Comparing region of interest selection and whole-field analysis for measurement of ciliary beat frequency in high-speed video analysis.

BACKGROUND: Ciliary beat frequency (CBF) is crucial in mucociliary clearance. High-speed video analysis (HSVA) is commonly used to measure CBF but lacks standardization. We compared visual observation and computer-assisted calculation using fast Fourier transformation (FFT) in freshly collected bronchial ciliary epithelial cells and cultured cells. METHODS: Bronchial epithelial cells were obtained from 12 patients who required bronchoscopic examination. Eighty-five videos of ciliary movement of freshly collected and cultured cells were recorded and used to calculate CBF using manual observation, region of interest (ROI) selection, and whole-field analysis. RESULTS: CBF measured by the ROI selection method strongly correlated with that measured using manual observation, especially in freshly collected cells. However, 27.8% of the manual observation method values were doubled in the ROI selection method, probably because a round trip of cilia was calculated as two cycles and needed to be corrected to 1/2 value. Upon increasing the number of ROIs, the results of the ROI selection method came closer to that of WFA. CONCLUSIONS: Computer-assisted calculation using FFT can aid in measuring CBF; however, current methods require visual confirmation. Further automated evaluation techniques are needed to establish more standardized and generalized CBF measurement methods using HSVA.

Effects of submucoperichondrial application of platelet-rich plasma on nasal mucosal healing after septoplasty.

OBJECTIVE(S): Our aim is to investigate the effects of the submucoperichondrial application of Platelet Rich Plasma (PRP) on nasal mucosal healing after septoplasty surgery. METHOD(S): This prospective randomized observational study was conducted between July 2019 and February 2021, with 40 patients aged 18-60 years who underwent closed the only septoplasty operation for similar septal deviations. Patient divided into two group; 21 patients were placed in PRP group to which PRP was applied on all mucosal surface and submucoperichondrial area of septum and 19 patients were placed in control group to which saline solution was applied on same regions. Nasal obstruction score, mucociliary clearance time, presence of nasal crusting, and bleeding time were evaluated on 5th, 10th, 15th day after surgery and compared between groups. RESULTS: Intranasal crusting on day 10 was found to be lower in the PRP group (n:13 68.4 %) than control group (n:7 33.3 %) with a statistically significant difference (p = 0.028). The nasal obstruction score on day 10 and 15 were found to be lower in the PRP group (3,33 ± 2,75, 2,07 ± 2,20) (than the control group (5,44 ± 2,26, 3,37 ± 1,92) with a statistically significant difference (p = 0,003,p = 0,009). The mucociliary clearance rate was found to be higher and the bleeding time was found to be lower in the PRP group, but a statistically significant difference was not observed. CONCLUSIONS: Application of submucoperichondrial PRP could have beneficial effects on nasal mucosal repair, nasal crusting, and congestion after septoplasty surgery.

Swimming short fibrous nasal drops achieving intraventricular administration.

Adequate drug delivery across the blood-brain barrier (BBB) is a critical factor in treating central nervous system (CNS) disorders. Inspired by swimming fish and the microstructure of the nasal cavity, this study is the first to develop swimming short fibrous nasal drops that can directly target the nasal mucosa and swim in the nasal cavity, which can effectively deliver drugs to the brain. Briefly, swimming short fibrous nasal drops with charged controlled drug release were fabricated by electrospinning, homogenization, the π-π conjugation between indole group of fibers, the benzene ring of leucine-rich repeat kinase 2 (LRRK2) inhibitor along with charge-dipole interaction between positively charged poly-lysine (PLL) and negatively charged surface of fibers; this enabled these fibers to stick to nasal mucosa, prolonged the residence time on mucosa, and prevented rapid mucociliary clearance. In vitro, swimming short fibrous nasal drops were biocompatible and inhibited microglial activation by releasing an LRRK2 inhibitor. In vivo, luciferase-labelled swimming short fibrous nasal drops delivered an LRRK2 inhibitor to the brain through the nasal mucosa, alleviating cognitive dysfunction caused by sepsis-associated encephalopathy by inhibiting microglial inflammation and improving synaptic plasticity. Thus, swimming short fibrous nasal drops is a promising strategy for the treatment of CNS diseases.

The primary ciliary dyskinesia-related genetic risk score is associated with susceptibility to adult-onset asthma.

