James V. Harmon

Transplantation of Cultured Islets from Two-Layer Preserved Pancreases in Type 1 Diabetes with Anti-CD3 Antibody

We sought to determine whether or not optimizing pancreas preservation, islet processing, and induction immunosuppression would facilitate sustained diabetes reversal after single‐donor islet transplants. Islets were isolated from two‐layer preserved pancreata, purified, cultured for 2 days; and transplanted into six C‐peptide‐negative, nonuremic, type 1 diabetic patients with hypoglycemia unawareness. Induction immunosuppression, which began 2 days pretransplant, included the Fc receptor nonbinding humanized anti‐CD3 monoclonal antibody hOKT3γ1 (Ala‐Ala) and sirolimus. Immunosuppression was maintained with sirolimus and reduced‐dose tacrolimus. Of our six recipients, four achieved and maintained insulin independence with normal HbA1c levels and freedom from hypoglycemia; one had partial islet graft function; and one lost islet graft function 2 weeks post‐transplant. The four insulin‐independent patients showed prolonged CD4+ T‐cell lymphocytopenia; inverted CD4:CD8 ratios; and increases in the percentage of CD4+CD25+ T cells. These cells suppressed the in‐vitro proliferative response to donor cells and, to a lesser extent, to third‐party cells. Severe adverse events were limited to a transient rash in one recipient and to temporary neutropenia in three. Our preliminary results thus suggest that a combination of maximized viable islet yield, pretransplant islet culture, and preemptive immunosuppression can result in successful single‐donor islet transplants.

Potent induction immunotherapy promotes long-term insulin independence after islet transplantation in type 1 diabetes.

The seemingly inexorable decline in insulin independence after islet transplant alone (ITA) has raised concern about its clinical utility. We hypothesized that induction immunosuppression therapy determines durability of insulin independence. We analyzed the proportion of insulin‐independent patients following final islet infusion in four groups of ITA recipients according to induction immunotherapy: University of Minnesota recipients given FcR nonbinding anti‐CD3 antibody alone or T cell depleting antibodies (TCDAb) and TNF‐α inhibition (TNF‐α‐i) (group 1; n = 29); recipients reported to the Collaborative Islet Transplant Registry (CITR) given TCDAb+TNF‐α‐i (group 2; n = 20); CITR recipients given TCDAb without TNF‐α‐i (group 3; n = 43); and CITR recipients given IL‐2 receptor antibodies (IL‐2RAb) alone (group 4; n = 177). Results were compared with outcomes in pancreas transplant alone (PTA) recipients reported to the Scientific Registry of Transplant Recipients (group 5; n = 677). The 5‐year insulin independence rates in group 1 (50%) and group 2 (50%) were comparable to outcomes in PTA (group 5: 52%; p>>0.05) but significantly higher than in group 3 (0%; p = 0.001) and group 4 (20%; p = 0.02). Induction immunosuppression was significantly associated with 5‐year insulin independence (p = 0.03), regardless of maintenance immunosuppression or other factors. These findings support potential for long‐term insulin independence after ITA using potent induction therapy, with anti‐CD3 Ab or TCDAb+TNF‐α‐i.

Outcome at 3 Years with a Prednisone-Free Maintenance Regimen: A Single-Center Experience with 349 Kidney Transplant Recipients

Historically, late steroid withdrawal after kidney transplants has been associated with an increased rejection rate. Recently, low rejection rates have been reported for recipients treated with complete avoidance or rapid elimination of steroids. However, follow‐up has been short. We herein report on 3‐year outcome in recipients whose prednisone was rapidly eliminated and who were maintained on a steroid‐free regimen. From 10/1/1999 through 5/1/2003, 349 recipients (254 LD, 95 CAD; 319 in first 30 s) were immunosuppressed with polyclonal antibody (Thymoglobulin), a calcineurin inhibitor, either mycophenolate mofetil or sirolimus, and rapid discontinuation of prednisone.

