Autoantibodies in diabetes

Management of endocrine immune-related adverse events of immune checkpoint inhibitors: an updated review

Immune checkpoint inhibitors (ICIs) belong to a new group of anticancer drugs targeting T-cell proteins involved in the activation of immune response toward malignancies. Their introduction into clinical practice was a milestone in modern cancer treatment. However, the significant advantage of ICIs over conventional chemotherapy in terms of therapeutic efficacy is accompanied by new challenges related to specific side effects. ICI-induced immune system activation could lead to the loss of self-tolerance, presenting as autoimmune inflammation and dysfunction of various tissues and organs. Thus, the typical side effects of ICIs include immune-related adverse events (irAEs), among which endocrine irAEs, affecting numerous endocrine glands, have been commonly recognized. This review aimed to outline the current knowledge regarding ICI-induced endocrine disorders from a clinical perspective. We present updated information on the incidence and clinical development of ICI-induced endocrinopathies, including the most frequent thyroiditis and hypophysitis, the rarely observed insulin-dependent diabetes mellitus and primary adrenal insufficiency, and the recently described cases of hypoparathyroidism and lipodystrophy. Practical guidelines for monitoring, diagnosis, and treatment of ICI-related endocrine toxicities are also offered. Rising awareness of endocrine irAEs among oncologists, endocrinologists, and other health professionals caring for patients receiving ICIs could contribute to better safety and efficacy. As immunotherapy becomes widespread and approved for new types of malignancies, increased incidences of endocrine irAEs are expected in the future.

New era of therapy for endocrine autoimmune disorders

The new era of immune and reconstitution therapy of autoimmune disorders is ongoing. However, endocrine autoimmune diseases comprise a group of elaborating pathologies where the development of new treatment strategies remains slow. Substitution of the missing hormones is still standard practice, taking care of the devastating symptoms but not the cause of disease. As our knowledge of the genetic contribution to the aetiology of endocrine disorders increases and early diagnostic tools are available, it is now possible to identify persons at risk before they acquire full-blown disease. This review summarizes current knowledge and treatment of endocrine autoimmune disorders, focusing on type 1 diabetes, Addison's disease, autoimmune thyroid diseases and primary ovarian insufficiency. We explore which new therapies might be used in the different stages of the disease, focus on legalized therapy and elaborate on the ongoing clinical studies for these diseases and the research front, before hypothesizing on the way ahead.

A plasmonic nanoledge array sensor for detection of anti-insulin antibodies of type 1 diabetes biomarker

Here we present a plasmonic nanoledge device with high sensitivity and selectivity used to detect protein biomarkers simply by functionalizing the device, which specifically binds to particular biomolecule or biomarkers. We employ this plasmonic nanoledge device for the detection of anti-insulin antibodies of type 1 diabetes (T1D) in buffer and human serum at the range of pg ml^-1 to 100 ng ml^-1. The signal transduction is based on the extraordinary optical transmission (EOT) through the nanoledge array and the optical spectral changes with the biological binding reaction between the surface functionalized insulin with anti-insulin antibody. Control experiments indicate little interferences from the human serum background and addition of other proteins such as bovine serum albumin (BSA) and epidermal growth factor (EGF) at 20 ng ml^-1. The high sensitivity, specificity and easy adaptability of the plasmonic device offer new opportunities in biosensing and diagnostic applications for T1D.

Evaluation of the usefulness of protocol-based pharmacist-facilitated laboratory monitoring to ensure the safety of immune checkpoint inhibitors in patients with lung cancer

WHAT IS KNOWN AND OBJECTIVE

Immune checkpoint inhibitors can cause immune-related adverse events (irAEs). Improved monitoring systems for irAEs, which include laboratory tests by a qualified multidisciplinary team, might prevent patients from irAE-associated events. Kobe City Medical Center General Hospital developed protocol-based pharmacist-facilitated laboratory tests named protocol-based pharmacotherapy management (PBPM) to aid the administration of immunotherapy to patients with lung cancer. The protocol defines the laboratory test items and times at which they should be performed. It requires pharmacists to check laboratory orders initiated by physicians and enter additional test items if the orders are incomplete. We evaluated the efficacy of PBPM in irAE monitoring and compared it with those of conventional care systems.

METHODS

From January 2016 to March 2018, 114 patients with lung cancer received immunotherapy, which was managed by conventional care (conventional group). From April to September 2018, 62 patients were managed by PBPM (PBPM group), among those 28 patients were transited from conventional group to PBPM group. Data on whether the laboratory tests were conducted or omitted were collected retrospectively for the conventional group and prospectively for the PBPM group.

RESULTS

Within the conventional group, 4604 (87.6%) out of the 5253 laboratory test items were ordered by physicians. Of the remaining 649 test items, 224 (4.3%) items were added by physicians based on recommendations by pharmacists. However, of the 1581 (86.6%, from among 1826) test items that were previously ordered by physicians, only 231 (12.7%) test items were added by pharmacists. The execution rate was found to be significantly higher in the PBPM group (99.2% vs 91.9%, P < .001).

WHAT IS NEW AND CONCLUSION

PBPM-based pharmacist-facilitated laboratory monitoring systems provided higher executing rate of laboratory order to monitor irAEs during immunotherapy.

Screening for autoantibody targets in post-vaccination narcolepsy using proteome arrays

Narcolepsy type 1 (NT1) is a chronic sleep disorder caused by a specific loss of hypocretin-producing neurons. The incidence of NT1 increased in Sweden, Finland and Norway following Pandemrix®-vaccination, initiated to prevent the 2009 influenza pandemic. The pathogenesis of NT1 is poorly understood, and causal links to vaccination are yet to be clarified. The strong association with Human leukocyte antigen (HLA) DQB1*06:02 suggests an autoimmune pathogenesis, but proposed autoantigens remain controversial. We used a two-step approach to identify autoantigens in patients that acquired NT1 after Pandemrix®-vaccination. Using arrays of more than 9000 full-length human proteins, we screened the sera of 10 patients and 24 healthy subjects for autoantibodies. Identified candidate antigens were expressed in vitro to enable validation studies with radiobinding assays (RBA). The validation cohort included NT1 patients (n = 39), their first-degree relatives (FDR) (n = 66), population controls (n = 188), and disease controls representing multiple sclerosis (n = 100) and FDR to type 1 diabetes patients (n = 41). Reactivity towards previously suggested NT1 autoantigen candidates including Tribbles homolog 2, Prostaglandin D2 receptor, Hypocretin receptor 2 and α-MSH/proopiomelanocortin was not replicated in the protein array screen. By comparing case to control signals, three novel candidate autoantigens were identified in the protein array screen; LOC401464, PARP3 and FAM63B. However, the RBA did not confirm elevated reactivity towards either of these proteins. In summary, three putative autoantigens in NT1 were identified by protein array screening. Autoantibodies against these candidates could not be verified with independent methods. Further studies are warranted to identify hypothetical autoantigens related to the pathogenesis of Pandemrix®-induced NT1.

Clinical guidelines for type 1 diabetes mellitus with an emphasis on older adults: an Executive Summary

We present a summary of a guideline produced by an international group of experts for managing type 1 diabetes in adults with an emphasis on the special needs of older people with this condition. The rationale for delivering high-quality diabetes care for adults with type 1 diabetes, why it is important to include older people in our considerations, and the key underpinning principles of the guideline are included. The structure of the recommendations given is described and consists of 'general' recommendations followed by 'specific' recommendations according to three categories depending on the characteristics of adults addressed, such as functional level or self-management ability. Recommendations are provided in the areas of: clinical diagnosis, establishing management plans and glucose regulation, diabetes self-management education, nutritional therapy, physical activity, exercise and lifestyle modification, insulin treatments and regimens, use of technology in diabetes management, hypoglycaemia, managing cardiovascular risk, management of microvascular risk, and inpatient management of type 1 diabetes and ketoacidosis.

Immune checkpoint inhibitors and type 1 diabetes mellitus: a case report and systematic review

OBJECTIVE

To better define the rare adverse event (AE) of diabetes mellitus associated with immune checkpoint inhibitors (ICIs).

