AB0912 RP-ILD IN PATIENTS WITH ANTI-MDA5 POSITIVE ANTIBODIES: CLINICAL EVALUATION AND PROGNOSIS. RETROSPECTIVE DATA FROM A SINGLE CENTER COHORT

Background Patients with anti-melanoma differentiation-associated gene 5 antibody-positive (anti-MDA5+) dermatomyositis (DM) often develop a rapidly progressive interstitial lung disease (RP-ILD) associated high mortality [1] . Objectives to evaluate clinical features and prognosis of patients anti-MDA5+ DM who developed RP-ILD. Methods Anti-MDA5+ were selected from single center cohort 198 idiopathic inflammatory myopathies (IIM) patients. Data collected retrospectively. Onset manifestations considered muscle, joint, skin involvement. All underwent chest resolution computed tomography (HRCT). RP-ILD was defined by hypoxemia dyspnea radiological worsening within 3 months pulmonary symptoms onset [2] The dosage ferritin during the follow up also evaluated. Muscle involvement assessed myocytolysis indexes Manual Test 8 (MMT-8). Joint judgment. therapeutic approach outcome for each patient. Results based on inclusion criteria 11 identified, 7 males 4 females, aged between 30 67 years (mean age 55.54±9.58 years). duration follow-up 19.9±24.25 months. Cutaneous, pulmonary, joint muscle at 63%, 36%, 36% 9% respectively. Complete serological data are shown in Table 1. Ten (91%) ILD most frequently observed pattern organizing pneumonia (OP) found 60% cases, followed OP/Nonspecific (NSIP) (30%), NSIP (10%). During course, mean time 7.8±7.13 onset. showed higher level than those without 13506±2219.05 vs 473±538.33 ug/L). Immunosuppressive therapy all cyclophosphamide plus tacrolimus and/or plasmapheresis. Two extracorporeal membrane oxygenation. Four died (66%), one SARS-CoV-2 infection three respiratory failure. None non-RP-ILD died. Conclusion our occurred MDA5+ characterized elevated levels. An intense immunosuppressive combination scheme always required. Nevertheless, rate remained high. References [1]M. McPherson et Al. Management MDA-5 antibody positive clinically amyopathic disease: A systematic review. Semin Arthritis Rheum (2022) [2]Y. Li Predictors Mortality Rapidly Progressive Interstitial Lung Disease myopathy: series 474 Front Med (2020) Patient’s Patient Sex Age Associated antibodies Clinical Ferritin (ug/L) Induction Outcome At Radiological RP Steroid Pulses* (mg) N° Cyc infusions ** Tacrolimus/die Plasmapheresis (n° session) ECMO Alive Improved PM 1 F 51 Anti-Ro52, ACPA C - N 1091 250 Y 2 M 59 Anti-Ro52 P OP/NSIP 6 C, 5777 1000 48 OP # 500 1566 55 RF, P, 5879 61 743 56 222 125 9 60 2400 10 Anti Jo-1 106 58 A, 4670 rheumatoid factor; ACPA, anti-citrullinated protein antibodies; OP, pneumonia; , nonspecific Cutaneous; Articular; Pulmonary; Cyc, **750 mg/m2/month; MMF, mycophenolate mofetil; ECMO, Extracorporeal Membrane Oxygenation; PM, pneumomediastinum; *Administered consecutive days; Asymptomatic ILD; Y, Yes; N, No. Acknowledgements: NIL. Disclosure Interests Declared.