Kidney-pancreas transplantation does not improve retinal arterial flow velocities in type 1 diabetic uremic patients

The impact of pancreas transplantation on diabetic complications: A systematic review

BACKGROUND

Pancreas Transplantation (PT) provides optimal treatment for patients with severe complicated Type 1 Diabetes Mellitus (T1DM). Restoration of beta-cell mass allows return to euglycaemia and insulin independence. We aimed to examine its impact on the secondary complications associated with severe T1DM including diabetic eye disease, neuropathy and cardiovascular disease.

METHODS

A database search using MedLINE to identify publications to April 2023 was conducted. Searches were performed using MeSH terms 'Pancreas Transplantation' AND 'Diabetes Mellitus, Type 1' 'Diabetic Retinopathy' OR 'Heart Disease' OR 'Cardiovascular Diseases' OR 'Peripheral Vascular Disease' OR "Amputation' OR 'Neuropathy."

RESULTS

All articles were retrospective with 51.1 % (n = 23) case control studies and 48.9 % (n = 22) cohort studies. 82.2 % (n = 37) examined simultaneous pancreas and kidney (SPK) transplantation and 17.8 % (n = 8) analysed pancreas transplant alone (PTA). Heterogenous outcomes metrics were employed. 15 studies examined diabetic retinopathy (DR) with 53.3 % (n = 8) demonstrated improvements after PT, while the remainder (n = 7) exhibited stabilisation. 16 studies assessed neuropathy and 87.5 % (n = 14) demonstrated beneficial effects of PT on nerve conduction studies, vibration perception threshold or corneal confocal microscopy. There was a positive effect on cardiovascular disease by reduction in the incidence of cardiac events, improvement in metabolic profile and increased left ventricular ejection fraction. 14 studies examined cardiovascular disease (71.4 % (n = 10) improvement; 14.2 % (n = 2) stabilisation; 14.2 % (n = 2) progression).

CONCLUSION

SPK and PTA have beneficial effects in ameliorating or stabilising diabetes complications. Future work should seek to reduce heterogeneity of outcome metrics assessing T1DM complication profile to facilitate robust comparison of beta-cell replacement interventions.

Role of macrophage in ocular neovascularization

Ocular neovascularization is the leading cause of blindness in clinical settings. Pathological angiogenesis of the eye can be divided into corneal neovascularization (CoNV), retinal neovascularization (RNV, including diabetic retinopathy and retinopathy of prematurity), and choroidal neovascularization (CNV) based on the anatomical location of abnormal neovascularization. Although anti-Vascular endothelial growth factor (VEGF) agents have wide-ranging clinical applications and are an effective treatment for neovascular eye disease, many deficiencies in this treatment strategy remain. Recently, emerging evidence has demonstrated that macrophages are vital during the process of physiological and pathological angiogenesis. Monocyte-macrophage lineage is diverse and plastic, they can shift between different activation modes and have different functions. Due to the obvious regulatory effect of macrophages on inflammation and angiogenesis, macrophages have been increasingly studied in the field of ophthalmology. Here, we detail how macrophage activated and the role of different subtypes of macrophages in the pathogenesis of ocular neovascularization. The complexity of macrophages has recently taken center stage owing to their subset diversity and tightly regulated molecular and metabolic phenotypes. In this review, we reveal the functional and phenotypic characterization of macrophage subsets associated with ocular neovascularization, more in-depth research is needed to explore the specific mechanisms by which macrophages regulate angiogenesis as well as macrophage polarization. Targeted regulation of macrophage differentiation based on their phenotype and function could be an effective approach to treat and manage ocular neovascularization in the future.

Allo- and auto-percutaneous intra-portal pancreatic islet transplantation (PIPIT) for diabetes cure and prevention: the role of imaging and interventional radiology

Although the life expectancy of patients with type 1 diabetes mellitus (T1DM) has improved since the introduction of insulin therapy, the acute life-threatening and long-term complications from diabetes mellitus are significant causes of both mortality and morbidity. Percutaneous intra-portal pancreatic islet transplantation (PIPIT) is a minimally invasive, repeatable procedure which allows a β-cell replacement therapy through a liver islet engraftment, leading to insulin release and glycaemic control restoration in patients with diabetes. Allo-PIPIT, in which isolated and purified islets from cadaveric donor are used, does not require major surgery, and is potentially less expensive for the recipient. In case of long-term T1DM, islet-after-kidney (IAK) transplantation can simultaneously cure diabetes and chronic renal failure, while islet-transplant-alone (ITA) is performed in brittle, short-term T1DM, based on the infusion of an adequate islet mass and on a steroid-free immunosuppressive regimen according to the Edmonton protocol. Results of the Collaborative Islet Transplant Registry (CITR) demonstrate that allo-PIPIT reduces episodes of hypoglycemia and diabetic complications, and improves quality of life of diabetic patients. Auto-PIPIT, in which the own patient's islets are used, has been investigated as a preventive treatment for pancreatogenic diabetes in patients who undergo extensive pancreatectomy for malignant and non-malignant disease. This Review outlines the role of imaging and interventional radiology in allo- and auto-PIPIT.