Primary ciliary dyskinesia in adults

Impact of Aerobic Exercise on Oxygenation, Pulmonary Function, and Nasal Nitric Oxide in Primary Ciliary Dyskinesia

Background

Primary Ciliary Dyskinesia (PCD) is a rare genetic disorder characterized by impaired mucociliary clearance, resulting in chronic respiratory complications. While exercise benefits respiratory health, its impacts on PCD remain understudied.

Objective

The objective of this study was to assess how moderate aerobic exercise influences FEV1, SpO2, and nNO levels in PCD patients, with a focus on short-term post-exercise changes.

Methods

This is a matched case-control pilot study involving 12 PCD patients homozygous for the RSPH4A (c.921+3_921+6del) mutation and 12 healthy controls (HC). Baseline FEV1, SpO2, and nNO levels were measured before participants underwent a six-minute exercise challenge test (ECT) on a stationary bicycle. Post-exercise measurements included FEV1 at 5, 10, 15, and 20 minutes, nNO after final spirometry, and SpO2 at 5 minutes.

Results

The PCD group experienced a significant increase in SpO2 from 95.5% ± 2.1 to 97.7% ± 1.5 post-exercise (p < 0.05), while the HC group had stable SpO2 levels with a minor increase from 97.9% ± 1.5 to 98.9% ± 1.4 (p = 0.14). No significant changes in FEV1 or nNO levels were observed post-exercise in either group. One HC participant exhibited exercise-induced bronchoconstriction.

Conclusion

Aerobic exercise improves oxygenation in PCD patients without adverse effects on pulmonary function or nNO levels. Further research is necessary due to the small sample size and genetic homogeneity to confirm these findings and evaluate long-term outcomes. Moreover, this pilot study highlights the safety and potential respiratory benefits of aerobic exercise in PCD patients, supporting further investigation into its role in clinical management.

In vivo volumetric depth-resolved imaging of cilia metachronal waves using dynamic optical coherence tomography

Motile cilia are dynamic hair-like structures covering epithelial surfaces in multiple organs. The periodic coordinated beating of cilia creates waves propagating along the surface, known as the metachronal waves, which transport fluids and mucus along the epithelium. Motile ciliopathies result from disrupted coordinated cilia beating and are associated with serious clinical complications, including reproductive disorders. Despite the recognized clinical significance, research of cilia dynamics is extremely limited. Here, we present quantitative imaging of cilia metachronal waves volumetrically through tissue layers using dynamic optical coherence tomography (OCT). Our method relies on spatiotemporal mapping of the phase of intensity fluctuations in OCT images caused by the ciliary beating. We validated our new method ex vivo and implemented it in vivo to visualize cilia metachronal wave propagation within the mouse fallopian tube. This method can be extended to the assessment of physiological cilia function and ciliary dyskinesias in various organ systems, contributing to better management of pathologies associated with motile ciliopathies.

Ear and upper airway clinical outcome measures for use in primary ciliary dyskinesia research: a scoping review

BACKGROUND

Primary ciliary dyskinesia (PCD) is a rare genetic disorder characterised by pulmonary, otological and sino-nasal manifestations. Well-defined clinical outcome measures are needed in such rare diseases research to improve follow-up and treatments. Pulmonary outcome measures have recently been described. The aim of this study was to identify ear and upper airway outcome measures that could be used for longitudinal follow-up of individuals with PCD.

METHODS

A scoping review was performed by systematically searching MEDLINE, Embase and Cochrane Database of Systematic Reviews online databases for studies published from January 1996 to March 2022 that included at least 10 adult or paediatric PCD patients and reported ear and upper airway outcomes.

RESULTS

33 studies (1794 patients) were included. 10 ear and upper airway outcomes were reported. 17 studies reported audiometry, 16 reported otoscopic findings, and 13 reported rhinoscopic findings and sinus imaging. Health-related quality of life questionnaires were performed in seven studies. There was a high variability in definitions and measurement of outcomes between studies.

