| Co-Investigator(Kenkyū-buntansha) |
ENDOH Munemiki University of Tokyo, Department of Cardothoracic Surgery, Associate, 医学部・附属病院, 助手 (30312309)
ONO Minoru University of Tokyo, Department of Cardothoracic Surgery, Associate, 医学部・附属病院, 助手 (40270871)
NAKAJIMA Jun University of Tokyo, Department of Cardothoracic Surgery, Lecturer, 医学部・附属病院, 講師 (90188954)
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| Research Abstract |
Background Chemically treated xeno-tissues, such as bio-prosthetic heart valves, have been widely used in clinical stage, however these are not "viable" in human body. On the other hand, cryo-preserved allograft, "homograft", has excellent viability in clinical us, although their supply is very limitted. Viable xeno-tissues, if possible, should show great advantages to these materials. To utilizing this, the suppression of rejection for the tissue should be necessary. To study about the rejection mechanisim, concordant or discordant transplantation model were studied Materials and methods: Single left lung transplantation from monkeys to baboons was studied, as the concordant model. The pathological or immunological study using the grafts was performed. As the discordnat model, hearts from miniture pigs were heterotopically transplanted into infantile monkeys. Results: The xenotransplanted lungs showed moderate to severe infiltration of inflammatory calls, which were mainly consisted of B cells. Anti-specific antibody titres increased as time after transplantation. The hearts transplanted from pig to monkeys were completely rejected within 9 minutes to 6 hours, and they showed the findings of hyperacute rejection, massive intestinal hemorrhage or edema and destruction of capillary destruction. In cases underwent immunosuppressive therapy, the graft survival was prolonged to 5 to 11 days, however, the grafts showed the similar pathological findings with mild cell infiltrations. Conclusions: The xenotransplanted tissues were considered to be rejected by the humoral response, not by the cellullar response as in the allo-transplantation. Immunosuppressive therapy using conservative regimens showed efficacy in suppressing the xeno-rejection mechanism, although not enough. Development of immunosuppressive therapy for the humoral rejection should be needed before utilizing viable xeno-tissues.
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