Blood transfusion groups (1965) Pt. 2 of 2

the best known example of this is the rhesus factor so called because rhesus monkey red cells carry an antigen related to that found in some human red cells in the British population amongst every hundred persons selected at random there are about 83 who possess this racist type antigen and who are classed as rhesus positive and about 17 rhesus negative subjects who like it if such a human rhesus negative subject is injected with rhesus positive red cells antibodies may develop against the rhesus vector for instance a pregnant woman can receive red cells with foreign antigens by transference from her unborn baby some red cells from the baby may enter the mother's circulation if the mother is rhesus negative and these cells are rhesus positive the rhesus positive antigen having been inherited from the father the cells can stimulate the production of anti recess antibodies these antibodies pass back into the unborn child and react with its red cells causing the child to be born suffering from anemia fortunately this is a very rare occurrence being found in only one out of every 200 pregnancies it happens sometimes that a patient develops a very unusual antibody or mixture of antibodies if a transfusion is required a panel of special blood donors from all over the country is consulted to find a donor whose blood is compatible blood donations are stored at above freezing point in a refrigerator so that they do not deteriorate it's the task of the pathologist to determine the blood group of any person likely to need a transfusion from a pilot tube at to the bottle blood is selected from a donor of the same group as the patient and to ensure as far as possible that no reaction will follow a transfusion a sample of the donors red cells is mixed with a sample of the patients in with the perfected techniques available today technical errors are very rare if control tests show the reagents to be working satisfactorily and if no agglutination or lysis of the donors red cells occurs then the blood is safe to be given clerical errors are a possible risk and constant checking of detail is necessary giving of the wrong blood can produce serious and sometimes fatal effects but the giving of blood correctly matched by the methods you briefly seen is often a life-saving measure in desperate circumstances