Warm and Cold Autoimmune Hemolytic Anemia in the Setting of COVID-19 Disease

The Importance of Early Suspicion for Cold Autoimmune Hemolytic Anemia

Cold autoimmune hemolytic anemia (cAIHA) is a form of autoimmune hemolytic anemia (AIHA) that most often involves agglutinin antibodies that specifically react to cold temperatures. This process most commonly involves an immunoglobulin M (IgM)-mediated agglutination of erythrocytes and can result in complement-mediated hemolysis, which can range greatly in severity from case to case. Here, we present a case of cAIHA in a 64-year-old male who presented with rapidly progressive and severe hemolytic anemia, which resulted in irreversible decompensation. This case highlights the importance of maintaining a high index of suspicion for cAIHA in patients older adult patients with a previous history of autoimmune hematologic diseases presenting in a rapidly progressive hemolytic state, which can allow for prompt diagnosis, treatment, and mitigation of adverse outcomes.

A Compelling Case of Autoimmune Hemolytic Anemia and Its Potential Association With SARS-CoV-2

Autoimmune hemolytic anemia can be caused by infections, lymphoproliferative disorders, autoimmune disorders, or triggered by drugs or toxins. We present the case of a 92-year-old man admitted with gastrointestinal symptoms. He presented with autoimmune hemolytic anemia. The etiologic study was negative for autoimmune conditions or solid masses. Viral serologies were negative, and RT-PCR for SARS-CoV-2 was positive. The patient began treatment with corticoid, with resulted in cessation of hemolysis and improvement of the anemia. A few cases of autoimmune hemolytic anemia have been reported in COVID-19 patients. In this case, the infection seems to coincide with the hemolysis period, and we found no other cause for this event. So, we highlight the need to search for SARS-CoV-2 as a possible infective cause of autoimmune hemolytic anemia.

Hemolytic anemia in COVID-19

COVID-19 is a global pandemic triggered by the severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2). The SARS-CoV-2 entry point involves the interaction with angiotensin-converting enzyme 2 (ACE2) receptor, CD147, and erythrocyte Band3 protein. Hemolytic anemia has been linked to COVID-19 through induction of autoimmune hemolytic anemia (AIHA) caused by the formation of autoantibodies (auto-Abs) or directly through CD147 or erythrocyte Band3 protein-mediated erythrocyte injury. Here, we aim to provide a comprehensive view of the potential mechanisms contributing to hemolytic anemia during the SARS-CoV-2 infection. Taken together, data discussed here highlight that SARS-CoV-2 infection may lead to hemolytic anemia directly through cytopathic injury or indirectly through induction of auto-Abs. Thus, as SARS-CoV-2-induced hemolytic anemia is increasingly associated with COVID-19, early detection and management of this condition may prevent the poor prognostic outcomes in COVID-19 patients. Moreover, since hemolytic exacerbations may occur upon medicines for COVID-19 treatment and anti-SARS-CoV-2 vaccination, continued monitoring for complications is also required. Given that, intelligent nanosystems offer tools for broad-spectrum testing and early diagnosis of the infection, even at point-of-care sites.