DESIGN AND METHODS

We report the case of a lung cancer patient with diabetic ketoacidosis (DKA) and autoimmune thyroiditis during pembrolizumab treatment. We provide a systematic review of all published cases (PubMed/Web of Science/Cochrane, through November 2018) of autoimmune diabetes mellitus related to blockade of the cytotoxic T-lymphocyte antigen 4 (CTLA-4)-, programmed cell death 1 (PD-1) receptor or its ligand (PD-L1) or combination (ICI) therapy.

RESULTS

Our literature search identified 90 patient cases (our case excluded). Most patients were treated with anti-PD-1 or anti-PD-L1 as monotherapy (79%) or in combination with CTLA-4 blockade (15%). On average, diabetes mellitus was diagnosed after 4.5 cycles; earlier for combination ICI at 2.7 cycles. Early-onset diabetes mellitus (after one or two cycles) was observed during all treatment regimens. Diabetic ketoacidosis was present in 71%, while elevated lipase levels were detected in 52% (13/25). Islet autoantibodies were positive in 53% of patients with a predominance of glutamic acid decarboxylase antibodies. Susceptible HLA genotypes were present in 65% (mostly DR4). Thyroid dysfunction was the most frequent other endocrine AE at 24% incidence in this patient population.

CONCLUSION

ICI-related diabetes mellitus is a rare but often life-threatening metabolic urgency of which health-care professionals and patients should be aware. Close monitoring of blood glucose and prompt endocrine investigation in case of hyperglycemia is advisable. Predisposing factors such as HLA genotype might explain why some individuals are at risk.

Molecular mimicry between Anoctamin 2 and Epstein-Barr virus nuclear antigen 1 associates with multiple sclerosis risk

Multiple sclerosis (MS) is a chronic inflammatory, likely autoimmune disease of the central nervous system with a combination of genetic and environmental risk factors, among which Epstein-Barr virus (EBV) infection is a strong suspect. We have previously identified increased autoantibody levels toward the chloride-channel protein Anoctamin 2 (ANO2) in MS. Here, IgG antibody reactivity toward ANO2 and EBV nuclear antigen 1 (EBNA1) was measured using bead-based multiplex serology in plasma samples from 8,746 MS cases and 7,228 controls. We detected increased anti-ANO2 antibody levels in MS (P = 3.5 × 10^-36) with 14.6% of cases and 7.8% of controls being ANO2 seropositive (odds ratio [OR] = 1.6; 95% confidence intervals [95%CI]: 1.5 to 1.8). The MS risk increase in ANO2-seropositive individuals was dramatic when also exposed to 3 known risk factors for MS: HLA-DRB1*15:01 carriage, absence of HLA-A*02:01, and high anti-EBNA1 antibody levels (OR = 24.9; 95%CI: 17.9 to 34.8). Reciprocal blocking experiments with ANO2 and EBNA1 peptides demonstrated antibody cross-reactivity, mapping to ANO2 [aa 140 to 149] and EBNA1 [aa 431 to 440]. HLA gene region was associated with anti-ANO2 antibody levels and HLA-DRB1*04:01 haplotype was negatively associated with ANO2 seropositivity (OR = 0.6; 95%CI: 0.5 to 0.7). Anti-ANO2 antibody levels were not increased in patients from 3 other inflammatory disease cohorts. The HLA influence and the fact that specific IgG production usually needs T cell help provides indirect evidence for a T cell ANO2 autoreactivity in MS. We propose a hypothesis where immune reactivity toward EBNA1 through molecular mimicry with ANO2 contributes to the etiopathogenesis of MS.

Autoantibodies in Pandemrix®-induced narcolepsy: Nine candidate autoantigens fail the conformational autoantibody test

Study objectives: Narcolepsy type 1 (NT1) is a chronic sleep disorder characterized by loss of hypocretin-producing neurons. Increased NT1 incidence was observed in Sweden following mass-vaccination with Pandemrix^®. Genetic association to HLA DQB1*06:02 implies an autoimmune origin, but target autoantigen remains unknown. Candidate autoantigens for NT1 have previously been identified in solid-phase immunoassays, while autoantibodies against conformation-dependent epitopes are better detected in radiobinding assays. The aims are to determine autoantibody levels against nine candidate autoantigens representing (1) proteins of the hypocretin transmitter system; Preprohypocretin (ppHypocretin), Hypocretin peptides 1 and 2 (HCRT1 and HCRT2) and Hypocretin receptor 2 (HCRTR2); (2) proteins previously associated with NT1; Tribbles homologue 2 (TRIB2), Pro-opiomelanocortin/alpha-melanocyte-stimulating-hormone (POMC/α-MSH) and Prostaglandin D2 Receptor DP1 (DP1); (3) proteins suggested as autoantigens for multiple sclerosis (another HLA DQB1*06:02-associated neurological disease); ATP-dependent Inwardly Rectifying Potassium Channel Kir4.1 (KIR4.1) and Calcium-activated chloride channel Anoctamin 2 (ANO2). Methods: Serum from post-Pandemrix^® NT1 patients (n = 31) and their healthy first-degree relatives (n = 66) were tested for autoantibody levels in radiobinding assays separating autoantibody bound from free labelled antigen with Protein A-Sepharose. ¹²⁵I-labelled HCRT1 and HCRT2 were commercially available while ³⁵S-methionine-labelled ppHypocretin, HCRTR2, TRIB2, α-MSH/POMC, DP1, KIR4.1 or ANO2 was prepared by in vitro transcription translation of respective cDNA. In-house standards were used to express data in arbitrary Units/ml (U/ml). Results: All radiolabelled autoantigens were detected in a concentration-dependent manner by respective standard sera. Levels of autoantibodies in the NT1 patients did not differ from healthy first-degree relatives in any of the nine candidate autoantigens. Conclusions: None of the nine labelled proteins proposed to be autoantigens were detected in the radiobinding assays for conformation-dependent autoantibodies. The results emphasise the need of further studies to identify autoantigen(s) and clarify the mechanisms in Pandemrix^®-induced NT1.

Study of the difficult glycemic control in relation to the presence of diabetes-autoantibodies in a sample of Egyptians with type 1 diabetes

BACKGROUND

T1DM is divided into 1A (immune-mediated), 1B (virus-triggered, genetic and idiopathic). Presence of auto-antibodies may be correlated to glycemic control.

AIM

Assessment relation between the autoantibodies and the poor glycemic control in T1DM.

METHODS

60 patients T1DM 30 males, 30 females, subjected to full history, clinical, anthropometric assessment and laboratory assessment of fasting C-peptide, FBS, 2 h PP glucose, HbA1c, GADA, ICA and IAA level. Classified into two groups; Group I: negative auto-antibodies, Group II: positive auto-antibodies, Group II was further classified into 3 sub-groups, Group II a:1 positive autoantibody, Group II b: 2 positive autoantibodies and Group II c: 3 positive autoantibodies.

RESULTS

HbA1c was significantly higher in group II than group I (11.85 ± 1.61% vs. 8.52 ± 0.41%, p = 0.000). HbA1c was highest in group IIc followed by IIb then IIa (12.25 ± 1.48% vs. 11.57 ± 1.59% vs. 10.78 ± 1.73%, p = 0.038). Total insulin units per day was significantly higher in group II than group I (109.83 ± 7.77 U/day vs. 100.83 ± 1.83 U/day, p = 0.007). Duration of diabetes was significantly higher in group I than group II (10.17 ± 1.94 years vs. 8.11 ± 2.20 years, p = 0.033). HbA1c, total insulin units per day and duration of diabetes were independent predictive factors for presence of autoantibodies (p = 0.007, p = 0.033 and p = 0.043 respectively).

CONCLUSION

Autoantibodies affect the glycemic control presented by high HbA1c; also it causes increase in total insulin units needed by patients; the more autoantibodies, the higher HbA1c, the more insulin units required to control glycemic state.