CONCLUSIONS

This scoping review highlights the lack of data regarding ear and upper airway outcomes in PCD. It also reports a high heterogeneity in outcome definitions or measures. We provide well-founded specific suggestions to standardise ear and upper airway outcome definitions and reporting for future PCD research studies.

CCNO mutation as a cause of primary ciliary dyskinesia: A case report

BACKGROUND

Primary ciliary dyskinesia (PCD) is an uncommon and genetically diverse condition. According to reports, most patients had more than 50 visits before being diagnosed with PCD, and the age at diagnosis was mostly in preschool, with an average age of about (10.9 ± 14.4) years old. CCNO is a pathogenic gene that regulates the cell cycle, and its mutation is linked to the uncommon human genetic disorder PCD. Although the prevalence of the CCNO mutation is regarded to be exceptionally low, new reports of this mutation have increased in comparison to prior ones. PCD patients with CCNO are rare, and the incidence rate is no more than 2% in whole PCD patients.

CASE SUMMARY

Here, we report a case of a young Chinese woman diagnosed with PCD, who was found to carry the CCNO gene by whole exon gene sequencing. In this case, a young non-smoking Chinese female exhibiting recurrent cough and sputum at birth. Chest computed tomography (CT) showed bronchiectasis with infection, and sinus CT showed chronic sinusitis. However, the patient had no visceral transposition and no history of infertility. Under electron microscope, it was found that cilia were short and reduced in number, and no power arm of cilia was observed. Whole exon sequencing analysis of the genome of the patient showed that the patient carried CCNO pathogenic gene, exon c.303C>A nonsense mutation and c.248_252dup frameshift mutation. Her clinical symptoms and CT images were improved after two months of treatment with aerosol inhalation and oral azithromycin.

CONCLUSION

The results showed that CCNO is an important cause of PCD. More mutant genes that may contribute to genetically diverse disorders like PCD have been discovered as sequencing technology has advanced. Furthermore, the increase of genetic information makes it easier to diagnose uncommon diseases in clinical practice.

Vestibular and Balance Impairment Is Common in Children With Primary Ciliary Dyskinesia

OBJECTIVE

Primary ciliary dyskinesia (PCD) is a rare genetic disorder that presents with a wide range of respiratory complaints. The most common otologic associated disorder is middle ear effusion. We ask if children with PCD suffer from vestibular impairment.

STUDY DESIGN

Cross-sectional cohort study.

SETTING

Tertiary pediatric referral hospital.

PATIENTS/PARTICIPANTS

Children with confirmed PCD.

INTERVENTION/METHODS

All included participants were clinically assessed to be at baseline then basic demographics and medical histories were collected, including the specific genetic mutation these patients have. After which, all patients underwent two vestibular tests. The first was to assess their ability to stand on one foot with their eyes open and then with their eyes closed and the second was video head impulse test (vHIT).

MAIN OUTCOME MEASURES

Ability standing on one foot with the eyes closed and vHIT.

RESULTS

During this period, 25 children with PCD were recruited for the study. The mean age at recruitment was 11.26 years (4-18 yr). There were 11 women and 14 men. All patients were able to participate in both tests. Nineteen participants (76%) had vestibular impairment. Fifteen of them failed to stand on one foot with their eyes closed and six of 25 had abnormal vHIT. The most common involved gene was DNAH5 8/25 (32%) and it was associated with vestibular impairment in seven of eight participants (87.5%).

CONCLUSION

The majority of children with PCD that we tested suffered from vestibular impairment that was previously undiagnosed. This potentially indicates that imbalance and vestibular pathology is under-diagnosed in children with PCD.

