Impact of GAD65 and IA2 autoantibodies on islet allograft survival.

Introduction: Islet transplantation (ITx) shows promise in treating T1D, but the role of islet autoantibodies on graft survival has not been clearly elucidated. We aimed to analyze the effect of GAD65 and IA2 autoantibody status on graft survival and attainment of insulin independence in subjects with T1D who underwent ITx. Method: We conducted a retrospective cohort study on 47 ITx recipients from 2000 to 2018. Islet infusion was performed via intrahepatic portal (n=44) or onto the omentum via laparoscopic approach (n=3). Immunosuppression involved anti-IL2 receptor antibody, anti-TNF, and dual combinations of sirolimus, tacrolimus, or mycophenolate mofetil (Edmonton-like) in 38 subjects (80.9%). T-cell depletion induction with Edmonton-like maintenance was used in 9 subjects (19%). GAD65 and IA2 autoantibodies were assessed pre-transplant and post-transplant (monthly) until graft failure, and categorized as persistently negative, persistently positive, or seroconverters. Graft survival was analyzed using U-Mann-Whitney test, and Quade's nonparametric ANCOVA adjusted for confounders. Kaplan-Meier and Log-Rank tests were employed to analyze attainment of insulin independence. P value <0.05 indicated statistical significance. Results: ITx recipients with persistent autoantibody negativity (n = 21) showed longer graft function (98 [61 - 182] months) than those with persistent autoantibody positivity (n = 18; 38 [13 - 163] months), even after adjusting for immunosuppressive induction protocol (P = 0.027). Seroconverters (n=8) had a median graft survival time of 73 (7.7 - 167) months, which did not significantly differ from the other 2 groups. Subjects with persistently single antibody positivity to GAD65 (n = 8) had shorter graft survival compared to negative islet autoantibody (GAD65/IA2) subjects (n = 21; P = 0.016). Time of graft survival did not differ in subjects with single antibody positivity to IA2. The proportion of insulin independence attainment was similar irrespective of autoantibody status. Conclusion: The persistence of islet autoantibodies, as markers of islet autoimmunity, may represent an underappreciated contributing factor to the failure of transplanted ß cells. Whether induction with T-cell depletion may lead to improved graft survival, independent of islet autoantibody status, could not be evaluated in our cohort. Larger prospective studies are needed to further address the role of islet autoantibody status on islet graft survival.

Papel inmunomodulador de la vitamina D y los ácidos grasos poliinsaturados omega-3 en trastornos autoinmunes: Revisión de la Literatura / Immunomodulatory role of vitamin D and omega-3 polyunsaturated fatty acids in autoinmune disorders: Literature Review

Los trastornos autoinmunes representan una familia de al menos 80 condiciones diferentes que surgen de una respuesta aberrante del sistema inmunológico resultando finalmente en la destrucción de tejidos y órganos específicos del cuerpo. Es importante destacar que durante las últimas tres décadas los estudios epidemiológicos han proporcionado evidencia de un aumento constante en la incidencia y prevalencia de trastornos autoinmunes. En los últimos años, varios estudios han demostrado que la vitamina D y los ácidos grasos poliinsaturados (AGPs) omega-3 ejercen propiedades inmunomoduladoras y antiinflamatorias sinérgicas que pueden aprovecharse positivamente para la prevención y el tratamiento de trastornos autoinmunes. En este sentido, el reciente ensayo clínico denominado VITAL (ensayo de vitamina D y omega 3); un estudio a gran escala, aleatorizado, doble ciego, controlado con placebo encontró que la suplementación conjunta de vitamina D y AGPs omega-3 (VIDOM) puede reducir la incidencia de enfermedades autoinmunes. En esta revisión de la literatura, resumimos los mecanismos moleculares detrás de las propiedades inmunomoduladoras y antiinflamatorias de la vitamina D y los AGPs omega-3, así como la posible interacción bidireccional entre el metabolismo de la vitamina D y el metabolismo de los AGPs omega-3 que justifica la co- suplementación VIDOM en trastornos autoinmunes(AU)

Autoimmune disorders represent a family of at least 80 different conditions that arise from an aberrant immune system response, which ultimately results in the destruction of specific body tissues and organs. It is important to highlight that during the last three decades epidemiological studies have provided evidence of a steady increase in the incidence and prevalence of autoimmune disorders. In recent years, several studies have shown that vitamin D and omega-3 polyunsaturated fatty acids (PUFAs) exert synergistic immunomodulatory and anti-inflammatory properties that can be positively harnessed for the prevention and treatment of autoimmune disorders. In this sense, the recent clinical trial called VITAL (Vitamin D and Omega 3 trial) - a large, randomized, double-blind, placebo- controlled study - found that co-supplementation of vitamin D and omega-3 PUFAs (VIDOM) can reduce the incidence of autoimmune diseases. In this literature review, we summarize the molecular mechanisms behind the immunomodulatory and anti-inflammatory properties of vitamin D and omega-3 PUFAs, as well as the possible bidirectional interaction between vitamin D metabolism and omega-3 PUFA metabolism that justifies VIDOM co- supplementation in autoimmune disorders(AU)

Prolonged clinical remission of type 1 diabetes sustained by calcifediol and low-dose basal insulin: a case report.

