Histologic characterization of primary ciliary dyskinesia chronic rhinosinusitis

KEY POINTS

We present the largest cohort of structured histopathology reports on primary ciliary dyskinesia-related chronic rhinosinusitis (PCD-CRS). Despite endoscopic differences, PCD-CRS and cystic fibrosis-related chronic rhinosinusitis (CF-CRS) had similar structured histopathology reports. Compared to healthy patients and those with idiopathic chronic rhinosinusitis without nasal polyps, patients with PCD-CRS had an increased neutrophil count.

Pathogenic variants in CLXN encoding the outer dynein arm docking-associated calcium-binding protein calaxin cause primary ciliary dyskinesia

PURPOSE

Primary ciliary dyskinesia (PCD) is a heterogeneous disorder that includes respiratory symptoms, laterality defects, and infertility caused by dysfunction of motile cilia. Most PCD-causing variants result in abnormal outer dynein arms (ODAs), which provide the generative force for respiratory ciliary beating and proper mucociliary clearance.

METHODS

In addition to studies in mouse and planaria, clinical exome sequencing and functional analyses in human were performed.

RESULTS

In this study, we identified homozygous pathogenic variants in CLXN (EFCAB1/ODAD5) in 3 individuals with laterality defects and respiratory symptoms. Consistently, we found that Clxn is expressed in mice left-right organizer. Transmission electron microscopy depicted ODA defects in distal ciliary axonemes. Immunofluorescence microscopy revealed absence of CLXN from the ciliary axonemes, absence of the ODA components DNAH5, DNAI1, and DNAI2 from the distal axonemes, and mislocalization or absence of DNAH9. In addition, CLXN was undetectable in ciliary axonemes of individuals with defects in the ODA-docking machinery: ODAD1, ODAD2, ODAD3, and ODAD4. Furthermore, SMED-EFCAB1-deficient planaria displayed ciliary dysmotility.

CONCLUSION

Our results revealed that pathogenic variants in CLXN cause PCD with defects in the assembly of distal ODAs in the respiratory cilia. CLXN should be referred to as ODA-docking complex-associated protein ODAD5.

Ciliary Dyneins and Dynein Related Ciliopathies

Although ubiquitously present, the relevance of cilia for vertebrate development and health has long been underrated. However, the aberration or dysfunction of ciliary structures or components results in a large heterogeneous group of disorders in mammals, termed ciliopathies. The majority of human ciliopathy cases are caused by malfunction of the ciliary dynein motor activity, powering retrograde intraflagellar transport (enabled by the cytoplasmic dynein-2 complex) or axonemal movement (axonemal dynein complexes). Despite a partially shared evolutionary developmental path and shared ciliary localization, the cytoplasmic dynein-2 and axonemal dynein functions are markedly different: while cytoplasmic dynein-2 complex dysfunction results in an ultra-rare syndromal skeleto-renal phenotype with a high lethality, axonemal dynein dysfunction is associated with a motile cilia dysfunction disorder, primary ciliary dyskinesia (PCD) or Kartagener syndrome, causing recurrent airway infection, degenerative lung disease, laterality defects, and infertility. In this review, we provide an overview of ciliary dynein complex compositions, their functions, clinical disease hallmarks of ciliary dynein disorders, presumed underlying pathomechanisms, and novel developments in the field.

Characterization of CCDC103 expression profiles: further insights in primary ciliary dyskinesia and in human reproduction

PROPOSE

To study CCDC103 expression profiles and understand how pathogenic variants in CCDC103 affect its expression profile at mRNA and protein level.

METHODS

To increase the knowledge about the CCDC103, we attempted genotype-phenotype correlations in two patients carrying novel homozygous (missense and frameshift) CCDC103 variants. Whole-exome sequencing, quantitative PCR, Western blot, electron microscopy, immunohistochemistry, immunocytochemistry, and immunogold labelling were performed to characterize CCDC103 expression profiles in reproductive and somatic cells.

RESULTS

Our data demonstrate that pathogenic variants in CCDC103 gene negatively affect gene and protein expression in both patients who presented absence of DA on their axonemes. Further, we firstly report that CCDC103 is expressed at different levels in reproductive tissues and somatic cells and described that CCDC103 protein forms oligomers with tissue-specific sizes, which suggests that CCDC103 possibly undergoes post-translational modifications. Moreover, we reported that CCDC103 was restricted to the midpiece of sperm and is present at the cytoplasm of the other cells.

CONCLUSIONS

Overall, our data support the CCDC103 involvement in PCD and suggest that CCDC103 may have different assemblies and roles in cilia and sperm flagella biology that are still unexplored.

A comparative study between adenoids and nasal mucosa for ciliated epithelium in children with recurrent or chronic rhinosinusitis

OBJECTIVE

To determine whether adenoid epithelium is superior to nasal mucosa for biopsy of ciliated epithelium for electron microscopy (EM) to evaluate pediatric patients with rhinosinusitis for primary ciliary dyskinesia (PCD).

METHODS

A retrospective review compared electron microscopic results in children with chronic or recurrent rhinosinusitis who underwent both adenoidectomy or nasopharyngeal biopsy and nasal mucosa biopsy in the course of evaluation for PCD at a tertiary care institution.

RESULTS

Forty pediatric patients met inclusion criteria for this study. Nine of these patients had a prior adenoidectomy and therefore underwent nasopharyngeal biopsy for collection of adenoid tissue. All nine of the nasopharyngeal biopsies and 25 of the 31 (80.6%) adenoid biopsies had sufficient cilia for EM evaluation of the ultrastructure. Of the 40 patients who also had a nasal biopsy, only 12 (30.0%) had sufficient cilia for EM analysis. The distribution of sufficient versus insufficient cilia for analysis between adenoid and nasal mucosa was statistically significant (P < 0.05). Abnormal cilia were found in only 2.5% of our patients.

CONCLUSIONS

In current practice, the nasal cavity is a common location for obtaining ciliated epithelium for EM analysis, as it is easily accessible for biopsy and the procedure itself causes relatively low patient morbidity. Chronic rhinosinusitis, however, has been associated with decreased cilia density on nasal respiratory epithelium. Given that adenoidectomies are often performed in children with chronic rhinosinusitis, our data suggest that adenoid tissue is a better source of ciliated tissue for analysis compared to turbinate epithelium.

Ciliated conical epithelial cell protrusions point towards a diagnosis of primary ciliary dyskinesia

BACKGROUND

Primary ciliary dyskinesia can result from a number of different ciliary defects that adversely affect ciliary function resulting markedly reduced or absent mucociliary clearance. Improvement in diagnostic testing is an area of current research. During diagnostic evaluation of PCD we observed ciliated conical protrusions from part of the apical surface of ciliated cells in those diagnosed with PCD. The aim of this study was to investigate if this abnormality was specific to PCD.

METHODS

Epithelial edges from 67 consecutively diagnosed PCD patients, 67 patients consecutively referred for PCD diagnostic testing in whom PCD was excluded, 22 with asthma and 18 with Cystic Fibrosis (CF) were studied retrospectively in a blinded manner using light microscopy.

