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Type 1 diabetes (T1D) is a prototypic T cell-mediated autoimmune disease. Because the islets of Langerhans are insulated from blood vessels by a double basement membrane and lack detectable lymphatic drainage, interactions between endocrine and circulating T cells are not permitted. Thus, we hypothesized that initiation and progression of anti-islet immunity required islet neolymphangiogenesis to allow T cell access to the islet. Combining microscopy and single cell approaches, the timing of this phenomenon in mice was situated between 5 and 8 wk of age when activated anti-insulin CD4 T cells became detectable in peripheral blood while peri-islet pathology developed. This peri-insulitis, dominated by CD4 T cells, respected the islet basement membrane and was limited on the outside by lymphatic endothelial cells that gave it the attributes of a tertiary lymphoid structure. As in most tissues, lymphangiogenesis seemed to be secondary to local segmental endothelial inflammation at the collecting postcapillary venule. In addition to classic markers of inflammation such as CD29, V-CAM, and NOS, MHC class II molecules were expressed by nonhematopoietic cells in the same location both in mouse and human islets. This CD45- MHC class II+ cell population was capable of spontaneously presenting islet Ags to CD4 T cells. Altogether, these observations favor an alternative model for the initiation of T1D, outside of the islet, in which a vascular-associated cell appears to be an important MHC class II-expressing and -presenting cell.

AimTo determine the effects of astaxanthin treatment on lipids, cardiovascular disease (CVD) markers, glucose tolerance, insulin action and inflammation in individuals with prediabetes and dyslipidaemia.Materials and methodsAdult participants with dyslipidaemia and prediabetes (n = 34) underwent baseline blood draw, an oral glucose tolerance test and a one-step hyperinsulinaemic-euglycaemic clamp. They were then randomized (n = 22 treated, 12 placebo) to receive astaxanthin 12 mg daily or placebo for 24 weeks. Baseline studies were repeated after 12 and 24 weeks of therapy.ResultsAfter 24 weeks, astaxanthin treatment significantly decreased low-density lipoprotein (-0.33 ± 0.11 mM) and total cholesterol (-0.30 ± 0.14 mM) (both P

Hyperglucagonemia contributes to hyperglycemia in patients with type 1 diabetes (T1D); however, novel therapeutics that block glucagon action could improve glycemic control. This phase 2 study evaluated the safety and efficacy of volagidemab, an antagonistic monoclonal glucagon receptor (GCGR) antibody, as an adjunct to insulin therapy in adults with T1D. The primary endpoint was change in daily insulin use at week 12. Secondary endpoints included changes in hemoglobin A1c (HbA1c) at week 13, in average daily blood glucose concentration and time within target range as assessed by continuous blood glucose monitoring (CGM) and seven-point glucose profile at week 12, incidence of hypoglycemic events, the proportion of subjects who achieve HbA1c reduction of ≥0.4%, volagidemab drug concentrations and incidence of anti-drug antibodies. Eligible participants (n = 79) were randomized to receive weekly subcutaneous injections of placebo, 35 mg volagidemab or 70 mg volagidemab. