Primary ciliary dyskinesia: overlooked and undertreated in children

Fertility care among people with primary ciliary dyskinesia

INTRODUCTION

Fertility care is important for people living with primary ciliary dyskinesia (PCD) who are at increased risk of fertility problems. We investigated fertility care in an international participatory study.

METHODS

Participants of the COVID-PCD study completed an online questionnaire addressing fertility issues. We used logistic regression to study factors associated with fertility specialist visits.

RESULTS

Among 384 respondents (response rate 53%), 266 were adults (median age 44 years, interquartile range [IQR]: 33-54, 68% female), 16 adolescents, and 102 parents of children with PCD. Only half of adult participants (128; 48%) received care from fertility specialists at a median age of 30 years (IQR: 27-33)-a median of 10 years after PCD diagnosis. Only 12% were referred to fertility specialists by their PCD physician. Fertility specialist visits were reported more often by adults with pregnancy attempts (odds ratio [OR]: 9.1, 95% confidence interval [CI]: 3.8-23.6) and among people who reported fertility as important for them (OR: 5.9, 95% CI: 2.6-14.6) and less often by females (OR: 0.4, 95% CI: 0.2-0.8). Only 56% of participants who talked with healthcare professionals about fertility were satisfied with information they received. They expressed needs for more comprehensive fertility information and reported dissatisfaction with physician knowledge about PCD and fertility.

CONCLUSION

People with PCD are inconsistently referred to fertility specialists. We recommend care from fertility specialists become standard in routine PCD care, and that PCD physicians provide initial fertility information either at diagnosis or no later than transition to adult care.

Analysis of motility and mucociliary function of tracheal epithelial cilia

The airway epithelium contains numerous multiciliated cells. The apical surface of multiciliated cells is covered with cilia that move at 15-25Hz. Ciliary movement is not a simple reciprocal movement and distinctly has forward and reverse movements called effective and recovery strokes, respectively. These "asymmetric" ciliary strokes push away the mucus covering the mucosa of the airway epithelium. Mucus flow created by ciliary stroke is important for capturing and expelling dust, pollen, PM2.5, pathogens, and other particles that enter the airways from outside the body. This mechanism for protecting the airways produced by ciliary movement is called mucociliary function. Defects in ciliary motility lead to impairment of mucociliary function, resulting in recurrent airway infections such as bronchitis and pneumonia, and consequently, bronchiectasis. While the analysis of ciliary beat frequency is relatively easy, the analyses of the amplitude, velocities of strokes, and the asymmetric level require specific techniques and tips. In this chapter, we present methods for the analysis of ciliary movements of a group of cilia on the luminal surface of the trachea ex vivo and individually isolated and ATP-reactivated cilia in vitro. In addition, a method for the analysis of mucociliary function is also presented.

Exploring factors associated with acquisition and chronicity of infection in bronchiectasis: A population-based study

INTRODUCTION

Chronic infection is associated with adverse outcomes among people with bronchiectasis. However, it is not known which factors are associated with a bacterial infection, and with persistence of an infection after the first episode. We aimed to determine factors associated with a new infection and with chronicity of Pseudomonas aeruginosa (PA) and H. influenzae (HI), the most common organisms in bronchiectasis infection.

METHODS

Using an Israeli population database, we identified individuals diagnosed with bronchiectasis. Cox proportional hazard models were used to assess risk factors for first isolation and Logistic regression for chronicity of infection after a first isolation of PA and HI.

RESULTS

We included 1305 people with a median of 5 respiratory samples per individual. PA was initially isolated in 297 people, of whom 97 (33%) developed chronic PA infection. HI was newly identified in 169 people, of whom 39 (23%) developed chronic infection (p = 0.029). Factors associated with increased risk of a new infection with PA were COPD (HR 1.87 [1.52-2.28], previous isolation of HI (HR 1.38 [1.07-1.78]), and alcohol abuse (HR 2.22 [1.13-4.3]). Younger age was associated with increased risk of HI infection, while COPD was associated with a lower risk of HI infection. Prescription of an anti- PA antibiotic was associated with chronic PA after a new infection (OR = 1.8 [1.09-2.9], p = 0.02). A landmark analysis showed that survival was worse in people with chronic PA infection vs. single or intermittent infection (Log rank: p = 0.034) CONCLUSIONS: Younger age and presence of PCD are associated with a new isolation of HI. A new infection with PA is associated with previous HI infection, PCD, COPD, and alcohol abuse. Unexpectedly, treatment with appropriate anti-PA antimicrobials was not associated with a reduced risk of chronicity.