RESULTS

Forty six out of 67 patients with PCD had ciliated conical epithelial protrusions, whereas none were seen in patients where PCD was excluded, or in patients with asthma or CF. The sensitivity, specificity, positive predictive value and negative predictive value for the presence of the ciliated conical protrusions to predict a diagnosis of PCD were 76.5, 100, 100 and 77% respectively.

CONCLUSIONS

Characteristic ciliated conical protrusions from ciliated epithelial cells maybe a useful pointer to the diagnosis of PCD. However, their absence does not exclude the diagnosis of PCD.

Live birth after Laser Assisted Viability Assessment (LAVA) to detect pentoxifylline resistant ejaculated immotile spermatozoa during ICSI in a couple with male Kartagener's syndrome

Primary ciliary dyskinesia (PCD) is a rare, autosomal recessive disease with abnormalities in the structure of cilia, causing impairment of muco-ciliary clearance with respiratory tract infections, heterotaxia and abnormal sperm motility with male infertility. Here, with a comprehensive literature review, we report a couple with an infertility history of 9 years and three unsuccessful IVF treatments, where male partner has Kartagener's Syndrome, a subtype of PCD, displaying recurrent respiratory infections, dextrocardia and total asthenozoospermia. His diagnosis was verified with transmission electron microscopy and genetic mutation screening, revealing total absence of dynein arms in sperm tails and homozygous mutation in the ZMYND10, heterozygous mutations in the ARMC4 and DNAH5 genes. Laser assisted viability assay (LAVA) was performed by shooting the sperm tails during sperm retrieval for microinjection, following detection of pentoxifylline resistant immotile sperm. Live births of healthy triplets, one boy and two monozygotic girls, was achieved after double blastocyst transfer.

Clinical and genetic analysis of a family with Kartagener syndrome caused by novel DNAH5 mutations

PURPOSE

Kartagener syndrome (KS), also known as visceral inversion-nasosinusitis-bronchiectasis syndrome, or familial bronchiectasis, is an autosomal recessive inherited disease. In this study, through two cases of KS, we aimed to assess the clinical and genetic characteristics of KS caused by DNAH5 mutations.

METHODS

The two cases of KS from the same family underwent extensive clinical assessments, with next-generation DNA sequencing and bioinformatics analysis to identify pathogenic genes. In addition, Sanger sequencing was used to verify the pedigrees.

RESULTS

The present study employed a directional capture strategy for hereditary disease screening, which correctly identified the virulence sites in the pedigree, and facilitated the differential diagnosis among multiple genes. Two novel mutations were detected in DNAH5: c.7778C>T (missense mutation) and c.13729G>A (nonsense mutation). They were not found in dbSNP, 1000 Genomes, and ExAC.

CONCLUSIONS

These findings demonstrated that new DNAH5 mutations could be used for molecular diagnosis of KS, providing families with genetic counseling and prenatal diagnosis.

ZMYND10--Mutation Analysis in Slavic Patients with Primary Ciliary Dyskinesia

Primary ciliary dyskinesia (PCD) is a rare recessive disease with a prevalence of 1/10,000; its symptoms are caused by a kinetic dysfunction of motile cilia in the respiratory epithelium, flagella in spermatozoids, and primary cilia in the embryonic node. PCD is genetically heterogeneous: genotyping the already known PCD-related genes explains the genetic basis in 60-65% of the cases, depending on the population. While identification of new genes involved in PCD pathogenesis remains crucial, the search for new, population-specific mutations causative for PCD is equally important. The Slavs remain far less characterized in this respect compared to West European populations, which significantly limits diagnostic capability. The main goal of this study was to characterize the profile of causative genetic defects in one of the PCD-causing genes, ZMYND10, in the cohort of PCD patients of Slavic origin. The study was carried out using biological material from 172 unrelated PCD individuals of Polish origin, with no causative mutation found in nine major PCD genes. While none of the previously described mutations was found using the HRM-based screening, a novel frameshift mutation (c.367delC) in ZMYND10, unique for Slavic PCD population, was found in homozygous state in two unrelated PCD patients. Immunofluorescence analysis confirmed the absence of outer and inner dynein arms from the ciliary axoneme, consistent with the already published ZMYND10-mutated phenotype; cDNA analysis revealed the lack of ZMYND10 mRNA, indicating nonsense-mediated decay of the truncated transcript.

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.

Clinical features of primary ciliary dyskinesia in Cyprus with emphasis on lobectomized patients

BACKGROUND

Despite the manifestations of primary ciliary dyskinesia (PCD) in early life, the diagnosis is often much delayed. Since 1998 in Cyprus, we have established the only national diagnostic and clinical referral center for PCD.

OBJECTIVE

To review the phenotypic features at presentation of PCD patients in Cyprus in relation to age at diagnosis, with emphasis on previously lobectomised patients.

METHODS

The medical records of the diagnosed PCD patients were retrospectively reviewed to obtain clinical data on presentation.

RESULTS

Thirty patients, aged 13.9 years (range 0.1, 58.4 years), were diagnosed with PCD. Twelve of them presented after the age of 18. The most common manifestations were chronic cough (100%), chronic rhinorrhea (96.7%), sputum production (92.9%), laterality defects (63.3%), a history of pneumonia (53.3%) and neonatal respiratory distress (50%). A history of lobectomy in the past was recorded in 16.7% (5 patients). Patients who presented in adulthood had significantly higher frequency of lobectomy (41.7% vs 0%, p-value = 0.006) and had more frequently low FEV1 (58.3% vs 0%, p-value = 0.015) than those who presented before. Serial measurements of FEV1 and FVC indicated significantly lower intercepts in lobectomised compared to the adult non-lobectomised patients both in terms of FEV1 (-4.90 vs -1.80, p-value = 0.022) and FVC (-5.43 vs -1.91, p-value = 0.029) z-score levels. Change in FEV1 and FVC across time was not statistically significant in either group.

CONCLUSIONS

PCD often remains undiagnosed up to adulthood accompanied by appearance of advanced lung disease. Performance of lobectomies seems to be a poor prognostic factor for PCD in adulthood.

[Clinical characteristics of primary ciliary dyskinesia]

OBJECTIVE

To analyze the clinical characteristics of primary ciliary dyskinesia(PCD) so as to improve the diagnostic level of this rarely seen disease.

METHODS

Ten patients with PCD were retrospectively reviewed, the medical history, symptoms, signs, lung CT or chest X-ray, rhino-sinus CT scan, nasal nitric oxide (NO) levels, nasal ciliary ultrastructure, DNAH5 and DNAH11 genetic mutation, as well as treatment outcome were analyzed.

RESULTS

All 10 patients had recurrent chronic sinusitis, otitis media, bronchitis/bronchiectasis since childhood. Nine cases with translocation of heart and big vessels were diagnosed as Kartagener syndrome. One woman was suffering from barrenness and one man sterility after marriage for long time without birth control. Nasal NO levels were significantly lower in 2 patients with PCD but it was almost normal in one patient. Ciliary ultrastructure investigated by transmission electron microscope were almost normal in 4 cases without missing of inner or outer dynein arms. Two cases taking exome capture sequencing showed that mutations happened in DNAH5 and DNAH11. Five subjects underwenting sanger sequencing on 6 common exon fragments of DNAH5 and DNAH11 did not show any abnormality. Ten cases took medication therapy, while 5 patients once underwent functional endoscope sinus surgery. All of the 10 patients had improvement of their symptoms and signs after treatment.

