[Anti-IL-5 in severe asthma associated with eosinophilic granulomatosis with polyangiitis. Real-life study]

INTRODUCTION

Eosinophilic granulomatosis with polyangiitis (EGPA) is a form of necrotizing vasculitis affecting small vessels and typically characterized by severe glucocorticoid (GC)-dependent eosinophilic asthma. While mepolizumab, which is indicated at a dose of 100mg/4weeks in severe eosinophilic asthma, has been shown to be an effective treatment for EGPA-related asthma at a dose of 300mg/4weeks, it was only recently approved at this dose.

METHODS

This retrospective, single-center, observational study was conducted to investigate over a 5-year period (2014-2019) the effect of mepolizumab 100mg/4weeks at 12months in patients with EGPA and glucocorticoid-dependant severe asthma. Response to treatment was defined as reduction in daily dose of oral corticosteroids to at most 5mg/day or reduction in annual exacerbation by at least 50%.

RESULTS

Thirty patients were included, of whom twenty-three were treated (two were not fully evaluable). Among the 21 evaluable treated patients, 13 (62%) had responded at 12months. At baseline, non-responders had lower FEV1 levels and lower blood eosinophil levels than responders.

CONCLUSIONS

Mepolizumab at a "severe asthma" dose (100mg/4weeks) is effective in treatment of GC-dependent severe asthma in most patients with EGPA.

[Allergic Broncho-Pulmonary Aspergillosis (ABPA) in cystic fibrosis: Mechanisms, diagnosis and therapeutic options]

INTRODUCTION

Fungal aspergillosis colonization and allergic bronchopulmonary aspergillosis (ABPA) can have a strong impact on the prognosis in cystic fibrosis (CF). We conducted round table discussions involving French experts from pediatric and adult centers caring for patients with CF, microbiologists, radiologists and pharmacists. The aim was to explore the current state of knowledge on: the pathophysiological mechanisms of Aspergillus and other micromycetes infections in CF (such as Scedosporium sp.), and on the clinico-biological diagnosis of ABPA. In perspective, the experts explored the role of imaging in the diagnosis of APBA, specifically CT and MRI; as well as the role of bronchoscopy in the management. We also reviewed the therapeutic management, including different corticosteroid regimens, antifungals and anti-IgE antibodies.

CONCLUSION

The diagnosis of ABPA in CF should be based on more standardized biological assays and imaging to optimize treatment and follow-up.

Prevalence and management of chronic breathlessness in COPD in a tertiary care center

Background

Breathlessness is the prominent symptom of chronic obstructive pulmonary disease (COPD). Despite optimal therapeutic management including pharmacological and non-pharmacological interventions, many COPD patients exhibit significant breathlessness. Chronic breathlessness is defined as breathlessness that persists despite optimal treatment of the underlying disease. Because of the major disability related to chronic breathlessness, symptomatic treatments including opioids have been recommended by several authors. The prevalence of chronic breathlessness in COPD and its management in routine clinical practice have been poorly investigated. Our aim was to examine prevalence, associated characteristics and management of chronic breathlessness in patients with COPD recruited in a real-life tertiary hospital-based cohort.

Methods

A prospective study was conducted among 120 consecutive COPD patients recruited, in stable condition, at Nancy University Hospital, France. In parallel, 88 pulmonologists of the same geographical region were asked to respond to an on-line questionnaire on breathlessness management.

Results

Sixty four (53%) patients had severe breathlessness (modified Medical Research Council scale≥3), despite optimal inhaled medications for 94% of them; 40% had undergone pulmonary rehabilitation within the past 2 years. The severity of breathlessness increased with increasing airflow limitation. Breathlessness was associated with increased symptoms of anxiety, depression and with osteoporosis. No relation was found with other symptoms, exacerbation rate, or cardiovascular comorbidities. Among the patients with chronic breathlessness and Hospitalized Anxiety and/or Depression score > 10, only 25% were treated with antidepressant or anxiolytic. Among the pulmonologists 46 (52%) answered to the questionnaire and expressed a high willingness to prescribe opioids forchronic breathlessness, which contrasted with the finding that none of these patients received such treatments against breathlessness.

