Kartagener's syndrome: a re-visit with Chinese perspectives

Clinical and genetic spectrum of primary ciliary dyskinesia in Chinese patients: a systematic review

Background

Primary ciliary dyskinesia (PCD) represents a highly heterogenous disorder with extensive clinical and genetic patterns among populations of different geographic location and ethnic origin. However, data about Chinese patients are limited. We aimed to summarize the clinical and genetic spectrum of Chinese PCD patients based on all available literatures.

Methods

We searched Embase, Pubmed, Web of Science and Chinese databases including CNKI, SinoMed and Wanfang from 1981 to 2021, to identify articles reporting patients with PCD in China, which had included information about transmission electron microscopy and/or genetic testing.

Results

A total of 244 Chinese PCD patients in 52 articles were included. Of these patients, the mean age was 13.1 years, and 55 patients (22.5%) were diagnosed with PCD after 18 years old. Compared with patients diagnosed with PCD in childhood or infancy, patients diagnosed with PCD in adulthood had a higher prevalence of chronic wet cough, sinusitis, Pseudomonas aeruginosa (PA) isolation and radiological bronchiectasis as well as worse lung function. 25 PCD-related genes were identified in 142 patients, and DNAH5, DNAH11, CCDC39 and CCDC40 were the most frequently detected mutations. More than half of genetic variants were loss-of-function mutations, and the majority of these variants were seen only once. Correlations between PCD phenotype, genotype and ciliary ultrastructure were also evidenced.

Conclusions

Diagnostic delay and under-recognition of PCD remain a big issue in China, which contributes to progressive lung disease and PA infection indicating worse outcome. Specialist equipment and expertise are urgently required to facilitate the early diagnosis and treatment of PCD.

Trial registry

PROSPERO; No.: CRD42021257804; URL:www.crd.york.ac.uk/prospero/

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02427-1.

A prospective study of respiratory ciliary structure and function after stem cell transplantation

We prospectively investigated the morphological and ciliary function abnormalities in 19 consecutive Chinese patients undergoing hemopoietic stem cell transplantation (HSCT) and studied their relationship with pulmonary complications. The percentage of structural ciliary abnormalities preceding HSCT was comparable to normal controls, but increased up to 1-year post-HSCT. However, the abnormalities did not correlate with ciliary or pulmonary function. Ciliary beat frequency (CBF) for patients undergoing autologous and allogeneic SCT was lower than that of matched controls, with a further decline at one year. There was, however, no significant change in pulmonary function for the whole cohort. There was considerable variation in CBF and ciliary abnormalities in all cases during 3-month interval assessments. Regular ciliary assessment did not predict the only two patients who eventually suffered from bronchiolitis obliterans (BO). We conclude that structural and functional ciliary abnormalities are common in recipients of HSCT, and predict post-HSCT deterioration. However, there is no evidence to show that CBF monitoring may be of prospective benefit.

Discinesia ciliar primária

Discinesia ciliar primária é uma doença autossômica recessiva caracterizada pela história de infecções repetidas do trato respiratório superior e inferior, otite média, bronquite e rinossinusite, associada a situs inversus na metade dos casos. O diagnóstico é estabelecido pela análise ciliar ultra-estrutural de espécimes respiratórios, após a exclusão inicial de outras doenças, como fibrose cística, deficiência de alfa-1-antitripsina, imunodeficiências (IgG, neutrófilos e complemento) e síndrome de Young. O propósito deste artigo é revisar os achados clínicos, o diagnóstico e o manejo da discinesia ciliar primária, incluindo um fluxograma diagnóstico.

Respiratory ciliary function in bone marrow recipients

Bone marrow transplantation (BMT) recipients, particularly those with chronic graft-versus-host disease (GVHD), suffer from respiratory tract problems, including bronchiolitis obliterans (BO) and recurrent lower respiratory tract infections. Minute cilia beat continuously on the surface of respiratory mucosa, and this beating maintains the sterility of the lower respiratory tract. Dysfunction of respiratory cilia could lead to development of recurrent respiratory tract infections, which are also features of BMT recipients, although ciliary function has not been systematically studied among these subjects. We have, therefore, investigated the ciliary beat frequency (CBF) of 36 Chinese patients who had undergone allogeneic BMT. The CBF was significantly lower in the BMT group compared to controls (P < 0.001). The reduction in CBF was more severe in patients with cGVHD and BO compared with their counterparts (P = 0.048 and P = 0.077, respectively). There was a correlation between CBF with forced expiratory flow rate FEF (P = 0.024) and forced expiratory volume FEV (P = 0.044). We conclude that abnormal ciliary clearance is a common feature after allogeneic BMT, particularly among patients with BO and cGVHD. Further studies are indicated to evaluate this important phenomenon, which could be an important cause of the susceptibility for BMT recipients to respiratory infections.

Ciliary assessment in bronchiectasis

Bronchiectasis is a common condition among the Oriental population and affected patients suffer from chronic sputum production punctuated by recurrent infective exacerbations. Cilia are minute structures present on the surface of respiratory and other epithelial cells that beat continuously to maintain a sterile mucosal surface in the respiratory tract. Patients with primary ciliary dyskinesia could potentially develop recurrent sinotrachrobronchitis, bronchiectasis, serous otitis media, hydrocephalus, and male infertility. The assessment of cilia has, however, received little attention until recently and generally involves elaborate methods that require complex and expensive technology. This brief article discusses application of the saccharine test, light microscopy assessment of ciliary beat, and transmission electron microscopy assessment of the ultrastructure of cilia. The rationale and indications for ciliary assessment are also listed along with illustrations showing ciliary structure, equipment required for sampling and assessment of cilia, and transmission electron micrographs of ciliary ultrastructural abnormalities.

Non cystic fibrosis bronchiectasis

Bronchiectasis is becoming less common as the treatment for acute lower respiratory tract infections improves and immunization programmes decrease the frequency of pertussis and measles. However bronchiectasis is still a challenge to the paediatric chest physicians in many developing parts of the world and it remains a frequent problem being the final common pathway of several different lower respiratory tract insults such as cystic fibrosis, immunodeficiency, ciliary dyskinesia. Although the treatment of patients with bronchiectasis is primarily medical, surgical treatment is required in a small group of patients with recurrent episodes of pneumonia and atelectasis localized to one area, severe or recurrent hemoptysis and in those unresponsive to aggressive medical treatment with abnormal growth and development. There are unanswered questions about childhood bronchiectasis, mainly on aetiology and treatment which require more research.