What is the initial step in determining kidney transplant compatibility?

The initial step in determining kidney transplant compatibility is blood type matching. This process involves comparing the blood types of the donor and recipient to ensure they are compatible. Blood type compatibility is crucial because patients can only receive kidneys from donors with compatible blood types; incompatible blood types can lead to severe immune reactions and transplant rejection.

Typically, the ABO blood group system is utilized to assess compatibility. If a recipient has type A blood, they can receive from donors with type A or type O blood. Type B recipients can accept kidneys from type B or type O donors, while type AB recipients can accept from any blood type, and type O recipients can only accept from type O donors.

While tissue typing and cross-matching are also important steps in the transplant process, they follow the initial determination of blood type compatibility. Tissue typing assesses the histocompatibility antigens and cross-matching checks for pre-existing antibodies against the donor's tissue. Evaluating donor age can be relevant for suitability but does not directly relate to immediate compatibility.