A Comprehensive Approach for the Diagnosis of Primary Ciliary Dyskinesia-Experiences from the First 100 Patients of the PCD-UNIBE Diagnostic Center

Primary ciliary dyskinesia (PCD) is a rare genetic disease characterized by dyskinetic cilia. Respiratory symptoms usually start at birth. The lack of diagnostic gold standard tests is challenging, as PCD diagnostics requires different methods with high expertise. We founded PCD-UNIBE as the first comprehensive PCD diagnostic center in Switzerland. Our diagnostic approach includes nasal brushing and cell culture with analysis of ciliary motility via high-speed-videomicroscopy (HSVM) and immunofluorescence labeling (IF) of structural proteins. Selected patients undergo electron microscopy (TEM) of ciliary ultrastructure and genetics. We report here on the first 100 patients assessed by PCD-UNIBE. All patients received HSVM fresh, IF, and cell culture (success rate of 90%). We repeated the HSVM with cell cultures and conducted TEM in 30 patients and genetics in 31 patients. Results from cell cultures were much clearer compared to fresh samples. For 80 patients, we found no evidence of PCD, 17 were diagnosed with PCD, two remained inconclusive, and one case is ongoing. HSVM was diagnostic in 12, IF in 14, TEM in five and genetics in 11 cases. None of the methods was able to diagnose all 17 PCD cases, highlighting that a comprehensive approach is essential for an accurate diagnosis of PCD.

Follow-Up and Management of Chronic Rhinosinusitis in Adults with Primary Ciliary Dyskinesia: Review and Experience of Our Reference Centers

Chronic rhinosinusitis is the foremost manifestation in adult patients with primary ciliary dyskinesia (PCD). We present a retrospective series of 41 adult patients with a confirmed diagnosis of PCD followed in our reference centers. As part of the diagnostic work up in our centers, sinus computed tomography scans (CTs) are systematically performed. All patients also undergo a sampling of purulent secretions sampled from the middle meatus under endoscopic view for bacteriological analysis. In our series, CT opacities were consistent in all the patients, as well as mainly partial and located in ethmoid cells (100% of patients) and in maxillary sinuses (85.4% of patients), and stayed stable over time. In the 31 patients who had purulent secretions, bacteriological culture showed at least one bacterium in 83.9% (n = 26). There was no significant difference in positive cultures for Pseudomonas aeruginosa in patients >40 years old versus those <40 (p = 0.17; Fisher). Surgical management was performed in only 19% of patients in order to improve sinonasal mechanical drainage. Our data support the hypothesis that the sinuses can be considered as a bacterial reservoir. From this retrospective study, we have introduced several changes into our routine clinical practice in our reference centers. Based on our analyses, medical and surgical treatments benefit from incorporating bacteriological information and sinonasal symptoms much more than CT scan evaluation alone. All patients now undergo systematically an annual simultaneous bacteriological sampling of the middle meatus and sputum to follow the relationship between ENT and lung disease and to help to antibiotic therapy strategy.

Prevalence and course of disease after lung resection in primary ciliary dyskinesia: a cohort & nested case-control study

Background

Lung resection is a controversial and understudied therapeutic modality in Primary Ciliary Dyskinesia (PCD). We assessed the prevalence of lung resection in PCD across countries and compared disease course in lobectomised and non-lobectomised patients.

Methods

In the international iPCD cohort, we identified lobectomised and non-lobectomised age and sex-matched PCD patients and compared their characteristics, lung function and BMI cross-sectionally and longitudinally.

Results

Among 2896 patients in the iPCD cohort, 163 from 20 centers (15 countries) underwent lung resection (5.6%). Among adult patients, prevalence of lung resection was 8.9%, demonstrating wide variation among countries. Compared to the rest of the iPCD cohort, lobectomised patients were more often females, older at diagnosis, and more often had situs solitus. In about half of the cases (45.6%) lung resection was performed before presentation to specialized PCD centers for diagnostic work-up. Compared to controls (n = 197), lobectomised patients had lower FVC z-scores (− 2.41 vs − 1.35, p = 0.0001) and FEV1 z-scores (− 2.79 vs − 1.99, p = 0.003) at their first post-lung resection assessment. After surgery, lung function continued to decline at a faster rate in lobectomised patients compared to controls (FVC z-score slope: − 0.037/year Vs − 0.009/year, p = 0.047 and FEV1 z-score slope: − 0.052/year Vs − 0.033/year, p = 0.235), although difference did not reach statistical significance for FEV1. Within cases, females and patients with multiple lobe resections had lower lung function.

