Rediscovering the Coombs test
The antiglobulin, or Coombs test is part of the compatibility tests that any patient who will receive a red blood cell transfusion must undergo. This test is also essential in the diagnostic work of patients with anemia whose origin is not easily determined and when the etiology must be identified precisely. In 1945, Robin Coombs, Arthur Mourant and Rob Race described a test to detect anti Rho (anti D) non agglutinant antibodies. Originally, the test was devised by Robin Coombs as part of his postgraduate studies at Race and Mourant's laboratory in Cambridge, England in 1945. His goal was to study the characteristics of the antibodies involved in the context of what was known as fetal erythroblastosis, which is now known as hemolytic disease of the newborn (HDN) caused most frequently by the incompatibility between an Rh negative mother sensitized during a previous pregnancy, who produces IgG anti D antibodies able to pass the placenta barrier due to their small size that then cover the fetal red blood cells. These are later phagocytosed in the spleen and liver, organs which, in addition to their other functions, maintain extramedullary hematopoiesis in the fetus to compensate for anemia resulting from hemolysis. Later, the Coombs test was used to demonstrate the presence of incomplete antibodies which covered the erythrocytes in vivo, such as is seen in cases of autoimmune hemolytic anemia (AHA) The description of the method,