BACKGROUND: Disturbance of mucociliary clearance is an important factor in the pathogenesis of asthma. We hypothesized that common variants in genes responsible for ciliary function may contribute to the development of asthma with certain phenotypes. METHODS: Three independent adult Japanese populations (including a total of 1,158 patients with asthma and 2,203 non-asthmatic healthy participants) were studied. First, based on the ClinVar database (https://www.ncbi.nlm.nih.gov/clinvar/), we selected 12 common single-nucleotide polymorphisms (SNPs) with molecular consequences (missense, nonsense, and 3'-untranslated region mutation) in 5 primary ciliary dyskinesia (PCD)-related genes and calculated a PCD-genetic risk score (GRS) as a cumulative effect of these PCD-related genes. Second, we performed a two-step cluster analysis using 3 variables, including PCD-GRS, forced expiratory volume in 1 second (%predicted FEV1), and age of asthma onset. RESULTS: Compared to adult asthma clusters with an average PCD-GRS, clusters with high and low PCD-GRS had similar overall characteristics: adult-onset, female predominance, preserved lung function, and fewer features of type 2 immunity as determined by IgE reactivity and blood eosinophil counts. The allele frequency of rs1530496, a SNP representing an expression quantitative trait locus (eQTL) of DNAH5 in the lung, showed the largest statistically significant difference between the PCD-GRS-High and PCD-GRS-Low asthma clusters (p = 1.4 x 10-15). CONCLUSION: Genes associated with PCD, particularly the common SNPs associated with abnormal expression of DNAH5, may have a certain influence on the development of adult-onset asthma, perhaps through impaired mucociliary clearance.

Combination treatment to improve mucociliary transport of Pseudomonas aeruginosa biofilms.

People with muco-obstructive pulmonary diseases such as cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD) often have acute or chronic respiratory infections that are difficult to treat due in part to the accumulation of hyperconcentrated mucus within the airway. Mucus accumulation and obstruction promote chronic inflammation and infection and reduce therapeutic efficacy. Bacterial aggregates in the form of biofilms exhibit increased resistance to mechanical stressors from the immune response (e.g., phagocytosis) and chemical treatments including antibiotics. Herein, combination treatments designed to disrupt the mechanical properties of biofilms and potentiate antibiotic efficacy are investigated against mucus-grown Pseudomonas aeruginosa biofilms and optimized to 1) alter biofilm viscoelastic properties, 2) increase mucociliary transport rates, and 3) reduce bacterial viability. A disulfide bond reducing agent (tris(2-carboxyethyl)phosphine, TCEP), a surfactant (NP40), a biopolymer (hyaluronic acid, HA), a DNA degradation enzyme (DNase), and an antibiotic (tobramycin) are tested in various combinations to maximize biofilm disruption. The viscoelastic properties of biofilms are quantified with particle tracking microrheology and transport rates are quantified in a mucociliary transport device comprised of fully differentiated primary human bronchial epithelial cells. The combination of the NP40 with hyaluronic acid and tobramycin was the most effective at increasing mucociliary transport rates, decreasing the viscoelastic properties of mucus, and reducing bacterial viability. Multimechanistic targeting of biofilm infections may ultimately result in improved clinical outcomes, and the results of this study may be translated into future in vivo infection models.

Effect of turbinate surgery on mucociliary clearance. A systematic review and metanalysis / Efecto de la cirugía turbinal en el aclaramiento mucociliar. Revisión sistemática y metaanálisis

Despite the fact that turbinate surgery provides satisfactory results regarding nasal obstruction, most of these procedures are destructive, to some extent, for the respiratory epithelium. There are valid hypotheses suggesting either that turbinate surgery may improve mucociliary clearance (MCC) by improving rhinitis, as well hypotheses suggesting that these surgeries may impair it by damaging the nasal ciliated epithelia. This systematic review is designed with the objective of exploring the effect of turbinate surgery on MCC. Pubmed (Medline), the Cochrane Library, EMBASE, SciELO were analyzed. Four authors members of the YO-IFOS rhinology study group independently analyzed the articles. Extracted variables encompassed: sample size, age, indication for surgery, surgical technique, method used to measure mucociliary clearance, mucociliary transport time before and after surgery, and main outcome. 15 studies with a total population of 1936 participants (1618 patients excluding healthy controls) met the inclusion criteria. 9 studies could be combined in a metanalysis, wich revealed a non-statistically significant decrease of 3.86 min in MCTT after turbinate surgery (p = 0.06). The subgroup analysis of the 5 cohorts who underwent microdebrider turbinoplasty reached statistical significance under a random effect model, revealing a 7.02 min decrease in MCTT (p < 0.001). The laser turbinoplasty subgroup, composed of 4 cohorts, also reached significance, although the difference was lower than that for microdebrider turbinoplasty, 1.01 min (p < 0.001). This systematic review and meta-analysis suggests that turbinate surgery does not compromise mucociliary clearance. The available evidence also suggests that turbinate surgery with mucosa sparing techniques improves MCC, while with aggressive techniques it increases or remains the same. ... . (AU)

