When you think you should transfuse…don't!

A 48-year-old female presented to the emergency department with severe fatigue. Admission laboratory test results were hemoglobin 6.6 g/dL, platelet count 287,000/μL, and white blood cell count 25,200/μL. Lactate dehydrogenase was elevated at 898 U/L, haptoglobin was markedly decreased (< 31 mg/dL), indirect bilirubin was elevated (5.3 mg/dL), and the absolute reticulocyte count was low at 0.0050/μL. A sample was sent to the immunohematology reference laboratory. The direct antiglobulin test immunoglobulin G was negative; C3 was 1+. All cells were reactive at immediate spin phase, indirect antiglobulin testing (IAT) with polyethylene glycol, with low ionic strength saline, neat, prewarm, and in the solid phase. All cells were nonreactive at IAT-ficin. Additional testing included a cold antibody titer that was 1:4096 and thermal amplitude studies demonstrating reactivity of 2+ at 37°C. These results were consistent with a clinically significant anti-Pr and cold agglutinin disease (CAD). Although rituximab is effective in autoimmune hemolytic anemia, this may take weeks. The patient was treated with pegcetacoplan, a pegylated peptide that targets C3 inhibiting hemolysis. The patient was discharged on day 29 with a hemoglobin of 8 g/dL. This is a report of one of the first patients successfully treated with pegcetacoplan for CAD.