Connective Tissue Disease-Associated Lung Disease
On this page
Direct answer
Connective tissue disease-associated lung disease is involvement of the interstitium, pleura or pulmonary vessels by autoimmune conditions such as rheumatoid arthritis, systemic sclerosis, lupus and myositis. Interstitial lung disease is the main form, and its pattern depends on the underlying disease. Non-specific interstitial pneumonia is typical of systemic sclerosis and myositis, while usual interstitial pneumonia is more often in rheumatoid arthritis. Immunosuppression treats inflammatory disease, and antifibrotics slow progressive fibrosis.
What you must remember
- Systemic sclerosis: NSIP is the usual pattern, and anti-topoisomerase I (anti-Scl-70) antibody marks a higher risk of lung fibrosis, while anticentromere antibody is linked with pulmonary arterial hypertension.
- Rheumatoid arthritis: UIP or NSIP pattern, plus pleural effusion, bronchiolitis obliterans, rheumatoid nodules and drug-related pneumonitis from methotrexate or leflunomide.
- SLE: pleurisy with or without effusion is the most frequent pulmonary feature, while acute lupus pneumonitis, pulmonary haemorrhage and shrinking lung syndrome are less common.
- Myositis: NSIP or organising pneumonia pattern, with anti-synthetase antibodies such as anti-Jo-1 linked to ILD and anti-MDA5 antibody linked to rapidly progressive disease.
- Sjogren syndrome: lymphocytic interstitial pneumonia or NSIP, with a raised risk of MALT lymphoma.
- Treatment: corticosteroids and immunosuppressants such as mycophenolate, azathioprine or cyclophosphamide for inflammatory disease, and nintedanib for progressive fibrosing ILD, per current guidance.
A breathless patient with known rheumatoid arthritis
A 52-year-old woman with long-standing rheumatoid arthritis has progressive exertional breathlessness and a dry cough. Her chest film shows basal reticular shadowing, and her HRCT shows subpleural basal fibrosis.
Lung involvement is usually found in a patient already known to have a rheumatological disease, though it can be the first presentation. The table compares the usual pattern and the clue for each disease.
| Disease | Usual lung pattern | Key lung clue |
|---|---|---|
| Systemic sclerosis | NSIP, UIP | Anti-Scl-70, basal fibrosis, PAH |
| Rheumatoid arthritis | UIP, NSIP, OP | Effusion, bronchiolitis obliterans, nodules |
| SLE | Pleuritis, NSIP, acute pneumonitis | Effusion, shrinking lung, haemorrhage |
| Myositis | NSIP, OP | Anti-synthetase, anti-MDA5 |
| Sjogren syndrome | LIP, NSIP | MALT lymphoma risk |
Histology overlaps between these diseases, so the pattern must be read alongside serology, drug history and HRCT. Lymphocytosis on bronchoalveolar lavage supports NSIP but is not specific. Pulmonary function tests with DLCO are repeated to track progression, since the pattern alone does not show whether disease is stable.
Where the exam tests the antibody link
The exam links each antibody and disease to a lung pattern, and the traps below are the common errors.
- Trap: assuming every fibrotic pattern in systemic sclerosis is UIP Correct: NSIP is the classic pattern in systemic sclerosis and generally carries a better outlook than UIP.
- Trap: blaming the connective tissue disease for every new lung shadow Correct: methotrexate and leflunomide can cause pneumonitis, so the drug history comes first.
- Trap: judging progress by one lung function test Correct: serial FVC and DLCO, along with HRCT, show whether fibrosis is progressing.
- Trap: giving antifibrotics alone for active inflammatory disease Correct: inflammatory ILD usually needs immunosuppression, while antifibrotics target progressive fibrosis.
Frequently asked questions
Which antibody in systemic sclerosis predicts interstitial lung disease?
Anti-topoisomerase I, also called anti-Scl-70, is the antibody most associated with interstitial lung disease in systemic sclerosis. The anticentromere antibody is instead linked with pulmonary arterial hypertension, so the antibody profile helps direct lung surveillance.
Which lung pattern is typical of rheumatoid arthritis?
Lung disease in rheumatoid arthritis commonly shows a usual interstitial pneumonia or NSIP pattern, and it can also cause pleural effusion and bronchiolitis obliterans. Methotrexate and leflunomide can cause drug-induced pneumonitis, so the drug history is always reviewed.
What is the commonest pleural manifestation of systemic lupus erythematosus?
Pleurisy, with or without a small pleural effusion, is the most frequent pulmonary feature of systemic lupus erythematosus. Acute lupus pneumonitis and shrinking lung syndrome are less common, and shrinking lung syndrome is linked with diaphragm weakness.
What is nintedanib used for in connective tissue disease-associated lung disease?
Nintedanib is an antifibrotic drug approved for progressive fibrosing interstitial lung disease, including some connective tissue disease-associated cases. It slows the decline in lung function rather than reversing established fibrosis, and its use follows specialist review.