Abstract
Introduction
Interstitial lung disease (ILD) is a progressive fibrotic disease of the lung parenchyma. The lungs are the most common site in rheumatic diseases. ILD may be idiopathic or caused by connective tissue diseases, rheumatoid arthritis, drugs, and infection and radiation therapy. The severity of lung involvement may vary considerably, and, in some cases, it can lead to irreversible fibrosis leading to respiratory failure and eventually death. Although progress has been made in understanding of the disease, there are still significant challenges with the diagnosis and treatment of ILD. This case illustrates the diagnostic and treatment dilemmas.
Case description
67-year-old gentleman presented with a 4-year history of gradual onset of shortness of breath and dry cough with worsening over 18 months. Additionally, he developed ENT problems including nasal obstruction, polyposis, intermittent crusting with epistaxis and change in voice. He was treated with nasal douches, intermittent short courses of Prednisolone and antibiotics. He then developed joint pains with stiffness and weight loss. He had no other features of CTD or vasculitis. He was a BT Telecom office worker with no exposure to environmental agents, no family history and was an ex-smoker. Other medical history included type 2 diabetes and benign prostate hypertrophy. He was on metformin, finasteride, tamsulosin, fluoxetine and omeprazole.
He had grade 2 finger clubbing with inspiratory bibasal crepitations. There was mild joint synovitis and systemic review was otherwise unremarkable. CT scan showed interstitial lung disease with UIP pattern. Initial lung function tests showed normal spirometry with TLCo 84% and KCO 86% predicted. Bloods revealed ACE 100, RF 16, MPO-ANCA 6.0, Eosinophilia 0.82 and CRP 7. A CT scan of the sinuses revealed bilateral ethmoidal polyps and moderate deviation of the nasal septum to the right.
Initial treatment with glucocorticoids improved his joints, ENT symptoms significantly and respiratory symptoms marginally. However, his breathlessness and cough deteriorated over the next 6 months alongside lung function and DLco. Repeat CT scan showed progression of ILD with interval worsening of the honeycomb with reducing lung volume. He was tried on MMF but unfortunately deteriorated rapidly which led to hospital admission. CT scan showed new ground glass changes; it was thought to be acute exacerbation of underlying ILD with possible super added infection. He received high dose steroids and antibiotics with no improvement. Serial CXR showed rapid progression consistent with diffuse alveolar damage and he died 8 days after hospital admission.
Discussion
This case wasn’t straightforward. It was difficult to make a unifying diagnosis based on clinical presentation and the investigations. Given the predominant ENT and respiratory symptoms with low levels of MPO the most likely unifying diagnosis considered was primary systemic ANCA vasculitis. Although rare, ILD changes are also seen in MPO positive ANCA vasculitis. The association between interstitial lung disease (ILD) and ANCA-associated vasculitis (AAV), particularly myeloperoxidase MPO - ANCA has been described in the last 2 decades. Given the mild clubbing and rapidly progressing UIP, the alternative diagnosis could have been IPF. However, ENT symptoms and joint pains are usually not associated with IPF. Given the initial response to steroids, further immunosuppression with MMF was started. However, a few days later he was hospitalised due to severe dyspnoea and episodes of haemoptysis. The CT showed new GCO changes on the background of UIP changes and no PE. The dilemma was whether it was drug-induced acute exacerbation of interstitial pneumonitis or natural acceleration of UIP. It was unclear whether he had 2 different pathologies. Disease stratification and early identification of patients who are more prone to progress, and thus in need of more aggressive treatment, is important in the field of ILD.
Key learning points
There is still significant challenge in the diagnosis and management of ILD. It was unclear whether this case was IPF or MPO vasculitis. There are no specific diagnostic markers and there are no consensus clear guidelines on managing ILD. Although considerable progress has been made in understanding ILD, curing and eliminating interstitial lung disease is still a distant goal. A clearer understanding of how the cells fail to adequately repair the lung and key pathogenetic pathways are much needed and require further exploration. Current clinical trials are studying agents that reduce the fibrotic signalling within the lung, reduce pulmonary hypertension associated with interstitial lung disease, and alleviate oxidative stress. Early diagnosis, monitoring and MDT input are essential to improve overall outcomes. This case illustrates the complexity faced by clinicians in the management of ILD patients in the real-life setting and raises a number of points outside of the clinical guidelines.
Conflict of interest
The authors declare no conflicts of interest.
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