Protein-engineered molecules carrying GAD65 epitopes and targeting CD35 selectively down-modulate disease-associated human B lymphocytes

Type 1 diabetes mellitus is an autoimmune metabolic disorder characterized by chronic hyperglycemia, the presence of autoreactive T and B cells and autoantibodies against self-antigens. A membrane-bound enzyme on the pancreatic beta-cells, glutamic acid decarboxylase 65 (GAD65), is one of the main autoantigens in type 1 diabetes. Autoantibodies against GAD65 are potentially involved in beta-cell destruction and decline of pancreatic functions. The human complement receptor type 1 (CD35) on B and T lymphocytes has a suppressive activity on these cells. We hypothesized that it may be possible to eliminate GAD65-specific B cells from type 1 diabetes patients by using chimeric molecules, containing an anti-CD35 antibody, coupled to peptides resembling GAD65 B/T epitopes. These molecules are expected to selectively bind the anti-GAD65 specific B cells by the co-cross-linking of the immunoglobulin receptor and CD35 and to deliver a suppressive signal. Two synthetic peptides derived from GAD65 protein (GAD65 epitopes) and anti-CD35 monoclonal antibody were used for the construction of two chimeras. The immunomodulatory activity of the engineered antibodies was tested in vitro using peripheral blood mononuclear cells (PBMCs) from type 1 diabetes patients. A reduction in the number of anti-GAD65 IgG antibody-secreting plasma cells and increased percentage of apoptotic B lymphocytes was observed after treatment of these PBMCs with the engineered antibodies. The constructed chimeric molecules are able to selectively modulate the activity of GAD65-specific B lymphocytes and the production of anti-GAD65 IgG autoantibodies by co-cross-linking of the inhibitory CD35 and the B cell antigen receptor (BCR). This treatment presents a possible way to alter the autoimmune nature of these cells.

N-Acetyl-l-Cysteine Supplement in Early Life or Adulthood Reduces Progression of Diabetes in Nonobese Diabetic Mice

BACKGROUND

Oxidative stress contributes to the pathologic process leading to the development, progression, and complications of type 1 diabetes (T1D).

OBJECTIVE

The aim of this study was to investigate the effect of the antioxidant N-acetyl-l-cysteine (NAC), supplemented during early life or adulthood on the development of T1D.

METHODS

NAC was administered to nonobese diabetic (NOD) female mice during pregnancy and lactation, and the development of diabetes was followed in offspring. In an additional set of experiments, offspring of untreated mice were given NAC during adulthood, and the development of T1D was followed. Morbidity rate, insulitis and serum cytokines were measured in the 2 sets of experiments. In addition, markers of oxidative stress, glutathione, lipid peroxidation, total antioxidant capacity and activity of antioxidant enzymes, were followed.

RESULTS

Morbidity rate was reduced in both treatment protocols. A decrease in interferon γ, tumor necrosis factor α, interleukin 1α, and other type 1 diabetes-associated proinflammatory cytokines was found in mice supplemented with NAC in adulthood or during early life compared with control NOD mice. The severity of insulitis was higher in control NOD mice than in treated groups. NAC administration significantly reduced oxidative stress, as determined by reduced lipid peroxidation and increased total antioxidant capacity in serum and pancreas of mice treated in early life or in adulthood and increased pancreatic glutathione when administrated in adulthood. The activity of antioxidant enzymes was not affected in mice given NAC in adulthood, whereas an increase in the activity of superoxide dismutase and catalase was demonstrated in the pancreas of their offspring.

CONCLUSION

NAC decreased morbidity of NOD mice by attenuating the immune response, presumably by eliminating oxidative stress, and might be beneficial in reducing morbidity rates of T1D in high-risk individuals.

Multiplexed In Situ Imaging Mass Cytometry Analysis of the Human Endocrine Pancreas and Immune System in Type 1 Diabetes

The interaction between the immune system and endocrine cells in the pancreas is crucial for the initiation and progression of type 1 diabetes (T1D). Imaging mass cytometry (IMC) enables multiplexed assessment of the abundance and localization of more than 30 proteins on the same tissue section at 1-μm resolution. Herein, we have developed a panel of 33 antibodies that allows for the quantification of key cell types including pancreatic exocrine cells, islet cells, immune cells, and stromal components. We employed this panel to analyze 12 pancreata obtained from donors with clinically diagnosed T1D and 6 pancreata from non-diabetic controls. In the pancreata from donors with T1D, we simultaneously visualized significant alterations in islet architecture, endocrine cell composition, and immune cell presentation. Indeed, we demonstrate the utility of IMC to investigate complex events on the cellular level that will provide new insights on the pathophysiology of T1D.

SLC30A8 Gene rs13266634 C/T Polymorphism in Children with Type 1 Diabetes in Tamil Nadu, India

Objective

Zinc transporter 8 (ZnT8) is a multi-transmembrane protein situated in the insulin secretory granule of the islets of β-cells and is identified as a novel auto-antigen in type 1 diabetes (T1D). The gene coding for ZnT8, solute carrier family 30 member 8 (SLC30A8) is located on chromosome 8q24.11. This study aimed to identify the association of SLC30A8 rs13266634 C/T gene polymorphism with T1D in a sample of T1D children in Tamil Nadu, India.

Methods

The family based study was conducted in 121 T1D patients and 214 of their family members as controls. The SLC30A8 gene rs13266634 C/T polymorphism was evaluated by polymerase chain reaction-restriction fragment length polymorphism.

Results

No significant differences were observed in either allele (odds ratio: 0.92; confidence interval: 0.33-2.58; p=0.88) and genotype (CC: p=0.74; CT: p=0.82; TT: p=0.80) frequencies of rs13266634 C/T between T1D patients and controls. Transmission disequilibrium test has identified over-transmission of mutant T allele from parents to affected children (T: U=9:7) without statistical significance. Metaanalysis on the overall effects of rs13266634 C allele frequency was not different (p=0.10 and Pheterogeneity=0.99) in T1D patients as compared to the controls.

Conclusion

The present study along with the meta-analysis does not show any substantial association of the rs13266634 C/T polymorphism with T1D development in this population.

Tolerogenic Dendritic Cells and T-Regulatory Cells at the Clinical Trials Crossroad for the Treatment of Autoimmune Disease; Emphasis on Type 1 Diabetes Therapy

Tolerogenic dendritic cells and T-regulatory cells are two immune cell populations with the potential to prevent the onset of clinical stage type 1 diabetes, and manage the beginning of underlying autoimmunity, at the time-at-onset and onwards. Initial phase I trials demonstrated that the administration of a number of these cell populations, generated ex vivo from peripheral blood leukocytes, was safe. Outcomes of some of these trials also suggested some level of autoimmunity regulation, by the increase in the numbers of regulatory cells at different points in a network of immune regulation in vivo. As these cell populations come to the cusp of pivotal phase II efficacy trials, a number of questions still need to be addressed. At least one mechanism of action needs to be verified as operational, and through this mechanism biomarkers predictive of the underlying autoimmunity need to be identified. Efficacy in the regulation of the underlying autoimmunity also need to be monitored. At the same time, the absence of a common phenotype core among the different dendritic cell and T-regulatory cell populations, that have completed phase I and early phase II trials, necessitates a better understanding of what makes these cells tolerogenic, especially if a uniform phenotypic core cannot be identified. Finally, the inter-relationship of tolerogenic dendritic cells and T-regulatory cells for survival, induction, and maintenance of a tolerogenic state that manages the underlying diabetes autoimmunity, raises the possibility to co-administer, or even to serially-administer tolerogenic dendritic cells together with T-regulatory cells as a cellular co-therapy, enabling the best possible outcome. This is currently a knowledge gap that this review aims to address.

Diabetes mellitus secondary to treatment with immune checkpoint inhibitors

Cancer immunotherapy has been one of the highlights in the advancement of cancer care. Certain immune checkpoint inhibitors bind to PD-1 on T cells and mediate an antitumour immune response. Given that immune checkpoint inhibitors are becoming part of standard care, a new class of adverse events-immune-related adverse events-has emerged. Among them is endocrine toxicity, most commonly targeting the thyroid, pituitary, or adrenal glands. New-onset diabetes mellitus has been reported in fewer than 1% of patients. We present a patient with type 1 diabetes mellitus secondary to immunotherapy, together with an overview of the associated literature. Patients who develop type 1 diabetes mellitus experience a rapid course, and diabetic ketoacidosis is commonly the presenting symptom. Insulin is currently the treatment of choice; oral antidiabetics or corticosteroids do not assist in management. Several predictive factors are under investigation, but physician awareness and prompt management are key to a positive outcome.