A pesar de que la cirugía turbinal tiene efectos positivos en la ventilación nasal, gran parte de estos procedimientos son agresivos con el epitelio respiratorio. Existen hipótesis que sugieren que la cirugía turbinal puede mejorar el aclaramiento mucociliar (AMC) al mejorar la rinitis, así como alterarlo al lesional el epitelio nasal. Esta revisión se diseña con el objetivo de explorar el efecto de la cirugía turbinal en el AMC. Se revisó Pubmed (Medline), the Cochrane Library, EMBASE, SciELO. 4 autores miembros de YO-IFOS grupo de estudio en rinología, analizaron de manera independiente los artículos. Las variables analizadas fueron tamaño muestral, edad, indicación quirúrgica, técnica quirúrgica, método de medición de AMC, AMC antes y después de la cirugía y resultado principal. Se incluyeron 15 estudios con 1936 participantes (1618 excluyendo controles sanos). 9 estudios fueron combinados en un metanálisis que demostró una diferencia no estadísticamente significativa de -3,86 minutos en AMC tras cirugía (p = 0,06). El análisis por subgrupos de las 5 cohortes sometidas a turbinoplastia con microdebridador si fueron estadísticamente significativas con una diferencia de -7,02 minutos (p < 0,001). El grupo sometido a laser (4 cohortes) también obtuvo diferencia estadística, aunque menor, -1,01 minutos (p < 0,001). Esta revision y metaanálisis sugiere que la cirugía turbinal no afecta al aclaramiento mucociliar. La evidencia disponible también sugiere que las técnicas menos agresivas con la mucosa mejoran el AMC, mientras que las agresivas podrían aumentarlo o no modificarlo. Este efecto beneficioso se observa desde el 1º al 3º mes postquirúrgico. Sin embargo, para poder obtener adecuadas conclusiones, debe existir un método estandarizado para medir el AMC, así como un método para describir adecuadamente la extensión quirúrgica. (AU)

Lianhua Qingke Preserves Mucociliary Clearance in Rat with Acute Exacerbation of Chronic Obstructive Pulmonary Disease by Maintaining Ciliated Cells Proportion and Protecting Structural Integrity and Beat Function of Cilia.

Purpose: Acute Exacerbation of Chronic Obstructive Pulmonary Disease (AECOPD) is a sudden worsening of symptoms in patients with Chronic Obstructive Pulmonary Disease (COPD), such as cough, increased sputum volume, and sputum purulence. COPD and AECOPD are characterized by damage to cilia and increased mucus secretion. Mucociliary clearance (MCC) functions as part of the primary innate system of the lung to remove harmful particles and pathogens together with airway mucus and is therefore crucial for patients with COPD. Methods: AECOPD was induced by cigarette smoke exposure (80 cigarettes/day, 5 days/week for 12 weeks) and lipopolysaccharide (LPS) instillation (200 µg, on days 1, 14, and 84). Rats administered Lianhua Qingke (LHQK) (0.367, 0.732, and 1.465 g/kg/d) or Eucalyptol, Limonene, and Pinene Enteric Soft Capsules (ELP, 0.3 g/kg/d) intragastrically. Pulmonary pathology, Muc5ac+ goblet cell and ß-tubulin IV+ ciliated cells, and mRNA levels of forkhead box J1 (Foxj1) and multiciliate differentiation and DNA synthesis associated cell cycle protein (MCIDAS) were assessed by hematoxylin and eosin staining, immunofluorescence staining, and RT-qPCR, respectively. Ciliary morphology and ultrastructure were examined through scanning electron microscopy and transmission electron microscopy. Ciliary beat frequency (CBF) was recorded using a high-speed camera. Results: Compared to the model group, LHQK treatment groups showed a reduction in inflammatory cell infiltration, significantly reduced goblet cell and increased ciliated cell proportion. LHQK significantly upregulated mRNA levels of MCIDAS and Foxj1, indicating promoted ciliated cell differentiation. LHQK protected ciliary structure and maintained ciliary function via increasing the ciliary length and density, reducing ciliary ultrastructure damage, and ameliorating random ciliary oscillations, consequently enhancing CBF. Conclusion: LHQK enhances the MCC capability of ciliated cells in rat with AECOPD by preserving the structural integrity and beating function of cilia, indicating its therapeutic potential on promoting sputum expulsion in patients with AECOPD.