A new enzyme mixture to increase the yield and transplant rate of autologous and allogeneic human islet products

Background. The optimal enzyme blend that maximizes human islet yield for transplantation remains to be determined. In this study, we evaluated eight different enzyme combinations (ECs) in an attempt to improve islet yield. The ECs consisted of purified, intact or truncated class 1 (C1) and class 2 (C2) collagenases from Clostridium histolyticum (Ch), and neutral protease (NP) from Bacillus thermoproteolyticus rokko (thermolysin) or Ch (ChNP). Methods. We report the results of 249 human islet isolations, including 99 deceased donors (research n=57, clinical n=42) and 150 chronic pancreatitis pancreases. We prepared a new enzyme mixture (NEM) composed of intact C1 and C2 collagenases and ChNP in place of thermolysin. The NEM was first tested in split pancreas (n=5) experiments and then used for islet autologous (n=21) and allogeneic transplantation (n=10). Islet isolation outcomes from eight different ECs were statistically compared using multivariate analysis. Results. The NEM consistently achieved higher islet yields from pancreatitis (P<0.003) and deceased donor pancreases (P<0.001) than other standard ECs. Using the NEM, islet products met release criteria for transplantation from 8 of 10 consecutive pancreases, averaging 6510±2150 islet equivalent number/gram (IEQ/g) pancreas and 694,681±147,356 total IEQ/transplantation. In autologous isolation, the NEM yielded more than 200,000 IEQ from 19 of 21 pancreases (averaging 422,893±181,329 total IEQ and 5979±1469 IEQ/kg recipient body weight) regardless of the severity of fibrosis. Conclusions. A NEM composed of ChNP with CIzyme high intact C1 collagenase recovers higher islet yield from deceased and pancreatitis pancreases while retaining islet quality and function.

Pancreas preservation for pancreas and islet transplantation.

Purpose of reviewTo summarize advances and limitations in pancreas procurement and preservation for pancreas and islet transplantation, and review advances in islet protection and preservation. Recent findingsPancreases procured after cardiac death, with in-situ regional organ cooling, have been successfully used for islet transplantation. Colloid-free Celsior and histidine-tryptophan-ketoglutarate preservation solutions are comparable to University of Wisconsin solution when used for cold storage before pancreas transplantation. Colloid-free preservation solutions are inferior to University of Wisconsin solution for pancreas preservation prior to islet isolation and transplantation. Clinical reports on pancreas transplants suggest that the two-layer method may not offer significant benefits over cold storage with the University of Wisconsin solution: improved oxygenation may depend on the graft size; benefits in experimental models may not translate to human organs. Improvements in islet yield and quality occurred from pancreases treated with inhibitors of stress-induced apoptosis during procurement, storage, isolation or culture desirable before islet isolation and transplantation and may improve islet yield and quality. Methods for real-time, noninvasive assessment of pancreas quality during preservation have been implemented and objective islet-potency assays have been developed and validated. These innovations should contribute to objective evaluation and establishment of improved pancreas-preservation and islet-isolation strategies. SummaryCold storage may be adequate for preservation before pancreas transplants, but insufficient when pancreases are processed for islets or when expanded donors are used. Supplementation of cold-storage solutions with cytoprotective agents and perfusion may improve pancreas and islet transplant outcomes.

Rapid Discontinuation of Prednisone in Higher-risk Kidney Transplant Recipients

Prednisone-minimization protocols have been successful in low-risk recipients. We report on the use of a protocol incorporating rapid discontinuation of prednisone in a cohort of kidney transplant recipients (n = 79) at increased immunologic risk. Our data suggests that such recipients should not be excluded from prednisone-minimization protocols.

