Although graft survival rates improved greatly now a days, sensitization of the recipient at the B-cell level and development of IgG antibodies still represents a major problem in kidney transplantation that detected in 17% of patients after first transplant by ELISA screening assay and using the more sensitive Luminex technology, HLA antibodies of the IgG, IgM or IgA isotypes were detected in almost all patients waiting for transplant. Other types of antibodies that directed against-non HLA antigens are important like against graft endothelium, MICA and Angiotensin type I receptor. To reduce such presumed undetected antibody activity below clinically relevant treshold levels peritransplant apharesis was indicated. Heinold et al reported that HLA compatibility significantly influences the outcome of kidney transplants in sensitized retransplant recipients even at the allele level. In addition to that, the interaction between recipient HLA ligand and donor KIR had a significant impact on the outcome of patients receiving HLA matched siblings.