The single most important factor in determining whether to perform a transplant between a specific donor and recipient is:
A. Mixed lymphocyte culture assays of the donor and recipientABO blood typing and HLA typing (HLA-A, -B, and - DR) are required before a kidney transplant. The method of screening for preformed antibodies against HLAs (because of prior transplants, blood transfusions, or pregnancies) is evolving. The panel-reactive antibody (PRA) assay is a screening test that examines the ability of serum from a kidney transplant candidate to lyse lymphocytes from a panel of HLA-typed donors. A numeric value, expressed as a percentage, indicates the likelihood of a positive cross-match with a donor. A higher PRA level identifies patients at high risk for a positive cross-match and therefore serves as a surrogate marker to measure the difficulty of finding a suitable donor and the risk of graft rejection.