Pulmonary Manifestations and Management of Giant Cell Arteritis

Epidemiology

Respiratory involvement is reported in fewer than 10 % of patients with giant cell arteritis (GCA); the most common pulmonary symptom is a chronic dry cough, and treatment with high‑dose oral prednisone (40–60 mg daily) typically leads to dramatic resolution of these respiratory manifestations. 1

In elderly patients, a chronic, harsh, non‑productive cough is the predominant respiratory symptom of GCA and may be the sole presenting feature. 1
The cough is frequently accompanied by sore throat, hoarseness, and tenderness of cervical structures. 1
In individuals older than 50 years who present with a troublesome cough of unknown cause together with headaches, GCA should be strongly suspected. 1
Additional pulmonary complications that have been documented in GCA include isolated small‑airway disease, lung nodules, interstitial infiltrates, pulmonary‑artery vasculitis, and ill‑defined granulomas within bronchial walls and the alveolar interstitium. 1

The exact mechanism producing cough in GCA is unknown; it may result from ischemia caused by vasculitis affecting bronchial or pulmonary arteries. 1
Most GCA patients who present with cough do not show other pulmonary abnormalities on chest imaging or pulmonary‑function testing. 1
Respiratory symptoms may reflect lymphocytic airway inflammation or bronchoalveolar lymphocytosis as part of the systemic autoimmune process underlying GCA. 2

Any patient over 50 years of age with an unexplained chronic dry cough and elevated inflammatory markers (erythrocyte sedimentation rate > 40 mm/h or C‑reactive protein ≥ 2.5 mg/dL) warrants evaluation for GCA. 1

Initiate high‑dose oral prednisone (40–60 mg daily) immediately upon clinical suspicion of GCA, without waiting for biopsy confirmation. 1
Prednisone therapy leads to rapid (days‑to‑weeks) and dramatic resolution of respiratory manifestations, including the characteristic harsh cough. 1
When cough is the primary respiratory manifestation, it typically resolves completely with appropriate glucocorticoid therapy. 1
The total duration of prednisone therapy is guided by clinical response and inflammatory markers and usually spans 1–2 years. 1

The American College of Rheumatology notes that characteristic findings of Giant Cell Arteritis include arterial wall thickening with narrowed lumen, presence of mononuclear inflammatory cells with invasion of the media layer, and multinucleated giant cells in the media, in patients with suspected large vessel vasculitis 3, 4

Respiratory involvement occurs in less than 10% of Giant Cell Arteritis cases, with chronic cough being the most frequent respiratory symptom, typically harsh and nonproductive, according to the American Thoracic Society, and may be related to isolated small airways disease, lung nodules and interstitial infiltrates, vasculitis of pulmonary arteries, or ill-defined granulomas within bronchial walls and alveolar interstitium 5, 6

The European League Against Rheumatism recommends that laboratory studies characteristically show marked elevations of acute-phase reactants, including erythrocyte sedimentation rate (ESR) typically exceeding 40 mm/h, with values above 100 mm/h having high specificity, and C-reactive protein (CRP) also elevated in most cases, in patients with suspected Giant Cell Arteritis 7

The American College of Rheumatology notes that Tocilizumab has demonstrated efficacy in reducing glucocorticoid requirements and flare rates, suggesting its effectiveness in modulating the underlying immune mechanisms, in patients with Giant Cell Arteritis 4