Coombs-Negative Hemolytic Anemia in an Elderly COVID-19 Patient

COVID-19 infections are known to cause multi-organ complications. Hematological complications like autoimmune hemolytic anemia with a positive direct antiglobulin test (DAT), are commonly encountered. However, Coombs-negative hemolytic anemia is extremely rare. We report an interesting case of an elderly female with moderate-severe acute respiratory distress syndrome in the setting of COVID-19 pneumonia-causing Coombs-negative hemolytic anemia. This patient initially presented with sudden onset abdominal pain and vomiting, found to have an incarcerated inguinal hernia with small bowel obstruction (SBO) on imaging. Additionally, labs revealed positive COVID-19 antigen test and normocytic anemia. The hospital course was complicated by worsening hemolytic anemia and thrombocytopenia requiring blood products. Extensive workup for hemolysis in this patient with no prior hematological abnormalities, was negative for DAT and other conditions associated with or causative of hemolysis. At discharge, hemolytic parameters improved and on follow-up, hemoglobin returned to baseline, and repeat hemolytic parameters were normal. This case emphasizes the importance of considering SARS-CoV-2 along with other viral infections as one of the differentials for Coombs-negative hemolytic anemia.