Conclusion

Treatment approaches to breathlessness and associated psychological distress are insufficient in COPD. This study highlights underuse of pulmonary rehabilitation and symptomatic treatment for breathlessness.

Electronic supplementary material

The online version of this article (10.1186/s12890-019-0851-5) contains supplementary material, which is available to authorized users.

A 3-year prognostic score for adults with cystic fibrosis

BACKGROUND

Therapeutic progress in patients with cystic fibrosis (CF) has resulted in improved prognosis over the past decades. We aim to reevaluate prognostic factors of CF and provide a prognostic score to predict the risk of death or lung transplantation (LT) within a 3-year period in adult patients.

METHODS

We developed a logistic model using data from the French CF Registry and combined the coefficients into a prognostic score. The discriminative abilities of the model and the prognostic score were assessed by c-statistic. The prognostic score was validated using a 10-fold cross-validation.

RESULTS

The risk of death or LT within 3years was related to eight characteristics. The development and the validation provided excellent results for the prognostic score; the c-statistic was 0.91 and 0.90 respectively.

CONCLUSION

The score developed to predict 3-year death or LT in adults with CF might be useful for clinicians to identify patients requiring specialized evaluation for LT.

Pseudomonas aeruginosa induces MUC5AC production via epidermal growth factor receptor

Hypersecretory disease associated with Pseudomonas aeruginosa (PA) infections is characterised by increased goblet cells and increased mucin production. Recently, an epidermal growth factor receptor (EGFR) signalling cascade was shown to be a common pathway through which many stimuli induce mucin MUC5AC expression in airways by differentiation to a goblet cell phenotype. This study looked at whether PA products induce EGFR expression and activation and thus result in mucin MUC5AC production. Human airway epithelial (NCI-H292) cells were stimulated with PA culture supernatant (Sup). MUC5AC protein production, MUC5AC and EGFR messenger ribonucleic acid (mRNA) expression, and phosphorylated EGFR and phosphorylated p44/42 mitogen-activated protein kinase (MAPK) were all examined using enzyme-linked immunosorbent assay, by in situ hybridisation and by immunoblotting. PA Sup induced MUC5AC mRNA and subsequent protein expression, EGFR and p44/42 MAPK phosphorylation and EGFR mRNA expression. Induction of MUC5AC mRNA and protein expression and EGFR and p44/42 MAPK phosphorylation were inhibited completely by pretreatment with a selective EGFR tyrosine kinase inhibitor. Pretreatment with a selective inhibitor of MAPK kinase prevented MUC5AC production and p44/42 MAPK phosphorylation but not EGFR phosphorylation. The authors conclude that PA products induce mucin MUC5AC production in human airway epithelial cells via the expression and activation of epidermal growth factor receptor.

Human eosinophils induce mucin production in airway epithelial cells via epidermal growth factor receptor activation

Eosinophil recruitment and mucus hypersecretion are characteristic of asthmatic airway inflammation, but eosinophils have not been shown to induce mucin production. Because an epidermal growth factor receptor (EGFR) cascade induces MUC5AC mucin in airways, and because EGFR is up-regulated in asthmatic airways, we examined the effect of eosinophils on MUC5AC mucin production in NCI-H292 cells (a human airway epithelial cell line that produces mucins). Eosinophils were isolated from the peripheral blood of allergic patients, and their effects on MUC5AC mucin gene and protein synthesis were assessed using in situ hybridization and ELISAs. When IL-3 plus GM-CSF or IL-3 plus IL-5 were added to eosinophils cultured with NCI-H292 cells, MUC5AC mucin production increased; eosinophils or cytokines alone had no effect. Eosinophil supernatant obtained by culturing eosinophils with IL-3 plus GM-CSF or IL-3 plus IL-5 also increased MUC5AC synthesis in NCI-H292 cells, an effect that was prevented by selective EGFR inhibitors (AG1478, BIBX1522). Supernatant of activated eosinophils induced EGFR phosphorylation in NCI-H292 cells. Supernatant of activated eosinophils contained increased concentrations of TGF-alpha protein (an EGFR ligand) and induced up-regulation of TGF-alpha expression and release in NCI-H292 cells. A blocking Ab to TGF-alpha reduced activated eosinophil-induced MUC5AC synthesis in NCI-H292 cells. These results show that activated eosinophils induce mucin synthesis in human airway epithelial cells via EGFR activation, and they implicate TGF-alpha produced by eosinophils and epithelial cells in the EGFR activation that results in mucin production in human airway epithelium.

