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Division of 1 Respirology, 2 Pathology, 3 Radiology, and 4 Thoracic Surgery, Dept of Medicine, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Canada.
CORRESPONDENCE: C. K. N. Chan, Head, Division of Respirology, Toronto General Hospital, 585 University Avenue, 9N945 Toronto, M5G 2N2 Ontario, Canada. Fax: 1 4169716427. E-mail: charles.chan{at}uhn.on.ca
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The patient's past medical history was unremarkable. Specifically, there was no history of childhood asthma or frequent infections. She was an ex-smoker with 15 pack-yrs. Family history, environmental allergies and occupational exposures were all unremarkable. At presentation her medications included salmeterol-fluticasone inhaler, tiotropium, montelukast, prednisone 30 mg daily and pantoprazole.
The patient appeared well with a blood pressure of 130/80 mmHg, heart rate of 80·min-1 and regular, respiratory rate of 18·min-1. Her saturation on room air was at 95%. Head and neck examination did not demonstrate lymphadenopathy or signs of chondral inflammation. Her cardiovascular examination revealed a normal jugular vein pulse with normal heart sounds and no pedal oedema. Respiratory examination demonstrated absence of clubbing and no evidence of wheezing or crackle. However, forced expiration produced an audible stridor sound.
Spirometry demonstrated a forced vital capacity (FVC) of 1.7 L (75% pred), FEV1 0.65 L (25% pred), and FEV1/FVC 35%. A flow/volume curve is shown in figure 1
. Diffusing capacity of the lung for carbon monoxide was 16.5 (95% pred). On presentation, chest radiography and computed tomography (CT) were performed (figs 2 and 3, respectively) followed by helical thoracic CT (fig. 4).
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The CT scan of the thorax at the carina level, in figure 3, demonstrates thickening of the anterior cartilaginous tracheal wall (3 mm) and narrowing of the luminal diameter (7–8 mm). No mediastinal or hilar lymphadenopathy was noted and the lungs fields are unremarkable.
The helical CT scan of the coronal and sagittal view (fig. 4) demonstrates diffuse narrowing of the tracheal lumen and thickening of the tracheal wall.
The histopathological slide of the transtracheal biopsy (fig. 5) indicates the presence of chronic inflammatory infiltrates with cartilage destruction and fibrosis, which are associated with reactive changes and osseous metaplasia.
Diagnosis: Respiratory relapsing polychondritis.
Treatment and clinical course
Transtracheal biopsy showed evidence of cartilage destruction and fibrosis, which is consistent with the diagnosis of relapsing polychondritis. The diagnosis of relapsing polychondritis was made according to the modified diagnostic criteria based on tracheal involvement and positive histology.
The patient was started on prednisone 60 mg daily, as well as calcium supplements. Upon follow-up 4 weeks later, she had noticed increased exercise capacity. A chest CT scan demonstrated minimal decrease in her tracheal narrowing, and there was minimal improvement in her PFTs. She was put on a very slow steroid taper (5 mg every 6 weeks) with the additional maintenance of cyclophosphamide at a dose of 100 mg·day-1. She was followed at 4-week intervals and continued to have exercise dyspnoea and stridor. A repeat bronchoscopy 8 weeks later showed persistent inflamed narrowed and collapsible trachea. FEV1 deteriorated further and the patient underwent stent insertion in the trachea and main bronchi. Although the procedure was successful, it was difficult to extubate the patient and while in the intensive care unit she acquired severe pneumonia and died 2 weeks later. An autopsy confirmed the diagnosis of respiratory chondritis and the cause of death was severe pneumonia.
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Involvement of the cartilaginous structures of the respiratory tract, although uncommon at presentation, occurs in almost half of relapsing polychondritis patients during the course of their illness 1. Respiratory involvement is a poor prognostic sign and accounts for >50% of relapsing polychondritis related deaths. Progression of tracheal disease leads to fibrotic changes and diffuse narrowing of the main airway and severe airflow impairment. Persistent bronchial cartilage inflammation may cause impairment of mucociliary function. Both factors, in addition to the use of steroids and other immunosuppressive drugs, predispose to recurrent respiratory tract infections. Pulmonary parenchymal involvement is not characteristic of relapsing polychondritis 1, 3, 4.
Most patients with respiratory involvement assume a fluctuating but progressive course. The polycyclic bouts of inflammation eventually lead to permanent destruction of the large airways. In severe cases, persistent inflammation can cause acute airway narrowing and destroy the cartilaginous rings, which creates luminal collapse. Obstruction may also be induced iatrogenically by bronchoscopy or tracheostomy. Intubation may be difficult and dangerous because of a small glottis caused by oedema or cartilage destruction. Another uncommon manifestation of respiratory polychondritis is the involvement of costosternal cartilages, which may lead to costochondritis that may further impair breathing 3, 4.