Conclusions

Prevalence of lung resection in PCD varies widely between countries, is often performed before PCD diagnosis and overall is more frequent in patients with delayed diagnosis. After lung resection, compared to controls most lobectomised patients have poorer and continuing decline of lung function despite lung resection. Further studies benefiting from prospective data collection are needed to confirm these findings.

Cost-effectiveness analysis of three algorithms for diagnosing primary ciliary dyskinesia: a simulation study

Background

Primary Ciliary Dyskinesia (PCD) diagnosis relies on a combination of tests which may include (a) nasal Nitric Oxide (nNO), (b) High Speed Video Microscopy (HSVM) and (c) Transmission Electron Microscopy (TEM). There is variability in the availability of these tests and lack of universal agreement whether diagnostic tests should be performed in sequence or in parallel. We assessed three combinations of tests for PCD diagnosis and estimated net sensitivity and specificity as well as cost-effectiveness (CE) and incremental cost-effectiveness (ICE) ratios.

Methods and results

A hypothetical initial population of 1000 referrals (expected 320 PCD patients) was followed through a probabilistic decision analysis model which was created to assess the CE of three diagnostic algorithms (a) nNO + TEM in sequence, (b) nNO + HSVM in sequence and (c) nNO/HSVM in parallel followed, in cases with conflicting results, by confirmatory TEM (nNO/HSVM+TEM). Number of PCD patients identified, CE and ICE ratios were calculated using Monte Carlo simulations. Out of 320 expected PCD patients, 313 were identified by nNO/HSVM+TEM, 274 with nNO + HSVM and 198 with nNO + TEM. The nNO/HSVM+TEM had the highest mean annual cost (€209 K) followed by nNO + TEM (€150 K) and nNO + HSVM (€136 K). The nNO + HSVM algorithm dominated the nNO + TEM algorithm (less costly and more effective). The ICE ratio for nNO/HSVM+TEM was €2.1 K per additional PCD patient identified.

Conclusions

The diagnostic algorithm (nNO/HSVM+TEM) with parallel testing outperforms algorithms with tests in sequence. These findings, can inform the dialogue on the development of evidence-based guidelines for PCD diagnostic testing. Future research in understudied aspects of the disease, such as PCD-related quality of life and PCD-associated costs, is needed to help the better implementation of these guidelines across various healthcare systems.

Electronic supplementary material

The online version of this article (10.1186/s13023-019-1116-3) contains supplementary material, which is available to authorized users.

Automated computed tomographic scoring of lung disease in adults with primary ciliary dyskinesia

Background

The present study aimed to develop an automated computed tomography (CT) score based on the CT quantification of high-attenuating lung structures, in order to provide a quantitative assessment of lung structural abnormalities in patients with Primary Ciliary Dyskinesia (PCD).

Methods

Adult (≥18 years) PCD patients who underwent both chest CT and spirometry within a 6-month period were retrospectively included. Commercially available lung segmentation software was used to isolate the lungs from the mediastinum and chest wall and obtain histograms of lung density. CT-density scores were calculated using fixed and adapted thresholds based on various combinations of histogram characteristics, such as mean lung density (MLD), skewness, and standard deviation (SD). Additionally, visual scoring using the Bhalla score was performed by 2 independent radiologists. Correlations between CT scores, forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC) were evaluated.

