Pancreas transplantation: The Wake Forest experience in the new millennium

Pancreas retransplantation

PURPOSE OF REVIEW

Pancreas retransplantation (PRT) remains a topic of debate due to the increased risks involved and advancements in diabetes mellitus management.

RECENT FINDINGS

The majority of PRT are pancreas after kidney (PAK) transplants, typically performed when a primary simultaneous pancreas-kidney (SPK) transplant results in pancreas graft failure while the kidney graft remains functioning. Over the past few decades, the number of PRT procedures has declined, mirroring the decrease in PAK transplant activity. Technical or late immunological loss of the initial pancreas is associated with better PRT outcomes, whereas early immunological failure and sensitization predict poor post-PRT outcome.

SUMMARY

Several critical factors must be considered when evaluating PRT, including the cause and timing of primary pancreas graft failure, as well as the recipient's surgical and immunological profile. PRT outcomes should be interpreted with caution, as most primary pancreas transplants (PT) are SPK, whereas the majority of PRT are solitary PT. When comparing only primary solitary PT to PRT, the outcomes are similar, particularly when performed in high-volume centers.

Banff 2022 pancreas transplantation multidisciplinary report: Refinement of guidelines for T cell-mediated rejection, antibody-mediated rejection and islet pathology. Assessment of duodenal cuff biopsies and noninvasive diagnostic methods

The Banff pancreas working schema for diagnosis and grading of rejection is widely used for treatment guidance and risk stratification in centers that perform pancreas allograft biopsies. Since the last update, various studies have provided additional insight regarding the application of the schema and enhanced our understanding of additional clinicopathologic entities. This update aims to clarify terminology and lesion description for T cell-mediated and antibody-mediated allograft rejections, in both active and chronic forms. In addition, morphologic and immunohistochemical tools are described to help distinguish rejection from nonrejection pathologies. For the first time, a clinicopathologic approach to islet pathology in the early and late posttransplant periods is discussed. This update also includes a discussion and recommendations on the utilization of endoscopic duodenal donor cuff biopsies as surrogates for pancreas biopsies in various clinical settings. Finally, an analysis and recommendations on the use of donor-derived cell-free DNA for monitoring pancreas graft recipients are provided. This multidisciplinary effort assesses the current role of pancreas allograft biopsies and offers practical guidelines that can be helpful to pancreas transplant practitioners as well as experienced pathologists and pathologists in training.

Influence of donor and recipient sex on outcomes following simultaneous pancreas-kidney transplantation in the new millennium: Single-center experience and review of the literature

INTRODUCTION

The influence of sex on outcomes following simultaneous pancreas-kidney transplantation (SPKT) in the modern era is uncertain.

METHODS

We retrospectively studied 255 patients undergoing SPKT from 11/2001 to 8/2020. Cases were stratified according to donor (D) sex, recipient (R) sex, 4 D/R sex categories, and D/R sex-matched versus mismatched.

RESULTS

D-male was associated with slightly higher patient (p = .08) and kidney (p = .002) but not pancreas (p = .23) graft survival rates (GSR) compared to D-female. There were no differences in recipient outcomes other than slightly higher pancreas thrombosis (8% R-female vs. 4.2% R-male, p = .28) and early relaparotomy rates in female recipients (38% R-female vs. 29% R-male, p = .14). When analyzing the 4 D/R sex categories, the two D-male groups had higher kidney GSRs compared to the two D-female groups (p = .01) whereas early relaparotomy and pancreas thrombosis rates were numerically higher in the D-female/R-female group compared to the other three groups. Finally, there were no significant differences in outcomes between sex-matched and sex-mismatched groups although overall survival outcomes were lower with female donors irrespective of recipient sex.

CONCLUSIONS

The influence of D/R sex following SPKT is subject to multiple confounding issues but survival rates appear to be higher in D-male/R-male and lower in D-female/R-male categories.

Patient and graft survival in pancreas transplant recipients: The EFISPAN study

INTRODUCTION AND OBJECTIVES

Graft outcomes in pancreas transplantation have improved in recent decades, but data are mainly derived from registries or prospective single-centre studies. This large epidemiological study was undertaken to investigate the impact of clinical and demographic factors on graft and patient survival in pancreas transplant recipients in Spain, and to provide robust, country-wide, practice-based data to complement registry findings.