The role of epidermal growth factor in mucus production

Airway hypersecretion is a serious and presently untreatable symptom of chronic inflammatory airway diseases. Recently, it has been discovered that epithelial growth factor receptor expression and activation causes mucin production in airways. An epithelial growth factor receptor pathway is implicated in mucus cell differentiation induced by various stimuli; therefore, inhibition of the epithelial growth factor receptor transduction cascade may provide effective new treatments for hypersecretory airway diseases.

Activation of epidermal growth factor receptors is responsible for mucin synthesis induced by cigarette smoke

Mucus hypersecretion from hyperplastic airway goblet cells is a hallmark of chronic obstructive pulmonary disease (COPD). Although cigarette smoking is thought to be involved in mucus hypersecretion in COPD, the mechanism by which cigarette smoke induces mucus overproduction is unknown. Here we show that activation of epidermal growth factor receptors (EGFR) is responsible for mucin production after inhalation of cigarette smoke in airways in vitro and in vivo. In the airway epithelial cell line NCI-H292, exposure to cigarette smoke upregulated the EGFR mRNA expression and induced activation of EGFR-specific tyrosine phosphorylation, resulting in upregulation of MUC5AC mRNA and protein production, effects that were inhibited completely by selective EGFR tyrosine kinase inhibitors (BIBX1522, AG-1478) and that were decreased by antioxidants. In vivo, cigarette smoke inhalation increased MUC5AC mRNA and goblet cell production in rat airways, effects that were prevented by pretreatment with BIBX1522. These effects may explain the goblet cell hyperplasia that occurs in COPD and may provide a novel strategy for therapy in airway hypersecretory diseases.

IL-13 induces mucin production by stimulating epidermal growth factor receptors and by activating neutrophils

Mucus hypersecretion contributes to the morbidity and mortality in acute asthma. Both T helper 2 (Th2) cytokines and epidermal growth factor receptor (EGFR) signaling have been implicated in allergen-induced goblet cell (GC) metaplasia. Present results show that a cascade of EGFR involving neutrophils is implicated in interleukin (IL)-13-induced mucin expression in GC. Treatment with a selective EGFR tyrosine kinase inhibitor prevented IL-13-induced GC metaplasia dose dependently and completely. Instillation of IL-13 also induced tumor necrosis factor-alpha protein expression, mainly in infiltrating neutrophils. Control airway epithelium contained few leukocytes, but intratracheal instillation of IL-13 resulted in time-dependent leukocyte recruitment by IL-13-induced IL-8-like chemoattractant expression in airway epithelium. Pretreatment with an inhibitor of leukocytes in the bone marrow (cyclophosphamide) or with a blocking antibody to IL-8 prevented both IL-13-induced leukocyte recruitment and GC metaplasia. These findings indicate that EGFR signaling is involved in IL-13-induced mucin production. They suggest a potential therapeutic role for inhibitors of the EGFR cascade in the hypersecretion that occurs in acute asthma.

Relation of epidermal growth factor receptor expression to goblet cell hyperplasia in nasal polyps

BACKGROUND

Because the epidermal growth factor receptor (EGFR) system regulates mucin production in airway epithelium, we hypothesized a role for this system in mucus hypersecretion that occurs in nasal polyposis.