Identification of Pathogenic Mutations and Investigation of the NOTCH Pathway Activation in Kartagener Syndrome

Primary ciliary dyskinesia (PCD), a rare genetic disorder, is mostly caused by defects in more than 40 known cilia structure-related genes. However, in approximately 20-35% of patients, it is caused by unknown genetic factors, and the inherited pathogenic factors are difficult to confirm. Kartagener syndrome (KTS) is a subtype of PCD associated with situs inversus, presenting more complex genetic heterogeneity. The aim of this study was to identify pathogenic mutations of candidate genes in Chinese patients with KTS and investigate the activation of the heterotaxy-related NOTCH pathway. Whole-exome sequencing was conducted in five patients with KTS. Pathogenic variants were identified using bioinformatics analysis. Candidate variants were validated by Sanger sequencing. The expression of the NOTCH pathway target genes was detected in patients with KTS. We identified 10 KTS-associated variants in six causative genes, namely, CCDC40, DNAH1, DNAH5, DNAH11, DNAI1, and LRRC6. Only one homozygote mutation was identified in LRRC6 (c.64dupT). Compound heterozygous mutations were found in DNAH1 and DNAH5. Six novel mutations were identified in four genes. Further analyses showed that the NOTCH pathway might be activated in patients with KTS. Overall, our study showed that compound heterozygous mutations widely exist in Chinese KTS patients. Our results demonstrated that the activation of the NOTCH pathway might play a role in the situs inversus pathogenicity of KTS. These findings highlight that Kartagener syndrome might be a complex genetic heterogeneous disorder mediated by heterozygous mutations in multiple PCD- or cilia-related genes.

Cilia distribution and polarity in the epithelial lining of the mouse middle ear cavity

The middle ear conducts sound to the cochlea for hearing. Otitis media (OM) is the most common illness in childhood. Moreover, chronic OM with effusion (COME) is the leading cause of conductive hearing loss. Clinically, COME is highly associated with Primary Ciliary Dyskinesia, implicating significant contributions of cilia dysfunction to COME. The understanding of middle ear cilia properties that are critical to OM susceptibility, however, is limited. Here, we confirmed the presence of a ciliated region near the Eustachian tube orifice at the ventral region of the middle ear cavity, consisting mostly of a lumen layer of multi-ciliated and a layer of Keratin-5-positive basal cells. We also found that the motile cilia are polarized coordinately and display a planar cell polarity. Surprisingly, we also found a region of multi-ciliated cells that line the posterior dorsal pole of the middle ear cavity which was previously thought to contain only non-ciliated cells. Our study provided a more complete understanding of cilia distribution and revealed for the first time coordinated polarity of cilia in the epithelium of the mammalian middle ear, thus illustrating novel structural features that are likely critical for middle ear functions and related to OM susceptibility.

Clinical manifestations in primary ciliary dyskinesia: systematic review and meta-analysis

Few original studies have described the prevalence and severity of clinical symptoms of primary ciliary dyskinesia (PCD). This systematic review and meta-analysis aimed to identify all published studies on clinical manifestations of PCD patients, and to describe their prevalence and severity stratified by age and sex.We searched PubMed, Embase and Scopus for studies describing clinical symptoms of ≥10 patients with PCD. We performed meta-analyses and meta-regression to explain heterogeneity.We included 52 studies describing a total of 1970 patients (range 10-168 per study). We found a prevalence of 5% for congenital heart disease. For the rest of reported characteristics, we found considerable heterogeneity (I² range 68-93.8%) when calculating the weighted mean prevalence. Even after taking into account the explanatory factors, the largest part of the between-studies variance in symptom prevalence remained unexplained for all symptoms. Sensitivity analysis including only studies with test-proven diagnosis showed similar results in prevalence and heterogeneity.Large differences in study design, selection of study populations and definition of symptoms could explain the heterogeneity in symptom prevalence. To better characterise the disease, we need larger, multicentre, multidisciplinary, prospective studies that include all age groups, use uniform diagnostics and report on all symptoms.

The impact of Primary Ciliary Dyskinesia on the upper respiratory tract

Primary Ciliary Dyskinesia (PCD) is an autosomal recessive genetic condition affecting the function of motile cilia. The upper respiratory tract is lined with ciliated epithelium and hence a hallmark of PCD is the development, from the neonatal period onwards, of persisting secretion retention and suppurative infection in the middle ear, nose and facial sinuses [1]. This review aims to remind the clinician involved in the care of a patient with PCD of the complexities of making the diagnosis of chronic rhinosinusitis (CRS) and chronic otitis media with effusion (ChOME), the morbidity associated with CRS and ChOME and of current evidence of best practice for the management of these conditions.

Diagnosis, monitoring, and treatment of primary ciliary dyskinesia: PCD foundation consensus recommendations based on state of the art review

Primary ciliary dyskinesia (PCD) is a genetically heterogeneous, rare lung disease resulting in chronic oto-sino-pulmonary disease in both children and adults. Many physicians incorrectly diagnose PCD or eliminate PCD from their differential diagnosis due to inexperience with diagnostic testing methods. Thus far, all therapies used for PCD are unproven through large clinical trials. This review article outlines consensus recommendations from PCD physicians in North America who have been engaged in a PCD centered research consortium for the last 10 years. These recommendations have been adopted by the governing board of the PCD Foundation to provide guidance for PCD clinical centers for diagnostic testing, monitoring, and appropriate short and long-term therapeutics in PCD patients.