High-Resolution CT of Patients with Primary Ciliary Dyskinesia

Management of primary ciliary dyskinesia: the lower airways

Primary ciliary dyskinesia (PCD) is a genetic disease associated with defective ciliary structure and function. Chronic oto-sino-pulmonary infection is the most common clinical presentation. Patients should be monitored in centres with expertise in PCD. Regular respiratory monitoring consists of lung function tests, adapted to the patient's age, and cough swab or sputum cultures. Chest X-rays are insensitive but the use of high-resolution computed tomography should be considered carefully to avoid excessive radiation. Treatment of the chronic suppuration of the lower airways relies on antibiotics to which the isolated bacteria are sensitive, together with respiratory physiotherapy and exercise to clear excessive bronchial secretions. Bronchodilators and anti-inflammatory agents have no proven benefit and should be prescribed, if at all, on an individual basis. Treatment of the lower airways should always be in conjunction with that of the upper airways. Importantly in PCD, respiratory disease may be controlled with the use of early, adequate and aggressive management.

Primary ciliary dyskinesia: improving the diagnostic approach

PURPOSE OF REVIEW

The diagnosis of primary ciliary dyskinesia (PCD) has relied on analysis of ciliary motility and ultrastructure; however, these tests are not readily available and have not been standardized. Consequently, the diagnosis of PCD may be delayed or missed or made incorrectly. This review outlines the potential utility of new diagnostic tests, including measurement of nasal nitric oxide production and systematic analysis for mutations in genes encoding ciliary proteins.

RECENT FINDINGS

Clinical manifestations of PCD have been expanded to include neonatal respiratory distress and heterotaxy. Measurement of nasal nitric oxide has emerged as a useful screening test for PCD based on the very low levels in PCD (approximately 1/10 of normal values). Genetic testing is emerging for PCD and demonstrates extensive genetic heterogeneity. Some genes and gene mutations involved in PCD have been defined. Approximately one-third of PCD cases have identifiable gene mutations in one of six different genes. An international effort is focused on defining PCD-causing defects in other genes.

SUMMARY

The incorporation of nasal nitric oxide measurement as a screening test to define probable PCD cases and gene mutation analysis to make a definitive diagnosis of PCD should enhance diagnostic evaluation of PCD.

Bronchiectasis

Bronchiectasis, which was once thought to be an orphan disease, is now being recognized with increasing frequency around the world. Patients with bronchiectasis have chronic cough and sputum production, and bacterial infections develop in them that result in the loss of lung function. Bronchiectasis occurs in patients across the spectrum of age and gender, but the highest prevalence is in older women. The diagnosis of bronchiectasis is made by high-resolution CT scans. Bronchiectasis, which can be focal or diffuse, may occur without antecedent disease but is often a complication of previous lung infection or injury or is due to underlying systemic illnesses. Patients with bronchiectasis may have predisposing congenital disease, immune disorders, or inflammatory disease. The treatment of bronchiectasis is multimodality, and includes therapy with antibiotics, antiinflammatory agents, and airway clearance. Resectional surgery and lung transplantation are rarely required. The prognosis for patients with bronchiectasis is variable given the heterogeneous nature of the disease. A tailored, patient-focused approach is needed to optimally evaluate and treat individuals with bronchiectasis.

Early adolescent primary ciliary dyskinesia associated with broncholithiasis

Primary ciliary dyskinesia (PCD), is a rare congenital disease group, and contained Kartageners syndrome. This syndrome is characterized with situs viscerum inversus, sinusitis and bronchiectasis. In some elderly patients, broncholithiasis may be associated with PCD. The coexistence of early adolescence PCD and broncolithiasis has not been reported yet. We report here a case of a 14-year-old early adolescent male who had typically presented as PCD-based Kartageners syndrome and developed broncholithiasis which diagnosed with computed tomography.

Ciliary syndromes and treatment

Abnormal visceral patterning has been known for centuries. However, it has not been associated with ciliary dysfunction until recently. Overlapping clinical entities including situs inversus, certain infertility disorders, as well as chronic respiratory infections have their roots in abnormal ciliary function. Current research focuses on causative factors and genes involved in signal transduction pathways that define ciliary function and structure, as well as treatment. In this review, attempts are made to outline selected, yet key topics related to ciliary function in health and disease.