CONCLUSIONS

The PCD is so rare in clinic that it is easily misdiagnosed. Clinical characteristics, nasal NO levels, ciliary ultrastructure and genetic testing are significant for clinical diagnosis.

Primary ciliary dyskinesia. Recent advances in diagnostics, genetics, and characterization of clinical disease

Primary ciliary dyskinesia (PCD) is a genetically heterogeneous recessive disorder of motile cilia that leads to oto-sino-pulmonary diseases and organ laterality defects in approximately 50% of cases. The estimated incidence of PCD is approximately 1 per 15,000 births, but the prevalence of PCD is difficult to determine, primarily because of limitations in diagnostic methods that focus on testing ciliary ultrastructure and function. Diagnostic capabilities have recently benefitted from (1) documentation of low nasal nitric oxide production in PCD and (2) discovery of biallelic mutations in multiple PCD-causing genes. The use of these complementary diagnostic approaches shows that at least 30% of patients with PCD have normal ciliary ultrastructure. More accurate identification of patients with PCD has also allowed definition of a strong clinical phenotype, which includes neonatal respiratory distress in >80% of cases, daily nasal congestion and wet cough starting soon after birth, and early development of recurrent/chronic middle-ear and sinus disease. Recent studies, using advanced imaging and pulmonary physiologic assessments, clearly demonstrate early onset of lung disease in PCD, with abnormal air flow mechanics by age 6-8 years that is similar to cystic fibrosis, and age-dependent onset of bronchiectasis. The treatment of PCD is not standardized, and there are no validated PCD-specific therapies. Most patients with PCD receive suboptimal management, which should include airway clearance, regular surveillance of pulmonary function and respiratory microbiology, and use of antibiotics targeted to pathogens. The PCD Foundation is developing a network of clinical centers, which should improve diagnosis and management of PCD.

Loss-of-function mutations in RSPH1 cause primary ciliary dyskinesia with central-complex and radial-spoke defects

Primary ciliary dyskinesia (PCD) is a rare autosomal-recessive respiratory disorder resulting from defects of motile cilia. Various axonemal ultrastructural phenotypes have been observed, including one with so-called central-complex (CC) defects, whose molecular basis remains unexplained in most cases. To identify genes involved in this phenotype, whose diagnosis can be particularly difficult to establish, we combined homozygosity mapping and whole-exome sequencing in a consanguineous individual with CC defects. This identified a nonsense mutation in RSPH1, a gene whose ortholog in Chlamydomonas reinhardtii encodes a radial-spoke (RS)-head protein and is mainly expressed in respiratory and testis cells. Subsequent analyses of RSPH1 identified biallelic mutations in 10 of 48 independent families affected by CC defects. These mutations include splicing defects, as demonstrated by the study of RSPH1 transcripts obtained from airway cells of affected individuals. Wild-type RSPH1 localizes within cilia of airway cells, but we were unable to detect it in an individual with RSPH1 loss-of-function mutations. High-speed-videomicroscopy analyses revealed the coexistence of different ciliary beating patterns-cilia with a normal beat frequency but abnormal motion alongside immotile cilia or cilia with a slowed beat frequency-in each individual. This study shows that this gene is mutated in 20.8% of individuals with CC defects, whose diagnosis could now be improved by molecular screening. RSPH1 mutations thus appear as a major etiology for this PCD phenotype, which in fact includes RS defects, thereby unveiling the importance of RSPH1 in the proper building of CCs and RSs in humans.

Primary ciliary dyskinesia presentation in 60 children according to ciliary ultrastructure

Primary ciliary dyskinesia (PCD) is an inherited disease related to ciliary dysfunction, with heterogeneity in clinical presentation and in ciliary ultrastructural defect. Our study intended to determine if there are phenotypic differences in patients with PCD based on ciliary ultrastructural abnormality. In this retrospective study carried out among 60 children with a definitive diagnosis of PCD, we analyzed clinical, radiological, and functional features at diagnosis and at last recorded visit, according to cilia defect (absence of dynein arms: DAD group, n = 36; abnormalities of the central complex: CCA group, n = 24). Onset of respiratory symptoms occurred later in the CCA than in the DAD group (9.5 versus 0.5 months, p = 0.03). Situs inversus was only observed in the DAD group, while respiratory disease in siblings were more frequent in the CCA group (p = 0.003). At diagnosis, clinical presentation was more severe in the CCA group: frequency of respiratory tract infections (p = 0.008), rhinosinusitis (p = 0.02), otitis complications (p = 0.0001), bilateral bronchiectasis (p = 0.04), and number of hypoxemic patients (p = 0.03). Pulmonary function remained stable in both groups, but outcome was better in the CCA than in the DAD group: less antibiotic therapy and hypoxemic patients (p = 0.004). In conclusion, our results underlined the relationship between the severity of clinical presentation and the ultrastructural ciliary defect.

Sperm-associated antigen-17 gene is essential for motile cilia function and neonatal survival

Primary ciliary dyskinesia (PCD), resulting from defects in cilia assembly or motility, is caused by mutations in a number of genes encoding axonemal proteins. PCD phenotypes are variable, and include recurrent respiratory tract infections, bronchiectasis, hydrocephaly, situs inversus, and male infertility. We generated knockout mice for the sperm-associated antigen-17 (Spag17) gene, which encodes a central pair (CP) protein present in the axonemes of cells with "9 + 2" motile cilia or flagella. The targeting of Spag17 resulted in a severe phenotype characterized by immotile nasal and tracheal cilia, reduced clearance of nasal mucus, profound respiratory distress associated with lung fluid accumulation and disruption of the alveolar epithelium, cerebral ventricular expansion consistent with emerging hydrocephalus, failure to suckle, and neonatal demise within 12 hours of birth. Ultrastructural analysis revealed the loss of one CP microtubule in approximately one quarter of tracheal cilia axonemes, an absence of a C1 microtubule projection, and other less frequent CP structural abnormalities. SPAG6 and SPAG16 (CP proteins that interact with SPAG17) were increased in tracheal tissue from SPAG17-deficient mice. We conclude that Spag17 plays a critical role in the function and structure of motile cilia, and that neonatal lethality is likely explained by impaired airway mucociliary clearance.

[Clinical analysis of four cases of primary ciliary dyskinesia and literature review]

OBJECTIVE

To study the clinical characteristics and diagnosis of primary ciliary dyskinesia (PCD).

METHODS

Four cases diagnosed as PCD by cilia electron microscopy examination from Jan. 2007 to Aug. 2009 in this hospital were retrospectively analyzed, and the related literature was reviewed.

