Skewed X-chromosome inactivation drives the proportion of DNAAF6-defective airway motile cilia and variable expressivity in primary ciliary dyskinesia.

BACKGROUND: Primary ciliary dyskinesia (PCD) is a rare airway disorder caused by defective motile cilia. Only male patients have been reported with pathogenic mutations in X-linked DNAAF6, which result in the absence of ciliary dynein arms, whereas their heterozygous mothers are supposedly healthy. Our objective was to assess the possible clinical and ciliary consequences of X-chromosome inactivation (XCI) in these mothers. METHODS: XCI patterns of six mothers of male patients with DNAAF6-related PCD were determined by DNA-methylation studies and compared with their clinical phenotype (6/6 mothers), as well as their ciliary phenotype (4/6 mothers), as assessed by immunofluorescence and high-speed videomicroscopy analyses. The mutated X chromosome was tracked to assess the percentage of cells with a normal inactivated DNAAF6 allele. RESULTS: The mothers' phenotypes ranged from absence of symptoms to mild/moderate or severe airway phenotypes, closely reflecting their XCI pattern. Analyses of the symptomatic mothers' airway ciliated cells revealed the coexistence of normal cells and cells with immotile cilia lacking dynein arms, whose ratio closely mirrored their XCI pattern. CONCLUSION: This study highlights the importance of searching for heterozygous pathogenic DNAAF6 mutations in all female relatives of male PCD patients with a DNAAF6 defect, as well as in females consulting for mild chronic respiratory symptoms. Our results also demonstrate that about one-third-ranging from 20% to 50%-normal ciliated airway cells sufficed to avoid severe PCD, a result paving the way for gene therapy.

TTC12 Loss-of-Function Mutations Cause Primary Ciliary Dyskinesia and Unveil Distinct Dynein Assembly Mechanisms in Motile Cilia Versus Flagella.

Cilia and flagella are evolutionarily conserved organelles whose motility relies on the outer and inner dynein arm complexes (ODAs and IDAs). Defects in ODAs and IDAs result in primary ciliary dyskinesia (PCD), a disease characterized by recurrent airway infections and male infertility. PCD mutations in assembly factors have been shown to cause a combined ODA-IDA defect, affecting both cilia and flagella. We identified four loss-of-function mutations in TTC12, which encodes a cytoplasmic protein, in four independent families in which affected individuals displayed a peculiar PCD phenotype characterized by the absence of ODAs and IDAs in sperm flagella, contrasting with the absence of only IDAs in respiratory cilia. Analyses of both primary cells from individuals carrying TTC12 mutations and human differentiated airway cells invalidated for TTC12 by a CRISPR-Cas9 approach revealed an IDA defect restricted to a subset of single-headed IDAs that are different in flagella and cilia, whereas TTC12 depletion in the ciliate Paramecium tetraurelia recapitulated the sperm phenotype. Overall, our study, which identifies TTC12 as a gene involved in PCD, unveils distinct dynein assembly mechanisms in human motile cilia versus flagella.

Otitis media in severe asthma associated with chronic rhinosinusitis with nasal polyps: a new therapeutic target for biologics.

Background: Chronic rhinosinusitis with nasal polyps (CRSwNPs) is associated with otitis media with effusion (OME) in about 25% of cases. The objective of this study was to assess the clinical efficacy of the 4 biologic agents currently available in France for severe asthma (omalizumab, mepolizumab, benralizumab and dupilumab) in 17 patients followed for both asthma and chronic rhinosinusitis with nasal polyps (CRSwNP) and presenting otitis media with effusion (OME) on otoscopy. Methods: It was a multicenter retrospective study performed in 4 academic ENT and respiratory departments in Paris, France, with assessment of the clinical evolution of 17 patients with severe eosinophilic asthma and with chronic refractory OME and CRSwNPs treated by biologic agents. Global evaluation of treatment effectiveness (GETE) on asthma, CRSwNP and OME was classified on a 5-point scale as 1, excellent; 2, good; 3, moderate; 4, poor; or 5, symptoms worsening. Response was defined as an excellent/good score (1 or 2). Results: 17 patients were prescribed a total of 30 biologics. The evolution of OME did not follow that of asthma and CRSwNPs in 15 (88%) and 12 (70%) cases, respectively. Concerning OME, 19/30 (63%) patients were non-responders. Among the 10 patients who successively received ≥ 2 biologic agents, the OME response differed, depending on the considered agent Dupilumab had the highest response rate. Conclusions: Resistant OME, associated with asthma and chronic rhinosinusitis with nasal polyps, can present a disconnected evolution under biologics. CRSwNP-associated OME requires a specific evaluation to define the best treatment.

