烧伤后皮肤混合移植中局部免疫抑制的研究

Study of the Immunosuppressive Effect of Intermingled Skin Grafting after Burn

目的 探讨混合皮肤移植的免疫学机制。方法 建立烧伤大鼠混合皮肤移植的动物模型及模拟混合皮肤移植的烧伤患者淋巴细胞、异体表皮细胞、自体表皮细胞的混合培养体系。进行大体和病理观察，淋巴细胞的增殖反应、细胞免疫和体液免疫指标的检测。结果 （１） 组织学检查显示，异体移植于术后１４～２１ 天遭排斥，混合移植处未见明显排异反应。（２） 体外模拟混合移植实验中，自体淋巴细胞对异体表皮细胞的免疫应答强度明显减弱。（３）混合淋巴细胞反应中，异体和混合移植大鼠的外周血淋巴细胞对供者外周血细胞的致敏程度基本相同。（４）ＩｇＧ、ＩｇＡ、ＩｇＭ 在烧伤早期均下降，１４ 天后逐渐恢复至正常范围，２８ 天时处于正常范围的上限。结论 混合皮肤移植中免疫抑制效应是局部而非全身性的，自体表皮起着关键作用；混合皮肤移植时，大鼠的免疫状态并不比单纯异体移植时低下；烧伤后整体免疫功能低下并不是缓解排异。

Objective To explore the immunological mechanism of intermingled skin grafting. Methods We established a rat model, a mixed cells reaction system using auto-lymphocytes and allo-epidermal cells (MELR) and a mixed lymphocyte reactions (MLR). Systemic immunological status were measured by means of MELR, MLR, histology and IgG, IgA, IgM. Results (1) Skin biopsies showed that the rejection of alloskin grafts became enhanced significantly and were higher than that of intermingled grafts after 14～21 days. (2)Adding some auto-epidermal cells to MELC system could induce significant immunosuppression.(3)There were correspondent immunocompetence between peripheral blood lymphocytes of rats in alloskin grafts and in intermingled grafts. (4) The changes of IgG, IgA, IgM in burned rat tended to weaken in the early phase, reached the normal level 14 days postburn,and were the greatest on 28th days. Conclusions The immunosuppressive effect of intermingled skin grafting is a local effect in which auto-skin in the allotypic portion of intermingled grafts played a role; the immunocompetence of the transplantation of intermingled grafts is not lower than that of the transplantation of allo-skin grafts; the cause that the prolonged survival of intermingled skin grafts is not the loss of immunocompetence after burn injury.