[Anti-HLA antibodies after bone graft and their impact on kidney transplant programs]

Immunological evaluation by panel reactive antibody (PRA) and determination of anti-HLA specificity is an important phase in the assessment of patients awaiting kidney transplant. The main causes of immunization are previous solid organ transplants, blood transfusions, and pregnancy; immunogenicity can also be triggered by vascularized tissue grafts. Immune induction by cryopreserved bone allografts is not yet fully understood. We report the case of a 19-year-old patient with osteosarcoma who underwent resection of the left proximal tibia with reconstruction using human bone in 1997 (donor typing: A3, A29 (19) - B44 (12), Bw4 - DR13 (6), DR7, DR52, DR53). The patient was subsequently placed on the waiting list for a cadaver donor kidney transplant because of chronic kidney failure caused by cisplatin toxicity. Pretransplant immunological screening using the CDC (complement dependent cytotoxicity) technique revealed a PRA of 63% and anti-A3 and anti-A68 antibodies. The presence of IgG antibody specificity against class I and class II donor antigens (specifically anti-A3, B44, DR7 antibodies) was highlighted using flow cytometry (Tepnel-Luminex). Further immunological studies using single HLA specificity analysis (LSA Class I - II - Tepnel-Luminex) detected direct antibodies against all donor antigen specificities. This is the first reported case of immune induction after a bone graft in a kidney transplant candidate. It underlines the importance of the availability of HLA typing data of all human allograft donors.