Insulin and glucose homeostasis in childhood cancer survivors treated with abdominal radiation: A pilot study

BACKGROUND

Childhood cancer survivors exposed to abdominal radiation (abdRT) are at increased risk for both insulin-dependent and non-insulin-dependent diabetes. We sought to clarify the pathophysiology of diabetes after abdRT by performing dynamic studies of insulin and glucose and testing for type 1 diabetes-associated autoantibodies.

PROCEDURE

Cross-sectional analysis of 2-year childhood cancer survivors treated with abdRT at age ≤21 years who underwent oral glucose tolerance testing and assessment of diabetes-related autoantibodies from December 2014 to September 2016. Prevalence of insulin/glucose derangements, indices of insulin sensitivity/secretion (homeostatic model assessment of insulin resistance [HOMA-IR], whole-body insulin sensitivity, insulinogenic index), autoantibody positivity, and treatment/demographic factors associated with adverse metabolic outcomes were assessed.

RESULTS

Among 40 participants previously exposed to abdRT (57.5% male; median age at cancer diagnosis, 3.3 years [range, 0.5-20.1]; median age at study 14.3 years [range, 8.3-49.8]; none with obesity), 9 (22.5%) had glucose derangements (n = 4 with impaired fasting glucose [≥100 mg/dL]; n = 4 with impaired glucose tolerance [2-hour glucose 140-199 mg/dL]; n = 1 with previously unrecognized diabetes [2-hour glucose ≥200 mg/dL]). Three of the four individuals with impaired fasting glucose also had insulin resistance, as measured by HOMA-IR; an additional four subjects with normal glucose tolerance were insulin resistant. The subject with diabetes had normal HOMA-IR. No participant had absolute insulinopenia or >1 positive diabetes-related autoantibody.

CONCLUSIONS

This study suggests that radiation-induced damage to the insulin-producing β-cells is an unlikely explanation for the early derangements in glucose metabolism observed after abdRT. Research into alternative pathways leading to diabetes after abdRT is needed.

Prevalence of islet autoantibodies in Thai juvenile-onset type 1 diabetes

BACKGROUND

Type 1 diabetes mellitus (T1DM) is caused by autoimmune destruction of islet β-cells of the pancreas. There are overlapping phenotypes in a significant proportion of youth with type 1 and 2 diabetes. Thus, positive pancreatic autoantibodies are helpful to diagnose T1DM. Zinc transporter 8 antibody (ZnT8A) is a recently identified autoantibody in T1DM and no data on ZnT8A in the Thai population have been reported. The aim of this study was therefore to estimate the prevalence of ZnT8A in Thai juvenile-onset T1DM and to evaluate its diagnostic value relative to glutamic acid decarboxylase and insulinoma-2 antigen antibodies (GADA and IA2A).

METHODS

In this cross-sectional study, patients with T1DM diagnosed before age 15 years, and disease duration <10 years were enrolled. Serum ZnT8A, GADA, and IA2A were measured using commercial enzyme-linked immunosorbent assay kits.

RESULTS

The subjects consisted of 81 youths (30 boys, 51 girls) aged 12.3 ± 4.5 years with T1DM. The median diabetes duration was 3 years (range, 0-10 years). The prevalence of ZnT8A, GADA, and IA2A was 54.3%, 75.3%, and 45.7%, respectively. ZnT8A were detected in 16% of T1DM patients negative for both GADA and IA2A. A combination of ZnT8A, GADA and IA2A could detect 80.2% of patients with T1DM. Combined use of ZnT8A and GADA identified 100% of antibody-positive patients.

CONCLUSION

The prevalence of ZnT8A in Thai juvenile-onset T1DM appears to be higher than in previous studies from Asia. ZnT8A could replace IA2A as an autoimmunity marker in Thai pediatric T1DM patients, with better diagnostic performance.

Programmed Cell Death-1 Inhibitor-Induced Type 1 Diabetes Mellitus

CONTEXT

Pembrolizumab (Keytruda; Merck Sharp & Dohme) is a humanized IgG4 monoclonal antibody used in cancer immunotherapy. It targets the programmed cell death-1 (PD-1) receptor, which is important in maintaining self-tolerance. However, immune checkpoint blockade is associated with a risk for immune-related adverse events (irAEs) potentially affecting the endocrine organs. Type 1 diabetes mellitus is a rare irAE of PD-1 inhibitors, occurring in 0.2% of cases.

EVIDENCE ACQUISITION

Systematic search of four databases (MEDLINE, Embase, Web of Science, and Cochrane Library) using the search terms "diabetes" or "ketoacidosis" and "pembrolizumab," "nivolumab," "PD-1 inhibitor," or "immunotherapy." Included were articles published in English between 1 January 2012 and 1 January 2018. The search was supplemented by bibliographic searches of the complete reference lists of all included papers.

EVIDENCE SYNTHESIS

We provide an overview of all published cases (n = 42) of PD-1 inhibitor-induced type 1 diabetes mellitus to date, including a well-characterized case of islet cell antibody and glutamic acid decarboxylase antibody-positive diabetes mellitus, in a patient with a diabetes-prone HLA genotype. She presented with diabetic ketoacidosis during pembrolizumab therapy for a metastatic uveal melanoma. Furthermore, we discuss potential pathogenic mechanisms, clinical presentation, prognostic markers (β-cell antibodies and HLA type), treatment, and a screening protocol.

CONCLUSIONS

Because the use of immunotherapy will increase, it is essential that all clinicians are aware of diabetic ketoacidosis as a rare and life-threatening side effect of immunotherapy. Blood glucose monitoring during anti-PD-1 therapy is necessary.

Relationship between islet autoantibody status and the clinical characteristics of children and adults with incident type 1 diabetes in a UK cohort

OBJECTIVES

To describe the characteristics of children and adults with incident type 1 diabetes in contemporary, multiethnic UK, focusing on differences between the islet autoantibody negative and positive.

DESIGN

Observational cohort study.

SETTING

146 mainly secondary care centres across England and Wales.

PARTICIPANTS

3312 people aged ≥5 years were recruited within 6 months of a clinical diagnosis of type 1 diabetes via the National Institute for Health Research Clinical Research Network. 3021 were of white European ethnicity and 291 (9%) were non-white. There was a small male predominance (57%). Young people <17 years comprised 59%.

MAIN OUTCOME MEASURES

Autoantibody status and characteristics at presentation.

RESULTS

The majority presented with classical osmotic symptoms, weight loss and fatigue. Ketoacidosis was common (42%), especially in adults, and irrespective of ethnicity. 35% were overweight or obese. Of the 1778 participants who donated a blood sample, 85% were positive for one or more autoantibodies against glutamate decarboxylase, islet antigen-2 and zinc transporter 8. Presenting symptoms were similar in the autoantibody-positive and autoantibody-negative participants, as was the frequency of ketoacidosis (43%vs40%, P=0.3). Autoantibody positivity was less common with increasing age (P=0.0001), in males compared with females (82%vs90%, P<0.0001) and in people of non-white compared with white ethnicity (73%vs86%, P<0.0001). Body mass index was higher in autoantibody-negative adults than autoantibody-positive adults (median, IQR 25.5, 23.1-29.2vs23.9, 21.4-26.7 kg/m²; P=0.0001). Autoantibody-negative participants were more likely to have a parent with diabetes (28%vs16%, P<0.0001) and less likely to have another autoimmune disease (4%vs8%, P=0.01).

CONCLUSIONS

Most people assigned a diagnosis of type 1 diabetes presented with classical clinical features and islet autoantibodies. Although indistinguishable at an individual level, autoantibody-negative participants as a group demonstrated features more typically associated with other diabetes subtypes.

TRIAL REGISTRATION NUMBER

ISRCTN66496918; Pre-results.