Performance of an active transcutaneous bone conduction implant, the Osia system, in high frequencies and hearing in noise in users converted from a Baha attract system: a prospective study.

PURPOSE: Hearing rehabilitation through middle ear surgery can be challenging, particularly for patients with chronic otitis media, but new hearing devices offer opportunity to reach this goal. The aim was to compare hearing outcomes and quality of life in patients who were converted from a Baha Attract system to the Osia system. METHODS: Prospective observational study, in which each subject acted as their own control. Six patients who were converted from a Baha Attract to an Osia system performed audiometric and quality of life assessments with different sound processor at fitting, 3, 6 and 12 months. The speech performance in noise with the Osia system at 12 months, expressed as dB SNR, was compared to the baseline condition (Baha 5). RESULTS: The PTA4 hearing thresholds improved from 42.6 ± 11 with Baha 5 Power to 34.8 ± 13.3 with Baha 5 SuperPower and to 25.4 ± 3.5 with the Osia at 12 months, leading to a significant functional gain of 17.2 ± 10.9 dB vs Baha 5 (p < 0.02). Speech understanding in both quiet and noise was clinically improved reaching a mean SNR of less than 1 dB at 12 months with the Osia system. Quality of life outcomes improved by more than 20% at 12-month follow-up. CONCLUSION: Aided hearing thresholds and speech understanding in noise improved when patients were converted from the Baha Attract system to the Osia system. The aided hearing threshold was maintained up to 8 kHz (26 dB) with the Osia system.

[Post-COVID-19 syndrome]. / Syndrome post-COVID-19.

In the aftermath of acute infection with the severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2), a large number of symptoms persist or appear, constituting a real syndrome called "long COVID-19" or "post-COVID- 19" or "post-acute COVID-19 syndrome". Its incidence is very high, half of patients showing at least one symptom at 4-6 months after Coronarovirus infectious disease 2019 (COVID-19). They can affect many organs. The most common symptom is persistent fatigue, similar to that seen after other viral infections. Radiological pulmonary sequelae are relatively rare and not extensive. On the other hand, functional respiratory symptoms, primarily dyspnoea, are much more frequent. Dysfunctional breathing is a significant cause of dyspnoea. Cognitive disorders and psychological symptoms are also very common, with anxiety, depression and post-traumatic stress symptoms being widely described. On the other hand, cardiac, endocrine, cutaneous, digestive or renal sequelae are rarer. The symptoms generally improve after several months, even if their prevalence at two years remains significant. Most of the symptoms are favored by the severity of the initial illness, and the psychic symptoms by the female sex. The pathophysiology of most symptoms is poorly understood. The influence of the treatments used in the acute phase is also important. Vaccination, on the other hand, seems to reduce their incidence. The sheer number of affected patients makes long-term COVID-19 syndrome a public health challenge.

Mutations in DNAH17, Encoding a Sperm-Specific Axonemal Outer Dynein Arm Heavy Chain, Cause Isolated Male Infertility Due to Asthenozoospermia.

