The airway epithelium is now considered to be central to the orchestration of pulmonary inflammatory and immune responses, and is also key to tissue remodelling. It acts as the first barrier in the ...defence against a wide range of inhaled challenges, and is critically involved in the regulation of both innate and adaptive immune responses to these challenges. Recent progress in our understanding of the developmental regulation of this tissue, the differentiation pathways, recognition of pathogens and antimicrobial responses is now exploited to help understand how epithelial cell function and dysfunction contributes to the pathogenesis of a variety of inflammatory lung diseases. Herein, advances in our knowledge of the biology of airway epithelium, as well as its role and (dys)function in asthma, chronic obstructive pulmonary fibrosis and cystic fibrosis will be discussed.
Abstract
Background
Alpha-1-antitrypsin deficiency (AATD) is a genetic disorder characterized by mutations in the SERPINA1 gene, primarily affecting the lungs and liver. The COVID-19 pandemic has ...raised questions about the susceptibility of individuals with AATD to COVID-19 and whether patients with rare lung disease might experience increased stress-related symptoms and mental health challenges. This study aims to investigate the impact of the COVID-19 pandemic on the quality of life of individuals living with AATD.
Methods
The study enrolled participants from the German registry for individuals with AATD. Questionnaires were sent to the 1250 participants, and a total of 358 patients were included in the analysis. The primary objective was to examine the influence of sociodemographic and disease-related factors on the occurrence of stress-related symptoms. This was accomplished through correlation and regression analyses. We also investigated the role of baseline quality of life (QoL), as measured by the St. George’s Respiratory Questionnaire (SGRQ), as a mediator of this relationship.
Results
Stress-related symptoms were predicted by young age, female gender, psychological disorders, and a history of exacerbations of lung disease, as determined by multiple regression analysis. QoL as measured by the SGRQ mediated the relationship between poor lung function, stress, and a decline in overall well-being.
Conclusion
The presented data demonstrate that the COVID-19 pandemic significantly affects the psychological well-being of patients with rare diseases, leading to increased levels of anxiety and stress. Disease-related factors can exacerbate stress manifestations, especially when compounded by sociodemographic and contextual factors. Thus, our study emphasizes the crucial role of taking these factors into account when managing individuals with AATD in pandemic situations.
One component of host defense at mucosal surfaces seems to be epithelium-derived antimicrobial peptides. Antimicrobial peptides are classified on the basis of their structure and amino acid motifs. ...Peptides of the defensin, cathelicidin, and histatin classes are found in humans. In the airways, alpha-defensins and the cathelicidin LL-37/hCAP-18 originate from neutrophils. beta-Defensins and LL-37/hCAP-18 are produced by the respiratory epithelium and the alveolar macrophage and secreted into the airway surface fluid. Beside their direct antimicrobial function, antimicrobial peptides have multiple roles as mediators of inflammation with effects on epithelial and inflammatory cells, influencing such diverse processes as proliferation, immune induction, wound healing, cytokine release, chemotaxis, protease-antiprotease balance, and redox homeostasis. Further, antimicrobial peptides qualify as prototypes of innovative drugs that might be used as antibiotics, anti-lipopolysaccharide drugs, or modifiers of inflammation.
The receptor for advanced glycation endproducts (RAGE) is highly expressed in the lung but its physiological functions in this organ is still not completely understood. To determine the contribution ...of RAGE to physiological functions of the lung, we analyzed pulmonary mechanics and structure of wildtype and RAGE deficient (RAGE-/-) mice. RAGE deficiency spontaneously resulted in a loss of lung structure shown by an increased mean chord length, increased respiratory system compliance, decreased respiratory system elastance and increased concentrations of serum protein albumin in bronchoalveolar lavage fluids. Pulmonary expression of RAGE was mainly localized on alveolar epithelial cells and alveolar macrophages. Primary murine alveolar epithelial cells isolated from RAGE-/- mice revealed an altered differentiation and defective barrier formation under in vitro conditions. Stimulation of interferone-y (IFNy)-activated alveolar macrophages deficient for RAGE with Toll-like receptor (TLR) ligands resulted in significantly decreased release of proinflammatory cytokines and chemokines. Exposure to chronic cigarette smoke did not affect emphysema-like changes in lung parenchyma in RAGE-/- mice. Acute cigarette smoke exposure revealed a modified inflammatory response in RAGE-/- mice that was characterized by an influx of macrophages and a decreased keratinocyte-derived chemokine (KC) release. Our data suggest that RAGE regulates the differentiation of alveolar epithelial cells and impacts on the development and maintenance of pulmonary structure. In cigarette smoke-induced lung pathology, RAGE mediates inflammation that contributes to lung damage.
