Detection of the marker for acute rejection in pancreas islet transplantation

胰岛移植与全胰腺移植相比有几个优点。这种疗法在临床上的建立是可取的。然而，仍有许多障碍限制了该疗法的广泛应用，难以从一个胰腺中分离出足够多的高质量胰岛就是其中之一。为了解决这一问题，我们在胰岛分离前将两层冷冻法应用于胰腺保存，单个胰腺的胰岛产量比通常的保存方法提高了2~3倍。到目前为止，还没有有效的手段来检测胰岛移植的移植排斥反应。为了更好地进行免疫抑制治疗，建立移植物监测系统是必不可少的。在此之前，我们曾报道血清PSTI(胰腺分泌型胰酶抑制物)是胰腺移植急性排斥反应的有用标记物。这一次，我们试图确定PSTI是否也适用于胰岛移植。不幸的是，由于技术原因，无法测量血清PSTI。然后我们把重点放在移植的胰岛所在的肝脏上。在犬自体和(或)同种异体胰岛移植模型中，观察每日血糖水平与肝酶GOT、GPT、β-GTP的关系。在一些同种异体移植模型中，血清GPT升高先于血糖水平升高。在自体移植中，没有观察到这样的变化。我们认为血清GPT可用于检测胰岛移植的急性排斥反应，但特异性不高。组织学检查显示常规HE染色未见明显改变。为了进一步了解胰岛移植中急性排斥反应的机制，必须进行额外的研究，包括特殊染色的组织学检查。

Pancreas islet transplantation has several advantages over whole pancreas transplantation. The clinical establishment of this therapy is desirable. However, there still remains many obstacles which limit widespread application of this therapy.Difficulty in isolating enough islets with sufficient quality from one pancreas is one of such obstacles. For resolve this problem, we applied the two-layer cold storage method to pancreas preservation before islet isolation.The yield of islets from one pancreas becomes two to three fold compared to that with usual preservation method.In this study, we focused on the marker for acute rejection in islet transplantation. So far no useful means to detect graft rejection in islet transplantation are available. For better immunosuppressive protocol, establishment of graft monitoring system is essential. Previously, we reported that serum PSTI (Pancreatic Secretory Trypsin Inhibitor) is an useful marker for acute rejection in pancreas transplantation. This time we sought to determine whether PSTI is also useful in islet transplantation. Unfortunately, for technical reason, measurement of serum PSTI was impossible. Then we focused on the liver where transplanted islets reside. We tried to investigate the relationship between daily blood sugar levels and liver enzymes, such as GOT, GPT, _-GTP in dog auto and/or allo islet transplantation models. Elevation of serum GPT preceding elevation of serum blood sugar level was observed in some allo transplant models. In auto transplant, no such changes were observed. We concluded that serum GPT may be used to detect acute rejection in islet transplant, although the specificity is not high.Histological examination showed no apparent changes in usual HE staining. For further understanding the mechanism of acute rejection in islet transplantation, additional study including histological examination using special staining is mandatory.