OBJECTIVE

We examined the relationship between goblet cell hyperplasia, EGFR expression, and inflammatory mediators produced by eosinophils and neutrophils in nasal polyp tissues.

METHODS

Nasal polyp tissue samples from 8 patients and nasal turbinate biopsy specimens from 6 normal control subjects were examined for alcian blue/PAS staining, mucin MUC5AC (MUC5AC), and EGFR immunoreactivity and EGFR gene expression (in situ hybridization). We also examined the role of eosinophils and neutrophils in goblet cell hyperplasia.

RESULTS

In control nasal mucosa alcian blue/periodic acid-Schiff- and MUC5AC-stained areas were 18.40% +/- 1.31% and 21.89% +/- 1.43%, respectively. In polyps the alcian blue/periodic acid-Schiff- and MUC5AC-stained areas were 51.30% +/- 5.85% and 52.07% +/- 6.58%, which was significantly larger than that found in control subjects (each comparison, P <.01). Four of 6 control specimens expressed EGFR messenger RNA and protein weakly in the epithelium. In polyps 4 of 8 specimens expressed EGFR gene and EGFR protein strongly; the EGFR-stained area was greater in hyperplastic than in pseudostratified epithelium. TNF-alpha immunoreactivity, expressed in eosinophils, was increased in EGFR-positive polyps compared with EGFR-negative polyps, suggesting a role for TNF-alpha in EGFR expression. Neutrophils were increased in the epithelium of EGFR-positive compared with EGFR-negative polyps, suggesting a role for these cells in mucin expression and in goblet cell degranulation.

CONCLUSION

These data suggest a role for EGFR cascade in the regulation of goblet cell mucins in nasal polyps. Proof of concept will require clinical studies using selective EGFR inhibitors.

Respiratory distress due to tracheal aspergillosis in a severely immunocompromised patient

A 23-year-old man, intensively treated for acute lymphoblastic leukaemia in relapse and with documented pulmonary aspergillosis, was admitted to the intensive care unit for acute respiratory failure. The diagnosis of invasive tracheal aspergillosis was made by bronchoscopy and biopsy. The lesions consisted of extensive necrotizing bronchitis with transmural and peribronchial extension associated with tracheal and bronchial obstruction due to the presence of pseudomembranes almost entirely composed of fungal hyphae. Despite treatment with amphotericin B and itraconazole, mechanical ventilation and bronchoscopy, the patient died 3 weeks later of massive bleeding.

Suplatast tosilate inhibits goblet-cell metaplasia of airway epithelium in sensitized mice

BACKGROUND

IL-4 and IL-13 play a putative role in mucus hypersecretion in asthma. Suplatast tosilate prevents the synthesis of T(H2) cytokines.

OBJECTIVE

Because suplatast tosilate inhibits T(H2) cytokines but does not inhibits IFN-gamma production, we examined the effect of suplatast on IL-4- or IL-13- and ovalbumin (OVA)-induced mucin synthesis in NCI-H292 cells in vitro and in bronchi of pathogen-free BALB/c mice in vivo.

METHODS

In vitro, NCI-H292 cells were preincubated with suplatast tosilate (0.1-100 microgram/mL) 1 hour before adding human recombinant IL-4 (10 ng/mL). In vivo, mouse recombinant IL-4 or IL-13 (250 ng per/mouse) was instilled intranasally in mice pretreated with suplatast tosilate (50 mg.kg(-1).d(-1)). Mucous glycoconjugates were stained with Alcian blue (AB)/periodic acid-Schiff (PAS) stain. To evaluate effects of suplatast tosilate on goblet-cell metaplasia in OVA-sensitized mice, animals were pretreated with suplatast tosilate (1-50 mg.kg(-1).d(-1)) intragastrically. IL-4 and IL-13 were measured, and allergic inflammatory cells were analyzed in bronchoalveolar lavage fluid of OVA-sensitized mice.