Conventional radiographs and CT scans identify laryngotracheal lesions, and thin-section CT defines abnormalities in both the trachea and lobar bronchi. Three-dimensional or spiral magnetic resonance imaging may provide better resolution 5, 6. The nature of airway obstruction, whether fixed or dynamic, and the location, whether intra- or extrathoracic, can be assessed by PFTs, especially flow–volume loops. PFTs are useful tools for monitoring change over time 7. In addition, CT scans and PFTs may detect otherwise asymptomatic airway involvement. Bronchoscopy may also be informative but carries a risk for exacerbating airway inflammation. The airways mucosa is typically inflamed and the involved segments are narrowed but there is nothing pathognomonic on direct visualisation.
When the respiratory complications appear in a patient with established relapsing polychondritis, the diagnosis is obvious. However, when the initial manifestation of relapsing polychondritis is respiratory there will be a delay in diagnosis in most cases. The clinical symptoms include cough and dyspnoea and have partial response to steroids, are nonspecific and usually attributed to more common diseases, such as asthma or chronic obstructive pulmonary disease. A chest radiograph, that in most cases will be normal, can also be misleading. The course is often progressive over several months. In some patients, constitutional symptoms, such as weight loss, fever and fatigue, may suggest a more systemic condition. Physical examination is often unremarkable, and when there is an abnormal finding it is most commonly stridor. As the disease progresses, there is further deterioration in FEV1, which is associated with the typical impairment of the inspiratory and expiratory curves. In such cases of suspected upper airway obstruction, a CT scan of the chest can demonstrate tracheal narrowing. In this instance the next diagnostic test would be bronchoscopy 3.
The differential diagnosis of tracheal wall narrowing includes infectious, inflammatory and neoplastic processes. In the paediatric population, infectious processes, such as acute tracheobronchitis (croup) or acute bacterial membranous tracheitis, which is less common, may cause stridor and tracheal narrowing. In the adult population, tuberculous tracheitis is relatively rare and is almost always associated with pulmonary cavitations. However, in the healing stage of the disease it can cause tracheal fibrosis with smooth narrowing of the wall. The most common form of primary pulmonary amyloidosis is tracheobronchial, and patients may present with multiple or localised masses on the tracheal wall or diffuse narrowing of the tracheal wall. The difference in the radiological appearance is the circumference of the amyloid lesions compared with the tendency to spare the posterior membranous portion in relapsing polychondritis disease. Sarcoidosis may also be reported to cause isolated tracheal narrowing.
The histopathological findings of tracheal biopsy in relapsing polychondritis typically include loss of basophilic staining of the cartilage matrix, perichondrial round cell infiltration and destruction of cartilage with fibrous replacement. Endobronchial biopsy tends not to provide cartilaginous materials for a firm diagnosis. Partial tracheal resection may yield sufficient materials for pathological confirmation 3.
Treatment with corticosteroids, alone or in combination with other immunosuppressive therapy, has been traditionally employed. Although its efficacy has not been assessed in randomised trials, it is the most effective treatment and can even lead to a dramatic response. Optimal dose and duration of therapy has again not been systematically evaluated. A reasonable regimen is 1 mg·kg-1 once daily for 8–12 weeks and re-evaluation of the patient with tapering to the lowest dose possible while maintaining disease control. Lifetime treatment may be necessary in patients with aggressive disease. Traditionally, drugs such as cyclophosphamide, dapsone and azathioprine have provided additional therapy with steroid sparing affect. Recent experience in an uncontrolled trial suggests that methotrexate and anti-tumour necrosis factor-
may be helpful 2.
The possible outcomes of respiratory involvement of relapsing polychondritis include spontaneous remission, stabilisation following treatment with corticosteroids or other immunosuppressive therapy, progression to life-threatening tracheal obstruction, or progression to tracheal obstruction and death despite interventional bronchoscopies with stents insertion 8. Secondary infections are another potential complication of the disease, and these were unfortunately the cause of death in the current authors’ patient.
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This article has been cited by other articles:
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  S. Decalmer, A. Woodcock, M. Greaves, M. Howe, and J. Smith Airway abnormalities at flexible bronchoscopy in patients with chronic cough Eur. Respir. J., December 1, 2007; 30(6): 1138 - 1142. [Abstract] [Full Text] [PDF]
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: normal predicted values for the patient.