Motile cilia and sperm flagella share an evolutionarily conserved axonemal structure. Their structural and/or functional defects are associated with primary ciliary dyskinesia (PCD), a genetic disease characterized by chronic respiratory-tract infections and in which most males are infertile due to asthenozoospermia. Among the well-characterized axonemal protein complexes, the outer dynein arms (ODAs), through ATPase activity of their heavy chains (HCs), play a major role for cilia and flagella beating. However, the contribution of the different HCs (γ-type: DNAH5 and DNAH8 and ß-type: DNAH9, DNAH11, and DNAH17) in ODAs from both organelles is unknown. By analyzing five male individuals who consulted for isolated infertility and displayed a loss of ODAs in their sperm cells but not in their respiratory cells, we identified bi-allelic mutations in DNAH17. The isolated infertility phenotype prompted us to compare the protein composition of ODAs in the sperm and ciliary axonemes from control individuals. We show that DNAH17 and DNAH8, but not DNAH5, DNAH9, or DNAH11, colocalize with α-tubulin along the sperm axoneme, whereas the reverse picture is observed in respiratory cilia, thus explaining the phenotype restricted to sperm cells. We also demonstrate the loss of function associated with DNAH17 mutations in two unrelated individuals by performing immunoblot and immunofluorescence analyses on sperm cells; these analyses indicated the absence of DNAH17 and DNAH8, whereas DNAH2 and DNALI, two inner dynein arm components, were present. Overall, this study demonstrates that mutations in DNAH17 are responsible for isolated male infertility and provides information regarding ODA composition in human spermatozoa.

Mutations in Outer Dynein Arm Heavy Chain DNAH9 Cause Motile Cilia Defects and Situs Inversus.

Motile cilia move body fluids and gametes and the beating of cilia lining the airway epithelial surfaces ensures that they are kept clear and protected from inhaled pathogens and consequent respiratory infections. Dynein motor proteins provide mechanical force for cilia beating. Dynein mutations are a common cause of primary ciliary dyskinesia (PCD), an inherited condition characterized by deficient mucociliary clearance and chronic respiratory disease coupled with laterality disturbances and subfertility. Using next-generation sequencing, we detected mutations in the ciliary outer dynein arm (ODA) heavy chain gene DNAH9 in individuals from PCD clinics with situs inversus and in one case male infertility. DNAH9 and its partner heavy chain DNAH5 localize to type 2 ODAs of the distal cilium and in DNAH9-mutated nasal respiratory epithelial cilia we found a loss of DNAH9/DNAH5-containing type 2 ODAs that was restricted to the distal cilia region. This confers a reduced beating frequency with a subtle beating pattern defect affecting the motility of the distal cilia portion. 3D electron tomography ultrastructural studies confirmed regional loss of ODAs from the distal cilium, manifesting as either loss of whole ODA or partial loss of ODA volume. Paramecium DNAH9 knockdown confirms an evolutionarily conserved function for DNAH9 in cilia motility and ODA stability. We find that DNAH9 is widely expressed in the airways, despite DNAH9 mutations appearing to confer symptoms restricted to the upper respiratory tract. In summary, DNAH9 mutations reduce cilia function but some respiratory mucociliary clearance potential may be retained, widening the PCD disease spectrum.

Topological data analysis reveals genotype-phenotype relationships in primary ciliary dyskinesia.

BACKGROUND: Primary ciliary dyskinesia (PCD) is a heterogeneous inherited disorder caused by mutations in approximately 50 cilia-related genes. PCD genotype-phenotype relationships have mostly arisen from small case series because existing statistical approaches to investigating relationships have been unsuitable for rare diseases. METHODS: We applied a topological data analysis (TDA) approach to investigate genotype-phenotype relationships in PCD. Data from separate training and validation cohorts included 396 genetically defined individuals carrying pathogenic variants in PCD genes. To develop the TDA models, 12 clinical and diagnostic variables were included. TDA-driven hypotheses were subsequently tested using traditional statistics. RESULTS: Disease severity at diagnosis, measured by forced expiratory volume in 1 s (FEV1) z-score, was significantly worse in individuals with CCDC39 mutations (compared to other gene mutations) and better in those with DNAH11 mutations; the latter also reported less neonatal respiratory distress. Patients without neonatal respiratory distress had better preserved FEV1 at diagnosis. Individuals with DNAH5 mutations were phenotypically diverse. Cilia ultrastructure and beat pattern defects correlated closely to specific causative gene groups, confirming these tests can be used to support a genetic diagnosis. CONCLUSIONS: This large scale, multi-national study presents PCD as a syndrome with overlapping symptoms and variations in phenotype according to genotype. TDA modelling confirmed genotype-phenotype relationships reported by smaller studies (e.g. FEV1 worse with CCDC39 mutation) and identified new relationships, including FEV1 preservation with DNAH11 mutations and diversity of severity with DNAH5 mutations.

