Dysfunctional Bronchial Cilia Are a Feature of Chronic Obstructive Pulmonary Disease (COPD).

Impaired mucociliary clearance may increase COPD exacerbation risk. We aimed to compare bronchial ciliary function and epithelial ultrastructure of COPD patients to healthy controls and explore its relationship to exacerbator phenotypes (frequent [FE] and infrequent [IFE] exacerbator). In this cross-sectional study, 16 COPD patients and 12 controls underwent bronchial brushings. Ciliary beat frequency (CBF) and dyskinesia index (DI; % of dyskinetic cilia) were assessed using digital high-speed video microscopy, and epithelial ultrastructure using transmission electron microscopy (TEM). Bronchial epithelium in COPD showed lower CBF and higher DI, compared to controls (median [IQR] CBF: 6.8 (6.1-7.2) Hz vs 8.5 (7.7-8.9) Hz, p<0.001 and DI: 73.8 (60.7-89.8) % vs 14.5 (11.2-16.9) %, p<0.001, respectively). This was true for FE and IFE phenotypes of COPD, which were similar in terms of bronchial CBF or DI. Subgroup analyses demonstrated lower CBF and higher DI in FE and IFE COPD phenotypes compared to controls, irrespective of smoking status. TEM showed more loss of cilia, extrusion of cells, cytoplasmic blebs and dead cells in COPD patients versus controls. Profound dysfunction of bronchial cilia is a feature of COPD irrespective of exacerbation phenotype and smoking status, which is likely to contribute to poor mucus clearance in COPD.Supplemental data for this article is available online at https://doi.org/10.1080/15412555.2021.1963695 .

Hydrocephalus and diffuse choroid plexus hyperplasia in primary ciliary dyskinesia-related MCIDAS mutation.

OBJECTIVE: To report a neuroradiologic phenotype associated with reduced generation of multiple motile cilia (RGMC) and mutations in the multicilin gene. We hypothesize that the observed phenotype may reflect the emerging role that ependymal cilia play in regulating CSF production. METHOD: Clinical and radiologic records were retrospectively reviewed for 7 consecutive patients diagnosed by the Leicester UK national primary ciliary dyskinesia (PCD) diagnostic laboratory. RESULTS: On MRI scanning, all patients demonstrated hydrocephalus, choroid plexus hyperplasia (CPH), and arachnoid cysts. No patient had any sign of neurologic deficit. All patients had significant lung disease. CONCLUSIONS: We conclude that there is a high incidence of hydrocephalus, arachnoid cysts, and CPH in MCIDAS-associated RGMC. In all cases, the observed hydrocephalus seems arrested in childhood without progression or adverse neurologic sequelae. Our new observation of CPH, which is associated with CSF overproduction, is the first macroscopic evidence that ependymal cilia may be involved in the regulation of CSF production and flow. We suggest that brain imaging should be performed in all cases of RGMC and that a diagnosis of PCD or RGMC be strongly considered in patients with unexplained hydrocephalus and a lifelong "wet"-sounding cough.

Clinical features and management of children with primary ciliary dyskinesia in England.

OBJECTIVE: In England, the National Health Service commissioned a National Management Service for children with primary ciliary dyskinesia (PCD). The aims of this study were to describe the health of children seen in this Service and compare lung function to children with cystic fibrosis (CF). DESIGN: Multi-centre service evaluation of the English National Management PCD Service. SETTING: Four nationally commissioned PCD centres in England. PATIENTS: 333 children with PCD reviewed in the Service in 2015; lung function data were also compared with 2970 children with CF. RESULTS: Median age at diagnosis for PCD was 2.6 years, significantly lower in children with situs inversus (1.0 vs 6.0 years, p<0.001). Compared with national data from the CF Registry, mean (SD) %predicted forced expiratory volume in one second (FEV1) was 76.8% in PCD (n=240) and 85.0% in CF, and FEV1 was lower in children with PCD up to the age of 15 years. Approximately half of children had some hearing impairment, with 26% requiring hearing aids. Children with a lower body mass index (BMI) had lower FEV1 (p<0.001). One-third of children had positive respiratory cultures at review, 54% of these grew Haemophilus influenzae. CONCLUSIONS: We provide evidence that children with PCD in England have worse lung function than those with CF. Nutritional status should be considered in PCD management, as those with a lower BMI have significantly lower FEV1. Hearing impairment is common but seems to improve with age. Well-designed and powered randomised controlled trials on management of PCD are needed to inform best clinical practice.

Evidence of Respiratory Syncytial Virus Spread by Aerosol. Time to Revisit Infection Control Strategies?

RATIONALE: Respiratory syncytial virus (RSV) is a highly contagious pathogen with a huge global health impact. It is a major cause of hospital-acquired infection; a large number of those exposed develop infection. Those infected in hospital are at increased risk of a severe clinical course. Prevention of nosocomial spread currently focuses on spread by hand and large droplets. There is little research evidence to determine if aerosol spread of infectious RSV is possible. OBJECTIVES: To determine if the air surrounding infants with RSV-positive bronchiolitis contains RSV in aerosolized particles that remain capable of causing infection. METHODS: The amount of RSV contained in aerosolized particles produced by infants with bronchiolitis due to RSV was measured using viable impactor sampling. The ability of RSV contained in these particles to infect healthy and chronic obstructive pulmonary disease (COPD) human ciliated respiratory epithelium was determined. RESULTS: We showed for the first time that infants with RSV-positive bronchiolitis nursed in a ward setting or ventilated in intensive care produced large numbers of aerosol particles containing RSV that remained infectious and were capable of infecting healthy and COPD human ciliated epithelium. A significant amount of RSV was found in particles with aerodynamic diameters less than 5 µm. CONCLUSIONS: Many of the aerosolized particles that contained RSV in the air surrounding infants with bronchiolitis were sufficiently small to remain airborne for a significant length of time and small enough to be inhaled and deposited throughout the respiratory tract. It is likely that this leads to spread of infection to others, with dissemination of infection throughout the respiratory tract.

The effect of viscous loading on brain ependymal cilia.

Ependymal cilia line the ventricular system moving cerebral spinal fluid close to the brain surface. They may be exposed to fluid of increasing viscosity in certain pathological conditions such as bacterial meningitis. Our aim was to determine the effect of increasing viscosity on ciliary function. Ciliated ependyma was exposed to solutions of different viscosities (1-60cP) and ciliary function assessed by high-speed digital imaging. The mean (S.D.) ciliary beat frequency (CBF), measured after 30min incubation in Medium 199 at 37 degrees C, was 34.9 (2.9)Hz. Increased viscous loading was followed by a rapid decrease in CBF compared to baseline readings (p<0.001). After 15min of exposure to the increased viscous load, CBF reached a new stable level while the viscous load was maintained. Compared to baseline measurements of CBF, viscous loading of 3.7cP caused a 16%, 10.4cP at 34% and 24cP a 70% decrease in beat frequency. Further viscous loading at levels up to 60cP resulted in no further reduction of ependymal CBF. Solutions of 24 and 40cP had no effect on ciliary amplitude. An increase in viscosity to 60cP caused a significant (30%: p=0.001) decrease in the ciliary beat amplitude.