RESULTS

In the 4 patients, there were 1 male and 3 females. The age at disease onset was 0 - 10 years, and the age at diagnosis was 15 - 53 years. The most common symptoms were productive cough (4/4), sinusitis (3/4), and shortness of breath (3/4). Other manifestations included situs inversus (2/4), infertility (1/4), and tympanitis (1/4). Hypoxemia was found in 3 cases. Obstructive ventilatory impairment accompanied with diffusion dysfunction was observed in 2 cases, while the pulmonary function tests were normal in the other 2 cases. All 4 cases received chest CT scan, and bronchiectasis was present in all of them. Bilateral diffuse micronodules and patchy infiltrates were found in 3 and 2 cases respectively. Electron microscopic examination of the endobronchial biopsy specimen showed lack of dynein arms in 4, lack of muco-cilia in 2, and abnormal arrangement of microtubules in 2 cases.

CONCLUSIONS

The Kartagener syndrome is relatively easy to be diagnosed, because it is characterized by the triad of sinusitis, bronchiectasis and situs inversus. However, PCD without situs inversus often goes unrecognized. PCD should be considered in patients with childhood onset disease, bronchiectasis, centrilobular micronodules or tree-in-bud signs in CT scan. Examination of the ciliary ultrastructure is essential to the confirmation of the diagnosis.

[Primary ciliary dyskinesia in highlights of consensus statement. Presentation of pediatric cases]

Cilia are evolutionarily conserved structures that play a role in diverse cell types. Motile cilia are involved in the most prominent ciliopathy called primary ciliary dyskinesia (PCD), which combines oto-sino-pulmonary symptoms (impaired mucociliary clearance that is important innate defense mechanism), male infertility and in nearly 50% cases situs inversus. Disease is usually inherited as autosomal recessive disorder, concerning mainly outer and/or inner dynein arms of cilia. Diagnosis of PCD requires the presence of characteristic clinical phenotype and confirmation the diagnosis by either identification of specific defect in electron microscopy or other evidence of abnormal ciliary function. The diagnosis of PCD may be delayed, missed or made incorrectly. The first ERS consensus statement which formulates recommendations regarding diagnostic as well as therapeutic approaches to children with PCD, is a very helpful tool in the management of this patients. We present our own experience with three children with PCD diagnosed in our Department.

CONCLUSION

in children with clinical symptoms suggesting PCD, even with negative screening tests, the estimation of specific cilia defect in electron microscopy is indicated.

Clinical and genetic aspects of primary ciliary dyskinesia/Kartagener syndrome

Primary ciliary dyskinesia is a genetically heterogeneous disorder of motile cilia. Most of the disease-causing mutations identified to date involve the heavy (dynein axonemal heavy chain 5) or intermediate(dynein axonemal intermediate chain 1) chain dynein genes in ciliary outer dynein arms, although a few mutations have been noted in other genes. Clinical molecular genetic testing for primary ciliary dyskinesia is available for the most common mutations. The respiratory manifestations of primary ciliary dyskinesia (chronic bronchitis leading to bronchiectasis, chronic rhino-sinusitis, and chronic otitis media)reflect impaired mucociliary clearance owing to defective axonemal structure. Ciliary ultrastructural analysis in most patients (>80%) reveals defective dynein arms, although defects in other axonemal components have also been observed. Approximately 50% of patients with primary ciliary dyskinesia have laterality defects (including situs inversus totalis and, less commonly, heterotaxy, and congenital heart disease),reflecting dysfunction of embryological nodal cilia. Male infertility is common and reflects defects in sperm tail axonemes. Most patients with primary ciliary dyskinesia have a history of neonatal respiratory distress, suggesting that motile cilia play a role in fluid clearance during the transition from a fetal to neonatal lung. Ciliopathies involving sensory cilia, including autosomal dominant or recessive polycystic kidney disease, Bardet-Biedl syndrome, and Alstrom syndrome, may have chronic respiratory symptoms and even bronchiectasis suggesting clinical overlap with primary ciliary dyskinesia.

Development of handed body asymmetry in mammals

We have proposed a three step model for the specification of left-right in mammalian embryos. The fundamental assumption is that handedness is imparted by an asymmetrical molecule. Conversion of molecular asymmetry to the cellular level gives a property to one side of the embryo to bias an otherwise random generation of an asymmetrical gradient which can be interpreted by developing organs. Rat embryos, treated at discrete stages, show a window of sensitivity for disruption of handedness, which may reflect the time of conversion/biasing. Heat shock and several chemicals cause left-right inversion in up to 50% of embryos exposed during neural groove formation. Earlier stages are less sensitive; no treatment begun after foregut pocket formation influences asymmetry. Evidence for cellular interactions in left-right specification comes from the apparent rescue of iv/iv mutant embryos in chimeras. We are looking for molecular left-right disparity before morphological asymmetry but detect no differences in two-dimensional protein profiles. Using an indirect measure, we find a right-left gradient of tissue oxygen in embryos at the 20-30 somite stage. This may reflect asymmetrical vasculature, as we have suggested to explain drug-induced asymmetrical limb malformations.

Tubal transport of spermatozoa does not appear to be dependent on normal cilia function

OBJECTIVE

To report the case of a woman with Kartagener's syndrome with complete immotility of ciliae and normal transport of spermatozoa.

DESIGN

Case report.

PATIENTS

A 31-year-old woman with Kartagener's syndrome.

SETTING

Medical university-affiliated teaching hospital.

INTERVENTION(S)

Ultrasonography, hysterosalpingoscintigraphy using technetium-99m-labeled macroaggregates of human serum albumin, application of oxytocin.

MAIN OUTCOME MEASURE(S)

Dynamic anteroposterior scintigraphy using a gamma camera.

RESULT(S)

The transport of labeled macrospheres through the fallopian tube into the peritoneal cavity on the side of the leading follicle, compared to the contralateral oviduct where the labeled material may have accumulated within the fallopian tube, is similar to those reported in normal fertile women.

CONCLUSION(S)

Transport of spermatozoa is not dependent on normal ciliary function.

Ciliary ultrastructure in two sisters with Kartagener's syndrome

Kartagener's syndrome (KS) is a clinical variant of primary ciliary dyskinesia involving situs inversus associated with chronic airway infections. We studied two sisters; the elder one had dextrocardia and scoliosis, and the younger one had situs inversus of the lung, liver, and stomach as well as dextrocardia. Both patients had chronic sinusitis and chronic bronchitis with bronchiectasis. In both cases, the ciliary defect associated with this syndrome is the absence of inner dynein arms.

[Clinical features of primary ciliary dyskinesia]

OBJECTIVE

To investigate the clinical features, diagnosis and treatment of primary ciliary dyskinesia (PCD).

METHODS

Three cases of PCD received endoscopic sinus surgery and were followed up for life quality and recovery. Among these 3 cases, two were twin brothers and the other girl was twin born with a healthy brother. The mucosa of inferior turbinate was extracted prior to the operation without narcotic and decongestant. The ultrastructure of mucosal cilia was detected with electron microscope. Nine exons of gene DNAH5 and chromosome in one case and her fraternal twin were evaluated.

RESULTS

Nasal and sinus CT imaging of the 3 cases showed chronic pansinusitis (1 case accompanied with situs inversus according with the diagnosis of Kartagener syndrome). The nasal polyp was resected, and the sinuses were opened. The twin brothers received the adenoidectomy. All patients felt nasal ventilation improved while the surgical field still covered with thick discharges during follow-up for 2 - 4 years. Ciliary ultrastructures of the three cases showed lateral dynein absent, the sequence of 9 exons of DNAH5 and chromosome presented no change in the fraternal twins.

