犬同种异体下颌区复合器官移植后排斥反应的组织学特征

HISTOLOGICAL FEATURES OF REJECTION PROCESS AFTER COMPOSITE MANDIBULAR ALLOGRAFTS IN CANINES

目的本研究探讨了犬下颌区复合器官移植后排斥反应的组织学特征。方法通过光镜和电镜观察，同种异体下颌区复合器官移植后早期不同器官和组织的组织学变化。结果发现同种异体下颌复合器官移植后不同组织的排斥反应过程是不同的，皮肤、粘膜、肌肉和血管是抗原性较强的组织，皮肤排斥反应过程最为严重且难以控制，肌肉显示出严重的退行性改变和明显的血管炎。牙髓均呈纤维化改变、网状变性或坏死，牙周的反应不十分强烈。长期存活者各个组织如皮肤、肌肉和血管均表现出接近正常的组织学形态。结论如果组织配型和免疫抑制药物得到改善，在将来下颌复合器官的移植的临床应用是完全可能的。感染是移植后局部严重的并发症，其可加重排斥反应对组织的破坏。

Organ allotransplantation has been applied to clinical practice. To research model for the treatmentof major clinical malformation and mutilations, we transplanted composite mandibular allografts in canines. Although mandibular compound organs allotransplantation preliminarily has been attempted in rabbits and monkeys,very little information is available regarding immunopathological characteristics of mandibular compound organs.The present study was undertaken to compare pathological histology features of various mandibular organs after allotranspalntation in canines.Methods: Out-bred canines were used as the recipients and donors. Thirteen canines composite mandibular allotransplantation were done and 5 canines were as control. Biopsy specimens were taken within 1 day, 5 days, 10days, 15 days, 22 days, 67 days and 76 days. Pathological-histology changes were observed using photology microscope and electron microscope.Results: In all operated animals widespread lymphocyte infiltration was seen in the skin, mucosa, muscle andblood vessels of the grafts. The lymphocytes were companied to varying degrees by other mononuclear inflammatorycells. Concentration of inflammatory cells was especially evident in perivascular areas and at the dermal-epidermaljunction. The rejection process was severe and difficult to control in the skin. The muscle showed severe degeneration and severe vasculities. Bone viability was lost, as evidenced by the absence of osteocytes in lacunae and fibrousreplacement of the marrow. Ultrastructural studies showed that the cells in allograft affected by rejection were vascular endothelium. Of interest, one animal had a near normal appearance in skin, mucosa, muscle and vessel afterpost-operated 67 days.Conclusions: Experimental vascularized composite mandibular allotransplantation was carried out, and pathological-histology changes in different tissues of the graft were observed and compared. The results of this study indicated that rejection was the most severe in skin, mucosa and vessel. The most significant complication of post transplantation was infection. Cyclosporine immunosuppressive regimen in this investigation was sufficient to achieveshort-term survival. The possible of long-term allograft survival were expected in future as matching techniques andimmunosuppressive agents improve.