Nasal polyps show decreased mucociliary transport despite vigorous ciliary beating.

OBJECTIVE: Mucociliary transport function in the airway mucosa is essential for maintaining a clean mucosal surface. This function is impaired in upper and lower airway diseases. Nasal polyps are a noticeable pathological feature that develop in some of the patients with chronic rhinosinusitis. Like ordinary nasal mucosae, nasal polyps have a ciliated pseudostratified epithelium with vigorous ciliary beating. We measured ex vivo Mucociliary Transport Velocity (MCTV) and Ciliary Beat Frequency (CBF) and explored the expressions of Planar Cell Polarity (PCP) proteins in nasal polyps in comparison with turbinate mucosae. METHODS: Inferior turbinates and nasal polyps were surgically collected from patients with chronic rhinosinusitis. Ex vivo MCTV and CBF were measured using a high-speed digital imaging system. Expressions of PCP proteins were explored by fluorescence immunohistochemistry and quantitative RT-PCR. RESULTS: The MCTV of nasal polyps was significantly lower than that of the turbinates (7.43 ±â€¯2.01 vs. 14.56 ±â€¯2.09 µm/s; p = 0.0361), whereas CBF did not differ between the two tissues. The MCTV vector was pointed to the posteroinferior direction in all turbinates with an average inclination angle of 41.0 degrees. Immunohistochemical expressions of Dishevelled-1, Dishevelled-3, Frizzled3, Frizzled6, Prickle2 and Vangl2 were lower in the nasal polyps than in the turbinates. Confocal laser scanning microscopy showed that Frizzled3 was localized along the cell junction on the apical surface. The expression levels of mRNAs for Dishevelled-1, Dishevelled-3 and Frizzled3 in the nasal polyps were also decreased in comparison with the turbinates. CONCLUSION: These results indicate that muco ciliary transport in nasal polyps is impaired although vigorous ciliary beating is maintained, and that the impairment may be caused by a decrease in Dishevelled/Frizzled proteins and resultant PCP disarrangement. LEVEL OF EVIDENCE: Level 3.

Tacrolimus impairs airway mucociliary clearance of rats.

OBJECTIVES: Tacrolimus (TAC) is the most widely used immunosuppressive agent after lung transplantation. Considering that the ciliary beat frequency (CBF) mainly depends on the cytoplasmic calcium concentration and that TAC can affect this due to its binding with the intracellular immunophilin FKBP12, we hypothesized that TAC could also impair the airway mucociliary clearance of rats. METHODS: Sixty rats were divided into two groups (n = 30 each): Control = water; TAC = tacrolimus. After 7, 15 or 30 days of treatment, ten animals from each group were euthanized and the following parameters were studied: mucus transportability, CBF, mucociliary transport velocity (MCTV), and neutral and acid mucus production. RESULTS: There was a significant decrease in CBF (Control vs TAC: 7 days, p = 0.008; 15 days, p = 0.007; 30 days, p = 0.001) and MCTV (Control vs TAC: 7 days, p = 0.004; 15 days, p < 0.001; 30 days, p < 0.001) in all immunosuppressed animals. TAC therapy also caused an increase in acid mucus production at all treatment times (Control vs TAC: 7 days, p = 0.001; 15 days, p = 0.043; 30 days, p = 0.001). CONCLUSIONS: TAC impairs airway mucociliary clearance of rats.

Histopathology of Recalcitrant Maxillary Sinusitis Necessitating Endoscopic Medial Maxillectomy.

OBJECTIVES: Endoscopic medial maxillectomy (EMM) is an effective intervention for patients with recalcitrant maxillary sinusitis after previous middle meatal antrostomy. The pathophysiology of refractory maxillary sinusitis is incompletely understood. We aim to identify trends in structured histopathology (SHP) to better understand how tissue architecture changes contribute to refractory sinusitis and impaired mucociliary clearance. METHODS: All patients who underwent EMM or standard maxillary antrostomy for recalcitrant maxillary sinusitis of various forms were included. Retrospective chart review was conducted to collect information on demographics, disease characteristics, comorbid conditions, culture data, and SHP reports. Chi-squared and logistic regression analyses were performed for SHP variables. RESULTS: Forty-one patients who underwent EMM and 464 patients who underwent maxillary antrostomy were included. On average, the EMM cohort was 10 years older (60.9 years vs. 51.1 years; p = 0.001) and more often had a history of prior sinus procedures (73.2% vs. 40.9%; p < 0.001). EMM patients had higher rates of fibrosis (34.1% vs. 15.1%, p = 0.002), and this remained statistically significant when controlling for prior sinus procedures and nasal polyposis (p = 0.001). Cultures positive for pseudomonas aeruginosa (38.2% vs. 5.6%, p < 0.001) and coagulase negative staphylococcus (47.1% vs. 23.5%, p = 0.003) were more prevalent in the EMM group. CONCLUSION: Fibrosis and bacterial infections with Pseudomonas and coagulase negative Staphylococcus were more prevalent in patients requiring EMM. This may contribute to the multifactorial etiology of impaired mucociliary clearance in patients with recalcitrant maxillary sinusitis. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:2646-2652, 2024.

