Transfusion laboratory

Transfusion medicine is a branch of medicine that deals with all aspects of transfusion of blood components, from blood donation, processing and preparation of blood components to clinical transfusionology. Clinical transfusionology includes pre-transfusion tests (analyses), administration of transfusion therapy, hemovigilance and the field of hemostasis.

Transfusiological analyzes include determination of the patient’s blood group in the ABO and Rh blood corpuscle systems, screening for the presence of antierythrocyte antibodies, indirect and direct Coombs’ test.

Determining the blood group in the ABO system includes determining the presence of a certain antigen on the surface of erythrocytes with the help of reagents. There are 4 blood groups in this system A, B, AB and O. It is possible to determine subgroups from this system (A2 and A2B). The Rh blood corpuscle system is more complex and consists of the RhD protein, its presence is marked as Rh+, and its absence as Rh-, and RhCcEe protein, which is determined as the Rh phenotype in Rh- routinely, and in Rh+ at the request of the doctor. It is also possible to determine rare variants from the RhD system (RhDweak) – weakly positive.

The blood group is routinely determined for the purpose of planning transfusion care in hospital conditions, but if it is necessary to apply blood components, it must be repeated and a compatibility test is performed in hospital transfusion services.

Antibody screening is carried out using the method of the indirect Coombs test. It is performed in order to examine the presence of clinically significant anti-erythrocyte antibodies in the patient’s plasma, most often during pregnancy, and in order to prevent the development of fetal anemia.

The indirect Coombs test is also performed for diagnostic purposes in patients with hemolytic anemias, autoimmune and malignant diseases.
The direct Coombs test is used to determine the presence of anti-erythrocyte antibodies bound to erythrocytes in the circulation and is also used for diagnostic purposes in hemolytic anemias (differential diagnosis) in autoimmune diseases and malignant diseases.