Op-brhe200588 1..4

SIR, Thrombosis in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection represents the most relevant extra-pulmonary manifestation of COVID-19 and recognizes a multifactorial pathogenesis [1]. Cases of SARS-CoV-2 disease (COVID-19)related vasculitis are reported in the literature [2–9] and this could represent a possible alternative mechanism of arterial thrombosis secondary to inflammation in COVID19. Herein, we report the first case of neutrophilic arterial vasculitis in COVID-19. A 73-year–old man with a past history of type II diabetes, chronic kidney disease (CKD) and ischaemic coronary disease was admitted to the University Hospital of Modena for shortness of breath and dry cough. Ororhino-pharyngeal swab was positive for SARS-CoV-2 and radiological findings showed interstitial pneumonia. At admission, he had abdominal pain, decompensated ketoacidosis, and acute on CKD (stage 3 b) although he had no respiratory failure (PaO2/FiO21⁄4 341 mmHg). He received antithrombotic prophylaxis with low-molecularweight heparin (LMWH) (4000 U once a day) and continued previous therapy with acetylsalicylic acid (100 mg once a day). Laboratory exams revealed elevated CRP (48 mg/dl) and D-dimer (6910 ng/ml) with normal prothrombin time and activated partial thromboplastin time. The Sequential Organ Failure Assessment (SOFA) score was 2. Antiphospholipid antibodies were not detected. The following day he presented an acute abdomen. Angio-CT showed arterial multifocal thrombosis with total occlusion involving coeliac tripod and superior mesenteric artery with splenic and distal ileum infarction (Fig. 1A). He underwent splenectomy and resection of the ischaemic bowel loop. Two days after surgery, he was discharged from the Intensive Care Unit. He has never been subjected to mechanical ventilation. His post-surgery course was characterized by a second episode of diabetic decompensation, intra-abdominal infection and acute exacerbation of CKD requiring temporary haemodialysis. Sixteen days after the first test, ororhino-pharyngeal swab for SARS-CoV-2 turned negative. Sixty days after admission, the patient is still hospitalized. Surgical complications led to prolonged hospitalization due to nosocomial infections that necessitated specific treatment, such as central venous catheter-related candidemia and infection of a sacral decubitus plaque. Then, in consideration of the patient’s frailty, he underwent a careful and prolonged rehabilitation programme. Histopathological findings confirmed mesenteric and splenic thrombosis with a large splenic infarction. In the splenic hilar area, thrombotic material was observed in the lumen of venous (Fig. 1B) and arterial blood vessels (Fig. 1C). The arterial wall showed transmural necrosis with massive infiltration of neutrophils, mainly in the adventitia and media, the intima being less affected (Fig. 1D and E), providing a histopathological diagnosis of neutrophilic vasculitis. Veins were not involved in the vasculitic process. SARS-CoV-2 was not detected by PCR performed on a paraffinized splenic artery wall specimen. As the patient’s clinical condition significantly improved after surgery, no immunosuppressive therapy was initiated, despite the detection of arterial vasculitis. This complex case scenario and the potential related clinical implications required multidisciplinary discussion among haematologist, rheumatologist, pneumologist and nephrologist. Herein, we report the main issues addressed by each specialist. The haematologic perspective: thrombosis related to inflammation is described both in systemic inflammatory response syndrome and in decompensated ketoacidosis [10]. Recent evidence suggests that patients with severe COVID-19 often meet sepsisinduced coagulopathy criteria and may benefit from anticoagulant therapy [10]. The rheumatologist perspective: histopathological findings of arterial thrombosis in the splenic hilum (Fig. 1C–E) appear to be related to a neutrophilic vasculitis process. These findings share similarities with those described in the acute stage of polyarteritis nodosa (PAN), a medium-sized vessel vasculitis [11] that recognizes an immune-pathogenetic mechanism sometimes associated with viral infections. Similarly to PAN, this patient presented gastrointestinal and splenic involvement with ischaemic complications. However, his clinical condition improved without immunosuppressive treatment while he was using anticoagulant therapy similar to that indicated in thrombotic complications of PAN [12]. The pneumologist perspective: in patients with COVID-19, lung involvement is sustained by direct viral infection alongside cytokine-driven endothelial damage that enhances local inflammation and promotes pulmonary vascular micro-thrombosis [13]. Given these premises, pulmonary vasculitis may enhance lung damage, Rheumatology key message