Identification of transplanted pancreatic islet cells by radioactive Dithizone-[131I]-Histamine conjugate. Preliminary report

Background: The unique mechanism of dithizone action in the interior of the viable pancreatic islet suggests the possible development of a specific radiopharmaceutical that may have a potential clinical application in the diagnosis of the pancreatic organ allografts or islets rejection. The radiodiagnostic properties of the newly developed radioactive analogue of dithizone, i.e. Dithizone-[131I]-Histamine conjugate have been evaluated in the present study. METHODS: The four islet cells transplantation models were chosen for this purpose. The most important feature of the Dithizone-[131I]-Histamine conjugate is its possessed ability of zinc chelation. As was presented in the recent study, the conjugate stains pink-reddish the isolated pancreatic islets in vitro. Among the studied transplantation models, only the islets grafting under testis capsule enabled determination of the pancreatic islets in rats by radioactive Dithizone-[131I]-Histamine conjugate. The level of the radioactivity in the recipient testis (right) was almost two times higher compared to the controls (0.24 vs. 0.13% ID/g, respectively). CONCLUSIONS:These preliminary data demonstrate the ability of the developed radioactive analogue of dithizone for in vivo identification of transplanted pancreatic islets, and suggests a potential clinical application of the radiodithizone in the diagnosis of the pancreatic islet rejection

Regulatory evaluation of Glybera in Europe-two committees, one mission

publishersversionPeer reviewe

A Multicenter Study: North American Islet Donor Score in Donor Pancreas Selection for Human Islet Isolation for Transplantation

Selection of an optimal donor pancreas is the first key task for successful islet isolation. We conducted a retrospective multicenter study in 11 centers in North America to develop an islet donor scoring system using donor variables. The data set consisting of 1,056 deceased donors was used for development of scoring system to predict islet isolation success (defined as post-purification islet yield >400,000 islet equivalents). With an aid of univariate logistic regression analyses, we developed North American Islet Donor Score (NAIDS) ranging 0 through 100 points. The c-index in the development cohort was 0.73 [95% confidence interval 0.70 - 0.76]. The success rate increased proportionally as NAIDS increased, from 6.8% success in NAIDS < 50 points to 53.7% success in NAIDS ≥ 80 points. We further validated NAIDS using a separate set of data consisting of 179 islet isolations. Comparable outcome of NAIDS was observed in the validation cohort. The NAIDS may be a useful tool for donor pancreas selection in the clinical practice. Apart from its utility in clinical decision-making, the NAIDS may also be used in research setting as a standardized measurement of pancreas quality