Results

Sixty-two adult patients with PCD were included. Of all histogram characteristics, those showing good positive or negative correlations to both FEV₁ and FVC were SD (R = − 0.63 and − 0.67; p < 0.001) and Skewness (R = 0.67 and 0.67; p < 0.001). Among all evaluated thresholds, the CT-density score based on MLD + 1SD provided the best negative correlation with both FEV₁ (R = − 0.68; p < 0.001) and FVC (R = − 0.71; p < 0.001), close to the correlations of the visual score (R = − 0.60; p < 0.001 for FEV₁ and R = − 0.62; p < 0.001, for FVC).

Conclusions

Automated CT scoring of lung structural abnormalities lung in primary ciliary dyskinesia is feasible and may prove useful for evaluation of disease severity in the clinic and in clinical trials.

[Bronchiectasis imaging]

Bronchiectasis are defined as an irreversible focal or diffuse dilatation of the bronchi and can be associated with significant morbidity. The prevalence is currently increasing, probably due to an increased use of thoracic computed tomography (CT). Indeed, the diagnosis relies on imaging and chest CT is the gold standard technique. The main diagnosis criterion is an increased bronchial diameter as compared to that of the companion artery. However, false positives are possible when the artery diameter is decreased, which is called pseudo-bronchiectasis. Other features such as the lack of bronchial tapering, and visibility of bronchi within 1cm of the pleural surface are also diagnostic criteria, and other CT features of bronchial disease are commonly seen. Thoracic imaging also allows severity assessment and long-term monitoring of structural abnormalities. The distribution pattern and the presence of associated findings on chest CT help identifying specific causes of bronchiectasis. Lung MRI and ultra-low dose CT and are promising imaging modalities that may play a role in the future. The objectives of this review are to describe imaging features for the diagnosis and severity assessment of bronchiectasis, to review findings suggesting the cause of bronchiectasis, and to present the new developments in bronchiectasis imaging.

Kartagener syndrome, current data on a classical disease. Case report

Introducción. El presente artículo aborda los aspectos generales (fisiopatología, embriología, presentación clínica y pronóstico) del síndrome de Kartagener (SK). Presentación del caso. Paciente masculino de 26 años, con antecedente de sinusitis complicada con absceso cerebral y epilepsia secundaria, quien consulta al Hospital Universitario Nacional de Colombia por cefalea, fiebre y expectoración mucosa. La presencia de situs inverso, sinusitis crónica y bronquiectasias sugieren diagnóstico de discinesia ciliar primaria y SK. Discusión. Los diagnósticos diferenciales del SK deben enmarcarse en la relación de causalidad posible con la discinesia ciliar primaria y de otros diagnósticos asociados a disfunción ciliar secundaria como fibrosis quística, inmunodeficiencia y condiciones anatómicas-funcionales con compromiso rinosenopulmonar. La sospecha clínica del SK se da cuando se ausculta el corazón a la derecha y se palpa el hígado a la izquierda. Su confirmación es mediante métodos de imagen que comprueban la heterotaxia visceral, por métodos indirectos de mal funcionamiento del barrido ciliar (óxido nítrico nasal, video microscopia) y por biopsia ciliar que demuestra el defecto de la ultraestructura ciliar. Conclusiones. El compromiso infeccioso respiratorio presentado por los pacientes que cursan con SK se explica por la alteración en la cilia, que conlleva tanto a la malposición de algunos órganos como a la alteración estructural y funcional de otros. Se detallan los hallazgos en las imágenes diagnósticas, se explican las alteraciones anatómicas, las bases moleculares y la relación con enfermedades respiratorias del síndrome. 

Bordetella pseudohinzii targets cilia and impairs tracheal cilia-driven transport in naturally acquired infection in mice