Structural and functional lung disease in primary ciliary dyskinesia

BACKGROUND

High-resolution CT (HRCT) scan data on primary ciliary dyskinesia (PCD) related lung disease are scarce.

STUDY OBJECTIVES

We evaluated the lung disease in children and adults with PCD by a modified Brody composite HRCT scan score to assess the prevalence of the structural abnormalities; to evaluate the correlation among HRCT scan scores, spirometry findings, and clinical data; and to compare the PCD scores with those of age-matched and sex-matched cystic fibrosis (CF) patients.

PATIENTS AND METHODS

Twenty PCD patients (age range, 4.6 to 27.5 years) underwent HRCT scanning, spirometry, and deep throat or sputum culture. A modified Brody score was used to assess bronchiectasis, mucous plugging, peribronchial thickening, parenchyma abnormalities, and mosaic perfusion.

RESULTS

The total HRCT scan score was 6% of the maximal score (range, 0.5 to 25.5). Subscores were as follows: bronchiectasis, 5.6%; mucous plugging, 5.6%; peribronchial thickening, 8.3%; parenchyma, 3%; and mosaic perfusion, 0%. The prevalence of lung changes were as follows: bronchiectasis, 80%; peribronchial thickening, 80%; mucous plugging, 75%; parenchyma, 65%; and mosaic perfusion, 45%. Sixteen of 19 PCD patients had positive culture findings, and the most common pathogen found was Haemophilus influenzae (84%). The total HRCT scan score was significantly related to age (p = 0.006), FEV(1) (p = 0.02), and FVC (p = 0.02). The bronchiectasis subscore was significantly related to FEV(1) (p = 0.04) and FVC (p = 0.03). In CF patients, the total HRCT scan score was significantly higher than that in PCD patients (p = 0.02).

CONCLUSIONS

PCD patients show significantly lower pulmonary HRCT scan scores than CF patients. The PCD total and bronchiectasis scores correlate with spirometry findings. The PCD HRCT scan score might be used for longitudinal assessment and/or represent an outcome surrogate in future studies.

Congenital heart disease and other heterotaxic defects in a large cohort of patients with primary ciliary dyskinesia

BACKGROUND

Primary ciliary dyskinesia (PCD) is a recessive genetic disorder that is characterized by sinopulmonary disease and reflects abnormal ciliary structure and function. Situs inversus totalis occurs in approximately 50% of PCD patients (Kartagener's syndrome in PCD), and there are a few reports of PCD with heterotaxy (situs ambiguus), such as cardiovascular anomalies. Advances in diagnosis of PCD, such as genetic testing, allow the systematic investigation of this association.

METHODS AND RESULTS

The prevalence of heterotaxic defects was determined in 337 PCD patients by retrospective review of radiographic and ultrasound data. Situs solitus (normal situs) and situs inversus totalis were identified in 46.0% and 47.7% of patients, respectively, and 6.3% (21 patients) had heterotaxy. As compared with patients with situs solitus, those with situs abnormalities had more ciliary outer dynein arm defects, fewer inner dynein arm and central apparatus defects (P<0.001), and more mutations in ciliary outer dynein arm genes (DNAI1 and DNAH5; P=0.022). Seven of 12 patients with heterotaxy who were genotyped had mutations in DNAI1 or DNAH5. Twelve patients with heterotaxy had cardiac and/or vascular abnormalities, and most (8 of 12 patients) had complex congenital heart disease.

CONCLUSIONS

At least 6.3% of patients with PCD have heterotaxy, and most of those have cardiovascular abnormalities. The prevalence of congenital heart disease with heterotaxy is 200-fold higher in PCD than in the general population (1:50 versus 1:10 000); thus, patients with PCD should have cardiac evaluation. Conversely, mutations in genes that adversely affect both respiratory and embryological nodal cilia are a significant cause of heterotaxy and congenital heart disease, and screening for PCD is indicated in those patients.