Airway Autoimmune Inflammatory Response (AAIR) Syndrome: An Asthma-Autoimmune Overlap Disorder?

Cryotherapy in the paediatric airway: Indications, success and safety

BACKGROUND AND OBJECTIVE

Cryotherapy in interventional bronchoscopy is a new treatment modality, which has recently been made available for the paediatric airway. Lack of experience and safety concerns have led to hesitant adaptation. The aim of this study was to assess indications, success rates and complications of airway cryotherapy in children.

METHODS

Bronchoscopists from medical centre performing cryotherapy in patients between 0 and 18 years were invited to participate in a prospective study based on an online questionnaire. Patient and participant data were collected between June 2020 and June 2021.

RESULTS

A total of 69 cryotherapy procedures were performed in 57 patients a for three main indications: Biopsy (30), restoration of airway patency (23) and foreign body aspiration (16). The overall success rate was 93%, the remaining 7% were performed for foreign body removal and required a switch of technique. Restoration of airway patency was successfully applied in various pathologies, including mucus plugs, bronchial casts and post traumatic stenosis. The diagnostic yield of transbronchial biopsies was 96%. No severe complications were encountered; one pneumothorax following a cryobiopsy required a chest drain for 48 h. No child was admitted to intensive care or died from a procedural complication.

CONCLUSION

In this largest paediatric case collection to date, cryotherapy was safe and carried a high success rate. Cryobiopsy compares favourably to the widely used forceps biopsy and could replace it in the future. Paediatric bronchoscopists are encouraged to add cryotherapy to their armamentarium of airway interventions.

Pediatric bronchoscopy: recent advances and clinical challenges

Introduction: During the last 40 years equipment has been improved with smaller instruments and sufficient size working channels. This has ensured that bronchoscopy offers therapeutic and interventional options.Areas covered: We provide a review of recent advances and clinical challenges in pediatric bronchoscopy. This includes single-use bronchoscopes, endobronchial ultrasound, and cryoprobe. Bronchoscopy in persistent preschool wheezing and asthma is included. The indications for interventional bronchoscopy have amplified and included balloon dilatation, endoscopic intubation, the use of airway stents, whole lung lavage, closing of fistulas and air leak, as well as an update on removal of foreign bodies. Others include the use of laser and microdebrider in airway surgery. Experience with bronchoscope during the COVID-19 pandemic has been included in this review. PubMed was searched for articles on pediatric bronchoscopy, including rigid bronchoscopy as well as interventional bronchoscopy with a focus on reviewing literature in the past 5 years.Expert opinion: As the proficiency of pediatric interventional pulmonologists continues to grow more interventions are being performed. There is a scarcity of published evidence in this field. Courses for pediatric interventional bronchoscopy need to be developed. The COVID-19 experience resulted in safer bronchoscopy practice for all involved.

Diagnosis and management of chronic cough: similarities and differences between children and adults

Cough is a natural process that protects the airway. Cough can occur spontaneously or voluntarily. It is considered chronic when it is present for longer than 4 weeks in children or 8 weeks in adults. In both, chronic cough causes patient distress and increased healthcare utilization. Etiologies of pediatric chronic cough include asthma, protracted bacterial bronchitis, tracheomalacia, habit cough, and various systemic disorders. While some diagnoses are identifiable by careful history alone, others require testing guided by specific pointers. Flexible fiberoptic bronchoscopy has been an important tool to identify etiologies of chronic cough that were not otherwise apparent. In adults, asthma and bronchitis are well-defined etiologies of chronic cough, but much chronic cough in adults is largely a conundrum.

Reviews of adult chronic cough report that at least 40% of adults with chronic cough have no medical explanation. Gastroesophageal reflux and upper airway cough syndrome (a.k.a. post-nasal drip) have been common diagnoses of chronic cough, but those diagnoses have no support from controlled clinical trials and have been subjected to multiple published critiques. Cough hypersensitivity is considered to be an explanation for chronic cough in adults who have no other confirmed diagnosis. Gabapentin, a neuromodulator, has been associated with a modest effect in adults, as has speech pathology. While habit cough has not generally been a diagnosis in adults, there is evidence for a behavioral component in adults with chronic cough. Treatment for a specific diagnosis provides a better outcome than trials of cough suppression in the absence of a specific diagnosis. More data are needed for chronic cough in adults to examine the hypothesized cough hypersensitivity and behavioral management. This article reviews etiologies and the treatment of chronic cough in children and the conundrum of diagnosing and treating chronic cough in adults.

Bronchoscopy in severe childhood asthma: Irresponsible or irreplaceable?

For children with severe asthma, guideline-based management focuses on the escalation of anti-inflammatory and bronchodilatory medications while addressing comorbid conditions. Bronchoscopy, in this context, has been relegated to ruling out asthma mimickers. More recently, however, there have been questions surrounding the clinical utility of bronchoscopy in severe childhood asthma. In this solicited lecture summary, we discuss the past, present, and potential future applications of bronchoscopy in severe childhood asthma.

Sputum Autoantibodies Are More Relevant in Autoimmune Responses in Asthma than Are Serum Autoantibodies

Purpose

The data on the differences between sputum autoantibodies (Sp-Abs) and serum autoantibodies (Se-Abs) in reflection of autoimmune responses to lungs is still lacking.

Methods

Ten types of Abs were investigated in matched Se and Sp samples collected from recruited subjects. Correlations between Ab levels and airway inflammatory parameters and measures of pulmonary function were assessed. The network-based and inter-correlated analysis was performed to explore the patterns of Sp- and Se-Ab profiles.

Results

Fifty stable asthmatic patients and 24 healthy volunteers were recruited for our study, 15 with mild asthma, 18 with moderate asthma and 17 with severe asthma. The concentrations of Sp-Ab against U1 small nuclear ribonucleoprotein (Sp-anti-U1-SnRNP), Sp-Ab against Smith antigen and Se-Ab against thyroid peroxidase (anti-TPO) in severe asthmatics and Sp-anti-U1-SnRNP in moderate asthmatics were significantly higher compared to healthy controls and mild asthmatic subjects (P < 0.05). Sp-anti-U1-SnRNP levels were positively correlated with the dose of inhaled corticosteroids, Sp eosinophil counts and fractional exhaled nitric oxide (r = 0.326, P = 0.022; r = 0.356, P = 0.012; r = 0.241, P = 0.025, respectively) and negatively correlated with Sp neutrophil counts (r = −0.308, P = 0.031) with adjustment for age. Spearman's correlation matrix showed multiple inter-correlations among Sp-Abs and Se-Abs (P < 0.05) while only the levels of Ab against DNA topoisomerase and anti-TPO in Se were correlated with those Sp-Ab counterparts (P < 0.05). The network-based analysis defined 2 clusters: clusters 1 and 2 contained 10 Sp-Abs and 10 Se-Abs, respectively.

Conclusions

This study observes that Sp-Abs are more associated with clinical parameters and the severity of disease in asthma compared to Se-Abs. Targeting on Sp-Abs which are the hallmark of the localized autoimmune event might help us better understand the role of autoimmunity in the pathological mechanism of asthma.