PATIENTS AND METHODS

We conducted a retrospective, longitudinal, epidemiological study to assess risk factors impacting patient and graft survival in pancreas transplant recipients in eight centres in Spain. All patients transplanted between 1 January 2008 and 31 December 2012 were included; data were collected until 31 December 2015. The Kaplan-Meier method was used for all time-to-event analyses, including patient survival, graft survival, acute rejection, and BPAR. For graft survival analysis, in cases of death with functioning graft, patients were censored without any event on the date of death. For acute rejection and BPAR, patients were censored without any event on the date of death or graft loss. Univariable and multivariable analyses (Cox proportional hazards model) were conducted to assess the association between baseline clinical and demographic characteristics and patient/graft survival.

RESULTS

Data were included for 241 (80.1%) simultaneous pancreas-kidney transplants, 56 (18.6%) pancreas-after-kidney transplants and 4 (1.3%) pancreas transplants alone. Mean±standard deviation time from diagnosis until transplantation was 26.1±7.5 years. Nineteen patients died, mainly due to infections (n=10); the remaining 282 patients (93.7%) survived from transplantation until the end of the study. Among 55 patients (18.3%) with pancreas graft loss, the main reasons were vascular thrombosis (n=19), chronic rejection (n=10), acute rejection (n=6) and death with a functioning graft (n=5). The overall rate of vascular-related death was 1.3% at 5 years post transplant. Univariable analysis showed that patient age and weight, donor age, previous kidney transplantation, previous cardiovascular events and need for insulin more than 48h post transplantation were significantly associated with pancreas graft survival. Of these, in multivariable analyses pancreas graft survival was inferior in patients who had received a previous kidney transplant prior to pancreas transplantation (log-rank test, p=0.0002). Glucose metabolism, renal function and cardiovascular risk factors were generally stable following transplantation.

CONCLUSIONS

The results of this multicentre study highlight the excellent patient and graft outcomes following pancreas transplantation, with a notably low incidence of cardiovascular events.

Simultaneous pancreas‐kidney transplantation in Caucasian versus African American patients: Does recipient race influence outcomes?

The influence of African American (AA) recipient race on outcomes following simultaneous pancreas‐kidney transplantation (SPKT) is uncertain.

Do pretransplant C-peptide levels predict outcomes following simultaneous pancreas-kidney transplantation? A matched case-control study

Following simultaneous pancreas-kidney transplantation (SPKT), survival outcomes are reported as equivalent in patients with detectable pretransplant C-peptide levels (Cp+) and a "type 2″ diabetes mellitus (DM) phenotype compared to type 1 (Cp negative [Cp-]) DM. We retrospectively compared 46 Cp+ patients pretransplant (≥2.0 ng/mL, mean 5.4 ng/mL) to 46 Cp- (level < 0.5 ng/mL) case controls matched for recipient age, gender, race, and transplant date. Early outcomes were comparable. Actual 5-year patient survival (91% versus 94%), kidney graft survival (69% versus 86%, p = .15), and pancreas graft survival (60% versus 86%, p = .03) rates were lower in Cp+ versus Cp- patients, respectively. The Cp+ group had more pancreas graft failures due to insulin resistance (13% Cp+ versus 0% Cp-, p = .026) or rejection (17% Cp+ versus 6.5% Cp-, p = .2). Post-transplant weight gain > 5 kg occurred in 72% of Cp+ versus 26% of Cp- patients (p = .0001). In patients with functioning grafts, mean one-year post-transplant HbA1c levels (5.0 Cp+ versus 5.2% Cp-) were comparable, whereas Cp levels were higher in Cp+ patients (5.0 Cp+ versus 2.6 ng/mL Cp-). In this matched case-control study, outcomes were inferior in Cp+ compared to Cp- patients following SPKT, with post-transplant weight gain, insulin resistance, and rejection as potential mitigating factors.

Recipient age and outcomes following simultaneous pancreas-kidney transplantation in the new millennium: Single-center experience and review of the literature

The influence of recipient age on outcomes following simultaneous pancreas-kidney transplantation (SPKT) in the modern era is uncertain.

METHODS

We retrospectively studied 255 patients undergoing SPKT from 11/01 to 8/20. Recipients were stratified according to age group: age <30 years (n = 16); age 30-39 years (n = 91); age 40-49 years (n = 86) and age ≥50 years (n = 62 [24.3%], including 9 patients ≥60 years of age).