Deep phenotyping, including quantitative ciliary beating parameters, and extensive genotyping in primary ciliary dyskinesia.

BACKGROUND: Primary ciliary dyskinesia (PCD) is a rare genetic disorder resulting in abnormal ciliary motility/structure, extremely heterogeneous at genetic and ultrastructural levels. We aimed, in light of extensive genotyping, to identify specific and quantitative ciliary beating anomalies, according to the ultrastructural phenotype. METHODS: We prospectively included 75 patients with PCD exhibiting the main five ultrastructural phenotypes (n=15/group), screened all corresponding PCD genes and measured quantitative beating parameters by high-speed video-microscopy (HSV). RESULTS: Sixty-eight (91%) patients carried biallelic mutations. Combined outer/inner dynein arms (ODA/IDA) defect induces total ciliary immotility, regardless of the gene involved. ODA defect induces a residual beating with dramatically low ciliary beat frequency (CBF) related to increased recovery stroke and pause durations, especially in case of DNAI1 mutations. IDA defect with microtubular disorganisation induces a low percentage of beating cilia with decreased beating angle and, in case of CCDC39 mutations, a relatively conserved mean CBF with a high maximal CBF. Central complex defect induces nearly normal beating parameters, regardless of the gene involved, and a gyrating motion in a minority of ciliated edges, especially in case of RSPH1 mutations. PCD with normal ultrastructure exhibits heterogeneous HSV values, but mostly an increased CBF with an extremely high maximal CBF. CONCLUSION: Quantitative HSV analysis in PCD objectives beating anomalies associated with specific ciliary ultrastructures and genotypes. It represents a promising approach to guide the molecular analyses towards the best candidate gene(s) to be analysed or to assess the pathogenicity of the numerous sequence variants identified by next-generation-sequencing.

Patient and otolaryngologist perceptions of telemedicine during COVID-19 pandemic.

BACKGROUND: The rapid spread of the coronavirus disease 2019 and the implementation of quarantine in many European countries led to a swift change in health care delivery. Telemedicine was implemented in many otolaryngological departments to ensure the continuous care. The purpose of this study is to report our experience about telemedicine in 86 patients consulting virtually in our departments. METHODS: A total of 86 patients benefited from telemedicine consultation from April to Mai May 2020. Patients and physicians were invited to fulfill a satisfaction survey over the 3 days after the consultation. RESULTS: Patients consulted in the following fields: laryngology, voice and swallowing (N=15; 17.4%), head and neck or plastic surgery (N=34; 39.5%), rhinology (N=31; 36.1%) and otology (N=6; 7.0%). Practitioners estimated that the clinical examination would not have changed the consultation issue in 73.2% of cases. The realization of delayed clinical examination was rapidly necessary in 9.3% of cases and useless in 33.7% of cases. Five percent of patients estimated that the consultation did not bring reliable conclusion. Although the majority of patient (87.7%) would recommend telemedicine consultation to friend/family in the context of pandemic, only 44.6% would accept to replace office- consultation by telemedicine consultation outside the pandemic. CONCLUSION: Telemedicine appears to be an interesting alternative approach in situation of pandemic and lock-down. Because the patient motivation to further participate to telemedicine appears to be conditioned by the context, efforts are still required to understand the patient perception, satisfaction and fears in view of future implementation outside pandemic.

Homozygous missense mutation L673P in adenylate kinase 7 (AK7) leads to primary male infertility and multiple morphological anomalies of the flagella but not to primary ciliary dyskinesia.