Effect of elexacaftor/tezacaftor/ivacaftor on mucus and mucociliary clearance in cystic fibrosis.

BACKGROUND: The cystic fibrosis transmembrane conductance regulator (CFTR) modulator elexacaftor/tezacaftor/ivacaftor (E/T/I) is highly effective clinically for those with at least one F508del-CFTR allele. The effects of E/T/I on mucociliary clearance (MCC) and sputum properties are unknown. We, therefore, sought to characterize the effects of E/T/I on in vivo MCC and sputum characteristics hypothesized to impact mucus transport. METHODS: Forty-four participants ≥12 years of age were enrolled into this prospective, observational trial prior to initiation of E/T/I and had baseline measurement of MCC and characterization of induced sputum and exhaled breath condensate (EBC) samples. Study procedures were repeated after 1 month of E/T/I treatment. RESULTS: Average age was 27.7 years with baseline forced expiratory volume in 1 second (FEV1) of 78.2 % predicted. 52 % of subjects had previously been treated with a 2-drug CFTR modulator combination. The average whole lung MCC rate measured over 60 min (WLAveClr60) significantly improved from baseline to post-E/T/I (14.8 vs. 22.8 %; p = 0.0002), as did other MCC indices. Sputum% solids also improved (modeled mean 3.4 vs. 2.2 %; p<0.0001), whereas non-significant reductions in sputum macrorheology (G', G") were observed. No meaningful changes in exhaled breath condensate endpoints (sialic acid:urea ratio, pH) were observed. CONCLUSIONS: E/T/I improved the hydration of respiratory secretions (% solids) and markedly accelerated MCC. These data confirm the link between CFTR function, mucus solid content, and MCC and help to define the utility of MCC and mucus-related bioassays in future efforts to restore CFTR function in all people with CF.

Effect of turbinate surgery on mucociliary clearance. A systematic review and metanalysis.

Despite the fact that turbinate surgery provides satisfactory results regarding nasal obstruction, most of these procedures are destructive, to some extent, for the respiratory epithelium. There are valid hypotheses suggesting either that turbinate surgery may improve mucociliary clearance (MCC) by improving rhinitis, as well hypotheses suggesting that these surgeries may impair it by damaging the nasal ciliated epithelia. This systematic review is designed with the objective of exploring the effect of turbinate surgery on MCC. Pubmed (Medline), the Cochrane Library, EMBASE, SciELO were analyzed. Four authors members of the YO-IFOS rhinology study group independently analyzed the articles. Extracted variables encompassed: sample size, age, indication for surgery, surgical technique, method used to measure mucociliary clearance, mucociliary transport time before and after surgery, and main outcome. 15 studies with a total population of 1936 participants (1618 patients excluding healthy controls) met the inclusion criteria. 9 studies could be combined in a metanalysis, wich revealed a non-statistically significant decrease of 3.86 min in MCTT after turbinate surgery (p = 0.06). The subgroup analysis of the 5 cohorts who underwent microdebrider turbinoplasty reached statistical significance under a random effect model, revealing a 7.02 min decrease in MCTT (p < 0.001). The laser turbinoplasty subgroup, composed of 4 cohorts, also reached significance, although the difference was lower than that for microdebrider turbinoplasty, 1.01 min (p < 0.001). This systematic review and meta-analysis suggests that turbinate surgery does not compromise mucociliary clearance. The available evidence also suggests that turbinate surgery with mucosa sparing techniques improves MCC, while with aggressive techniques it increases or remains the same. This beneficial effect is evident since the first to third month after surgery. However, for solid conclusions, a standard way to measure MCTT should be stablished, as well as a method to appropriately describe the extension of the surgery.

