P121 A complex case of systemic autoimmune rheumatic disease associated with interstitial lung disease

Abstract Introduction We present a case of a patient with systemic autoimmune rheumatic disease associated with interstitial lung disease (SARD-ILD) from acute presentation to long term management over ten years. SARD-ILDs are associated with high morbidity and mortality and can significantly impact a patient’s quality of life. The management of patients with SARD-ILD remains complex. There remains a lack of robust clinical trial evidence to guide treatment. Increasing use of rituximab and publication of NICE guidelines for use of nintedanib for progressive pulmonary fibrosis have improved outcomes. Case description A 50-year-old male presented in 2014 with a cough and progressive breathlessness, initially diagnosed with a community-acquired pneumonia. He required escalation to ITU with severe ARDS, intubation and ventilation. Evaluation, including bronchoscopy, identified no causative organism. Despite extensive courses of antibiotics and antifungals, he deteriorated further. Autoantibody screen including extended myositis screen was notable for positive Anti-Ro52, PM-Scl and weakly positive anti-EJ. High-resolution CT (HRCT) showed extensive consolidation, ground-glass changes and significant established lung scarring. Rheumatology, respiratory, radiology, infectious diseases and ITU teams worked closely together in managing his care. He was treated as a probable cryptogenic organising pneumonia due to underlying SARD-ILD. He initially responded well to IV cyclophosphamide with methylprednisolone pulses, receiving an initial course of nine pulses. Then, in the absence of alternative effective available treatments at the time, maintenance therapy. In total, he received 30 pulses, accumulating a total dose of 40.5g. He subsequently commenced mycophenolate (MMF) with low-dose prednisolone, remaining stable for some years. When antifibrotics became available in 2023, MDT decision was not to start due to stable pulmonary function and lack of progressive fibrotic changes. Subsequently, he developed worsening inflammatory changes on imaging. Rituximab was commenced in addition to ongoing MMF to good effect. In April 2025, he deteriorated again, becoming more breathless over a week. His oxygen saturation was 93% at rest with desaturation on walking to 80%. He was admitted from clinic, the main differential diagnoses were infectious or non-infectious exacerbation of ILD including atypical injections or disease progression despite recently escalated treatment. HRCT showed a massive left pneumothorax which required a chest drain then management under the cardiothoracic surgery team. He responded well and remains stable on rituximab and MMF. He remains under close review and will be commenced on nintedanib if he fulfils criteria via regional ILD MDT. Discussion This case report illustrates some challenges in the long term management of SARD-ILD and how treatments have changed over time. First-line treatments now include short-term steroids in combination with immunosuppressants including MMF, rituximab, cyclophosphamide or azathioprine. Rituximab was not available for this indication when our patient first presented but it is likely this would be given at the outset for a similar presentation today associated with a myositis specific antibody. Antifibrotic medications, specifically nintedanib, have been shown to slow the decline of pulmonary function in patients with ILD. Nintedanib can be used as an add-on treatment in patients with evidence of progressing fibrosis. Indications for this include a decline of ≥ 10% in forced vital capacity, worsening respiratory symptoms, or increased fibrotic changes on HRCT within 24 months. The patient’s clinical deterioration was initially assumed to be an exacerbation of known SARD-ILD, either due to infection or a disease flare or progression, but was ultimately found to be a pneumothorax. A comprehensive assessment for breathlessness is essential to identify alternative causes. Performing an ambulatory desaturation test, which measures oxygen desaturation on walking, can efficiently detect an early desaturation even if resting oxygen saturations are reassuring. This case highlights that the main goals of long-term management are to control the systemic autoimmune disease, as well as prevent or slow down the progression of the ILD in patients with SARDs. Main learning points 1. This case highlights the importance of multidisciplinary working between rheumatology, respiratory, radiology, infectious diseases and intensive care in the acutely sick patient, and early involvement of cardiothoracics in the case of a large pneumothorax. 2. The long-term management of SARD-ILD and how this has evolved over time, including current guideline-based management and indications for antifibrotics. 3. Importance of checking for exertional desaturation in clinic in a breathless patient and not being falsely reassured by oxygen saturations at rest. 4. Consider a broad range of causes for an acute clinical deterioration in an immunosuppressed patient with ILD. Prompt recognition guides targeted interventions and effective management. Learning objectives • To reflect on MDT approaches in the management of patients with SARD-ILD. • To discuss current best practice guidelines for the long-term management of SARD-ILD, including the use for antifibrotics. • To appreciate the clinical significance of various investigations that can be used for ILD patients. • To evaluate alternative causes for acutely deteriorating immunosuppressed ILD patients.