In vitro studies regarding the feasibility of bovine erythrocyte xenotransfusion.

摘要

Pigs are considered the most likely source of organs and tissues should the barriers to xenotransplantation be overcome. The use of animal blood for transfusion, xenotransfusion, would have advantages over blood from random human donors with respect to supply and infection control. Large animals such as cows would be more suitable than pigs for blood donation because of easier venous access and large volume phlebotomy. Blood from 12 Holstein cows was typed and then tested for hemagglutination assay (HA), complement mediated lysis (CML), human IgM and IgG antibody binding, anti-human globulin augmented clinical cross-match and osmotic fragility with normal human serum. Results were compared with porcine erythrocytes (pRBC) and with human type O controls (hRBC). The frequency of ultra-low xenoantigen expressors was tested in a larger herd of various breeds using HA and CML. Median HA and CML titers were one of six (no HA-one of 64) and one of 26 (no CML-one of 64), respectively for bovine erythrocytes (bRBC). Hemagglutination titer was significantly higher for pRBC at one of 170 (one of four-one of 1024). HA and CML were lowest with bovine blood group J. Repeated HA and CML were negative with bRBC from one cow that also tested negative by anti-human globulin augmented cross-match with seven of nine random human sera representing the different blood groups. However, flow cytometry showed that bRBC from all cows bound human IgM and IgG. IgM mean channel fluorescence (MCF) was positively correlated with HA titer. The mean corpuscular fragility of pRBC, bRBC, and hRBC was 0.56, 0.48 and 0.41%, respectively. The frequency of HA-negative and CML-negative cows were 20 and 35%, respectively in herds of 49 animals. Bovine RBC elicit variable in vitro responses from human serum but these are uniformly much less than those seen with pRBC. Bovine RBC is more robust than pRBC. These characteristics including the potential ease and volume of blood collection make the cow a more suitable blood donor than the pig.