Current Challenges in Pancreas and Islet Transplantation: A Scoping Review

Type 1 diabetes mellitus is an autoimmune condition characterized by the destruction of pancreatic β-cells, necessitating insulin therapy to prevent life-threatening complications such as diabetic ketoacidosis. Despite advancements in glucose monitoring and pharmacological treatments, managing this disease remains challenging, often leading to long-term complications and psychological burdens, including diabetes distress. Advanced treatment options, such as whole-pancreas transplantation and islet transplantation, aim to restore insulin production and improve glucose control in selected patients with diabetes. The risk of transplant rejection necessitates immunosuppressive therapy, which increases susceptibility to infections and other adverse effects. Additionally, surgical complications, including infection and bleeding, are significant concerns, particularly for whole-pancreas transplantation. Recently, stem cell-derived therapies for type 1 diabetes have emerged as a promising alternative, offering potential solutions to overcome the limitations of formerly established transplantation methods. The purpose of this scoping review was to: (1) summarize the current evidence on achieved insulin independence following various transplantation methods of insulin-producing cells in patients with type 1 diabetes; (2) compare insulin independence rates among whole-pancreas transplantation, islet cell transplantation, and stem cell transplantation; and (3) identify limitations, challenges and potential future directions associated with these techniques. We systematically searched three databases (PubMed, Scopus, and Web of Science) from inception to November 2024, focusing on English-language, peer-reviewed clinical studies. The search terms used were 'transplantation' AND 'type 1 diabetes' AND 'insulin independence'. Studies were included if they reported on achieved insulin independence, involved more than 10 patients with type 1 diabetes, and had a mean follow-up period of at least one year. Reviewers screened citations and extracted data on transplant type, study population size, follow-up duration, and insulin independence rates. We identified 1380 papers, and after removing duplicates, 705 papers remained for title and abstract screening. A total of 139 English-language papers were retrieved for full-text review, of which 48 studies were included in this review. The findings of this scoping review indicate a growing body of literature on transplantation therapy for type 1 diabetes. However, significant limitations and challenges, like insufficient rates of achieved insulin independence, risks related to immunosuppression, malignant diseases, and ethical issues remain with each of the established techniques, highlighting the need for innovative approaches such as stem cell-derived islet transplantation to promote β-cell regeneration and protection.