Motile cilia and sperm flagella share an extremely conserved microtubule-based cytoskeleton, called the axoneme, which sustains beating and motility of both organelles. Ultra-structural and/or functional defects of this axoneme are well-known to cause primary ciliary dyskinesia (PCD), a disorder characterized by recurrent respiratory tract infections, chronic otitis media, situs inversus, male infertility and in most severe cases, hydrocephalus. Only recently, mutations in genes encoding axonemal proteins with preferential expression in the testis were identified in isolated male infertility; in those cases, individuals displayed severe asthenozoospermia due to Multiple Morphological Abnormalities of the sperm Flagella (MMAF) but not PCD features. In this study, we performed genetic investigation of two siblings presenting MMAF without any respiratory PCD features, and we report the identification of the c.2018T > G (p.Leu673Pro) transversion in AK7, encoding an adenylate kinase, expressed in ciliated tissues and testis. By performing transcript and protein analyses of biological samples from individual carrying the transversion, we demonstrate that this mutation leads to the loss of AK7 protein in sperm cells but not in respiratory ciliated cells, although both cell types carry the mutated transcript and no tissue-specific isoforms were detected. This work therefore, supports the notion that proteins shared by both cilia and sperm flagella may have specific properties and/or function in each organelle, in line with the differences in their mode of assembly and organization. Overall, this work identifies a novel genetic cause of asthenozoospermia due to MMAF and suggests that in humans, more deleterious mutations of AK7 might induce PCD.

Pathogenesis of chronic rhinosinusitis with nasal polyps: role of IL-6 in airway epithelial cell dysfunction.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by an alteration in airway epithelial cell functions including barrier function, wound repair mechanisms, mucociliary clearance. The mechanisms leading to epithelial cell dysfunction in nasal polyps (NPs) remain poorly understood. Our hypothesis was that among the inflammatory cytokines involved in NPs, IL-6 could alter epithelial repair mechanisms and mucociliary clearance. The aim of this study was to evaluate the in vitro effects of IL-6 on epithelial repair mechanisms in a wound repair model and on ciliary beating in primary cultures of Human Nasal Epithelial Cells (HNEC). METHODS: Primary cultures of HNEC taken from 38 patients during surgical procedures for CRSwNP were used in an in vitro model of wound healing. Effects of increasing concentrations of IL-6 (1 ng/mL, 10 ng/mL, and 100 ng/mL) and other ILs (IL-5, IL-9, IL-10) on wound closure kinetics were compared to cultures without IL-modulation. After wound closure, the differentiation process was characterized under basal conditions and after IL supplementation using cytokeratin-14, MUC5AC, and ßIV tubulin as immunomarkers of basal, mucus, and ciliated cells, respectively. The ciliated edges of primary cultures were analyzed on IL-6 modulation by digital high-speed video-microscopy to measure: ciliary beating frequency (CBF), ciliary length, relative ciliary density, metachronal wavelength and the ciliary beating efficiency index. RESULTS: Our results showed that: (i) IL-6 accelerated airway wound repair in vitro, with a dose-response effect whereas no effect was observed after other ILs-stimulation. After 24 h, 79% of wounded wells with IL6-100 were fully repaired, vs 46% in the IL6-10 group, 28% in the IL6-1 group and 15% in the control group; (ii) specific migration analyses of closed wound at late repair stage (Day 12) showed IL-6 had the highest migration compared with other ILs (iii) The study of the IL-6 effect on ciliary function showed that CBF and metachronal wave increased but without significant modifications of ciliary density, length of cilia and efficiency index. CONCLUSION: The up-regulated epithelial cell proliferation observed in polyps could be induced by IL-6 in the case of prior epithelial damage. IL-6 could be a major cytokine in NP physiopathology.

Mutations in DNAJB13, Encoding an HSP40 Family Member, Cause Primary Ciliary Dyskinesia and Male Infertility.

