1. Prepared by Dr. Monica Butcher and reviewed by Lorraine N. Blagg, MA, MLS(ASCP)SBB.

Clinical vignette: A middle aged patient was admitted for a neurosurgical procedure requiring transfusion of two pRBC units intraoperatively. Their post-operative hemoglobin initially remained stable between 10 - 11 mg/dL, however down trended to 6.7 mg/dL on post-operative day 12. They have a history of one prior RBC transfusion several years ago and prior pregnancies. The patient types as an A positive with the following antibody detection and direct antiglobulin test (DAT) results on their admission and current sample (day 12).





Question: What is the likely source of reactivity for the positive DAT battery with polyspecific and anti-IgG reagents?