Coronavirus disease 2019 and cold agglutinin syndrome: An interesting case

The coronavirus disease 2019 (COVID-19) pandemic has caused significant morbidity and mortality worldwide. While patients with COVID-19 most frequently present with pneumonia, respiratory failure and acute respiratory distress syndrome, increasing cases of immune-mediated disorders such as autoimmune thrombocytopenia, haemolytic anaemia and antiphospholipid syndrome have been reported. In this article we describe a rare case of cold agglutinin syndrome (CAS) in a patient with COVID-19. The patient was a 77-year-old man with a history of glucose-6-phosphate dehydrogenase (G6PD) deficiency who presented with COVID-19 infection and acute respiratory failure. Initially he was started on intravenous steroids, antibiotics and hydroxychloroquine. Laboratory analysis revealed haemolytic anaemia with a positive direct anti-globulin test (DAT) and high titres of cold agglutinins. Hydroxychloroquine was stopped due to suspicion of haemolysis due to G6PD deficiency but the haemolysis persisted. Unfortunately, the respiratory failure progressed and the patient died. In summary, this article describes a rare case of CAS associated with COVID-19. CAS is a heterogenous group of cold autoimmune haemolytic anaemias occurring secondary to infections or malignancies. No definite treatment for CAS in COVID-19 patients has been approved so far.