Historic milestones in the evolution of the crossmatch

The introduction of the serologic crossmatch—first proposed by Hektoen (1907) and first performed by Ottenberg (1908)—made it possible to transfuse blood without fear of unpredictable and potentially disastrous acute hemolytic reactions, most of which were attributable to direct agglutinating (IgM) anti-A, anti-B, or anti-A,B. Previously transfused or previously pregnant recipients continued to experience sporadic hemolytic transfusion reactions as a result of “incomplete” (IgG) blood group antibodies. Coombs’ introduction of the antiglobulin test (1945) made it possible to detect “incomplete” (IgG) antibodies and to develop laboratory methods to identify and transfuse serologically compatible RBCs. During the past 50 years, the antibody screen has evolved to be more effective than the crossmatch for detecting the presence of potential serologic incompatibility and has, in fact, replaced the crossmatch as the key step in pretransfusion compatibility testing. The antibody screen has become the serologic surrogate for the crossmatch and, currently, the computer crossmatch is becoming the electronic surrogate for the crossmatch. In historical perspective, the past 100 years witnessed the rise and fall of the cross-match. Today, hemolytic transfusion reactions are more likely to be the result of misidentifying the intended transfusion recipient than of failure of routine compatibility testing to detect serologic incompatibility. The introduction of the serologic crossmatch—100 years ago—had a major positive impact on all aspects of clinical medicine. As a result of these advances, we are quickly approaching the limits of improving the safety and efficacy of blood transfusions by conventional serologic methods. Future improvements are more likely to be the result of applications of molecular genotyping—which could not have become available at a more perfect time. When Immunohematology publishes its 50th-anniversary issue, the improvements in transfusion science are more likely to be based on molecular methods than on conventional blood bank serology. Immunohematology2009;25:147–151.