To Transfuse or Not to Transfuse: A Case of Unresectable Renal Cell Carcinoma-Induced Warm Autoimmune Hemolytic Anemia.

Warm autoimmune hemolytic anemia (WAIHA) is a rare disease. Roughly half of all cases are considered either primary or idiopathic. The remaining cases are typically secondary to a drug reaction or an underlying disease state such as malignancy, infection, or chronic autoimmune disease. Treatments for WAIHA include corticosteroids, intravenous immunoglobulin (IVIG), rituximab, and splenectomy. We present a case of WAIHA with underlying clear cell renal cell carcinoma (RCC) that was unresectable, creating a difficult treatment course. A 76-year-old male with recently diagnosed clear cell RCC was admitted with symptomatic WAIHA and significant hemodynamic instability. Over the course of his admission, he received 25 blood transfusions, erythropoietin, methylprednisolone, IVIG, rituximab, and mycophenolate mofetil in an attempt to control his disease state. He suffered end-organ damage in the form of heart failure with reduced ejection fraction. He was deemed too unstable for RCC resection or interventional cardiac procedures. Determining an appropriate transfusion threshold proved to be a noteworthy challenge. His hemoglobin eventually stabilized to 7.4 g/dL upon discharge over the course of 27 days of treatment. The underlying cause of his WAIHA was believed to be most likely secondary to RCC. WAIHA may have a prolonged treatment course with high risk of mortality if the underlying cause is not resolvable. If this is the case, it can be difficult to determine a hemoglobin transfusion threshold that maintains normal vital signs while minimizing the risk of transfusion-associated circulatory overload (TACO) and transfusion-related acute lung injury (TRALI). Prolonged hemodynamic instability may result in end-organ damage. For our patient, we aimed for a hemoglobin transfusion threshold of 5.0-6.0 g/dL based on his mean arterial pressure (MAP), heart rate, and subjective symptoms.