Primary ciliary dyskinesia (PCD) is an autosomal-recessive disease due to functional or ultra-structural defects of motile cilia. Affected individuals display recurrent respiratory-tract infections; most males are infertile as a result of sperm flagellar dysfunction. The great majority of the PCD-associated genes identified so far encode either components of dynein arms (DAs), which are multiprotein-ATPase complexes essential for ciliary motility, or proteins involved in DA assembly. To identify the molecular basis of a PCD phenotype characterized by central complex (CC) defects but normal DA structure, a phenotype found in ∼15% of cases, we performed whole-exome sequencing in a male individual with PCD and unexplained CC defects. This analysis, combined with whole-genome SNP genotyping, identified a homozygous mutation in DNAJB13 (c.833T>G), a gene encoding a HSP40 co-chaperone whose ortholog in the flagellated alga Chlamydomonas localizes to the radial spokes. In vitro studies showed that this missense substitution (p.Met278Arg), which involves a highly conserved residue of several HSP40 family members, leads to protein instability and triggers proteasomal degradation, a result confirmed by the absence of endogenous DNAJB13 in cilia and sperm from this individual. Subsequent DNAJB13 analyses identified another homozygous mutation in a second family; the study of DNAJB13 transcripts obtained from airway cells showed that this mutation (c.68+1G>C) results in a splicing defect consistent with a loss-of-function mutation. Overall, this study, which establishes mutations in DNAJB13 as a cause of PCD, unveils the key role played by DNAJB13 in the proper formation and function of ciliary and flagellar axonemes in humans.

Nasal response to stress test in healthy subjects: an experimental pilot study.

PURPOSE: Stress has been suspected to play a role in rhinitis. The role of stress on nasal patency has been not yet elucidated. The aim was to evaluate the potential effects of stress on nasal patency in healthy subjects. METHODS: We conducted a prospective pilot study including 12 healthy subjects. Experimental protocol was divided in three periods (pre-task, task and recovery). In the task period, subjects were exposed to the "Trier Social Stress Test" (TSST), a standardized laboratory stressor. Different parameters including Spielberger State Anxiety Inventory (SSAI) score, visual analogic scale (VAS) of nasal patency feeling, heart rate, acoustic rhinometry measurements have been compared between the three different periods. The study population was divided into two groups according to the Spielberger Trait Anxiety Inventory (STAI) score: A "non anxious" group and a "weakly anxious" group. RESULTS: Seven subjects were in the "non anxious" group and five in the "weakly anxious" group. TSST significantly increased heart rate in all volunteers. SSAI score was significantly increased (p = 0.04) after the task period (36.6 ± 11.3) when compared to the SSAI score in pre-task period (31.9 ± 12.6). VAS score of nasal patency feeling significantly decreased from pre-task to task and recovery periods. Mean minimal cross-sectional areas and mean volumes of the nasal cavities were not significantly different between the three periods, except in "weakly anxious" group, but the small number of subjects does not allow to draw a definite conclusion. CONCLUSION: We observed that stress influenced the feeling of nasal patency in healthy subjects. However, the objective effects of stress on nasal geometry were globally non-significant except in "weakly anxious" group. This latter result of our pilot study needs to be confirmed in a larger cohort.

FcRn-Dependent Transcytosis of Monoclonal Antibody in Human Nasal Epithelial Cells In Vitro: A Prerequisite for a New Delivery Route for Therapy?

Monoclonal antibodies (mAbs) are promising therapies to treat airway chronic inflammatory disease (asthma or nasal polyps). To date, no study has specifically assessed, in vitro, the potential function of neonatal Fc receptor (FcRn) in IgG transcytosis through the human nasal airway epithelium. The objective of this study was to report the in vitro expression and function of FcRn in nasal human epithelium. FcRn expression was studied in an air⁻liquid interface (ALI) primary culture model of human nasal epithelial cells (HNEC) from polyps. FcRn expression was characterized by quantitative RT-PCR, western blot, and immunolabeling. The ability of HNECs to support mAb transcytosis via FcRn was assessed by transcytosis assay. This study demonstrates the expression of FcRn mRNA and protein in HNEC. We report a high expression of FcRn in the cytosol of ciliated, mucus, and basal cells by immunohistochemistry with a higher level of FcRn proteins in differentiated HNEC. We also proved in vitro transepithelial delivery of an IgG1 therapeutic mAb with a dose⁻response curve. This is the first time that FcRn expression and mAb transcytosis has been shown in a model of human nasal respiratory epithelium in vitro. This study is a prerequisite for FcRn-dependent nasal administration of mAbs.

