51: The Westmead Islet Transplant Program Evaluation of Factors Influencing Islet Isolation Outcomes Over 20 Years

Abstract

Aims: Successful islet cell isolation to treat type 1 diabetes is influenced by multiple factors including donor selection, organ procurement and isolation parameters. This study aimed to identify the key contributing factors that affected the outcome of islet preparations in order to proceed to transplantation. Methods: Islets were isolated from DBD donor pancreata using collagenase and neutral protease (SERVA). Donor characteristics, procurement data, isolation yield and outcomes were analysed to determine variables associated with transplantable yields. Data was further divided into Transplanted (Tx) and Non-transplanted (NTx) to identify factors significantly related to successful outcomes. Results: Data collected from 250 islet isolations between July 2000 and February 2019 were evaluated. On average, 28% of islet preparations were transplanted, with 54% of isolations transplanted in the period between 2016–2019. Transplantable yields (were defined as >300,000 IEQ; 4,000 IEQ/kg for a 75kg recipient) were obtained from donors aged between 20–60 years, with BMI >20kg/m2, and weight >60kg. Cold ischaemia times exceeding 10hrs were found to negatively affect isolation yields. Compared to NTx (n=180), Tx (n=70) had significantly higher total IEQ (573,977±29,352 VS 325,563±14,625 IEQ) and IEQ/g pancreas (7,018±388 VS 5,085±274 IEQ/g). The Tx group was significantly associated (p<0.01) with higher donor weight, BMI, pancreas weight, and significantly lower CIT compared to NTx. Tx islets also exhibited significantly higher viability, purity, beta cell viability and stimulation indices compared to Non-tx (p<0.05). Conclusion: Our focus has been to improve our overall outcomes and minimize our costs. A focus on increased donor BMI/weight and lower CIT have contributed significantly to successful islet isolation outcomes, resulting in significant improvements to transplantable yields of islets for treatment of our patients suffering hypoglycemic unaware Type 1 diabetes.