Abstract
Autoimmunity has been extensively established as a characteristic feature of the post-COVID-19 syndrome. There is evolving evidence of immune system dysregulation leading to the development of autoimmune phenomena in patients with COVID-19. This immune dysregulation may range from the production of autoantibodies to the new onset of rheumatic autoimmune diseases. An extensive literature search in databases from December 2019 to date revealed that no cases of autoimmune pulmonary alveolar proteinosis (PAP) were reported in post-COVID patients. In this context, we report a novel case series of two cases of new-onset autoimmune PAP in post-COVID patients, an entity that has not been described before. We recommend further studies to better understand this association between new-onset autoimmune PAP and SARS-CoV-2.