CONCLUSIONS

Surgery could improve the symptoms of sinusitis in PCD. Change of ciliary ultrastructure was an important indication of its pathological changes and molecular biology evaluation needs further study.

Nasal Nitric Oxide in Atypical Primary Ciliary Dyskinesia

BACKGROUND

Atypical cases of primary ciliary dyskinesia (PCD) may present with minimal transmission electron microscopy (TEM) defects. The diagnostic role of nasal nitric oxide (nNO) levels was evaluated in those patients.

METHODS

Sixty-four children with recurrent pneumonia were studied with ciliary motion analysis, TEM, and nNO.

RESULTS

Investigations indicated PCD in 12 patients, secondary ciliary dyskinesia (SCD) in 50 patients, and normal results in 2 patients. In 4 of 50 children with SCD, atypical PCD was considered possible. The mean (+/- SD) nNO was 130 +/- 46.95 parts per billion in children affected by PCD, 127.79 +/- 68.58 parts per billion in atypical patients, and 760 +/- 221 parts per billion in children with SCD. Three to 5 months later, the nNO level was 132.75 +/- 55.76 parts per billion in children with atypical disease and 778.00 +/- 197 parts per billion in children with SCD.

CONCLUSION

Low levels of nNO may help to identify patients with atypical PCD.

A common variant in combination with a nonsense mutation in a member of the thioredoxin family causes primary ciliary dyskinesia

Thioredoxins belong to a large family of enzymatic proteins that function as general protein disulfide reductases, therefore participating in several cellular processes via redox-mediated reactions. So far, none of the 18 members of this family has been involved in human pathology. Here we identified TXNDC3, which encodes a thioredoxin-nucleoside diphosphate kinase, as a gene implicated in primary ciliary dyskinesia (PCD), a genetic condition characterized by chronic respiratory tract infections, left-right asymmetry randomization, and male infertility. We show that the disease, which segregates as a recessive trait, results from the unusual combination of the following two transallelic defects: a nonsense mutation and a common intronic variant found in 1% of control chromosomes. This variant affects the ratio of two physiological TXNDC3 transcripts: the full-length isoform and a novel isoform, TXNDC3d7, carrying an in-frame deletion of exon 7. In vivo and in vitro expression data unveiled the physiological importance of TXNDC3d7 (whose expression was reduced in the patient) and the corresponding protein that was shown to bind microtubules. PCD is known to result from defects of the axoneme, an organelle common to respiratory cilia, embryonic nodal cilia, and sperm flagella, containing dynein arms, with, to date, the implication of genes encoding dynein proteins. Our findings, which identify a another class of molecules involved in PCD, disclose the key role of TXNDC3 in ciliary function; they also point to an unusual mechanism underlying a Mendelian disorder, which is an SNP-induced modification of the ratio of two physiological isoforms generated by alternative splicing.

[Kartagener sindrome (primary ciliary dyskinesia). Report of a case and literature review]

Kartagener syndrome (a clinical variant of primary ciliary dyskinesia) is a recessive autossomical disease characterized by the triad of chronic sinusitis, bronchiectasis and situs inversus with dextrocardia. We report one case described in a 8 years old boy who besides presented a seromucous otitis and bronchitis of repetition. Finally we performed a short bibliographic review at respect of this uncommon pathology.

Calcium stone lithoptysis in primary ciliary dyskinesia

BACKGROUND

An association between lithoptysis and primary ciliary dyskinesia (PCD) has not been previously reported. However, reports of lithoptysis from 2 older patients (>60 yr) prompted a study of this association.

METHODS

We performed a prospective study of all PCD patients presenting to our institution between August 2003 and March 2006, seeking the symptom of lithoptysis or calcium deposition on radiology. A retrospective analysis of all PCD patients presenting prior to August 2003 was also performed. Patients age > or = 40 previously reviewed were recontacted. If a history of lithoptysis or calcium deposition was present, we further reviewed radiographic, microbiologic, and biochemical data, including serum calcium and phosphate. Broncholiths were analyzed by light and electron microscopy- and electron-dispersive X-ray analysis.

RESULTS

In total, 142 patients (n=28 age > or = 40) were included, 41 in the prospective and 91 in the retrospective study. Lithoptysis was reported in 5 patients (all age > or = 40). Chest CT scans identified calcification (4/5), involving bronchiectatic airways in 3 patients and focal nodular calcification in 1 patient. Two other patients (age 46, 59) were identified with airway calcification without lithoptysis. Available broncholiths from 2 of these patients were composed of calcite, whereas a broncholith from 1 patient with focal nodular calcification contained calcium phosphate. Sputum was positive for Pseudomonas aeruginosa in all 7 patients, but negative for mycobacterial and fungal cultures.

CONCLUSION

There is an association between lithoptysis and PCD in patients age > or = 40. We hypothesize that calcite stone formation is a biomineralization response to chronic airway inflammation and retention of infected airway secretions in PCD in a subset of PCD patients.

Primary ciliary dyskinesia: a review

The entity sinusitis, bronchiectasis, and situs inversus is since long named Kartagener syndrome. Nowadays the designation used is primary ciliary dyskinesia (PCD), which implies cilia with decreased or total absence of motility, which may result in sinusitis, chronic bronchitis, bronchiectasis, and male infertility. A large number of deficiencies detectable on the ultrastructural level give rise to PCD. There may also be aberrations not detected up to the present. The normal left-right asymmetry of the body is thought to be due to the beating of the cilia in the embryonic (Hensen's) node. Total immotility of the cilia should therefore result in random asymmetry of the body that is situs inversus in 50% of the cases. It has also been claimed that 50% of cases with PCD have situs inversus. However, several deficiencies apparently do not cause total immotility, and all ultrastructural variants are not associated with situs inversus in 50% of the cases. Several of the deficiencies are difficult to detect. Optimal fixation and handling are therefore obligatory. The genetic changes behind the variants are now being studied in several laboratories. Patients with PCD have very low levels of nasal nitric oxide, which is of increasing diagnostic importance. Other established diagnostic methods are the saccharine test and determination of ciliary beat frequency.

Ultrastructural patterns of primary ciliar dyskinesia syndrome

Clinical presentation, ciliary ultrastructure, and nasal mucociliary transport by a radioisotopic technique were analyzed in 14 Kartagener syndrome patients. In this study the most common pattern was the absence of outer and inner dynein arms in 57% of cases. Also reported are 14% patients with short inner dynein arms. A total of 29% of the patients showed normal dynein arms. Mucociliary stasis was observed in 13 cases. Primary ciliary dyskinesia syndrome and Kartagener syndrome are clinically homogeneous and morphologically heterogeneous. The authors conclude that a typical clinical presentation with an altered mucociliary transport obtained by radioisotopic technique is diagnostic although ciliary ultrastructure is normal.

[The respiratory mucociliary system and its exploration in primary ciliary dyskinesia]

BACKGROUND

We analyzed the main characteristic features of the respiratory epithelium mucociliary system and the different tests of ciliary beat and mucociliary transport (mucociliary clearance). This knowledge is necessary for an often interdisciplinary diagnosis and treatment of primary ciliary dyskinesia.