Herein, we describe an unusually prolonged duration (31 months) of the clinical remission phase in a 22-year-old Italian man with new-onset type 1 diabetes. Shortly after the disease diagnosis, the patient was treated with calcifediol (also known as 25-hydroxyvitamin D3 or calcidiol), coupled with low-dose basal insulin, to correct hypovitaminosis D and to exploit the anti-inflammatory and immunomodulatory properties of vitamin D. During the follow-up period, the patient retained a substantial residual ß-cell function and remained within the clinical remission phase, as evidenced by an insulin dose-adjusted glycated hemoglobin value <9. At 24 months, we detected a peculiar immunoregulatory profile of peripheral blood cells, which may explain the prolonged duration of the clinical remission sustained by calcifediol as add-on treatment to insulin.

We describe the case of a 22-year-old Italian man who was treated with a form of vitamin D called calcifediol shortly after the diagnosis of type 1 diabetes, which is an autoimmune condition leading to insulin deficiency and to the lifelong need for insulin therapy. Calcifediol was administered, coupled with low-dose insulin, to correct vitamin D insufficiency and to exploit the anti-inflammatory properties of vitamin D. During the follow-up period (31 months), the patient unexpectedly remained on once-daily insulin injection therapy and maintained near-normal blood glucose levels. These findings suggest that calcifediol administration may represent a valid add-on treatment to insulin, with the aim of reducing daily insulin requirements and improving glucose control in patients with recent-onset type 1 diabetes.

BNT162b2 mRNA COVID-19 Vaccine Does Not Impact the Honeymoon Phase in Type 1 Diabetes: A Case Report.

Type 1 diabetes (T1D), which is caused by the autoimmune destruction of insulin-secreting pancreatic beta cells, represents a high-risk category requiring COVID-19 vaccine prioritization. Although COVID-19 vaccination can lead to transient hyperglycemia (vaccination-induced hyperglycemia; ViHG), its influence on the course of the clinical remission phase of T1D (a.k.a. "honeymoon phase") is currently unknown. Recently, there has been an increasing concern that COVID-19 vaccination may trigger autoimmune phenomena. We describe the case of a 24-year-old young Italian man with T1D who received two doses of the BNT162b2 mRNA (Pfizer-BioNTech) COVID-19 vaccine during a prolonged honeymoon phase. He experienced a transient impairment in glucose control (as evidenced by continuous glucose monitoring) that was not associated with substantial changes in stimulated C-peptide levels and islet autoantibody titers. Nonetheless, large prospective studies are needed to confirm the safety and the immunometabolic impact of the BNT162b2 vaccine in T1D patients during the honeymoon phase. Thus far, T1D patients who are going to receive COVID-19 vaccination should be warned about the possible occurrence of transient ViHG and should undergo strict postvaccination surveillance.

Diabetes-Modifying Antirheumatic Drugs: The Roles of DMARDs as Glucose-Lowering Agents.

Systemic inflammation represents a shared pathophysiological mechanism which underlies the frequent clinical associations among chronic inflammatory rheumatic diseases (CIRDs), insulin resistance, type 2 diabetes (T2D), and chronic diabetes complications, including cardiovascular disease. Therefore, targeted anti-inflammatory therapies are attractive and highly desirable interventions to concomitantly reduce rheumatic disease activity and to improve glucose control in patients with CIRDs and comorbid T2D. Therapeutic approaches targeting inflammation may also play a role in the prevention of prediabetes and diabetes in patients with CIRDs, particularly in those with traditional risk factors and/or on high-dose corticosteroid therapy. Recently, several studies have shown that different disease-modifying antirheumatic drugs (DMARDs) used for the treatment of CIRDs exert antihyperglycemic properties by virtue of their anti-inflammatory, insulin-sensitizing, and/or insulinotropic effects. In this view, DMARDs are promising drug candidates that may potentially reduce rheumatic disease activity, ameliorate glucose control, and at the same time, prevent the development of diabetes-associated cardiovascular complications and metabolic dysfunctions. In light of their substantial antidiabetic actions, some DMARDs (such as hydroxychloroquine and anakinra) could be alternatively termed "diabetes-modifying antirheumatic drugs", since they may be repurposed for co-treatment of rheumatic diseases and comorbid T2D. However, there is a need for future randomized controlled trials to confirm the beneficial metabolic and cardiovascular effects as well as the safety profile of distinct DMARDs in the long term. This narrative review aims to discuss the current knowledge about the mechanisms behind the antihyperglycemic properties exerted by a variety of DMARDs (including synthetic and biologic DMARDs) and the potential use of these agents as antidiabetic medications in clinical settings.

