Sylvain Blanchon

Quantitative analysis of ciliary beating in primary ciliary dyskinesia: a pilot study

BackgroundPrimary ciliary dyskinesia (PCD) is a rare congenital respiratory disorder characterized by abnormal ciliary motility leading to chronic airway infections. Qualitative evaluation of ciliary beat pattern based on digital high-speed videomicroscopy analysis has been proposed in the diagnosis process of PCD. Although this evaluation is easy in typical cases, it becomes difficult when ciliary beating is partially maintained. We postulated that a quantitative analysis of beat pattern would improve PCD diagnosis. We compared quantitative parameters with the qualitative evaluation of ciliary beat pattern in patients in whom the diagnosis of PCD was confirmed or excluded.MethodsNasal nitric oxide measurement, nasal brushings and biopsies were performed prospectively in 34 patients with suspected PCD. In combination with qualitative analysis, 12 quantitative parameters of ciliary beat pattern were determined on high-speed videomicroscopy recordings of beating ciliated edges. The combination of ciliary ultrastructural abnormalities on transmission electron microscopy analysis with low nasal nitric oxide levels was the “gold standard” used to establish the diagnosis of PCD.ResultsThis “gold standard” excluded PCD in 15 patients (non-PCD patients), confirmed PCD in 10 patients (PCD patients) and was inconclusive in 9 patients. Among the 12 parameters, the distance traveled by the cilium tip weighted by the percentage of beating ciliated edges presented 96% sensitivity and 95% specificity. Qualitative evaluation and quantitative analysis were concordant in non-PCD patients. In 9/10 PCD patients, quantitative analysis was concordant with the “gold standard”, while the qualitative evaluation was discordant with the “gold standard” in 3/10 cases. Among the patients with an inconclusive “gold standard”, the use of quantitative parameters supported PCD diagnosis in 4/9 patients (confirmed by the identification of disease-causing mutations in one patient) and PCD exclusion in 2/9 patients.ConclusionsWhen the beat pattern is normal or virtually immotile, the qualitative evaluation is adequate to study ciliary beating in patients suspected for PCD. However, when cilia are still beating but with moderate alterations (more than 40% of patients suspected for PCD), quantitative analysis is required to precise the diagnosis and can be proposed to select patients eligible for TEM.

Delineation of CCDC39/CCDC40 mutation spectrum and associated phenotypes in primary ciliary dyskinesia

Background CCDC39 and CCDC40 genes have recently been implicated in primary ciliary dyskinesia (PCD) with inner dynein arm (IDA) defects and axonemal disorganisation; their contribution to the disease is, however, unknown. Aiming to delineate the CCDC39/CCDC40 mutation spectrum and associated phenotypes, this study screened a large cohort of patients with IDA defects, in whom clinical and ciliary phenotypes were accurately described. Methods All CCDC39 and CCDC40 exons and intronic boundaries were sequenced in 43 patients from 40 unrelated families. The study recorded and compared clinical features (sex, origin, consanguinity, laterality defects, ages at first symptoms and at phenotype evaluation, neonatal respiratory distress, airway infections, nasal polyposis, otitis media, bronchiectasis, infertility), ciliary beat frequency, and quantitative ultrastructural analyses of cilia and sperm flagella. Results Biallelic CCDC39 or CCDC40 mutations were identified in 30/34 (88.2%) unrelated families with IDA defects associated with axonemal disorganisation (22 and eight families, respectively). Fourteen of the 28 identified mutations are novel. No mutation was found in the six families with isolated IDA defects. Patients with identified mutations shared a similar phenotype, in terms of both clinical features and ciliary structure and function. The sperm flagellar ultrastructure, analysed in 4/7 infertile males, showed evidence of abnormalities similar to the ciliary ones. Conclusions CCDC39 and CCDC40 mutations represent the major cause of PCD with IDA defects and axonemal disorganisation. Patients carrying CCDC39 or CCDC40 mutations are phenotypically indistinguishable. CCDC39 and CCDC40 analyses in selected patients ensure mutations are found with high probability, even if clinical or ciliary phenotypes cannot prioritise one analysis over the other.

Remodelling and inflammation in preschoolers with severe recurrent wheeze and asthma outcome at school age

The influence of airway remodelling and inflammation in preschoolers with severe recurrent wheeze on asthma outcomes is poorly understood.

Pulmonary complications after liver transplantation in children: risk factors and impact on early post-operative morbidity

Liver transplantation (LT) is associated with high post‐operative morbidity, despite excellent survival rates. With this retrospective study, we report the incidence of early and late pulmonary complications (PC) after LT, identify modifiable risk factors for PC and analyzed the role of PC in post‐operative ventilation duration and hospital length of stay. In a series of 79 children (0‐16 years) with LT over a 12 years period, early (<3 months post‐LT) and/or late (>3 months post‐LT) PC occurred in 68 patients (86%). Sixty‐four percent (64%) developed early major complications such as pulmonary edema, atelectasis, or pleural effusion. Atelectasis requiring an intervention (P ≤ .02), pulmonary edema (P ≤ .02), or elevated PELD/MELD scores (P = .05) were associated with an increase in total ventilation duration and length of stay in the ICU. Risk factors for early PC included preoperative hypoxemia (P = .005), low serum albumin at LT admission (P = .003), or early rejection (P = .002). About 20% of patients experienced late PC of which 81% were infections. Risk factor assessment prior to LT may ultimately help reduce early PC thereby possibly minimizing post‐operative morbidity and ICU length of stay.

Diagnostic of Primary Ciliary Dyskinesia: guidelines to obtain appropriate ciliate cell samples

Background Primary Ciliary Dyskinesia (PCD) is a rare inherited disease (~1/20,000), characterized by ciliary structure/function abnormalities, responsible for impaired muco-ciliary transport, leading to recurrent upper and lower airways infections early in life and infertility. The diagnosis is confirmed on ciliate cell samples, collected by nasal and/or bronchial endoscopy. Patients usually need several samples, due to difficulties to get reliable results, especially during respiratory tract infections which are frequent in PCD. We created national guidelines aimed at obtaining the more efficient quality of ciliate cell samples for children and adults.

Diagnostic algorithm for Primary Ciliary Dyskinesia: recommendations of the French National Centre for Rare Respiratory Diseases

Background Primary Ciliary Dyskinesia (PCD) is a inherited disorder characterized by abnormal ciliary structure/function, responsible for impaired muco-ciliary transport and infertility. The diagnosis is often delayed for several years though PCD is a rare (~1/20,000) and heterogeneous disease. We elaborated recommendations aiming at improving the quality and efficacy of PCD diagnosis. Methods A multicentric working group, created in 2009 within the French National Centre for Rare Respiratory Diseases, elaborated precise and practical algorithm for PCD diagnosis, based on their experience and the recent literature. It includes adults and paediatric physicians, biologists and technicians involved in PCD, dealing since many years with the difficulties to confirm this diagnosis.