Reactive lysis--a phenomenon of delayed hemolytic transfusion reactions.

A 62-year-old female with Gaucher's disease demonstrated alloanti-c on pretransfusion testing. She was transfused with five units of c-negative red blood cells (RBCs) preoperatively and intraoperatively. The hemoglobin (Hb) level was slightly lower initially, hut was markedly lower on day 10 posttransfusion. Serologic results indicated a delayed hemolytic transfusion reaction (DHTR) due to alloanti-s, -Fya, and -Jkb, present both on the RBCs and in the serum. As late as day 35 posttransfusion, a mixed-field anti-IgG direct antiglobulin test (DAT) indicated that there were two cell populations present. The DAT remained positive with anti-C3b, -C3d throughout the course of the reaction. Because of the substantially lower Hb and the severity of symptoms, immunologic clearance of the antigen-positive donor RBCs was expected. However, we demonstrated their persistence. Our data corroborates the observation that complement activation occurring during DHTRs can result in the hemolysis of innocent bystander (autologous) cells.