'25-Hydroxyvitamin D, Autoantigenic and Total Antibody Concentrations: Results from a Danish Case-control Study of Newly Diagnosed Patients with Childhood Type 1 Diabetes and their Healthy Siblings'

B cells have recently entered the stage as an important accessory player in type 1 diabetes (T1D) etiopathogenesis. Experimental studies suggest regulatory functions of vitamin D on B cells. However, only a few human studies, with considerable methodological limitations, have been conducted within this field. Our objective was to investigate whether higher 25-hydroxyvitamin D (25(OH)D) concentrations were inversely associated with β-cell autoantigens glutamic acid decarboxylase (isoform 65) (GADA) and insulinoma-associated antigen-2A (IA-2A). Further, we also wanted to examine the relationship between 25(OH)D and total antibody concentrations. We randomly selected 500 patients with newly diagnosed T1D and 500 siblings for 25(OH)D, antibody and genetic analysis from the population-based Danish Registry of Childhood and Adolescent Diabetes. The relative change (RC) in the mean concentration of GADA, IA-2A and antibody isotypes by a 10 nmol/l increase in 25(OH)D concentration was modelled by a robust log-normal regression model. We found no association between 25(OH)D and GADA [adjusted RC per 10 nmol/l increase: 1.00; 95% confidence interval (CI): 0.98-1.02] and IA-2A [adjusted RC per 10 nmol/l increase: 0.92; CI: 0.76-1.12]. Further, 25(OH)D was not associated with the total concentration of antibody isotypes [immunoglobulin (Ig)A, IgE, IgG and IgM]. All null findings were unaltered after adjustment for genetic variation in the vitamin D pathway. Physiological concentrations of 25(OH)D are unlikely to have a clinically important effect on antibody concentrations in a paediatric population of newly diagnosed patients with T1D and their healthy siblings.

Harnessing the power of regulatory T-cells to control autoimmune diabetes: overview and perspective

Type 1 diabetes (T1D) is a T-cell-mediated autoimmune disease resulting in islet β-cell destruction, hypoinsulinaemia and severely altered glucose homeostasis. Although the mechanisms that initiate T1D still remain elusive, a breakdown of immune tolerance between effector T-cells (T_eff ) and regulatory T-cells (T_reg ) is considered to be the crucial component leading to autoimmunity. As such, strategies have been developed to boost the number and/or function of T_reg in the hope of specifically hampering the pathogenic T_eff activity. In this review, we will summarize the current understanding of biomarkers and functions of both forkhead box protein 3 (FoxP3)⁺ T_reg and type 1 regulatory T (Tr1) cells in health and in T1D, examine the outcome of experimental therapies in both animal models and humans via manipulation of T_reg responses and also provide an outlook on the potential of T_reg -based immunotherapies in the prevention and treatment of this disease. Discussed immunotherapies include adoptive transfer of ex-vivo expanded FoxP3⁺ T_reg , manipulation of T_reg cells via the interleukin (IL)-2/IL-2R pathway and induction of T_reg by tolerogenic peptides, tolerogenic dendritic cells or altered gut microbiota.

Coincidence of PTPN22 c.1858CC and FCRL3 -169CC genotypes as a biomarker of preserved residual β-cell function in children with type 1 diabetes

BACKGROUND

Genotype-phenotype studies in type 1 diabetes (T1DM) patients are needed for further development of therapy strategies.

OBJECTIVE

Our aims were to investigate the distribution of selected PTPN22 and FCRL3 gene polymorphisms and their associations with clinical course of disease in children with newly diagnosed T1DM from the Pomeranian region of Poland.

SUBJECTS/METHODS

The prospective, longitudinal study of 147 children with newly diagnosed T1DM-autoimmune subtype was conducted. The PTPN22 c.1858T>C (rs2476601) and FCRL3 -169C>T (rs7528684) polymorphisms were analyzed using polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP) and DNA sequencing. The frequencies of genotypes were compared between the study and population-matched control group (327 random anonymous samples from the Pomeranian region). Selected patients underwent a 24-monthly follow up [periodic re-evaluation of fasting C-peptide concentration (FCP) and hemoglobin A1c (HbA1c ) level].

RESULTS

A significantly lower coincidence of the PTPN22 c.1858CC and FCRL3 -169CC genotypes was found in the study group compared with controls (P = 0.04). The PTPN22 c.1858CC and FCRL3 -169CC genotype combination, restricted to female patients only, was associated with well-preserved residual β-cell function throughout the entire follow up (prolonged FCP level increase up to the sixth month of disease, with further very stable dynamics-FCP median level ≥0.67 ng/mL without significant decrease up to the 24th month). HbA1c levels in this subgroup also remained the lowest during the observation period.

CONCLUSIONS/INTERPRETATION

Ascertained phenomenon could be explained by an interacting mechanism of the two polymorphisms through estrogen-regulated nuclear factor kappa B signaling in regulatory T (T_reg ) lymphocytes. This hypothesis, if confirmed, may lead to further development of T_reg administration-based therapies.

Autoantibodies against PFDN2 are associated with an increased risk of type 2 diabetes: A case-control study

BACKGROUND

The adaptive immune system is involved in type 2 diabetes mellitus (T2DM), indicating the presence of unidentified autoantibodies that might be useful biomarkers for emerging immunomodulatory therapy. A prior microarray study with a small number of participants suggested the association of novel autoantibodies with T2DM in Southwest American Indians. We therefore sought to determine whether antibodies against 14 target proteins are associated with T2DM in a large case-control study.

METHODS

Participants were adults (age 20-59 y) of Southwest American Indian heritage. Plasma antibodies against 14 possible target proteins were measured in 476 cases with T2DM of less than 5 years duration and compared with 424 controls with normal glucose regulation.

RESULTS

Higher levels of antibodies against prefoldin subunit 2 (PFDN2) were associated with T2DM (P = .0001; Bonferroni-corrected threshold for multiple tests = 0.0036 [α = 0.05]). The association between anti-PFDN2 antibodies and T2DM remained in multivariable logistic regression (odds ratio 1.27; 95% confidence interval, 1.09-1.49; per one SD difference in anti-PFDN2 antibody). The odds of T2DM were increased in the highest anti-PFDN2 antibody quintile by 66% compared with the lowest quintile. Differences in anti-PFDN2 antibodies were most prominent among cases with earlier onset of disease (ie, age 20-39 y) compared with controls.

CONCLUSIONS

Anti-PFDN2 antibodies are associated with T2DM and might be a useful biomarker. These findings indicate that autoimmunity may play a role in T2DM in Southwest American Indians, especially among adults presenting with young onset of disease.

Autoantibodies against voltage-gated potassium channel and glutamic acid decarboxylase in psychosis: A systematic review, meta-analysis, and case series

Antibodies to the voltage-gated potassium channel (VGKC) complex and glutamic acid decarboxylase (GAD) have been reported in some cases of psychosis. We conducted the first systematic review and meta-analysis to investigate their prevalence in people with psychosis and report a case series of VGKC-complex antibodies in refractory psychosis. Only five studies presenting prevalence rates of VGKC seropositivity in psychosis were identified, in addition to our case series, with an overall prevalence of 1.5% (25/1720) compared to 0.7% in healthy controls (12/1753). Meta-analysis established that the pooled prevalence of GAD65 autoantibodies was 5.8% (95% confidence interval [CI]: 2.0-15.6%; I²  = 91%; nine studies) in psychotic disorders, with a prevalence of 4.6% (95%CI: 1.2-15.9%; nine studies; I²  = 89%) and 6.2% (95%CI: 1.2-27.0%; two studies; I²  = 69%) in schizophrenia and bipolar disorder, respectively. People with psychosis were more likely to have GAD65 antibodies than controls (odds ratio [OR], 2.24; 95%CI: 1.28-3.92%; P = 0.005; eight studies; I²  = 0%). Among 21 participants with treatment-resistant psychosis, none had VGKC antibodies. The prevalence of VGKC antibodies is low in psychosis. Our preliminary meta-analysis suggests that GAD autoantibodies are more common in people with psychosis than in controls, although few studies accounted for the possibility of co-existing type 1 diabetes mellitus and the clinical significance of reported GAD titers remains unclear. The paucity of studies reporting thresholds for defining GAD abnormality and rates of comorbid type 1 diabetes mellitus precludes interpretations regarding the influence of GAD antibodies on the development of psychotic disorders and may have led to an overestimate of the prevalence of GAD. Our case series fails to support the hypothesis that VGKC antibodies are linked to treatment resistance in psychosis, but the literature to date is remarkably sparse.