Summary α1-Antitrypsin (AAT) is the archetype member of the serine protease inhibitor ( SERPIN ) supergene family. The AAT deficiency is most often associated with the Z mutation, which results in ...abnormal Z AAT folding in the endoplasmic reticulum of hepatocytes during biogenesis. This causes intra-cellular retention of the AAT protein rather than efficient secretion with consequent deficiency of circulating AAT. The reduced serum levels of AAT contribute to the development of chronic obstructive pulmonary disease (COPD) and the accumulation of abnormally folded AAT protein increases risk for liver diseases. In this review we show that with the discovery of AAT deficiency in the early 60s as a genetically determined predisposition to the development of early-onset emphysema, intensive investigations of enzymatic mechanisms that produce lung destruction in COPD were pursued. To date, the role of AAT in other than lung and liver diseases has not been extensively examined. Current findings provide new evidence that, in addition to protease inhibition, AAT expresses anti-inflammatory, immunomodulatory and antimicrobial properties, and highlight the importance of this protein in health and diseases. In this review co-occurrence of several diseases with AAT deficiency is discussed.
The role of vitamin D (VitD) in calcium and bone homeostasis is well described. In the last years, it has been recognized that in addition to this classical function, VitD modulates a variety of ...processes and regulatory systems including host defense, inflammation, immunity, and repair. VitD deficiency appears to be frequent in industrialized countries. Especially patients with lung diseases have often low VitD serum levels. Epidemiological data indicate that low levels of serum VitD is associated with impaired pulmonary function, increased incidence of inflammatory, infectious or neoplastic diseases. Several lung diseases, all inflammatory in nature, may be related to activities of VitD including asthma, COPD and cancer. The exact mechanisms underlying these data are unknown, however, VitD appears to impact on the function of inflammatory and structural cells, including dendritic cells, lymphocytes, monocytes, and epithelial cells. This review summarizes the knowledge on the classical and newly discovered functions of VitD, the molecular and cellular mechanism of action and the available data on the relationship between lung disease and VitD status.
Purpose
In this retrospective study, we compared inhaled sedation with isoflurane to intravenous propofol in invasively ventilated COVID-19 patients with ARDS (Acute Respiratory Distress Syndrome).
...Methods
Charts of all 20 patients with COVID-19 ARDS admitted to the ICU of a German University Hospital during the first wave of the pandemic between 22/03/2020 and 21/04/2020 were reviewed. Among screened 333 days, isoflurane was used in 97 days, while in 187 days, propofol was used for 12 h or more. The effect and dose of these two sedatives were compared. Mixed sedation days were excluded.
Results
Patients’ age (median interquartile range) was 64 (60–68) years. They were invasively ventilated for 36 21–50 days. End-tidal isoflurane concentrations were high (0.96 ± 0.41 Vol %); multiple linear regression yielded the ratio (isoflurane infusion rate)/(minute ventilation) as the single best predictor. Infusion rates were decreased under ECMO (3.5 ± 1.4 versus 7.1 ± 3.2 ml∙h
−1
;
p
< 0.001). In five patients, the maximum recommended dose of propofol of 4 mg∙hour
−1
∙kg
−1
ABW was exceeded on several days. On isoflurane compared to propofol days, neuro-muscular blocking agents (NMBAs) were used less frequently (11% versus 21%;
p
< 0.05), as were co-sedatives (7% versus 31%,
p
< 0.001); daily opioid doses were lower (720 720–960 versus 1080 720–1620 mg morphine equivalents,
p
< 0.001); and RASS scores indicated deeper levels of sedation (− 4.0 − 4.0 to − 3.0 versus − 3.0 − 3.6 to − 2.5;
p
< 0.01).