METHODS

Review of the literature and personal experience of the different tests of ciliary structure and function.

RESULTS

This disease is characterized by abnormalities in ciliary structure/function. The genetic mechanisms and the ultrastructural abnormalities that are involved are heterogenous compared to the relative homogeneity of the clinical presentation.

CONCLUSION

The diagnostic criteria are compatible clinical features (chronic upper airway and bronchopulmonary infections, situs inversus...) coupled with tests of ciliary structure and function.

[Study of mucociliary transport and nasal ciliary ultrastructure in patients with Kartagener's syndrome]

OBJECTIVE

Kartagener's syndrome (KS) is a clinical variant of primary ciliary dyskinesia involving situs inversus associated with chronic airway infections. The ciliary defect associated with this syndrome is the absence of dynein arms. The aim of this study was to evaluate mucociliary transport and ciliary ultrastructure in 14 patients with KS.

PATIENTS AND METHODS

We studied nasal mucociliary transport using a radioisotopic technique and ciliary ultrastructure in 14 patients with KS.

RESULTS

Thirteen patients had mucociliary stasis and 1 had severely slowed transport (1.3 mm/min). Four patients (29%) had cilia with normal dynein arms, 2 patients (14%) had short inner dynein arms, and 8 patients (57.1%) had total absence of inner and outer dynein arms.

CONCLUSIONS

We conclude that the typical clinical presentation, together with altered mucociliary transport as identified by an isotopic technique, is diagnostic of KS, even when the ciliary ultrastructure is normal. KS is clinically homogenous and morphologically heterogenous.

Absent inner dynein arms in a fetus with familial hydrocephalus-situs abnormality

We report a family in which a healthy, unrelated couple had a male fetus with bilateral ventriculomegaly, a normal liveborn girl, a hydatidiform molar pregnancy, a female fetus with ventriculomegaly and situs abnormalities, and a male fetus with hydrocephalus, a three-lobed left lung, and defective tracheal cilia with absent inner dynein arms and a single centriole. A mutation analysis of FOXJ1 and POLL in the last fetus with ciliary defect revealed no mutation within their coding regions. The presence of three affected fetuses of both sexes in a family with phenotypically normal parents suggests that the condition was inherited as an autosomal recessive trait. A thorough evaluation of the thoracic and abdominal situs is recommended before counseling a family of a child with hydrocephalus, because the recognition of situs defects may point to the diagnosis of primary ciliary defect and recurrence risk of 25% for siblings. This figure is much higher than the general risk of 1-2% for siblings of a patient with isolated hydrocephalus.

[Ciliary changes with abscence of dynein arms in Kartagener's syndrome]

A 33 years-old female with a diagnosis of Kartagener's syndrome was studied. She had a clinical history of chronic sinusitis with nasal obstruction and rhinorrea, and a chronic cough with mucopurulent sputum. A paranasal sinus CT showed hypertrophyc mucosa. A thoracic CT showed a situs inversus and chronic bronchitis with bronchiectasis. The saccharin test lasted 55 minutes. The electron microscopy study showed in a a cross-sectional axoneme a total absence of the outer and inner arm of the 9th outer doublet in over a 100 cilias studied. No others ultrastructure anormalities were observed.

The secondary nature of ciliary (dis)orientation in secondary and primary ciliary dyskinesia

OBJECTIVE

Ciliary orientation (COR) is an important parameter of mucociliary clearance and ciliary disorientation has been reported in cases of acquired abnormalities [secondary ciliary dyskinesia (SCD)] and in a very few cases as the single abnormality in primary ciliary dyskinesia (PCD). The etiology, pathogenesis, consequences and relevance of ciliary (dis)orientation are still unclear.

MATERIAL AND METHODS

To elucidate the primary or secondary nature of ciliary (dis)orientation, COR was measured in 179 non-PCD and 59 PCD patients. COR was measured in biopsies and after ciliogenesis in culture and was correlated with a number of functional and ultrastructural parameters. COR was defined as the SD of the angles of lines through the central pair of microtubules using transmission electron microscopy. Internationally accepted normal values for COR are < or = 20 degrees; COR values of 20-35 degrees indicate increased disorientation; and COR values > 35 degrees represent a random orientation.

RESULTS

For non-PCD biopsies, COR increased with increasing SCD, from 15 +/- 7 degrees (n = 54) for normal (< 5%) SCD to 28 +/- 8 degrees (n = 16) for severe (> 25%) SCD. No correlation was found between COR and ciliary beat frequency. However, increased COR values (28 +/- 8 degrees) were found for immotility (n = 8), compared to (coordinated) ciliary activity (19 +/- 9 degrees) (n = 121). After ciliogenesis no ultrastructural abnormalities were found and COR was normal (13 +/- 5 degrees; n = 308). COR can therefore be considered to be secondary in non-PCD and correlates with SCD percentage and ciliary motility. In biopsies from PCD patients with dynein deficiency and with normal ultrastructure, COR was increased, to 28 +/- 11 degrees (n = 32) and 21 +/- 7 degrees (n = 15), respectively, and in cases with central pair abnormalities COR was random (38 +/- 11 degrees; n = 12). After ciliogenesis COR remained random in the PCD group with central pair abnormalities (38 +/- 9 degrees; n = 15), and was increased in the PCD groups with dynein deficiency (24 +/- 10 degrees; n = 35) and normal ultrastructure (25 +/- 8 degrees; n = 17). Ciliary disorientation was never found as the single abnormality.

CONCLUSION

COR can be considered to be secondary in PCD. Both ciliary (im)motility and SCD percentage contribute to COR.

Radiofrequency Catheter Ablation of an Accessory Pathway in a Patient with Wolff‐Parkinson‐White and Kartagener's Syndrome

We report a case of a manifest left free wall accessory pathway in a patient with Kartagener's syndrome and recurrent episodes of orthodromic atrioventricular reentrant tachycardia. To the best of our knowledge, it is the first report of Wolff-Parkinson-White syndrome associated with Kartagener's syndrome. Situs inversus and mirror image dextrocardia occurred with no additional detectable cardiac structural abnormalities. Diagnostic and therapeutic electrophysiological study was carried out via transaortic approach and a left-to-right reversal of monoplane fluoroscopic image.

Primary ciliary dyskinesia: diagnostic and phenotypic features

Primary ciliary dyskinesia (PCD) is a genetic disease characterized by abnormalities in ciliary structure/function. We hypothesized that the major clinical and biologic phenotypic markers of the disease could be evaluated by studying a cohort of subjects suspected of having PCD. Of 110 subjects evaluated, PCD was diagnosed in 78 subjects using a combination of compatible clinical features coupled with tests of ciliary ultrastructure and function. Chronic rhinitis/sinusitis (n = 78; 100%), recurrent otitis media (n = 74; 95%), neonatal respiratory symptoms (n = 57; 73%), and situs inversus (n = 43; 55%) are strong phenotypic markers of the disease. Mucoid Pseudomonas aeruginosa (n = 12; 15%) and nontuberculous mycobacteria (n = 8; 10%) were present in older (> 30 years) patients with PCD. All subjects had defects in ciliary structure, 66% in the outer dynein arm. Nasal nitric oxide production was very low in PCD (nl/minute; 19 +/- 17 vs. 376 +/- 124 in normal control subjects). Rigorous clinical and ciliary phenotyping and measures of nasal nitric oxide are useful for the diagnosis of PCD. An increased awareness of the clinical presentation and diagnostic criteria for PCD will help lead to better diagnosis and care for this orphan disease.

