Blood type definition and tissue typing

There are several blood types: A, B, AB and O. For a donation the blood types do not have to be the same, but they have to be able to tolerate each other, for which special rules apply.

A donor with blood type O is called 'the universal donor'. This donor can donate to a patient with blood type A, B, AB and O. When a patient with blood type O needs an organ him/herself, he/she can only receive from a donor with blood type O.

A donor with blood typ AB is called 'the universal recipient'. This donor can only donate to a patient with blood type AB. When a patient with blood type AB requires an organ him/herself, he/she can receive from the blood types A, B, AB and O.

A donor with blood type A can donate to a recipient with blood type A and AB. When he/she is the patient, he/she can receive from a donor with blood type A or O. 

A donor with blood type B can donate to a recipient with blood type B and AB. When he/she is the patient, he/she can receive from a donor with blood type B or O.

In a diagram the blood type (in)compatibility looks as follows.

Blood types A and O are the most common blood types in Europe. Blood types B and AB are less common. When a donor cannot donate as a result of the blood type, this is called blood type incompatibility (non-matching blood types). 

Tissue typing (HLA typing)

There are many different types of tissue, characterized by special body identification substances; the so-called HLA system. This is a type of unique barcode on your cells, on the basis of which your cells can distinguish foreign cells from their own cells.

We determine the type of tissue via HLA typing through a blood test. The purpose of HLA typing is to find the best possible matching donor for the recipient. If you are a blood relation of the potential recipient, HLA typing may already have been performed in the dialysis center

This test is carried out for living donations to determine the similarities and differences between the tissue types of the potential donor and recipient. This is one of the factors on the basis of which the success of a possible transplantation can be assessed.

Cross-matching

To see whether the recipient has antibodies against the tissue of the donor, we perform cross-matching. In the laboratory we compare the blood of the donor and the recipient.

It may be that the recipient has antibodies against the donor. In that case we speak of positive cross-matching (not good). If cross-matching is positive, transplantation is not possible. If the recipient does not have any antibodies against the donor (negative cross-matching), transplantation is in principle possible.