Donor-specific portal blood transfusion in intestinal transplantation: A prospective, preclinical large animal study

BACKGROUND Unlike in kidney and heart transplantation, the role of pretransplant donor-specific blood transfusion (DST) has not been studied prospectively in a large animal model of bowel transplantation. We investigated the impact of portal versus systemic DST on overall survival, rejection, graft-versus-host disease (GVHD), and infection after total (small and large) bowel transplantation in pigs. METHODS Mixed lymphocyte culture-reactive, outbred pigs underwent total enterectomy and orthotopic total bowel transplantation with portal vein graft drainage. One unit of donor blood was transfused via the portal or systemic circulation (according to a randomization protocol) before graft implantation was begun. We studied six groups, all of which underwent at least a total bowel transplant: group 1 (n=5) comprised nonimmunosuppressed control pigs with portal DST; group 2 (n=6), nonimmunosuppressed control pigs with systemic DST; group 3 (n=5), cyclosporine (CsA)-treated pigs with portal DST; group 4 (n=5), CsA-treated pigs with systemic DST; group 5 (n=5), tacrolimus-treated pigs with portal DST; and group 6 (n=5), tacrolimus-treated pigs with systemic DST. All immunosuppressed pigs received prednisone (2 mg/kg/day) and either CsA (to maintain levels between 250 and 350 ng/ml) or tacrolimus (to maintain levels between 10 and 30 ng/ml). Stomal biopsies and autopsies were obtained to study the incidence of rejection, GVHD, and infection. RESULTS Portal DST and tacrolimus-based immunosuppression resulted in the highest survival rates. At 7, 14, and 28 days after transplantation, survival rates in group 5 were 100%, 100%, and 80%; in group 6, 100%, 60%, and 40%; and in group 3, 100%, 0%, and 0%, respectively. Only the combination of portal DST and tacrolimus prevented the occurrence of, and death from, rejection. Death from rejection at 7, 14, and 28 days in group 5 was 0%, 0%, and 0%; in group 6, 0%, 33%, and 67%; and in group 3, 0%, 100%, and 100%, respectively. Of note, if immunosuppression was used, the groups with portal (versus systemic) DST had a higher risk of death from infection but a lower risk of death from GVHD. Simultaneous immunologic events were noted more frequently in groups with systemic (versus portal) DST. Long-term survival was noted only in groups with tacrolimus-based immunosuppression and was more common for those with portal (versus systemic) DST. CONCLUSIONS Portal DST at the time of total bowel transplantation and posttransplant immunosuppression with tacrolimus prevent rejection and significantly increase graft survival. The combination of portal antigen presentation and tacrolimus needs to be studied in clinical bowel transplantation.

Hemolysis during percutaneous mechanical thrombectomy can mimic a hemolytic transfusion reaction

BACKGROUND: Interventional radiologists have developed percutaneous mechanical thrombectomy (PMT) devices to remove intravascular thrombi. Hemolysis, secondary to thrombus destruction from these devices, has been described in radiology journals, but similar reports appear to be lacking in the transfusion medicine literature. Two cases of hemolysis after PMT are described that involved the transfusion service, one of which was reported as a hemolytic transfusion reaction.

Simulation-based education for transfusion medicine.

The administration of blood products is frequently determined by physicians without subspecialty training in transfusion medicine (TM). Education in TM is necessary for appropriate utilization of resources and maintaining patient safety. Our institution developed an efficient simulation‐based TM course with the goal of identifying key topics that could be individualized to learners of all levels in various environments while also allowing for practice in an environment where the patient is not placed at risk.

Death Caused by Splenic Artery Aneurysm Rupture during Dobutamine–Atropine Stress Echocardiography: Case Report and Literature Review

A 55‐year‐old man developed hypertension and acute epigastric pain during dobutamine–atropine stress echocardiography (DASE). Evaluation—including a helical computed tomography (CT) scan of the abdomen and pelvis, as well as surgical exploration—revealed a ruptured splenic artery aneurysm. The patient died, despite multiple surgical interventions and a massive blood product transfusion. Impressively, no deaths from DASE have been previously reported. Additionally, no adverse sequelae during DASE have been reported in patients with an unruptured abdominal aortic aneurysm ≥4 cm in diameter or with an unruptured intracranial aneurysm. We report the first case, to our knowledge, of death caused by splenic artery aneurysm rupture during DASE. Splenic artery aneurysm rupture during DASE, though rare, can lead to death.