Conclusion
Isoflurane provided sufficient sedation with less NMBAs, less polypharmacy and lower opioid doses compared to propofol. High doses of both drugs were needed in severely ill COVID-19 patients.
In innate immune responses, activation of Toll-like receptors (TLRs) triggers direct antimicrobial activity against intracellular bacteria, which in murine, but not human, monocytes and macrophages ...is mediated principally by nitric oxide. We report here that TLR activation of human macrophages up-regulated expression of the vitamin D receptor and the vitamin D-1-hydroxylase genes, leading to induction of the antimicrobial peptide cathelicidin and killing of intracellular Mycobacterium tuberculosis. We also observed that sera from African-American individuals, known to have increased susceptibility to tuberculosis, had low 25-hydroxyvitamin D and were inefficient in supporting cathelicidin messenger RNA induction. These data support a link between TLRs and vitamin D-mediated innate immunity and suggest that differences in ability of human populations to produce vitamin D may contribute to susceptibility to microbial infection.
Neutrophilic inflammation results in loss of lung function in chronic obstructive pulmonary disease (COPD). Gram-negative bacteria, such as nontypeable Haemophilus influenzae (NTHi), trigger acute ...exacerbations of COPD (AECOPD) and contribute to chronic lung inflammation. The pro-inflammatory cytokine interleukin-17C (IL-17C) is expressed by airway epithelial cells and regulates neutrophilic chemotaxis. Here, we explored the function of IL-17C in NTHi- and cigarette smoke (CS)-induced models of COPD. Neutrophilic inflammation and tissue destruction were decreased in lungs of IL-17C-deficient mice (Il-17c-/-) chronically exposed to NTHi. Numbers of pulmonary neutrophils were decreased in Il-17c-/- mice after acute exposure to the combination of NTHi and CS. However, Il-17c-/- mice were not protected from CS-induced lung inflammation. In a preliminary patient study, we show that IL-17C is present in sputum samples obtained during AECOPD and associates with disease severity. Concentrations of IL-17C were significantly increased during advanced COPD (GOLD III/IV) compared to moderate COPD (GOLD I/II). Concentrations of IL-17A and IL-17E did not associate with disease severity. Our data suggest that IL-17C promotes harmful pulmonary inflammation triggered by bacteria in COPD.
The objective was to assess quality of life (QoL) in lung cancer survivors, compare it to the general population, and identify factors associated with global QoL, physical functioning, emotional ...functioning, fatigue, pain, and dyspnea.
Data from NSCLC patients who had survived 1 year or longer after diagnosis were collected cross-sectionally in a multicenter study. QoL was assessed with the European Organisation for the Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ)-C30 and the lung cancer module QLQ-LC13 across different clinical subgroups and compared to age- and sex-standardized general population reference values. Multivariable linear regression analyses were performed to test the associations of patient-, tumor-, and treatment-related factors with the six primary QoL scales.
Six hundred fifty-seven NSCLC patients participated in the study with a median time since diagnosis of 3.7 years (range, 1.0–21.2 years). Compared to the age- and sex-standardized general population, clinically meaningful differences in the QoL detriment were found on almost all domains: lung cancer survivors had clinically relevant poorer global QoL (10 points, p < 0.001). Whereas in 12 months or longer treatment-free patients this detriment was small (8.3), it was higher in patients currently in treatment (16.0). Regarding functioning and symptom scales, respective detriments were largest for dyspnea (41 points), role function (33 points), fatigue (27 points), social function (27 points), physical function (24 points), and insomnia (21 points) observed across all subgroups. The main factor associated with poorer QoL in all primary QoL scales was mental distress (β |19-31|, all p < 0.001). Detriments in QoL across multiple primary QoL scales were also observed with current treatment (β |8-12|, p < 0.01), respiratory comorbidity (β |4-5|, p < 0.01), and living on a disability pension (β |10-11|, p < 0.01). The main factor associated with better QoL in almost all primary QoL scales was higher physical activity (β |10-20|, p < 0.001). Better QoL was also observed in patients with high income (β |10-14|, p < 0.01).
Lung cancer survivors experience both functional restrictions and symptoms that persist long term after active treatment ends. This substantiates the importance of providing long-term supportive care.
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