Safety and efficacy of the epithelial sodium channel blocker idrevloride in people with primary ciliary dyskinesia (CLEAN-PCD): a multinational, phase 2, randomised, double-blind, placebo-controlled crossover trial.

BACKGROUND: Mucociliary clearance is dysfunctional in people with primary ciliary dyskinesia, resulting in the accumulation of dehydrated mucus in the airways that is difficult to clear. We undertook a study to assess the benefit on lung function of treatment with a nebulised epithelial sodium channel (ENaC) blocker, idrevloride, with or without hypertonic saline, in people with primary ciliary dyskinesia. METHODS: The CLEAN-PCD trial was a phase 2, randomised, double-blind, placebo-controlled crossover trial conducted at 32 tertiary adult and paediatric care centres and university hospitals in Canada, Denmark, Germany, Italy, the Netherlands, Poland, the UK, and the USA. People with a confirmed diagnosis of primary ciliary dyskinesia, aged 12 years or older, with a percentage of predicted FEV1 (ppFEV1) in the range of 40% to <90%, were randomly assigned in a 2:2:1:1 ratio (block size=6), stratified by ppFEV1 at screening, to one of four sequences: (1) idrevloride in hypertonic saline in treatment period 1 then hypertonic saline in treatment period 2; (2) hypertonic saline in treatment period 1 then idrevloride in hypertonic saline in treatment period 2; (3) idrevloride in treatment period 1 then placebo in treatment period 2; and (4) placebo in treatment period 1 then idrevloride in treatment period 2. The idrevloride dose was 85 µg and hypertonic saline was 4·2% NaCl. 3 mL of each study treatment was nebulised twice daily for 28 days in treatment periods 1 and 2; the two 28-day treatment periods were separated by a 28-day washout period. The primary endpoint was absolute change from baseline in ppFEV1 after 28 days. Safety assessments and reports of adverse events were made at clinic visits during each treatment period and by a follow-up telephone call 28 days after the last dose of study drug. Additionally, adverse events could be reported at a follow-up telephone call 3 days after the start of dosing and as they arose. Participants who received at least one dose of study drug were included in the safety analyses (safety set), and those who also had spirometry data were included in the efficacy analyses (full analysis set). The completed study is registered (EudraCT 2015-004917-26; ClinicalTrials.govNCT02871778). FINDINGS: Between Sep 14, 2016, and May 31, 2018, 216 patients were screened and 123 were randomly assigned to one of four crossover sequences. Across the two treatment periods, treatment with idrevloride in hypertonic saline was initiated in 80 patients and completed in 78 patients (all 78 had data available and were included in the analysis); hypertonic saline initiated in 81 patients and completed in 76 patients (75 had data available and were included in the analysis); idrevloride initiated in 37 patients and completed in 35 patients (34 had data available and were included in the analysis); and placebo initiated in 36 patients and completed in 34 patients (all 34 had data available and were included in the analysis). Greater absolute increases in ppFEV1 from baseline to 28 days of treatment were seen with idrevloride in hypertonic saline (least-squares mean absolute change from baseline 1·0 percentage points, 95% CI -0·4 to 2·4) than with hypertonic saline alone (least-squares mean absolute change from baseline of -0·5 percentage points, -2·0 to 0·9; difference 1·5 percentage points, 95% CI <0·1 to 3·0; p=0·044). There was no significant difference in ppFEV1 for the parallel comparison of idrevloride in hypertonic saline compared with placebo or the crossover comparison of idrevloride with placebo. Adverse events were similar across treatments (57 to 65% of patients). Cough occurred in a greater proportion of participants during treatments that contained idrevloride or hypertonic saline compared with placebo, and oropharyngeal pain occurred in a greater proportion of participants during idrevloride treatments than during treatment with hypertonic saline alone or placebo, whereas chest discomfort was more common during treatments that included hypertonic saline. INTERPRETATION: In this phase 2 crossover study, idrevloride in hypertonic saline was safe and associated with improved lung function over a 28-day period in people with primary ciliary dyskinesia compared with hypertonic saline alone. Larger, longer clinical studies are warranted to explore the potential benefits of idrevloride in combination with hypertonic saline in people with primary ciliary dyskinesia. FUNDING: Parion Sciences, under agreement with Vertex Pharmaceuticals.

Airway ciliated cells in adult lung homeostasis and COPD.

