COVID-19-associated large-vessel vasculitis with elevated anti-angiotensin converting enzyme 2 antibody: three cases and a review of the literature.

introductionSince the COVID-19 pandemic, a growing number of reports suggest an association between severe acute respiratory syndrome coronavirus 2 and autoimmune diseases, including large-vessel vasculitis (LVV). However, the mechanism remains unclear. This report describes three cases of COVID-19-associated LVV with elevated anti-angiotensin-converting enzyme 2 (ACE2) antibodies. CASE PRESENTATIONS: The first case was a 59-year-old man who developed a persistent headache and fever 2 weeks after SARS-CoV-2 infection. FDG-PET/CT revealed diffuse vascular inflammation extending from the carotid arteries to the abdominal aorta. The second case was a 71-year-old man who presented with prolonged fever after SARS-CoV-2 infection. Imaging demonstrated vascular wall enhancement and FDG uptake from the thoracic aorta to the iliac aorta. The third case was a 67-year-old man who had persistent fever 10 days after COVID-19, with FDG-PET/CT showing uptake from the ascending aorta to the aortic arch. In all cases, workups for immune and infectious diseases were negative. Symptoms and inflammatory markers resolved spontaneously or with nonsteroidal anti-inflammatory drugs. Serum anti-ACE2 IgG was positive during the active phase in all three patients and became negative during remission. DISCUSSION: We have encountered three cases of COVID-19-associated LVV with elevated anti-ACE2 antibodies that normalized after clinical remission. There have been multiple reports of LVV following SARS-CoV-2 infection, with onset typically within weeks of infection, and of elevated anti-ACE2 antibody levels in patients with COVID-19-related neurological complications. Further studies are warranted to determine if anti-ACE2 antibodies are associated with the pathogenesis of post-COVID-19 vasculitis.