P154 Real-world audit of patients with idiopathic inflammatory myositis-related interstitial lung disease in a European population

Abstract

Abstract Background/Aims The British Society for Rheumatology (BSR) has released guidelines for managing idiopathic inflammatory myositis (IIM). Our centre operates specialist clinics for scleroderma and lupus, but to date, IIM patients are seen in a general CTD clinic. As part of work to establish a dedicated myositis clinic, we collated data on 71 patients under active follow-up with myositis spectrum disease deemed appropriate for follow-up within a specialist clinic. We aimed to review patients diagnosed with IIM-ILD and review serological immune profile, screening practices for pulmonary involvement, findings on CT/pulmonary function tests (PFTs) and pharmacological management. Methods We performed a detailed retrospective review of the notes of suitable patients, identified using diagnostic codes attached to clinic letters. Results 71 patients were identified: 14 with anti-synthetase syndrome (ARS), 21 with dermatomyositis (DM), 13 with polymyositis (PM), 3 with immune-mediated necrotising myopathy (IMNM) and 17 with overlap syndrome. 65% (46/70) of adult IIM patients were screened for pulmonary involvement. Screening practices of patients based on antibody profile and myositis subtype are further described in the table. 31% of patients (22/70) had IIM-ILD, of which 12 had ARS, 4 had PM, 1 had DM and 5 had overlap disease (2 PM/scleroderma, 1 DM/ARS, 1 DM/scleroderma and 1 scleroderma/ARS). 21/22 underwent PFTs; 53% of patients had active ILD over an average of 51.8 months. On imaging, 76.2% (16/22) had changes consistent with ILD. Ground glass change and reticulation were demonstrated in 50% of scans. In comparison, honeycombing and traction bronchiectasis was found in 22% and 44% of scans, respectively. A non-specific interstitial pneumonia (NSIP) pattern was described in 44% of scans, organising pneumonia (OP) pattern in 22%, and 17% had a mixed OP and NSIP pattern. 20/22 patients were prescribed high-dose steroids, csDMARD therapy or aggressive immunosuppression (cyclophosphamide or rituximab). Conclusion Our review demonstrates that 65% of patients with adult IIM were screened for ILD. NSIP and OP were the most common radiological appearances. Half of our cohort required aggressive immunosuppression, cyclophosphamide being the most commonly prescribed agent and mycophenolate being preferred for maintenance therapy. No patients were prescribed tacrolimus or ciclosporin. Despite treatment, 52% of patients had evidence of progressive disease on serial PFTs. Disclosure A. Loganathan: Grants/research support; Arthritis Australia. S. Sturney: None. N. Foley: None. T. Hartley: None. S. Tansley: None.