Cilia are organelles emanating from the cell surface, consisting of an axoneme of microtubules that extends from a basal body derived from the centrioles. They are either isolated and nonmotile (primary cilia), or grouped and motile (motile cilia). Cilia are at the centre of fundamental sensory processes and are involved in a wide range of human disorders. Pulmonary cilia include motile cilia lining the epithelial cells of the conductive airways to orchestrate mucociliary clearance, and primary cilia found on nondifferentiated epithelial and mesenchymal cells acting as sensors and cell cycle keepers. Whereas cilia are essential along the airways, their regulatory molecular mechanisms remain poorly understood, resulting in a lack of therapeutic strategies targeting their structure or functions. This review summarises the current knowledge on cilia in the context of lung homeostasis and COPD to provide a comprehensive overview of the (patho)biology of cilia in respiratory medicine with a particular emphasis on COPD.

Human airway tuft cells influence the mucociliary clearance through cholinergic signalling.

BACKGROUND: Airway tuft cells, formerly called brush cells have long been described only morphologically in human airways. More recent RNAseq studies described a chemosensory cell population, which includes tuft cells, by a distinct gene transcription signature. Yet, until which level in the tracheobronchial tree in native human airway epithelium tuft cells occur and if they function as regulators of innate immunity, e.g., by regulating mucociliary clearance, remained largely elusive. METHODS: We performed immunohistochemistry, RT-PCR and immunoblotting analyses for various tuft cell markers to confirm the presence of this cell type in human tracheal samples. Immunohistochemistry was conducted to study the distribution of tuft cells along the intrapulmonary airways in humans. We assessed the influence of bitter substances and the taste transduction pathway on mucociliary clearance in mouse and human tracheal samples by measuring particle transport speed. RESULTS: Tuft cells identified by the expression of their well-established marker POU class 2 homeobox 3 (POU2F3) were present from the trachea to the bronchioles. We identified choline acetyltransferase in POU2F3 expressing cells as well as the transient receptor potential melastatin 5 (TRPM5) channel in a small population of tracheal epithelial cells with morphological appearance of tuft cells. Application of bitter substances, such as denatonium, led to an increase in mucociliary clearance in human tracheal preparations. This was dependent on activation of the TRPM5 channel and involved cholinergic and nitric oxide signalling, indicating a functional role for human tuft cells in the regulation of mucociliary clearance. CONCLUSIONS: We were able to detect tuft cells in the tracheobronchial tree down to the level of the bronchioles. Moreover, taste transduction and cholinergic signalling occur in the same cells and regulate mucociliary clearance. Thus, tuft cells are potentially involved in the regulation of innate immunity in human airways.

BPIFB1 loss alters airway mucus properties and diminishes mucociliary clearance.

Airway mucociliary clearance (MCC) is required for host defense and is often diminished in chronic lung diseases. Effective clearance depends upon coordinated actions of the airway epithelium and a mobile mucus layer. Dysregulation of the primary secreted airway mucin proteins, MUC5B and MUC5AC, is associated with a reduction in the rate of MCC; however, how other secreted proteins impact the integrity of the mucus layer and MCC remains unclear. We previously identified the gene Bpifb1/Lplunc1 as a regulator of airway MUC5B protein levels using genetic approaches. Here, we show that BPIFB1 is required for effective MCC in vivo using Bpifb1 knockout (KO) mice. Reduced MCC in Bpifb1 KO mice occurred in the absence of defects in epithelial ion transport or reduced ciliary beat frequency. Loss of BPIFB1 in vivo and in vitro altered biophysical and biochemical properties of mucus that have been previously linked to impaired MCC. Finally, we detected colocalization of BPIFB1 and MUC5B in secretory granules in mice and the protein mesh of secreted mucus in human airway epithelia cultures. Collectively, our findings demonstrate that BPIFB1 is an important component of the mucociliary apparatus in mice and a key component of the mucus protein network.NEW & NOTEWORTHY BPIFB1, also known as LPLUNC1, was found to regulate mucociliary clearance (MCC), a key aspect of host defense in the airway. Loss of this protein was also associated with altered biophysical and biochemical properties of mucus that have been previously linked to impaired MCC.

The destruction of mucosal barriers, epithelial remodeling, and impaired mucociliary clearance: possible pathogenic mechanisms of Pseudomonas aeruginosa and Staphylococcus aureus in chronic rhinosinusitis.

