Connective tissue disease-related interstitial lung disease (CTD-ILD): symptoms, tests and treatment

The lungs contain delicate tissue around the tiny air sacs where oxygen passes into the blood. Asthma + Lung UK explains that interstitial lung disease damages this tissue rather than the airways, so the lungs cannot fill with as much air as normal. Scarring and thickening of lung tissue is called pulmonary fibrosis.

In CTD-ILD, the damage is connected to an autoimmune condition, meaning one in which the immune system attacks the body's own tissues. A report from Royal Brompton and Harefield hospitals explains that connective tissue diseases such as scleroderma, polymyositis and dermatomyositis affect multiple organs, and that people with these conditions are often found to have associated lung disease because of the high activity of the immune system, which causes inflammation and scarring of lung tissue.

The pattern differs from one person to another. Some people have mainly inflammation, which may respond to immune-suppressing treatment, some have mainly scarring and some have a mix. That is why the same autoimmune diagnosis can lead to quite different lung problems.

Asthma + Lung UK gives rheumatoid arthritis, systemic sclerosis (scleroderma) and Sjogren syndrome as examples. The NHS page on scleroderma says that in some cases of systemic sclerosis organs such as the heart, lungs or kidneys are affected, and that the limited form can eventually affect the lungs and digestive system too. The NHS rheumatoid arthritis page says some people with the condition experience problems in other parts of the body.

Having one of these conditions does not mean lung disease will develop. The general ILD risk factors listed by Asthma + Lung UK include being over 50 (though ILD can happen at any age), smoking or having smoked, exposure to certain dusts or chemicals, taking certain medicines, having an autoimmune condition and having a family member with an ILD.

Asthma + Lung UK lists the common ILD symptoms as breathlessness that gets worse after movement or exercise, a cough that does not go away, feeling very tired and losing weight for no reason. In someone with an autoimmune condition, these can be mistaken for the effects of the joint or skin disease, or for deconditioning, and early lung changes may produce few symptoms at all. For that reason, people with scleroderma and some other conditions are often checked for lung involvement with breathing tests even when they feel well.

The charity describes a flare-up, sometimes called an exacerbation, as a sudden worsening of usual symptoms: more breathlessness, a changed or worse cough, more tiredness than usual or lower oxygen levels than usual if you have been advised to monitor them. It advises speaking to a specialist nurse or other healthcare professional for advice.

Asthma + Lung UK says to call 999 or go to A&E immediately if you suddenly feel much more breathless, are finding it very hard to breathe, are coughing up a lot of blood (more than a few streaks or spots), have new or severe chest pain or feel unusually drowsy or confused.

A gradual change that is not an emergency still needs attention. See a GP, or contact your own specialist team, if breathlessness is creeping up, a dry cough lasts for several weeks or you are less able to walk or climb stairs than you were. Do not wait for the next routine appointment.

Asthma + Lung UK says getting a diagnosis for an ILD can take time, because the team wants to find the cause and rule out other lung conditions such as asthma or COPD. A GP will ask about symptoms, medicines, family history, smoking, work, hobbies and pets, and may listen to the chest. They then refer to a specialist team.

A multidisciplinary team of specialists works together to make the diagnosis. The tests the charity lists are chest X-ray or CT scan (which show whether the lungs are scarred), blood tests for infections, autoimmune conditions and inflammation, lung function tests including spirometry, lung volume and gas transfer, and, only if the diagnosis is uncertain, bronchoscopy or a lung biopsy. When someone already has a known connective tissue disease, the CT pattern and lung function results are often enough to make the diagnosis without a biopsy.

The first step, according to Asthma + Lung UK, is working out what is causing the symptoms and treating the underlying autoimmune condition in a connective tissue-related ILD. It says corticosteroids such as prednisolone and other immunosuppressants such as azathioprine can calm inflammation, and that people with connective tissue-related ILD may be prescribed a corticosteroid and another immunosuppressant to take together.

For lung scarring, the charity says treatments can slow it but cannot reverse it, and that someone with a CT-ILD such as rheumatoid arthritis-ILD or systemic sclerosis-ILD may be prescribed an antifibrotic and an immunosuppressant together. Supportive care includes oxygen therapy if oxygen levels are low, pulmonary rehabilitation, stopping smoking, vaccination against flu and pneumonia, and a lung transplant assessment in very rare cases.

The Royal Brompton and Harefield report notes that cyclophosphamide was at that time the standard of care for severe or progressive CTD-ILD in the NHS, and describes the RECITAL trial comparing cyclophosphamide and rituximab. Prescribing practice changes, so a specialist team can say what is currently used.

Asthma + Lung UK says it is hard to predict how an ILD will progress because it depends on the type, the response to treatment, age and lifestyle. Some ILDs stay stable for years and some are progressive. Most people have a review at least once a year, and every 3 to 4 months if treated at a specialist centre or if the condition is getting worse.

Tracking symptoms in a diary or app can help you and the team recognise a change. Staying active, pulmonary rehabilitation, breathing techniques and managing a cough all help day to day. The charity also notes that an ILD may count as a disability under the Equality Act 2010, which can open the way to support and workplace adjustments.

In the UK, CTD-ILD is usually looked after by a respiratory ILD team working with the rheumatology service treating the underlying condition, and many of the treatments, scans and lung function tests are provided through the NHS. Private respiratory or rheumatology consultations can offer a second opinion or faster scanning, but long-term prescribing, monitoring and access to specialist ILD multidisciplinary meetings are normally arranged through the NHS team.