B cell-derived IL-6 initiates spontaneous germinal center formation during systemic autoimmunity

Arkatkar et al. report that B cell–derived IL-6 is critical for T follicular helper cell differentiation, spontaneous germinal center formation, and class-switched autoantibody production during humoral autoimmunity.

Recent studies have identified critical roles for B cells in triggering autoimmune germinal centers (GCs) in systemic lupus erythematosus (SLE) and other disorders. The mechanisms whereby B cells facilitate loss of T cell tolerance, however, remain incompletely defined. Activated B cells produce interleukin 6 (IL-6), a proinflammatory cytokine that promotes T follicular helper (T_FH) cell differentiation. Although B cell IL-6 production correlates with disease severity in humoral autoimmunity, whether B cell–derived IL-6 is required to trigger autoimmune GCs has not, to our knowledge, been addressed. Here, we report the unexpected finding that a lack of B cell–derived IL-6 abrogates spontaneous GC formation in mouse SLE, resulting in loss of class-switched autoantibodies and protection from systemic autoimmunity. Mechanistically, B cell IL-6 production was enhanced by IFN-γ, consistent with the critical roles for B cell–intrinsic IFN-γ receptor signals in driving autoimmune GC formation. Together, these findings identify a key mechanism whereby B cells drive autoimmunity via local IL-6 production required for T_FH differentiation and autoimmune GC formation.

Apoptosis of pancreatic β-cells in Type 1 diabetes

Type 1 diabetes mellitus (T1DM) results from autoimmune destruction of pancreatic β-cells after an asymptomatic period over years. Insulitis activates antigen presenting cells, which trigger activating CD4+ helper-T cells, releasing chemokines/cytokines. Cytokines activate CD8+ cytotoxic-T cells, which lead to β-cell destruction. Apoptosis pathway consists of extrinsic (receptor-mediated) and intrinsic (mitochondria-driven) pathway. Extrinsic pathway includes Fas pathway to CD4+-CD8+ interaction, whereas intrinsic pathway includes mitochondria-driven pathway at a balance between anti-apoptotic B-cell lymphoma (Bcl)-2 and Bcl-xL and pro-apoptotic Bad, Bid, and Bik proteins. Activated cleaved caspse-3 is the converging point between extrinsic and intrinsic pathway. Apoptosis takes place only when pro-apoptotic proteins exceed anti-apoptotic proteins. Since the concordance rate of T1DM in identical twins is about 50%, environmental factors are involved in the development of T1DM, opening a door to find means to detect and prevent further development of autoimmune β-cell destruction for a therapeutic application.

Tolerogenic Nanoparticles to Treat Islet Autoimmunity

PURPOSE OF REVIEW

The current standard therapy for type 1 diabetes (T1D) is insulin replacement. Autoimmune diseases are typically treated with broad immunosuppression, but this has multiple disadvantages. Induction of antigen-specific tolerance is preferable. The application of nanomedicine to the problem of T1D can take different forms, but one promising way is the development of tolerogenic nanoparticles, the aim of which is to mitigate the islet-destroying autoimmunity. We review the topic and highlight recent strategies to produce tolerogenic nanoparticles for the purpose of treating T1D.

RECENT FINDINGS

Several groups are making progress in applying tolerogenic nanoparticles to rodent models of T1D, while others are using nanotechnology to aid other potential T1D treatments such as islet transplant and islet encapsulation. The strategies behind how nanoparticles achieve tolerance are varied. It is likely the future will see even greater diversity in tolerance induction strategies as well as a greater focus on how to translate this technology from preclinical use in mice to treatment of T1D in humans.

Myelin Oligodendrocyte Glycoprotein: Deciphering a Target in Inflammatory Demyelinating Diseases

Myelin oligodendrocyte glycoprotein (MOG), a member of the immunoglobulin (Ig) superfamily, is a myelin protein solely expressed at the outermost surface of myelin sheaths and oligodendrocyte membranes. This makes MOG a potential target of cellular and humoral immune responses in inflammatory demyelinating diseases. Due to its late postnatal developmental expression, MOG is an important marker for oligodendrocyte maturation. Discovered about 30 years ago, it is one of the best-studied autoantigens for experimental autoimmune models for multiple sclerosis (MS). Human studies, however, have yielded controversial results on the role of MOG, especially MOG antibodies (Abs), as a biomarker in MS. But with improved detection methods using different expression systems to detect Abs in patients' samples, this is meanwhile no longer the case. Using cell-based assays with recombinant full-length, conformationally intact MOG, several recent studies have revealed that MOG Abs can be found in a subset of predominantly pediatric patients with acute disseminated encephalomyelitis (ADEM), aquaporin-4 (AQP4) seronegative neuromyelitis optica spectrum disorders (NMOSD), monophasic or recurrent isolated optic neuritis (ON), or transverse myelitis, in atypical MS and in N-methyl-d-aspartate receptor-encephalitis with overlapping demyelinating syndromes. Whereas MOG Abs are only transiently observed in monophasic diseases such as ADEM and their decline is associated with a favorable outcome, they are persistent in multiphasic ADEM, NMOSD, recurrent ON, or myelitis. Due to distinct clinical features within these diseases it is controversially disputed to classify MOG Ab-positive cases as a new disease entity. Neuropathologically, the presence of MOG Abs is characterized by MS-typical demyelination and oligodendrocyte pathology associated with Abs and complement. However, it remains unclear whether MOG Abs are a mere inflammatory bystander effect or truly pathogenetic. This article provides deeper insight into recent developments, the clinical relevance of MOG Abs and their role in the immunpathogenesis of inflammatory demyelinating disorders.

Altered B cell signalling in autoimmunity

Recent work has provided new insights into how altered B cell-intrinsic signals - through the B cell receptor (BCR) and key co-receptors - function together to promote the pathogenesis of autoimmunity. These combined signals affect B cells at two distinct stages: first, in the selection of the naive repertoire; and second, during extrafollicular or germinal centre activation responses. Thus, dysregulated signalling can lead to both an altered naive BCR repertoire and the generation of autoantibody-producing B cells. Strikingly, high-affinity autoantibodies predate and predict disease in several autoimmune disorders, including type 1 diabetes and systemic lupus erythematosus. This Review summarizes how, rather than being a downstream consequence of autoreactive T cell activation, dysregulated B cell signalling can function as a primary driver of many human autoimmune diseases.

The Clonal Invariant NKT Cell Repertoire in People with Type 1 Diabetes Is Characterized by a Loss of Clones Expressing High-Affinity TCRs

Invariant NKT (iNKT) cells in healthy people express iNKT-TCRs with widely varying affinities for CD1d, suggesting different roles for high- and low-affinity iNKT clones in immune regulation. However, the functional implications of this heterogeneity have not yet been determined. Functionally aberrant iNKT responses have been previously demonstrated in different autoimmune diseases, including human type 1 diabetes, but their relationship to changes in the iNKT clonal repertoire have not been addressed. In this study, we directly compared the clonal iNKT repertoire of people with recent onset type 1 diabetes and age- and gender-matched healthy controls with regard to iNKT-TCR affinity and cytokine production. Our results demonstrate a selective loss of clones expressing high-affinity iNKT-TCRs from the iNKT repertoire of people with type 1 diabetes. Furthermore, this bias in the clonal iNKT repertoire in type 1 diabetes was associated with increased GM-CSF, IL-4, and IL-13 cytokine secretion among Ag-stimulated low-affinity iNKT clones. Thus, qualitative changes of the clonal iNKT repertoire with the potential to affect the regulatory function of this highly conserved T cell population are already established at the early stages in type 1 diabetes. These findings may inform future rationales for the development of iNKT-based therapies aiming to restore immune tolerance in type 1 diabetes.

Assessment of the link between in utero exposure to 2-aminoanthracene (2AA) and type-1 diabetes (T1D)

BACKGROUND

A recent diabetes report revealed an increased incidence in diabetes including type 1-diabetes (T1D). The increase in the numbers of T1D incidences are thought to be related to environmental reasons such as the exposure to environmental chemicals including arylamine 2-aminoanthracene (2AA). T1D is an autoimmune disease of the pancreatic islet in which insulin-producing beta cells are destroyed by auto-reactive T-cells and monocytic cells.