Long-term Persistence of Allosensitization After Islet Allograft Failure.

BACKGROUND: Allosensitization has been reported after discontinuation of immunosuppression following graft failure in islet transplantation (ITx) recipients, though duration of its persistence is unknown. METHODS: We evaluated 35 patients with type 1 diabetes who received ITx, including 17 who developed graft failure (ITx alone, n = 13; ITx plus bone marrow-derived hematopoietic stem cells, n = 4) and 18 with persistent graft function. Panel-reactive antibody (PRA) was measured yearly for the duration of graft function within 1 y after graft failure at enrollment and yearly thereafter. RESULTS: In ITx alone graft failure patients, 61% (8/13) were PRA-positive at 6 y postgraft failure, and 46% (6/13) developed donor-specific anti-HLA antibodies (DSA to 2 ± 1 donors) during follow-up. The degree of sensitization was variable (cPRA ranging between 22% and 100% after graft failure). Allosensitization persisted for 7-15 y. Three subjects (3/13) were not allosensitized. In ITx plus bone marrow-derived hematopoietic stem cell recipients, cPRA-positivity (88%-98%) and DSA positivity persisted for 15 y in 75% (3/4) of subjects. CONCLUSIONS: Allosensitization was minimal while subjects remained on immunosuppression, but after discontinuation of immunosuppressive therapy, the majority of subjects (77%) became allosensitized with persistence of PRA positivity for up to 15 y. Persistence of allosensitization in this patient population is of clinical importance as it may result in longer transplant waiting list times for identification of a suitable donor in the case of requiring a subsequent transplant.

The Role of Vitamin D and Omega-3 PUFAs in Islet Transplantation.

Recurrence of autoimmunity and allograft rejection represent major challenges that impact the success of islet transplantation. Despite the remarkable improvements achieved in immunosuppression strategies after the publication of the Edmonton protocol, long-term data of intra-hepatic islet transplantation show a gradual decline in beta-cell function. Therefore, there is a growing interest in the investigation of novel, safe and effective anti-inflammatory and immunomodulatory strategies able to promote long-term islet graft survival and notable improvements in clinical outcomes of islet transplant recipients. Vitamin D has been shown to exert anti-inflammatory and immunomodulatory effects. Pre-clinical studies investigating the use of vitamin D and its analogs (alone or in combination with immunosuppressive agents and/or other anti-inflammatory agents, such as omega-3 polyunsaturated fatty acids) showed beneficial results in terms of islet graft survival and prevention of recurrence of autoimmunity/allograft rejection in animal models of syngeneic and allogeneic islet transplantation. Moreover, epidemiologic studies demonstrated that vitamin D deficiency is highly prevalent after solid organ transplantation (e.g., heart, liver or kidney transplantation). However, studies that critically assess the prevalence of vitamin D deficiency among islet transplant recipients have yet to be conducted. In addition, prospective studies aimed to address the safety and efficacy of vitamin D supplementation as an adjuvant immunomodulatory strategy in islet transplant recipients are lacking and are therefore awaited in the future.

Influence of Vitamin D on Islet Autoimmunity and Beta-Cell Function in Type 1 Diabetes.

Type 1 diabetes (T1D) is a chronic autoimmune disease leading to immune-mediated destruction of pancreatic beta cells, resulting in the need for insulin therapy. The incidence of T1D is increasing worldwide, thus prompting researchers to investigate novel immunomodulatory strategies to halt autoimmunity and modify disease progression. T1D is considered as a multifactorial disease, in which genetic predisposition and environmental factors interact to promote the triggering of autoimmune responses against beta cells. Over the last decades, it has become clear that vitamin D exerts anti-inflammatory and immunomodulatory effects, apart from its well-established role in the regulation of calcium homeostasis and bone metabolism. Importantly, the global incidence of vitamin D deficiency is also dramatically increasing and epidemiologic evidence suggests an involvement of vitamin D deficiency in T1D pathogenesis. Polymorphisms in genes critical for vitamin D metabolism have also been shown to modulate the risk of T1D. Moreover, several studies have investigated the role of vitamin D (in different doses and formulations) as a potential adjuvant immunomodulatory therapy in patients with new-onset and established T1D. This review aims to present the current knowledge on the immunomodulatory effects of vitamin D and summarize the clinical interventional studies investigating its use for prevention or treatment of T1D.