Investigation of the possible role of a novel gene, DPCD, in primary ciliary dyskinesia

Primary ciliary dyskinesia (PCD) is an autosomal recessive disease caused by mutations that affect the proper function of cilia. Recently, deletion of DNA polymerase lambda (Poll) in mice produced a phenotype characteristic of PCD (Kobayashi et al., 2002, Mol. Cell. Biol. 22:2769-2776). Because it is unclear how a mutation in a DNA polymerase would result in a specific defect in axonemes, the targeting construct was examined further. Analysis of the genomic region surrounding the Poll gene revealed an uncharacterized gene, named Dpcd, that is predicted to be transcribed from the opposite strand relative to Poll. The deletion of Poll would also remove the first exon of Dpcd. Because it is possible that the PCD phenotype observed is due to the absence of either gene, the expression of these genes during ciliogenesis of human airway epithelial cells was examined. Northern analysis demonstrated that DPCD expression increases during ciliated cell differentiation; the expression of POLL decreases. To examine directly whether DPCD is mutated in cases of human PCD, the complete coding sequence of DPCD was sequenced from 51 unrelated PCD patients. No disease-causing mutations were confirmed; however, one variant could not be excluded. Therefore, DPCD remains a novel candidate gene for PCD.

Ciliary beat pattern is associated with specific ultrastructural defects in primary ciliary dyskinesia

BACKGROUND

The main symptoms of primary ciliary dyskinesia (PCD) are nasal rhinorrhea or blockage and moist-sounding cough. Diagnosis can be difficult and is based on an abnormal ciliary beat frequency, accompanied by specific abnormalities of the ciliary axoneme. It is unknown whether determining ciliary beat pattern related to specific ultrastructural ciliary defects might help in the diagnosis of PCD.

OBJECTIVE

We sought to determine ciliary beat pattern and beat frequency (CBF) associated with the 5 common ultrastructural defects responsible for PCD.

METHODS

Nasal brushings were performed on 56 children with PCD. Ciliary movement was recorded using digital high-speed video imaging to assess beat frequency and pattern. Electron microscopy was performed.

RESULTS

In patients with an isolated outer dynein arm or with an outer and inner dynein arm defect, 55% and 80% of cilia were immotile, respectively. Cilia that moved were only flickering. Mean CBF (+/- 95% CI) was 2.3 Hz (+/- 1.2) and 0.8 Hz(+/- 0.8), respectively. Cilia with an isolated inner dynein arm or a radial spoke defect had similar beat patterns. Cilia appeared stiff, had a reduced amplitude, and failed to bend along their length. Immotile cilia were present in 10% of cilia with an inner dynein arm defect and in 30% of radial spoke defects. Mean CBF was 9.3 Hz (+/- 2.6) and 6.0 Hz (+/- 3.1), respectively. The ciliary transposition defect produced a large circular beat pattern (mean CBF, 10.7 Hz [+/- 1.1]). No cilia were immotile.

CONCLUSIONS

Different ultrastructural defects responsible for PCD result in predictable beat patterns. Recognition of these might help in the diagnostic evaluation of patients suspected of having PCD.

Isomerism of the right atrial appendages: clinical, anatomical, and microscopic study of a long-surviving case with asplenia and ciliary abnormalities

This study describes a case of isomerism of the right atrial appendages (bilateral morphologically right atrial appendages associated with complex congenital cardiac lesions) with ciliary abnormalities. Detailed investigation included gross anatomic dissection, review of the clinical history, and light, confocal, and electron microscopy. Clinically, this 40-year-old, long-surviving male patient had relatively good health until 4 years before death, which was due to cardiac failure. Surgical intervention consisted only of a Blalock-Taussig shunt (anastomosis of the right subclavian artery to the right pulmonary artery) at 6 years of age. Despite the presence of complex cardiac malformations and asplenia, his longevity may be attributed to the connection of the pulmonary veins to the atrium without pulmonary venous obstruction, pulmonary valvar stenosis rather than atresia, no significant atrioventricular valve regurgitation, and no serious infections during his life. Microscopic examination of bronchial epithelium revealed a narrow, disorganized epithelium with abundant goblet cells and short, angulated cilia with a random orientation and possibly an abnormal central microtubule doublet. These abnormalities were not present in controls, and have been noted in primary ciliary dyskinesia (PCD) or Kartagener's syndrome. Because this syndrome has classically been thought to cause random lateralization resulting in a mirror-imaged arrangement of the organs, the occurrence of truly isomeric patterns is not widely recognized. Whereas polysplenia and left bronchial isomerism have been reported to occur in immotile cilia syndrome, this is the first report to present detailed postmortem anatomic evidence of isomerism of the right atrial appendages, right bronchial isomerism, and asplenia in association with microscopy suggesting ciliary abnormalities.

Absence of nexin links as a possible cause of primary ciliary dyskinesia

Transmission electron microscopy of nasal cilia was performed in three patients, two of them siblings, with repeated respiratory infections. Number of microtubuli and dynein arms were within normal limits and they had an ordered arrangement except for a disarray of the microtubuli in some areas of the biopsies from two of the patients. In the normal areas radial spokes and sheaths were easily found but nexin links could not be discerned in any of the patients. The orientation of the cilia was partly random. As all patients repeatedly and constantly had very low nasal NO (range 9-15 ppb; normal findings for persons <10 years old are > 50 ppb), the diagnoses were very likely primary ciliary dyskinesia (PCD). Absence of nexin links may be an ultrastructural variant of PCD. Deficiency of these structures might be the cause of the microtubular disarray observed in some areas of the biopsies.

Lateralization defects and ciliary dyskinesia: lessons from algae

Flagella and cilia are two very similar organelles that "beat" to move cells and to propel fluid over tissues. They are highly conserved, being found in organisms ranging from prokaryotes to plant and animal eukaryotes. In humans, cilia are present in almost every organ, and several human conditions involve dysfunctional cilia; for example, lateralization defects, where the positions of organs are reversed, and primary ciliary dyskinesia, a rare condition where patients suffer from recurrent respiratory infections. In this article, we will discuss how information gained from studies on algae has aided research into these human diseases. These studies found a variety of functions that was previously unsuspected, renewing interest in cilia.

Correlation of presentation and pathologic condition in primary ciliary dyskinesia

OBJECTIVES

To better characterize primary ciliary dyskinesia (PCD) and improve the diagnosis of this uncommon disorder.

STUDY DESIGN AND SETTING

We retrospectively reviewed the records of 118 patients with ciliary biopsy or brushing specimens examined at Yale University School of Medicine from 1991 to 2001.

RESULTS

Sinonasal, middle ear, and pulmonary infections were more common in patients with PCD-positive biopsy results than in those with negative results. In addition, PCD caused by random ciliary orientation presented similarly to PCD caused by other ultrastructural defects.