METHODS

The purpose of this study is to examine the extent to which 2AA exposure contributes to T1D. Three groups of pregnant Sprague Dawley dams ingested various concentrations of dietary 2AA from gestation through the postnatal period. A select number of cytokines and adipokines previously noted to play a significant role in inflammatory response were analyzed in the pancreas of the pups for alteration. The anatomy of the pancreas was also evaluated to determine any histological changes.

RESULTS

Results showed over-expression of pro-inflammatory protein IL-6. Up-regulation of humoral genes IL-7 and IL-21 were also noted. Pathologic characterization showed no significant changes. Moreover, serum total protein was significantly reduced in exposed groups. Elevated serum glucose concentration seems to correspond to slightly lower insulin levels in serum. Cumulative neonatal weight gain analysis showed no major alterations between the control and gestationally-exposed rats.

CONCLUSION

It appears that systemic effects of 2AA ingestion were mild in the neonates. Further assessments of pups who lived longer than two weeks could be a useful way to measure the progression and possibly further support our hypothesis that 2AA can lead to systemic effects that are indicative of inducing T1D.

Pathogenic and Protective Autoantibodies in Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy (APECED)

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare disorder caused by mutations in the autoimmune regulator (AIRE) gene, leading to defects in T cell selection. The disease manifestations include both autoimmune tissue destruction and immunodeficiency, with specific susceptibility to chronic mucocutaneous candidiasis. Studies have demonstrated a wide repertoire of high affinity tissue- and cytokine-specific antibodies in patients with APECED. Here, we review the antigenic targets and function of these disease-causing and disease-ameliorating antibodies.

Beta-cell Specific Autoantibodies: Are they Just an Indicator of Type 1 Diabetes?

BACKGROUND

Autoantibodies (AAbs) against islet autoantigens (AAgs) are used for type 1 diabetes (T1D) diagnosis and prediction. Islet-specific AAbs usually appear early in life and may fluctuate in terms of number and titer sometimes for over 20 years before T1D develops. Whereas their predictive power is high for pediatric subjects with high genetic risk who rapidly progress to multiple AAb positivity, they are less reliable for children with low genetic risk, single AAb positivity and slow disease progression.

OBJECTIVE

It is unknown how AAbs develop and whether they are involved in T1D pathogenesis. So far an increase in AAb number seems to only indicate AAg spreading and progression towards clinical T1D. The goal of this review is to shed light on the possible involvement of AAbs in T1D development.

METHOD

We thoroughly review the current literature and discuss possible mechanisms of AAb development and the roles they may play in disease pathogenesis.

RESULTS

Genetic and environmental factors instigate changes at the molecular and cellular levels that promote AAb development. Although direct involvement of AAbs in T1D is less clear, autoreactive B cells are clearly involved in various immune and autoimmune responses via antigen presentation, immunoregulation and cytokine production.

CONCLUSION

Our analysis suggests that understanding the mechanisms that lead to islet-specific AAb development and the diabetogenic processes that autoreactive B cells promote may uncover additional biomarkers and therapeutic targets.

Glucocorticoids did not reverse type 1 diabetes mellitus secondary to pembrolizumab in a patient with metastatic melanoma

Immune checkpoint inhibitors offer patients with advanced melanoma substantial improvements in survival. Unlike chemotherapy, immune checkpoint inhibitors such as ipilimumab and pembrolizumab cause unique immune-related adverse events (irAEs), including the development of endocrinopathies. We report a case of a man aged 60 years who developed diabetic ketoacidosis (DKA) following the use of pembrolizumab for the treatment of metastatic melanoma. He received four cycles of ipilimumab, before proceeding to pembrolizumab. Five weeks after initiating pembrolizumab, he presented in DKA with a pH of 7.0, bicarbonate of 7 mmol/L, blood glucose of 27 mmol/L and serum ketones of 5.9 mmol/L. Antibodies to glutamic acid decarboxylase (anti-GAD) and Islet antigen 2 (IA-2) were negative and C-peptide was low at 57 pmol/L (300-2350 pmol/L). There was no personal or family history of autoimmune conditions. Standard immunosuppression for irAEs was started using prednisolone in an attempt to salvage β cell function but was unsuccessful. To the best of our knowledge, this is the first reported attempt at reversing pembrolizumab-induced type 1 diabetes using glucocorticoids.

The course of diabetes in children, adolescents and young adults: does the autoimmunity status matter?

BACKGROUND

Initial classification of diabetes of young may require revision to improve diagnostic accuracy of different forms of diabetes. The aim of our study was to examine markers of beta-cell autoimmunity in a cohort of young (0-25 years) patients with type 1 diabetes and compare the presentation and course of the disease according to the presence of pancreatic antibodies.

METHODS

Cross-sectional population-based study was performed covering 100% of pediatric (n = 860) and 70% of 18-25 years old adult patients (n = 349) with type 1 diabetes in Lithuania.

RESULTS

No antibodies (GAD65, IA-2, IAA and ICA) were found in 87 (7.5%) cases. Familial history of diabetes was more frequent in those with antibodies-negative diabetes (24.1 vs. 9.4%, p < 0.001). Gestational age, birth weight and age at diagnosis was similar in both groups. Ketosis at presentation was more frequent in patients with autoimmune diabetes (88.1 vs. 73.5%, p < 0.05). HbA1c at the moment of investigation was 8.6 (3) vs. 8.7 (2.2)% in antibodies-negative and antibodies-positive diabetes groups, respectively, p > 0.05. In the whole cohort, neuropathy was found in 8.8% and nephropathy - in 8.1% of cases, not depending on autoimmunity status. Adjusted for age at onset, disease duration and HbA1c, retinopathy was more frequent in antibodies-negative subjects (13.8 vs. 7.8%, p < 0.05).

CONCLUSION

Antibodies-negative pediatric and young adult patients with type 1 diabetes in this study had higher incidence of family history of diabetes, higher frequency of retinopathy, less frequent ketosis at presentation, but similar age at onset, HbA1c, incidence of nephropathy and neuropathy compared to antibodies-positive patients.

Clinical Recommendations for the Use of Islet Cell Autoantibodies to Distinguish Autoimmune and Non-Autoimmune Gestational Diabetes

Gestational diabetes mellitus (GDM) is defined as carbohydrate intolerance that begins or is first recognized during pregnancy. The prevalence of GDM is highly variable, depending on the population studied, and reflects the underlying pattern of diabetes in the population. GDM manifests by the second half of pregnancy and disappears following delivery in most cases, but is associated with the risk of subsequent diabetes development. Normal pregnancy induces carbohydrate intolerance to favor the availability of nutrients for the fetus, which is compensated by increased insulin secretion from the maternal pancreas. Pregnancy shares similarities with adiposity in metabolism to save energy, and both conditions favor the development of insulin resistance (IR) and low-grade inflammation. A highly complicated network of modified regulatory mechanisms may primarily affect carbohydrate metabolism by promoting autoimmune reactions to pancreatic β cells and affecting insulin function. As a result, diabetes development during pregnancy is facilitated. Depending on a pregnant woman's genetic susceptibility to diabetes, autoimmune mechanisms or IR are fundamental to the development autoimmune or non-autoimmune GDM, respectively. Pregnancy may facilitate the identification of women at risk of developing diabetes later in life; autoimmune and non-autoimmune GDM may be early markers of the risk of future type 1 and type 2 diabetes, respectively. The most convenient and efficient way to discriminate GDM types is to assess pancreatic β-cell autoantibodies along with diagnosing diabetes in pregnancy.

Targeting erythrocyte carbonic anhydrase and 18O-isotope of breath CO2 for sorting out type 1 and type 2 diabetes

The inability to envisage the acute onset and progression of type 1 diabetes (T1D) has been a major clinical stumbling block and an important area of biomedical research over the last few decades. Therefore there is a pressing need to develop a new and an effective strategy for early detection of T1D and to precisely distinguish T1D from type 2 diabetes (T2D). Here we describe the precise role of the enzymatic activity of carbonic anhydrase (CA) in erythrocytes in the pathogenesis of T1D and T2D. We show that CA activities are markedly altered during metabolism of T1D and T2D and this facilitates to the oxygen-18 (¹⁸O) isotopic fractionations of breath CO₂. In our observations, T1D exhibited considerable depletions of ¹⁸O-isotopes of CO_2, whereas T2D manifested isotopic enrichments of ¹⁸O in breath CO₂, thus unveiling a missing link of breath¹⁸O-isotopic fractionations in T1D and T2D. Our findings suggest that the alterations in erythrocytes CA activities may be the initial step of altered metabolism of T1D and T2D, and breath ¹⁸O-isotope regulated by the CA activity is a potential diagnostic biomarker that can selectively and precisely distinguish T1D from T2D and thus may open a potential unifying strategy for treating these diseases.