Chronic rhinosinusitis (CRS) is a pathological condition characterized by persistent inflammation in the upper respiratory tract and paranasal sinuses. The epithelium serves as the first line of defense against potential threats and protects the nasal mucosa. The fundamental mechanical barrier is formed by the cell-cell contact and mucociliary clearance (MCC) systems. The physical-mechanical barrier is comprised of many cellular structures, including adhesion junctions and tight junctions (TJs). To this end, different factors, such as the dysfunction of MCC, destruction of epithelial barriers, and tissue remodeling, are related to the onset and development of CRS. Recently published studies reported the critical role of different microorganisms, such as Staphylococcus aureus and Pseudomonas aeruginosa, in the induction of the mentioned factors. Bacteria could result in diminished ciliary stimulation capacity, and enhance the chance of CRS by reducing basal ciliary beat frequency. Additionally, bacterial exoproteins have been demonstrated to disrupt the epithelial barrier and induce downregulation of transmembrane proteins such as occludin, claudin, and tricellulin. Moreover, bacteria exert an influence on TJ proteins, leading to an increase in the permeability of polarized epithelial cells. Noteworthy, it is evident that the activation of TLR2 by staphylococcal enterotoxin can potentially undermine the structural integrity of TJs and the epithelial barrier through the induction of pro-inflammatory cytokines. The purpose of this article is an attempt to investigate the possible role of the most important microorganisms associated with CRS and their pathogenic mechanisms against mucosal surfaces and epithelial barriers in the paranasal sinuses. Video Abstract.

An assessment of the effects of adenoid hypertrophy on mucociliary clearance and nasal cytology in children.

AIM/OBJECTIVE: The aim of this study was to demonstrate the benefits of the systematic use of nasal cytology and mucociliary clearance in the diagnostic workup of nasal disorders in children with adenoid hypertrophy (AH) to reach a well-defined diagnosis, establish a rational therapeutic approach, avert from complications, and develop the patient's life quality. MATERIALS/METHODS: In this prospective study, a total of 61 pediatric patients (aged 5-12 years) were evaluated. The case group consisted of 31 children with AH symptoms, while the control group comprised 30 children without AH symptoms.Exclusions included previous adenoidectomy/adenotonsillectomy, cardiovascular/neurological diseases, acute/allergic rhinitis, genetic disorders (e.g., Down syndrome), and immunodeficiency. The control group consisted of children without nasal obstruction symptoms and without AH, who admitted for various reasons. Medical history, examinations, fiberoptic nasopharyngoscopy, cephalometric evaluations, AST, and nasal cytology were conducted. RESULTS: At the end of the study, a significant increase in the mucociliary clearance time was observed in the group with AH compared to the control group (p < 0.05). Although AH may disrupt MCC, there is no correlation between the size of the hypertrophy and MCC time.When the distribution of cells in the nasal cytology is evaluated, no difference was detected between the AH group and control groups. CONCLUSION: Nasal mucociliary clearance has been found to be decreased, particularly in the presence of significant AH.

SNSP113 (PAAG) improves mucociliary transport and lung pathology in the Scnn1b-Tg murine model of CF lung disease.

BACKGROUND: Mucus stasis, a hallmark of muco-obstructive disease, results from impaired mucociliary transport and leads to lung function decline and chronic infection. Although therapeutics that target mucus stasis in the airway, such as hypertonic saline or rhDNAse, show some therapeutic benefit, they do not address the underlying electrostatic defect apparent in mucins in CF and related conditions. We have previously shown poly (acetyl, arginyl) glucosamine (PAAG, developed as SNSP113), a soluble, cationic polymer, significantly improves mucociliary transport in a rat model of CF by normalizing the charge defects of CF mucin. Here, we report efficacy in the CFTR-sufficient, ENaC hyperactive, Scnn1b-Tg mouse model that develops airway muco-obstruction due to sodium hyperabsorption and airway dehydration. METHODS: Scnn1b-Tg mice were treated with either 250 µg/mL SNSP113 or vehicle control (1.38% glycerol in PBS) via nebulization once daily for 7 days and then euthanized for analysis. Micro-Optical Coherence Tomography-based evaluation of excised mouse trachea was used to determine the effect on the functional microanatomy. Tissue analysis was performed by routine histopathology. RESULTS: Nebulized treatment of SNSP113 significantly improved mucociliary transport in the airways of Scnn1b-Tg mice, without altering the airway surface or periciliary liquid layer. In addition, SNSP113 significantly reversed epithelial hypertrophy and goblet cell metaplasia. Finally, SNSP113 significantly ameliorated eosinophilic crystalline pneumonia and lung consolidation in addition to inflammatory macrophage influx in this model. CONCLUSION: Overall, this study extends the efficacy of SNSP113 as a potential therapeutic to alleviate mucus stasis in muco-obstructive diseases in CF and potentially in related conditions.