RESULTS

Pretreatment with suplastast did not prevent IL-4- or IL-13-induced increase in mucous glycoconjugate production in NCI-H292 cells or in mice. OVA sensitization increased AB/PAS-stained area of the epithelium (48.1% +/- 2.4%, P <.01 compared with control mice). Suplatast tosilate inhibited OVA-induced goblet-cell metaplasia in airway epithelium in a dose-dependent fashion; 50 mg.kg(-1).d(-1) decreased the AB/PAS area to 22.7% +/- 2.7% (P <.05 compared with OVA sensitization alone). Pretreatment with suplatast tosilate also prevented OVA-induced increase in IL-4 and IL-13 levels and decreased the number of lymphocytes and eosinophils in bronchoalveolar lavage fluid (P <.05 compared with values of mice given OVA alone).

CONCLUSION

These results indicate that suplatast tosilate prevents allergen-induced goblet-cell metaplasia and the recruitment of eosinophils and lymphocytes into the airways. These results suggest that this effect is due to the prevention of the production of T(H2) cytokines in airways.

[Pulmonary manifestations associated with malaria]

Pulmonary manifestations are frequently observed in children, pregnant women and travellers with malaria. The pathophysiology of these pulmonary manifestations is poorly understood but would appear to be secondary to an interaction between the parasitized red cells and the pulmonary capillary endothelium. Bronchitis and pneumonia do not directly compromise outcome but, left unrecognized, the delay in diagnosis and treatment may be fatal. Acute respiratory distress in children is the first cause of overmortality, coming before neurological involvement. The acute respiratory distress caused by severe malaria has no specific characteristics. Iatrogenic complications and pulmonary superinfections must be differentiated. The prevention of pulmonary manifestations associated with malaria can easily be accomplished by limiting water intake and carefully monitoring urinary output and weight. Treatment is the same as for acute flare-ups in combination with symptomatic respiratory treatment when required.

[Pleuropulmonary manifestations of amebiasis]

Amibiasis is the third leading cause of death due to parasitic infections in the world. Amibiasis is endemic in the warm regions of the world with deficient hygiene and socio-economic situations. Entamoeba histolytica is the causal agent of invasive amibiasis, unlike Entamoeba dispar which is not a pathogen for humans. Amibian colitis and amibian abscess of the liver are the most frequent intestinal and extra-intestinal manifestations. Pleuropulmonary complications almost always occur in patients with a liver abscess, the intrathoracic contamination via transphrenic dissemination predominating. Respiratory signs are inaugural in 80% of the cases. Pleuropulmonary ambiasis designates the localization of the amibian infestation, but the clinical expression may vary: pneumonia, lung abscess, pleurisy, hepatobronchial fistulization and more infrequently pulmonary embolism. The preferential localization is the right hemithorax related to abscess in the right lobe of the liver. Left lobe abscesses lead to left-sided pleuropulmonary complications with the risk of rupture into the pericardium. Chocolate-colored pus from a pleural or abscess puncture or vomitus strongly suggests the diagnosis, which is confirmed by highly-positive serology. Metronidazole is the treatment of choice, providing cure without sequellae. In Africa, mortality and morbidity due to ambiasis are high. In Abidjan, 92% of cured patients have sequella, and mortality reaches 15%, the consequence of late diagnosis.

[Pulmonic plague]

One hundred years after Yersin discovered Yersinia pestis during the plague epidemic in Hong Kong in 1894, human plague still has not been eliminated. The epidemic in 1994 in India, a country where no cases had been observed since 1996, raised great concern. Plague is an epizootic bacterial infection caused by a Gram negative coccobacillus, Y. pestis, transmitted by the bite of infected fleas. Bubonic plague is the most common form. Other clinical presentations include asymptomatic plague, abortive plague, pharyngeal plague, septicemic plague, meningeal plague, and primary or secondary pneumonic plague which is observed in 5 to 20% of cases. Plague is a highly communicable disease between humans despite antibiotic therapy which has reduced mortality by 80%. The prognosis depends on early diagnosis. Streptomycin and cyclines are the gold standard treatment.