Islet cell allotransplantation in diabetic patients. Histologic findings in four adults simultaneously receiving kidney or liver transplants

Refined methods of islet cell purification have led to unprecedented success of islet cell allotransplantation via portal vein infusion in diabetic patients, resulting in marked reduction of exogenous insulin requirements and recently even insulin independence. The authors report the histologic findings of islet cell allografts in the liver of four patients who had undergone combined kidney-islet or liver-islet transplantation. Islet cell clusters were detected in subcapsular location at the edge of portal triads. The early post-transplant period was characterized by patchy mixed portal infiltrates. Only minimal inflammation but decreased islet cell granulation was observed in one patient 6 months after transplantation. As histologic detection of transplanted islet cells becomes available, additional parameters for evaluation of graft survival might be defined by morphologic assessment.

Conversion of liver allograft recipients from cyclosporine to FK506 immunosuppressive therapy--a clinicopathologic study of 96 patients

The effect of conversion from cyclosporine-steroid immunosuppression to the new agent FK506 was studied in 96 liver allograft recipients who were experiencing graft dysfunction or cyclosporine toxicity. Patients were stratified according to the cause of graft dysfunction that ultimately led to conversion to FK506. Response to FK506 introduction was monitored pathologically and biochemically. The outcome of a switch from CsA to FK506 was highly favorable in patients experiencing acute and the early stages of chronic rejection, despite optimal conventional therapy. Patients with later stages of chronic rejection did not respond to conversion to FK506 and most eventually lost their liver grafts in this process. Patients in whom we had difficulty separating chronic rejection from chronic persistent or low-grade chronic active hepatitis were mostly unaffected by conversion to FK506. Active hepatitis was a poor indication for conversion, because most of the patients experienced graft failure or died from liver failure. As a group, there was no statistically significant change in renal function 180 days after conversion to FK506. These findings expand the experience with FK506 in human liver allograft recipients.

Cadaveric small bowel and small bowel-liver transplantation in humans

Five patients had complete cadaveric small bowel transplants under FK506 immunosuppression, one as an isolated graft and the other 4 in continuity with a liver. Three were children and two were adults. The five patients are living 2-13 months posttransplantation with complete alimentation by the intestine. The typical postoperative course was stormy, with sluggish resumption of gastrointestinal function. The patient with small intestinal transplantation alone had the most difficult course of the five, including two severe rejections, bacterial and fungal translocation with bacteremia, renal failure with the rejections, and permanent consignment to renal dialysis. The first four patients (studies on the fifth were incomplete) had replacement of the lymphoreticular cells in the graft lamina propria by their own lymphoreticular cells. Although the surgical and after-care of these patients was difficult, the eventual uniform success suggests that intestinal transplantation has moved toward becoming a practical clinical service.

Human islet isolation and allotransplantation in 22 consecutive cases

This report provides our initial experience in islet isolation and intrahepatic allotransplantation in 21 patients. In group 1, 10 patients underwent combined liver-islet allotransplantation following upper-abdominal exenteration for cancer. In group 2, 4 patients received a combined liver-islet allograft for cirrhosis and diabetes. One patients had plasma C-peptide greater than 3 pM and was therefore excluded from analysis. In group 3, 7 patients received 8 combined cadaveric kidney-islet grafts (one retransplant) for end-stage renal disease secondary to type 1 diabetes mellitus. The islets were separated by a modification of the automated method for human islet isolation and the preparation were infused into the portal vein. Immunosuppression was with FK506 (group 1) plus steroids (groups 2 and 3). Six patients in group 1 did not require insulin treatment for 5 to greater than 16 months. In groups 2 and 3 none of the patients became insulin-independent, although decreased insulin requirement and stabilization of diabetes were observed. Our results indicate that rejection is still a major factor limiting the clinical application of islet transplantation in patients with type 1 diabetes mellitus, although other factors such as steroid treatment may contribute to deteriorate islet engraftment and/or function.

Immunopathology of antibodies as effectors of orthotopic liver allograft rejection

We have come a long way in our understanding of antibodies as effectors of liver graft damage, but we still have much to learn. Animal heterografts provided the first evidence that livers are susceptible to antibody-mediated damage. The pathophysiologic events are similar to those of extrahepatic organ grafts, but the liver is relatively resistant and rapidity of graft destruction is slower, if it occurs at all. Nevertheless, the ABO isoagglutinins can predictably cause human liver allograft failure, often in a quickened, but rarely a hyperacute fashion. The liver is more resistant to lymphocytotoxins, and in many cases will suffer no apparent damage. However, when present, a spectrum of graft pathologic changes can be seen. Early manifestations include hemorrhagic necrosis and lesions mimicking "preservation" injury. Later on, ischemic biliary necrosis and small bile duct loss may be seen. The variability is likely related to a balance between destructive antibody class, specificity, and titers and the ability of the liver to withstand the assault. More precise characterization of lymphocytotoxic antibodies is needed in clinical practice. In addition, antigen distribution in the graft, release of soluble MHC antigens, the role of Kupffer cells and other mechanisms of liver resistance are likely areas of fruitful investigation.

