Is there a difference between positive or negative group in blood transfusion? Let's say: can the first long-term be a donor for the first negative one?

Antigens of the Rh system (there are more than a dozen of them, but the most immunogenic, that is, the one that can cause the strongest reaction of the immune system, is antigen D - the same positive Rh factor) differ from antigens A and B in that for Rh antigens, there are no preexisting agglutinin antibodies. That is, if a person with blood group A has antigens to the lacking antigen B (those same beta agglutinins), then a person with a negative Rh factor does not have congenital antibodies to D, but he can develop these antibodies if he receives a Rh transfusion -positive or such blood will get through the umbilical cord from the Rh-positive mother during childbirth.

In principle, if an Rh-negative person is transfused with the blood of a Rh-positive donor once, there should not be a big trouble. But often, conditions requiring blood transfusion are not corrected with a single transfusion. A single dose transfusion can raise hemoglobin by about 5 units, that is, for example, a person's hemoglobin is 55 g / l, after a transfusion - 60, and the norm is from 120 in women and from 130 in men. Of course, blood transfusions will not be given to such patients until they reach 120-130, but one transfusion will not be enough. And it will be poured not at one time, but over several days - at a dose per day, say. Under these conditions, when a patient sensitized by this Rh antigen will receive new doses of donor blood in the near future, transfusion of blood of different groups becomes dangerous. Therefore, in modern transfusiology, they try to select a donor not only by the group and Rh factor, but also by 4 more antigens of the Rh system (c, C, E, e) and by the antigen of the Kell system - in order to reduce the number of antigens foreign to it to a minimum (to reduce them to zero is impossible in any case, because there are more than 250 of them, and the ideal donor for any person is either himself or his monozygotic twin).

However, I heard that in the States they bother selecting a donor blood only for antigens A and B, but in such cases, I think, when a transfusion is required, a person will be selected donor blood not just by its group, but by individual selection: that is, they will simply mix a patient's blood sample with a donor blood sample and transfuse only in the event that the reaction of gluing erythrocytes does not appear.

Of course there are. When we say that the blood type is "positive", we mean that there is a certain configuration of proteins on the blood cells that play a role in the recognition of blood cells by the body's defense cells. If we transfuse a person who has Rh negative blood from a person who is positive for this parameter, then the immune defense cells will begin to destroy the infused blood cells, recognizing them as potentially dangerous "outsiders".