RSPH3 Mutations Cause Primary Ciliary Dyskinesia with Central-Complex Defects and a Near Absence of Radial Spokes.

Primary ciliary dyskinesia (PCD) is a rare autosomal-recessive condition resulting from structural and/or functional defects of the axoneme in motile cilia and sperm flagella. The great majority of mutations identified so far involve genes whose defects result in dynein-arm anomalies. By contrast, PCD due to CC/RS defects (those in the central complex [CC] and radial spokes [RSs]), which might be difficult to diagnose, remains mostly unexplained. We identified non-ambiguous RSPH3 mutations in 5 of 48 independent families affected by CC/RS defects. RSPH3, whose ortholog in the flagellated alga Chlamydomonas reinhardtii encodes a RS-stalk protein, is mainly expressed in respiratory and testicular cells. Its protein product, which localizes within the cilia of respiratory epithelial cells, was undetectable in airway cells from an individual with RSPH3 mutations and in whom RSPH23 (a RS-neck protein) and RSPH1 and RSPH4A (RS-head proteins) were found to be still present within cilia. In the case of RSPH3 mutations, high-speed-videomicroscopy analyses revealed the coexistence of immotile cilia and motile cilia with movements of reduced amplitude. A striking feature of the ultrastructural phenotype associated with RSPH3 mutations is the near absence of detectable RSs in all cilia in combination with a variable proportion of cilia with CC defects. Overall, this study shows that RSPH3 mutations contribute to disease in more than 10% of PCD-affected individuals with CC/RS defects, thereby allowing an accurate diagnosis to be made in such cases. It also unveils the key role of RSPH3 in the proper building of RSs and the CC in humans.

A new index for characterizing micro-bead motion in a flow induced by ciliary beating: Part I, experimental analysis.

Mucociliary clearance is one of the major lines of defense of the respiratory system. The mucus layer coating the pulmonary airways is moved along and out of the lung by the activity of motile cilia, thus expelling the particles trapped in it. Here we compare ex vivo measurements of a Newtonian flow induced by cilia beating (using micro-beads as tracers) and a mathematical model of this fluid flow, presented in greater detail in a second companion article. Samples of nasal epithelial cells placed in water are recorded by high-speed video-microscopy and ciliary beat pattern is inferred. Automatic tracking of micro-beads, used as markers of the flow generated by cilia motion, enables us also to assess the velocity profile as a function of the distance above the cilia. This profile is shown to be essentially parabolic. The obtained experimental data are used to feed a 2D mathematical and numerical model of the coupling between cilia, fluid, and micro-bead motion. From the model and the experimental measurements, the shear stress exerted by the cilia is deduced. Finally, this shear stress, which can easily be measured in the clinical setting, is proposed as a new index for characterizing the efficiency of ciliary beating.

Transcutaneous Baha Attract system: Long-term outcomes of the French multicenter study.