CONCLUSIONS

Patients who present with cough alone are highly unlikely to have PCD (chi(2 ) test, 24.85; P<.001). In contrast, patients who present with multiple manifestations are highly likely to have PCD (chi(2) test, 22.2; P<.001). This information may assist the clinician in the diagnosis of PCD.

Loss of function of axonemal dynein Mdnah5 causes primary ciliary dyskinesia and hydrocephalus

Primary ciliary dyskinesia (PCD), also known as Kartagener's syndrome, is a human syndrome that results from ciliary dysfunction. This syndrome is characterized by recurrent respiratory infections, situs inversus and infertility. In some cases, hydrocephalus is also observed. We have characterized an insertional mutation in a mouse axonemal dynein heavy chain gene (Mdnah5) that reproduces most of the classical features of PCD, including recurrent respiratory infections, situs inversus and ciliary immotility. These mice also suffer from hydrocephalus and die perinatally. Electron microscopic studies demonstrate the loss of axonemal outer arms. These results show that mutations in Mdnah5 are a primary cause of PCD and provide direct evidence that mutations in an axonemal dynein can cause hydrocephalus. Mutations in the human DNAH5 have recently been identified in PCD patients. Comparison of the mouse model and the human data suggests that the degree of ciliary dysfunction is causally related to the severity of human PCD, particularly the presence of hydrocephalus.

Isolation and expression of the human hPF20 gene orthologous to Chlamydomonas PF20: evaluation as a candidate for axonemal defects of respiratory cilia and sperm flagella

Primary ciliary dyskinesia (PCD) is a heterogeneous congenital disorder characterized by bronchiectasis and chronic sinusitis, sometimes associated with situs inversus (i.e., Kartagener's syndrome) and male infertility. At the cell level, the disease phenotype includes various axonemal abnormalities of respiratory cilia and sperm flagella. We have previously isolated DNAI1, the first gene involved in these diseases in patients lacking outer dynein arms. In this study, designed to find additional genes for other axonemal defects, we report the isolation of a novel human gene, hPF20, which is orthologous to Chlamydomonas pf20. The hPF20 gene is expressed as two major transcripts: one is expressed in testis only, whereas the second is weakly expressed in many other tissues. As flagella of Chlamydomonas strains carrying pf20 mutations lack the axonemal central complexes, we tested the involvement of the hPF20 gene in the disease phenotype of five patients in whom cilia or flagella display abnormal central complexes. Five intragenic polymorphisms were identified and used to exclude hPF20 in two consanguineous patients, while no mutation was found in the remaining patients. However, given the genetic heterogeneity of PCD, we consider that this gene remains a good candidate to be investigated in patients with abnormal central complexes.

Optimal biopsy techniques in the diagnosis of primary ciliary dyskinesia

OBJECTIVE

Adequate biopsy specimens that clearly demonstrate cilia, and therefore enable the determination of the presence or absence of primary cilia dyskinesia, may be difficult to obtain. This study is an attempt to identify the optimal sampling technique to best examine respiratory tract cilia.

DESIGN

A prospective comparison of the four sampling techniques was carried out: nasal brushing, nasal biopsy, bronchial brushing, and tracheal biopsy.

SETTING

Tertiary care pediatric hospital: Children's Hospital of Eastern Ontario.

METHODS

Ten consecutive patients booked for bronchoscopy and tracheal biopsy underwent all four procedures. Specimens were examined under light microscopy for an assessment of quality.

RESULTS

The nasal brushing and tracheal biopsy specimens provide superior quality (p = .22); however, nasal brushing is more cost efficient. Nasal biopsy samples frequently are metaplastic and therefore are inferior to nasal brushing samples (p = .02).

CONCLUSION

With equal efficiency demonstrated, the reduction in potential morbidity and health care costs suggests nasal brushings to be the optimal initial investigation for primary ciliary dyskinesia.

Germline mutations in an intermediate chain dynein cause primary ciliary dyskinesia

Primary ciliary dyskinesia (PCD) is a genetically heterogeneous, autosomal recessive disorder caused by abnormal ciliary ultrastructure and function, characterized clinically by oto-sino-pulmonary disease. Mutations in an intermediate chain dynein (DNAI1; IC78) have recently been described in PCD patients, with outer dynein arm (ODA) defects. The aims of the current study were to test for novel DNAI1 mutations in 13 PCD patients with ODA defects (from 7 unrelated families) and to assess genotype/phenotype correlations in patients and family members. A previously reported mutation (219+3insT) was detected in three PCD patients from two families. The opposite allele had the novel missense mutation G1874C (W568S) in both affected individuals from one family, and a nonsense mutation G1875A (W568X) in an affected individual from another family. The tryptophan at position 568 is a highly conserved residue in the WD-repeat region, and a mutation is predicted to lead to abnormal folding of the protein and loss of function. None of these mutations were found in 32 other PCD patients with miscellaneous ciliary defects. Mutations in DNAI1 are causative for PCD with ODA defects, and are likely the genetic origin of clinical disease in some PCD patients with ultrastructural defects in the ODA.

[Observation of nasal mucosal cilia ultrastructure of Kartagener's syndrome]

OBJECTIVE

To report the ultrastructure of nasal mucosal cilia of Kartagener's syndrome and the operative results of 2 cases.

METHODS

Both two cases were underwent endoscopic sinus surgery. Transmission and scanning electron microscopic examinations of nasal mucosa for case 1 were performed.

RESULTS

All 2 cases presented situs inversus, chronic paranasal sinusitis and bronchiectasis. The electron microscopic examination showed that the shape of nasal cilia and "9 + 2" structure were normal, but the lack of inner dynein arm of cilia and confused arrangement of central pair of microtubules were confirmed. The recurrent of nasal polyps after 1-year follow-up was observed in case 1.

CONCLUSIONS

The disturbance of mucociliary clearance due to congenital ciliary structure defect might be the cause of chronic sinusitis and polyps, which might be one of reasons for poor prognosis after operation and we should pay more close attention.

Axonemal dynein intermediate-chain gene (DNAI1) mutations result in situs inversus and primary ciliary dyskinesia (Kartagener syndrome)

Kartagener syndrome (KS) is a trilogy of symptoms (nasal polyps, bronchiectasis, and situs inversus totalis) that is associated with ultrastructural anomalies of cilia of epithelial cells covering the upper and lower respiratory tracts and spermatozoa flagellae. The axonemal dynein intermediate-chain gene 1 (DNAI1), which has been demonstrated to be responsible for a case of primary ciliary dyskinesia (PCD) without situs inversus, was screened for mutation in a series of 34 patients with KS. We identified compound heterozygous DNAI1 gene defects in three independent patients and in two of their siblings who presented with PCD and situs solitus (i.e., normal position of inner organs). Strikingly, these five patients share one mutant allele (splice defect), which is identical to one of the mutant DNAI1 alleles found in the patient with PCD, reported elsewhere. Finally, this study demonstrates a link between ciliary function and situs determination, since compound mutation heterozygosity in DNAI1 results in PCD with situs solitus or situs inversus (KS).