eng Science and Education Publishing American Journal of Medical Case Reports 2374-216X 2021-03-18 9 6 328 330 10.12691/ajmcr-9-6-6 AJMCR2021966 article Amandeep S. Saini 1 Kevin Shayani 1 Jacob Schwartz Jschwartz5@northwell.edu 1 Lenox Hill Hospital, Department of Internal Medicine New York, NY, 10075 Autoimmune hemolytic anemia (AIHA) is an acquired autoimmune disorder characterized by the production of antibodies against red blood cell (RBC) antigens causing reduced circulation time. Diagnosis is based on clinical and laboratory signs of hemolysis and a positive direct antiglobulin test (DAT) after excluding alternative causes for those findings. AIHA is sub-classified according to auto-antibody, cold versus warm, and whether primary or secondary in nature. Warm AIHA is associated with the IgG antibody type and generally causes extravascular hemolysis in the spleen. Cold AIHA is less common, associated with the IgM antibody type, and leads to intravascular hemolysis after activating the classical complement pathway. Throughout the COVID-19 pandemic, it has been noted that hospitalized patients are in a pro-inflammatory state (e.g. elevated D-dimer, ferritin, C-reactive protein) that predisposes them to hematological complications such as venous thromboembolisms (VTE). Although the exact pathophysiology remains unclear, evidence points towards fatal cytokine release. Moreover, there have been case reports of AIHA in a subset of COVID-19 patients and researchers postulate molecular mimicry amongst the epitopes of Ankyrin 1 and viral spike protein as a potential culprit. This case report discusses an elderly patient with multiple co-morbidities who was admitted for acute hypoxemic respiratory failure from COVID-19 and found to have cold agglutinin hemolytic anemia. We are looking to contribute to the current understanding of AIHA as a complication of COVID-19 infection. http://pubs.sciepub.com/ajmcr/9/6/6/ajmcr-9-6-6.pdf coronavirus COVID-19 AIHA anemia hemolysis DAT Coombs test