BACKGROUND: Bone conduction implants based on abutment-driven acoustic transmission result in good hearing outcomes; however, skin complications impact the quality of life (QOL) and possibly the viability of the device for many patients. The transcutaneous magnetic Baha® Attract technology was developed with the goal of minimising skin complications. OBJECTIVES: To analyse surgical, auditory and QOL outcomes for patients implanted with the Baha® Attract. DESIGN: Prospective multicentre cohort study. SETTING: Four French tertiary referral centres. PARTICIPANTS: Thirty-two patients implanted with the Baha® Attract, including 25 with conductive and mixed hearing loss and 7 with single-sided deafness. MAIN OUTCOME MEASURES: Postoperative follow-up involved the visual analysis of soft tissue adaptation and sound processor magnet strength measurement. The audiometric outcomes were evaluated in quiet and noise, and the QOL was assessed using three different questionnaires. RESULTS: After 12 months of use, soft tissue was thinner, and mean magnet strength was significantly decreased (3.7-3.1, P < 0.05) relative to measures during surgery. The speech recognition threshold in quiet significantly improved compared to unaided situation (73-44 dB HL respectively, P < 0.001) as did functional gain in noise (+2.8). All QOL scores improved, and the APHAB questionnaire score correlated with the audiometric outcomes. CONCLUSIONS: The Baha® Attract technology results in significant hearing gain and improves QOL. Skin complications were not observed, although surgeons, audiologists and patients should be aware of soft tissue evolution during the first postoperative year. The reversibility of this implant is a major advantage that allows switching to another system if hearing degrades.

Clinical characteristics, functional respiratory decline and follow-up in adult patients with primary ciliary dyskinesia.

INTRODUCTION: Primary ciliary dyskinesia (PCD) is a genetic disease characterised by abnormalities in ciliary function, responsible for chronic pulmonary and sinonasal diseases. Adult clinical features and outcome are poorly described. OBJECTIVES: To assess the clinical characteristics and disease progression in adults with PCD. METHODS: Bicentric retrospective study, focusing on adults (≥18 years) with an asserted diagnosis of PCD based on the presence of bronchiectasis with typical ultrastructural defect of cilia and/or situs inversus (SI). Clinical symptoms, respiratory function, extent of bronchiectasis, microbiology and molecular analysis were assessed. Results are expressed as median (25th; 75th centile). RESULTS: 78 patients were included with a median follow-up of 8.1 years. 91% of patients had respiratory symptoms and 95% had chronic rhinosinusitis. Half of ultrastructural defects concerned dynein arms. Respiratory function was significantly lower in women (FEV1=60% predicted (50; 76), vs 77% (62; 95), p=0.009) and in patients with chronic airway Pseudomonas aeruginosa (PA, n=21) infection (FEV1=60% (48; 71) vs 75% (55; 89), p=0.04). FEV1 was associated with gender (regression coefficient for men =13.8, p=0.009), chest CT score (r=-0.42, p<0.001) but not with age at diagnosis, SI or body mass index. FEV1 decline was -13.4 mL/year (-42.8; +11.9) and was greater in women (-29.3 mL/year, (-59.7; -11.9), vs -2.0 mL/year (-26.9; +25.4), p=0.002). Three patients had severe respiratory failure. CONCLUSIONS: Alteration of respiratory function in adults with PCD is heterogeneous and usually moderate but appears more severe in women and in patients with chronic PA infection. Only 4% of patients develop chronic respiratory failure.

European Respiratory Society guidelines for the diagnosis of primary ciliary dyskinesia.

The diagnosis of primary ciliary dyskinesia is often confirmed with standard, albeit complex and expensive, tests. In many cases, however, the diagnosis remains difficult despite the array of sophisticated diagnostic tests. There is no "gold standard" reference test. Hence, a Task Force supported by the European Respiratory Society has developed this guideline to provide evidence-based recommendations on diagnostic testing, especially in light of new developments in such tests, and the need for robust diagnoses of patients who might enter randomised controlled trials of treatments. The guideline is based on pre-defined questions relevant for clinical care, a systematic review of the literature, and assessment of the evidence using the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach. It focuses on clinical presentation, nasal nitric oxide, analysis of ciliary beat frequency and pattern by high-speed video-microscopy analysis, transmission electron microscopy, genotyping and immunofluorescence. It then used a modified Delphi survey to develop an algorithm for the use of diagnostic tests to definitively confirm and exclude the diagnosis of primary ciliary dyskinesia; and to provide advice when the diagnosis was not conclusive. Finally, this guideline proposes a set of quality criteria for future research on the validity of diagnostic methods for primary ciliary dyskinesia.