations remain predominantly time-like, and the synchronized cluster can be viewed as a bound state of N relativistic particle constituents. We extend the defining equations of the system to higher dimensions by means of vector equations which are covariant with respect to SO(p, q).

Clinical spectrum and features of activated phosphoinositide 3-kinase δ syndrome: A large patient cohort study.

BACKGROUND: Activated phosphoinositide 3-kinase δ syndrome (APDS) is a recently described combined immunodeficiency resulting from gain-of-function mutations in PIK3CD, the gene encoding the catalytic subunit of phosphoinositide 3-kinase δ (PI3Kδ). OBJECTIVE: We sought to review the clinical, immunologic, histopathologic, and radiologic features of APDS in a large genetically defined international cohort. METHODS: We applied a clinical questionnaire and performed review of medical notes, radiology, histopathology, and laboratory investigations of 53 patients with APDS. RESULTS: Recurrent sinopulmonary infections (98%) and nonneoplastic lymphoproliferation (75%) were common, often from childhood. Other significant complications included herpesvirus infections (49%), autoinflammatory disease (34%), and lymphoma (13%). Unexpectedly, neurodevelopmental delay occurred in 19% of the cohort, suggesting a role for PI3Kδ in the central nervous system; consistent with this, PI3Kδ is broadly expressed in the developing murine central nervous system. Thoracic imaging revealed high rates of mosaic attenuation (90%) and bronchiectasis (60%). Increased IgM levels (78%), IgG deficiency (43%), and CD4 lymphopenia (84%) were significant immunologic features. No immunologic marker reliably predicted clinical severity, which ranged from asymptomatic to death in early childhood. The majority of patients received immunoglobulin replacement and antibiotic prophylaxis, and 5 patients underwent hematopoietic stem cell transplantation. Five patients died from complications of APDS. CONCLUSION: APDS is a combined immunodeficiency with multiple clinical manifestations, many with incomplete penetrance and others with variable expressivity. The severity of complications in some patients supports consideration of hematopoietic stem cell transplantation for severe childhood disease. Clinical trials of selective PI3Kδ inhibitors offer new prospects for APDS treatment.

Corticosteroids and infliximab impair the performance of interferon-γ release assays used for diagnosis of latent tuberculosis.

The impact of immunosuppression on interferon-γ release assays and novel cytokine biomarkers of TB infection, mycobacteria-specific IL-2, IP-10 and TNF-α responses was investigated in an ex vivo model. Cytokine responses in standard QuantiFERON-TB Gold in-Tube (QFT-GIT) assays were compared with duplicate assays containing dexamethasone or infliximab. Dexamethasone converted QFT-GIT results from positive to negative in 30% of participants. Antigen-stimulated interferon-γ, IL-2 and TNF-α responses were markedly reduced, but IP-10 responses were preserved. Infliximab caused QFT-GIT result conversion in up to 30% of participants and substantial reductions in all cytokine responses. Therefore, corticosteroids and anti-TNF-α agents significantly impair interferon-γ release assay performance. IP-10 may be a more robust TB biomarker than interferon-γ in patients receiving corticosteroids.

A prospective, observational cohort study of the seasonal dynamics of airway pathogens in the aetiology of exacerbations in COPD.

BACKGROUND: The aetiology of acute exacerbations of COPD (AECOPD) is incompletely understood. Understanding the relationship between chronic bacterial airway infection and viral exposure may explain the incidence and seasonality of these events. METHODS: In this prospective, observational cohort study (NCT01360398), patients with COPD aged 40-85 years underwent sputum sampling monthly and at exacerbation for detection of bacteria and viruses. Results are presented for subjects in the full cohort, followed for 1 year. Interactions between exacerbation occurrence and pathogens were investigated by generalised estimating equation and stratified conditional logistic regression analyses. FINDINGS: The mean exacerbation rate per patient-year was 3.04 (95% CI 2.63 to 3.50). At AECOPD, the most common bacterial species were non-typeable Haemophilus influenzae (NTHi) and Moraxella catarrhalis, and the most common virus was rhinovirus. Logistic regression analyses (culture bacterial detection) showed significant OR for AECOPD occurrence when M. catarrhalis was detected regardless of season (5.09 (95% CI 2.76 to 9.41)). When NTHi was detected, the increased risk of exacerbation was greater in high season (October-March, OR 3.04 (1.80 to 5.13)) than low season (OR 1.22 (0.68 to 2.22)). Bacterial and viral coinfection was more frequent at exacerbation (24.9%) than stable state (8.6%). A significant interaction was detected between NTHi and rhinovirus presence and AECOPD risk (OR 5.18 (1.92 to 13.99); p=0.031). CONCLUSIONS: AECOPD aetiology varies with season. Rises in incidence in winter may be driven by increased pathogen presence as well as an interaction between NTHi airway infection and effects of viral infection. TRIAL REGISTRATION NUMBER: Results, NCT01360398.