No Contribution of GAD-65 and IA-2 Autoantibodies around Time of Diagnosis to the Increasing Incidence of Juvenile Type 1 Diabetes: A 9-Year Nationwide Danish Study

Aims. A new perspective on autoantibodies as pivotal players in the pathogenesis of type 1 diabetes (T1D) has recently emerged. Our key objective was to examine whether increased levels of autoantibodies against the β-cell autoantigens glutamic acid decarboxylase (isoform 65) (GADA) and insulinoma associated antigen-2A (IA-2A) mirrored the 3.4% annual increase in incidence of T1D. Methods. From the Danish Childhood Diabetes Register, we randomly selected 500 patients and 500 siblings for GADA and IA-2A analysis (1997 through 2005). Blood samples were taken within three months after onset. A robust log-normal regression model was used. Nine hundred children and adolescents had complete records and were included in the analysis. Cochran-Armitage test for trend was used to evaluate changes in prevalence of autoantibody positivity by period. Results. No significant changes in levels of GADA and IA-2A were found over our 9-year study period. No trends in autoantibody positivity-in either patients or siblings-were found. Levels of GADA and IA-2A were significantly associated with HLA risk groups and GADA with age. Conclusion. The prevalence of positivity and the levels of GADA and IA-2A have not changed between 1997 and 2005 in newly diagnosed patients with T1D and their siblings without T1D.

CRISPR-Cas9-Mediated Modification of the NOD Mouse Genome With Ptpn22R619W Mutation Increases Autoimmune Diabetes

An allelic variant of protein tyrosine phosphatase nonreceptor type 22 (PTPN22), PTPN22(R620W), is strongly associated with type 1 diabetes (T1D) in humans and increases the risk of T1D by two- to fourfold. The NOD mouse is a spontaneous T1D model that shares with humans many genetic pathways contributing to T1D. We hypothesized that the introduction of the murine orthologous Ptpn22(R619W) mutation to the NOD genome would enhance the spontaneous development of T1D. We microinjected CRISPR-Cas9 and a homology-directed repair template into NOD single-cell zygotes to introduce the Ptpn22(R619W) mutation to its endogenous locus. The resulting Ptpn22(R619W) mice showed increased insulin autoantibodies and earlier onset and higher penetrance of T1D. This is the first report demonstrating enhanced T1D in a mouse modeling human PTPN22(R620W) and the utility of CRISPR-Cas9 for direct genetic alternation of NOD mice.

The role of adipose-derived inflammatory cytokines in type 1 diabetes

Adipose tissue dysfunction correlates with the development of diabetes. Mice with an adipocyte-specific deletion of the SUMO-specific protease SENP1 develop symptoms of type-1 diabetes mellitus (T1DM). Peri-pancreatic adipocytes (PATs) exert both systemic and paracrine effects on pancreases function. Our recent studies report that PATs of SENP1-deficient mice have increased proinflammatory cytokine production compared with other adipose depots. Proinflammatory cytokines produced from PATs not only have direct cytotoxic effects on pancreatic islets, but also increase CCL5 expression in adjacent pancreatic islets, which induces persistent inflammation in pancreases by acquisition of Th1 and Th17 effector T cell subsets. Small ubiquitin-like modifier (SUMO) can post-translationally conjugate to cellular proteins (SUMOylation) and modulate their biological functions. Several components in SUMOylation associate with T1DM susceptibility. We find that SUMOylation of NF-κB essential molecule NEMO augments NF-κB activity, NF-κB-dependent cytokine production and pancreatic inflammation. NF-κB inhibitor should provide therapeutic approach to block PAT inflammation and ameliorate the T1DM phenotype. We further propose that adipocytes in PATs may play a primary role in establishing pancreatic immune regulation at onset of diabetes, providing new insights into the molecular pathogenesis of type 1 diabetes.

Chemical Tools To Monitor and Manipulate Adaptive Immune Responses

Methods to monitor and manipulate the immune system are of enormous clinical interest. For example, the development of vaccines represents one of the earliest and greatest accomplishments of the biomedical research enterprise. More recently, drugs capable of "reawakening" the immune system to cancer have generated enormous excitement. But, much remains to be done. All drugs available today that manipulate the immune system cannot distinguish between "good" and "bad" immune responses and thus drive general and systemic immune suppression or activation. Indeed, with the notable exception of vaccines, our ability to monitor and manipulate antigen-specific immune responses is in its infancy. Achieving this finer level of control would be highly desirable. For example, it might allow the pharmacological editing of pathogenic immune responses without restricting the ability of the immune system to defend against infection. On the diagnostic side, a method to comprehensively monitor the circulating, antigen-specific antibody population could provide a treasure trove of clinically useful biomarkers, since many diseases expose the immune system to characteristic molecules that are deemed foreign and elicit the production of antibodies against them. This Perspective will discuss the state-of-the-art of this area with a focus on what we consider seminal opportunities for the chemistry community to contribute to this important field.

Incidence of Type 1 Diabetes among Children and Adolescents in Italy between 2009 and 2013: The Role of a Regional Childhood Diabetes Registry

BACKGROUND

Surveillance represents a key strategy to control type 1 diabetes mellitus (T1DM). In Italy, national data are missing. This study aimed at evaluating the incidence of T1DM in subjects <18 year olds in Apulia (a large southeastern region, about 4,000,000 inhabitants) and assessing the sensitivity of the regional Registry of Childhood-Onset Diabetes (RCOD) in the 2009-2013 period.

METHODS

We performed a retrospective study matching records from regional Hospital Discharge Registry (HDR), User Fee Exempt Registry (UFER), and Drugs Prescription Registry (DPR) and calculated T1DM incidence; completeness of each data source was also estimated. In order to assess the RCOD sensitivity we compared cases from the registry to those extracted from HDR-UFER-DPR matching.

RESULTS

During 2009-2013, a total of 917 cases (about 184/year) in at least one of the three sources and an annual incidence of 25.2 per 100,000 were recorded, lower in infant, increasing with age and peaked in 5- to 9-year-olds. The completeness of DPR was 78.7%, higher than that of UFER (64.3%) and of HDR (59.6%). The RCOD's sensitivity was 39.05% (360/922; 95% CI: 34.01%-44.09%).

CONCLUSIONS

Apulia appeared as a high-incidence region. A full, active involvement of physicians working in paediatric diabetes clinics would be desirable to improve the RCOD performance.

SENP1-mediated NEMO deSUMOylation in adipocytes limits inflammatory responses and type-1 diabetes progression

Adipocyte dysfunction correlates with the development of diabetes. Here we show that mice with a adipocyte-specific deletion of the SUMO-specific protease SENP1 gene develop symptoms of type-1 diabetes mellitus (T1DM), including hyperglycaemia and glucose intolerance with mild insulin resistance. Peri-pancreatic adipocytes from SENP1-deficient mice exhibit heightened NF-κB activity and production of proinflammatory cytokines, which induce CCL5 expression in adjacent pancreatic islets and direct cytotoxic effects on pancreatic islets. Mechanistic studies show that SENP1 deletion in adipocytes enhances SUMOylation of the NF-κB essential molecule, NEMO, at lysine 277/309, leading to increased NF-κB activity, cytokine production and pancreatic inflammation. We further show that NF-κB inhibitors could inhibit pre-diabetic cytokine production, β-cell damages and ameliorate the T1DM phenotype in SENP1-deficient mice. Feeding a high-fat diet augments both type-1 and type-2 diabetes phenotypes in SENP1-deficient mice, consistent with the effects on adipocyte-derived NF-κB and cytokine signalling. Our study reveals previously unrecognized mechanism regulating the onset and progression of T1DM associated with adipocyte dysfunction.