Retrospective assessment of islet cell autoantibodies in pancreas organ donors

Organ donor specimens: What can they tell us about type 1 diabetes?

Type 1 diabetes (T1D) is a chronic disease resulting from the destruction of pancreatic beta cells, due to a poorly understood combination of genetic, environmental, and immune factors. The JDRF Network for Pancreatic Organ donors with Diabetes (nPOD) program recovers transplantation quality pancreas from organ donors throughout the USA. In addition to recovery of donors with T1D, non-diabetic donors include those with islet autoantibodies. Donors with type 2 diabetes and other conditions are also recovered to aid investigations directed at the full spectrum of pathophysiological mechanisms affecting beta cells. One central processing laboratory conducts standardized procedures for sample processing, storage, and distribution, intended for current and future cutting edge investigations. Baseline histology characterizations are performed on the pancreatic samples, with images of the staining results provided though whole-slide digital scans. Uniquely, these high-grade biospecimens are provided without expense to investigators, working worldwide, seeking methods for disease prevention and reversal strategies. Collaborative working groups are highly encouraged, bringing together multiple investigators with different expertise to foster collaborations in several areas of critical need. This mini-review will provide some key histopathological findings emanating from the nPOD collection, including the heterogeneity of beta cell loss and islet inflammation (insulitis), beta cell mass, insulin-producing beta cells in chronic T1D, and pancreas weight reductions at disease onset. Analysis of variations in histopathology observed from these organ donors could provide for mechanistic differences related to etiological agents and serve an important function in terms of identifying the heterogeneity of T1D.

Network for Pancreatic Organ Donors with Diabetes (nPOD): developing a tissue biobank for type 1 diabetes

BACKGROUND

The Network for Pancreatic Organ Donors with Diabetes (nPOD) was established to recover and characterize pancreata and related organs from cadaveric organ donors with various risk levels for type 1 diabetes (T1D). These biospecimens are available to investigators for collaborative studies aimed at addressing questions related to T1D natural history and pathogenesis.

RESEARCH DESIGN AND METHODS

Organ donors included T1D patients (new onset to long term), non-diabetic autoantibody-positive subjects, non-diabetic controls and individuals with disorders relevant to β-cell function. Pancreas recovery and transport met transplant-grade criteria. Additional samples recovered included serum, whole blood, spleen and pancreatic and non-pancreatic lymph nodes. Biospecimens were processed for cryopreserved cells, fixed paraffin and fresh frozen blocks and snap frozen samples. T1D autoantibodies, C-peptide levels and high-resolution HLA genotyping for risk alleles were also determined.

RESULTS

Over 160 donors have been enrolled (ages of 1 day to >90 years). Standard operating procedures were established along with a quality management system. Donor demographics, laboratory assays and histopathological characterizations were shared through an open online informatics system. Biospecimens were distributed to more than 60 investigators.

CONCLUSIONS

The nPOD programme provides access to high quality biospecimens without cost to investigators. Collaborations and open data sharing are emphasized to maximize research potential of each donor. On the basis of initial successes, the nPOD programme is expanding to recover additional organs relevant to T1D pathogenesis and complications from European countries (PanFin network).

Collecting high-quality pancreatic tissue for experimental study from organ donors with signs of β-cell autoimmunity

BACKGROUND

The aim of this study was to create a new research strategy to obtain high-quality pancreatic tissues from subjects with preclinical or clinical type 1 diabetes, which would open up new avenues for studying the mechanisms of the β-cell damaging process in humans.

RESEARCH DESIGN AND METHODS

A nationwide collaboration network (the PanFin network) was established in Finland to start an on-call screening of diabetes-associated autoantibodies from deceased organ donors and subsequent processing of pancreases from autoantibody-positive donors. This protocol was integrated into the national organ transplantation procedure.

RESULTS

Only a few modifications were needed to the normal transplantation practices. One additional blood sample was obtained from donors for autoantibody analyses, the transplantation team was informed about the autoantibody result and the pancreas of autoantibody-positive donors was transported to the core laboratory. Altogether, 307 donors were screened and 22 (7.2%) were positive for at least one autoantibody and 3 tested positive for two or more autoantibodies out of the five tested (islet cell antibodies, insulin autoantibodies and autoantibodies to glutamic acid decarboxylase, islet antigen 2 and zinc transporter 8). The quality of collected pancreatic tissue was superior to that from autopsies and allowed the detection of both RNA and proteins.

CONCLUSIONS

The study protocol was proven feasible to be carried out on a nationwide scale. It did not interfere with the normal transplantation activities and provided valuable tissue material for research.

The pancreas in human type 1 diabetes: providing new answers to age-old questions

PURPOSE OF REVIEW

Although studies of pancreata from type 1 diabetes (T1D) patients largely fell dormant for a period of decades, research efforts have recently been 'rekindled' in this area to address, using modern techniques, many unanswered questions related to the pathogenesis of this disease.

RECENT FINDINGS

As historically noted, a pancreatic infiltrate commonly referred to as 'insulitis' is present at the symptomatic onset of T1D. Recent studies have further characterized this infiltrate both in terms of its cellular composition as well as the mechanisms that likely underlie beta cell death in T1D. In addition, the notion that the pancreas from T1D patients is completely devoid of insulin producing cells years after the onset of disease has been challenged, whereas the concepts of whether beta cell regeneration or replication are present have also been subject to much debate. Novel concepts regarding the rate and degree of beta cell loss throughout the natural history of the disease have also been put forward to aid in explaining the disorder's pathogenesis.

SUMMARY

Although answers to many long-standing questions in T1D have recently been addressed, perhaps the main finding has been one supporting a disease of remarkable heterogeneity. However, additional lessons remain to be learned from the pancreas in T1D. Hence, attempts aimed at organizing the scientific community to address these issues are ongoing, particularly those from collaborative efforts, including the Belgium Organ Donor Consortium and the Network for Pancreatic Organ Donors with Diabetes (nPOD).