Upregulation of FcγRIIb on monocytes is necessary to promote the superagonist activity of TGN1412.

The anti-CD28 superagonist antibody TGN1412 caused life-threatening cytokine release syndrome (CRS) in healthy volunteers, which had not been predicted by preclinical testing. T cells in fresh peripheral blood mononuclear cells (PBMCs) do not respond to soluble TGN1412 but do respond following high-density (HD) preculture. We show for the first time that this response is dependent on crystallizable fragment gamma receptor IIb (FcγRIIb) expression on monocytes. This was unexpected because, unlike B cells, circulating monocytes express little or no FcγRIIb. However, FcγRIIb expression is logarithmically increased on monocytes during HD preculture, and this upregulation is necessary and sufficient to explain TGN1412 potency after HD preculture. B-cell FcγRIIb expression is unchanged by HD preculture, but B cells can support TGN1412-mediated T-cell proliferation when added at a frequency higher than that in PBMCs. Although low-density (LD) precultured PBMCs do not respond to TGN1412, T cells from LD preculture are fully responsive when cocultured with FcγRIIb-expressing monocytes from HD preculture, which shows that they are fully able to respond to TGN1412-mediated activation. Our novel findings demonstrate that cross-linking by FcγRIIb is critical for the superagonist activity of TGN1412 after HD preculture, and this may contribute to CRS in humans because of the close association of FcγRIIb-bearing cells with T cells in lymphoid tissues.

Steroid-induced Deficiency of Mucosal-associated Invariant T Cells in the Chronic Obstructive Pulmonary Disease Lung. Implications for Nontypeable Haemophilus influenzae Infection.

RATIONALE: Mucosal-associated invariant T (MAIT) cells are a recently described abundant, proinflammatory T-cell subset with unknown roles in pulmonary immunity. Nontypeable Haemophilus influenzae (NTHi) is the leading bacterial pathogen during chronic obstructive pulmonary disease (COPD) exacerbations and is a plausible target for MAIT cells. OBJECTIVES: To investigate whether MAIT cells respond to NTHi and the effects of inhaled corticosteroids (ICS) on their frequency and function in COPD. METHODS: Eleven subjects with COPD receiving ICS, 8 steroid-naive subjects with COPD, and 21 healthy control subjects underwent phlebotomy, sputum induction, bronchoalveolar lavage, and endobronchial biopsy. Pulmonary and monocyte-derived macrophages were cultured in vitro with NTHi. MEASUREMENTS AND MAIN RESULTS: Frequencies of Vα7.2+CD161+ MAIT cells, surface expression of the major histocompatibility complex-related protein 1 (MR1), and intracellular IFN-γ expression were measured by flow cytometry. MAIT-cell frequencies were reduced in peripheral blood of ICS-treated subjects with COPD (median 0.38%; interquartile range [IQR], 0.25-0.96) compared with healthy control subjects (1.8%; IQR, 1.4-2.5; P = 0.001) or steroid-naive patients with COPD (1.8%; IQR, 1.2-2.3; P = 0.04). MAIT cells were reduced in bronchial biopsies from subjects with COPD treated with steroids (0.73%; IQR, 0.46-1.3) compared with healthy control subjects (4.0%; IQR, 1.6-5.0; P = 0.02). Coculture of live NTHi increased macrophage surface expression of MR1 and induced IFN-γ from CD4 cells and CD8 cells, but most potently from MAIT cells (median IFN-γ-positive frequencies, 2.9, 8.6, and 27.6%, respectively). In vitro fluticasone and budesonide reduced MR1 surface expression twofold and decreased NTHi-induced IFN-γ secretion eightfold. CONCLUSIONS: MAIT cells are deficient in blood and bronchial tissue in steroid-treated, but not steroid-naive, COPD. NTHi constitutes a target for pulmonary MAIT-cell immune responses, which are significantly impaired by corticosteroids.