Autoinflammation Leading to Autoimmunity in Adult Onset Still’s Disease, More Than Simple Coincidence?

Background: Adult onset Still’s disease (AOSD) should be considered in the differential diagnosis of patients with endocarditis, with or without a cardiac decompensation. Case presentation: We report the case of a 68-year-old Caucasian male diagnosed with AOSD after an initial acute manifestation of endocarditis with severe aortic acute manifestation of endocarditis with severe aortic insufficiency. The histological findings revealed Libman-Sacks endocarditis. He was treated with the IL-1 receptor inhibitor anakinra. Two years later the patient developed a symptomatic dilated cardiomyopathy with reduced ejection fraction (23.5%) and functional anti-beta-1-adrenergic receptor antibodies, which was initially treated with plasmapheresis; anakinra was maintained. While his AOSD symptoms responded well, our patient presented with recurrent arthritis in multiple joints, dual energy-CT showed urate deposition compatible with a gouty arthropathy. Over seven years, he presented with recurrent episodes of arthritis and the adjustment of dosages of colchicine and febuxostat was needed. In 2018, our patient died due to a deterioration of his underlying cardiac disease. Conclusions: Only two cases with initial endocarditis prior to AOSD diagnosis have been published and we are not aware of any other cases reporting -β1AR-Ab development with DCM and gout in the setting of AOSD treated with anakinra.