IN-VITRO AND IN-VIVO GRAFTING OF XENO PIG FETAL LIVER FRAGMENTS USINGULTRAFILTRATION MEMBRANE

Transplantation of xeno fetal liver fragments (FLF) could be an altern ative or supplementary therapy for acute and chronic liver failure not resolved by routine medical therapies. However, the xenografts themse lves are rejected by the host immune system. To overcome these problem s, immunoisolate capsules with various cutoff points, from 50,000 (YM3 0) to 500,000 (ZM500) were tested for their protective effects on FLF graft survival. In an in vitro study, the capsule with the smallest cu toff size (YM30) had an excellent protective effect on the grafts it c ontained, and showed the Lowest GOT values in the culture supernatant and the normal histological structure. In an in vivo study using rats, the same capsule enabled a FLF graft to survive as long as 21 days, e ven with severe IgG deposition on and within the graft. In another in vivo study, which used beagle dog, however, it did not improve the nat ural course of survival of the graft, which had totally degenerated by day 7. In conclusion, 1) Immunocapsules, especially those with the sm allest cutoff values, impeded the infiltration of the (xeno) humoral a ttacking fatter, but the blocking effect was not complete, as shown by the immunoglobulin (IgG) deposit on the grafts they contained, 2) The FLFs with capsules survived longer than those without capsules-only i n rats, not in beagles, This difference may be attributable to the dif ference of the extent of humoral or nutritional response to the xenogr afts, (C) 1998 Elsevier Science Inc.