Detection of intrahepatic human islets following combined liver-islet allotransplantation

This article describes the localization of intact insulin-containing intrahepatic islets after combined liver-islet allotransplantation. The patient was a 36-year-old woman who underwent upper abdominal exenteration for neuroendocrine carcinoma; 289,000 islets were transplanted via portal vein infusion immediately after complete revascularization of the liver. Immunosuppression was with low-dose FK-506. OKT3 and steroids were used to treat one rejection episode 2 weeks after transplantation, but the patient subsequently developed multiple infections and died 109 days after transplantation. At autopsy, the transplanted liver did not show any sign of rejection and well-preserved islets were present in portal triads sampled from the anterior inferior edge of the right lobe. Immunohistochemical labeling confirmed the presence of insulin-containing cells. This finding indicated that human islets can survive after intrahepatic allotransplantation, despite positive cross-match with no HLA antigen match, suggesting that upper abdominal exenteration and liver transplantation may constitute a protective factor for the survival of allogeneic human islets.

Composition of human islet cell preparations for transplantation

To study the cellular composition of human islet cell isolates for transplantation, formalin-fixed and paraffin-embedded cell pellets were stained by the immunoperoxidase method with a panel of antibodies characterising endocrine, epithelial, soft tissue and haematolymphoid components. Immediately after separation, the isolates contained 30-80% islet cells, differing mainly in the content of islet and acinar cells, whereas the soft tissue, ductal/ductular and haematolymphoid elements comprised a relatively constant 10-20%. After 1 week in culture the islet cell content of less highly purified isolates (30-40% islets) dropped dramatically to 5%. The highly purified isolates (70-80% islets) showed only a minimal change in cellular composition; however, approximately two-thirds of islet cells were degranulated and did not stain for insulin. Haematolymphoid components were still present in all cultured isolates. We conclude that primarily mechanical purification methods and short-term culture are not sufficient to eliminate highly immunogenic cells. In addition, short-term culture is deleterious to the isolate if a significant number of acinar cells is still present after enrichment.

Outcome of human islet isolation and allotransplantation in 20 consecutive cases

This report provides our initial experience on islet isolation and intrahepatic allotransplantation in 20 patients. In Group 1, 10 patients underwent combined liver-islet allotransplantation following upper-abdominal exenteration for cancer. One patient underwent pancreatic islet allograft after near total pancreatectomy for chronic pancreatitis. In Group 2, 3 Type I diabetic patients received a combined liver-islet allograft for cirrhosis and diabetes. In Group 3, 7 Type I diabetic patients received 8 combined cadaveric kidney-islet grafts (one retransplant) for end stage renal disease. The islets were separated by a modification of the automated method for human islet isolation and the preparations were infused into the portal vein. Immunosuppression was with FK-506 (Group 1) plus steroids (Groups 2 and 3). Six patients in Group 1 did not require insulin treatment for 5 to >16 mo. In Groups 2 and 3 none of the patients became insulin-independent, although ongoing C-peptide secretion, decreased insulin requirement and stabilization of diabetes were observed. Our results indicate that islet transplantation is most effective in pancreatectomy induced diabetes. However, rejection is still a major factor limiting the clinical application of islet transplantation in patients with Type I diabetes mellitus. Other factors such as steroid treatment may contribute to deteriorate islet engraftment and/or function.

Stability and sorption of FK 506 in 5% dextrose injection and 0.9% sodium chloride injection in glass, polyvinyl chloride, and polyolefin containers

The effects of the diluent, the storage container, light, and infusion through various types of tubing on the stability and sorption of FK 506 were studied. Solutions of FK 506 in 0.9% sodium chloride injection or 5% dextrose injection were stored at room temperature (24 +/- 2 degrees C) in glass i.v. bottles, polyvinyl chloride (PVC) minibags, and polyolefin containers. FK 506 solution in 0.9% sodium chloride injection was stored in plastic syringes at room temperature and either exposed to normal room light or stored in the dark. FK 506 solution in 5% dextrose injection was placed in plastic syringes and infused through PVC anesthesia extension tubing, PVC i.v. administration set tubing, and fat emulsion tubing over a two-hour period. The infused samples and samples collected from the containers and syringes at intervals up to 48 hours were analyzed for FK 506 concentration by high-performance liquid chromatography. FK 506 concentrations remained greater than 90% of initial concentration for admixtures in 5% dextrose injection stored in glass bottles for 48 hours and for admixtures in 5% dextrose injection or 0.9% sodium chloride injection stored in polyolefin containers for 48 hours. No change in concentration was measured for admixtures in 0.9% sodium chloride injection stored in plastic syringes, and exposure to light did not affect the stability of FK 506 solution. No substantial change in concentration occurred in FK 506 solution in 5% dextrose injection infused through PVC anesthesia extension tubing, PVC i.v. administration set tubing, or fat emulsion tubing. FK 506 admixtures prepared with 5% dextrose injection or 0.9% sodium chloride injection should be stored in polyolefin containers. If polyolefin containers are not available, solutions should be prepared with 5% dextrose injection and stored in glass bottles.