Several species of the Gram-negative genus Bordetella are the cause of respiratory infections in mammals and birds, including whooping cough (pertussis) in humans. Very recently, a novel atypical species, Bordetella pseudohinzii, was isolated from laboratory mice. These mice presented no obvious clinical symptoms but elevated numbers of neutrophils in bronchoalveolar lavage fluid and inflammatory signs in histopathology. We noted that this species can occur at high prevalence in a mouse facility despite regular pathogen testing according to the FELASA-recommendations. Affected C57BL/6 J mice had, in addition to the reported pulmonary alterations, tracheal inflammation with reduced numbers of ciliated cells, slower ciliary beat frequency, and largely (>50%) compromised cilia-driven particle transport speed on the mucosal surface, a primary innate defence mechanism. In an in vitro-model, Bordetella pseudohinzii attached to respiratory kinocilia, impaired ciliary function within 4 h and caused epithelial damage within 24 h. Regular testing for this ciliotropic Bordetella species and excluding it from colonies that provide mice for lung research shall be recommended. On the other hand, controlled colonization and infection with Bordetella pseudohinzii may serve as an experimental model to investigate mechanisms of mucociliary clearance and microbial strategies to escape from this primary innate defence response.

Clinical care for primary ciliary dyskinesia: current challenges and future directions

Primary ciliary dyskinesia (PCD) is a rare genetic disease that affects the motility of cilia, leading to impaired mucociliary clearance. It is estimated that the vast majority of patients with PCD have not been diagnosed as such, providing a major obstacle to delivering appropriate care. Challenges in diagnosing PCD include lack of disease-specific symptoms and absence of a single, "gold standard", diagnostic test. Management of patients is currently not based on high-level evidence because research findings are mostly derived from small observational studies with limited follow-up period. In this review, we provide a critical overview of the available literature on clinical care for PCD patients, including recent advances. We identify barriers to PCD research and make suggestions for overcoming challenges.

Diagnosis of primary ciliary dyskinesia: When and how?

INTRODUCTION

Primary ciliary dyskinesia (PCD) is a rare congenital disorder involving permanent ubiquitous structural and/or functional ciliary abnormalities.

METHODS

A single-center retrospective study included 56 cases of PCD (respiratory form) out of a cohort of 280 patients with suspected PCD. The main features of history-taking and clinical examination were analyzed, to formulate a pragmatic diagnostic procedure, easy to implement in clinical practice.

RESULTS

Chronic respiratory tract infectious symptoms are sensitive but non-specific for the diagnosis of PCD. Nasal brushing for phase-contrast microscopy study of ciliary morphology and activity proved to be a fast, easy, non-invasive, cost-effective and age-independent diagnostic method. In doubtful cases, depending on local availability, further tests are indicated: nasal nitric oxide level, electronic microscopy, genetic study and cell culture.

CONCLUSIONS

In suspected PCD, there being no gold standard method of screening and early diagnosis, nasal brushing with ciliary study is contributive, alongside numerous other complementary tests, on condition that the clinician is experienced and results are interpreted in the light of clinical examination and history-taking.

Raising awareness of bronchiectasis in primary care: overview of diagnosis and management strategies in adults

Bronchiectasis is a chronic lung disease characterised by recurrent infection, inflammation, persistent cough and sputum production. The disease is increasing in prevalence, requiring a greater awareness of the disease across primary and secondary care. Mild and moderate cases of bronchiectasis in adults can often be managed by primary care clinicians. Initial assessments and long-term treatment plans that include both pharmacological and non-pharmacological treatments, however, should be undertaken in collaboration with a secondary care team that includes physiotherapists and specialists in respiratory medicine. Bronchiectasis is often identified in patients with other lung diseases, such as chronic obstructive pulmonary disease, asthma, and in a lesser but not insignificant number of patients with other inflammatory diseases, such as rheumatoid arthritis and inflammatory bowel disease. Overall goals of therapy are to prevent exacerbations, improve symptoms, improve quality of life and preserve lung function. Prompt treatment of exacerbations with antibiotic therapy is important to limit the impact of exacerbations on quality of life and lung function decline. Patient education and cooperation with health-care providers to implement treatment plans are key to successful disease management. It is important for the primary care provider to work with secondary care providers to develop an individualised treatment plan to optimise care with the goal to delay disease progression. Here, we review the diagnosis and treatment of bronchiectasis with a focus on practical considerations that will be useful to primary care.