RESULTS

Three-month and one-year outcomes were comparable. The eight-year patient survival rate was lowest in the oldest age group (47.6% vs 78% in the 3 younger groups combined, p < .001). However, eight-year kidney and pancreas graft survival rates were comparable in the youngest and oldest age groups combined (36.5% and 32.7%, respectively), but inferior to those in the middle 2 groups combined (62% and 50%, respectively, both p < .05). Death-censored kidney and pancreas graft survival rates increased from youngest to oldest recipient age category because of a higher incidence of death with functioning grafts (22.6% in oldest group compared to 8.3% in the 3 younger groups combined, p = .005).

CONCLUSIONS

Recipient age did not appear to significantly influence early outcomes following SPKT. Late outcomes are similar in younger and older recipients, but inferior to the middle 2 age groups.

Outcomes after pancreas retransplantation: is the juice worth the squeeze?

PURPOSE OF REVIEW

Pancreas retransplantations are rarely carried out, and their outcomes are still debatable because of a lack of studies and clinical series on this issue.

RECENT FINDINGS

In general, pancreas retransplantations achieve similar or even higher patient survival than primary transplantations; however, it should be noted that this finding may be biased, as only healthier patients are selected for retransplantation. Graft survival in retransplantations is usually lower than that in primary transplantation, but this comparison may also be biased, as most retransplantations are solitary pancreas transplantations (which are known to have lower graft survival), whereas primary transplantations are mostly simultaneous kidney-pancreas transplantations. Technical loss is similar between primary pancreas transplantations and pancreas retransplantations, but the occurrence of surgical complications is greater in the latter.

SUMMARY

This review summarizes the literature on pancreas retransplantations, comparing them with primary transplantations, and demonstrates that in selected patients in experienced centres, retransplantation can be a valid and effective option for returning the patient to an insulin-free state.

Pancreas-After-Islet Transplantation in Nonuremic Type 1 Diabetes: A Strategy for Restoring Durable Insulin Independence

Islet transplantation offers a minimally invasive approach for β cell replacement in diabetic patients with hypoglycemic unawareness. Attempts at insulin independence may require multiple islet reinfusions from distinct donors, increasing the risk of allogeneic sensitization. Currently, solid organ pancreas transplant is the only remaining surgical option following failed islet transplantation in the United States; however, the immunologic impact of repeated exposure to donor antigens on subsequent pancreas transplantation is unclear. We describe a case series of seven patients undergoing solid organ pancreas transplant following islet graft failure with long-term follow-up of pancreatic graft survival and renal function. Despite highly variable panel reactive antibody levels prior to pancreas transplant (mean 27 ± 35%), all seven patients achieved stable and durable insulin independence with a mean follow-up of 6.7 years. Mean hemoglobin A1c values improved significantly from postislet, prepancreas levels (mean 8.1 ± 1.5%) to postpancreas levels (mean 5.3 ± 0.1%; p = 0.0022). Three patients experienced acute rejection episodes that were successfully managed with thymoglobulin and methylprednisolone, and none of these preuremic type 1 diabetic recipients developed stage 4 or 5 chronic kidney disease postoperatively. These results support pancreas-after-islet transplantation with aggressive immunosuppression and protocol biopsies as a viable strategy to restore insulin independence after islet graft failure.

Practical Applications in Immunohistochemistry: Evaluation of Rejection and Infection in Organ Transplantation

CONTEXT

-Immunohistochemical analysis of tissue biopsy specimens is a crucial tool in diagnosis of both rejection and infection in patients with solid organ transplants. In the past 15 years, the concept of antibody-mediated rejection has been refined, and diagnostic criteria have been codified in renal, heart, pancreas, and lung allografts (with studies ongoing in liver, small intestine, and composite grafts), all of which include immunoanalysis for the complement split product C4d.

OBJECTIVES

-To review the general concepts of C4d biology and immunoanalysis, followed by organ-allograft-specific data, and interpretative nuances for kidney, pancreas, and heart, with discussion of early literature for lung and liver biopsies. Additionally, practical applications and limitations of immunostains for infectious organisms (Polyomavirus, Adenoviridae [adenovirus], and the herpes virus family, including Herpes simplex virus, Cytomegalovirus, Human herpes virus 8, and Epstein-Barr virus) are reviewed in the context of transplant recipients.

DATA SOURCES

-Our experience and published primary and review literature.

CONCLUSIONS

-Immunohistochemistry continues to have an important role in transplant pathology, most notably C4d staining in assessment of antibody-mediated rejection and assessment of viral pathogens in tissue. In all facets of transplant pathology, correlation of morphology with special studies and clinical data is critical, as is close communication with the transplant team.