Q. A 50-year-old female was admitted to the hospital last night with complaints of weakness, easy bruising, and petechiae all over her body. Her platelet count was found to be significantly low on admission laboratory testing, and further evaluation revealed that she was suffering from thrombotic thrombocytopenic purpura (TTP). Her medical history is significant for hypertension and a previous episode of TTP three years ago. On admission, she was started on intravenous immunoglobulin therapy, but her condition did not improve, and her platelet count continued to decrease. Given the severity of her condition and the lack of response to IVIG therapy, you decided that she needed plasma exchange. In addition to plasma exchange, you also start her on high-dose steroid therapy to help control the autoimmune process underlying her TTP. After three plasma exchange procedures, her platelet count is showing a marked improvement today, and you are planning to discharge her from the hospital. Which of the following statements is true regarding blood and plasma ABO compatibility?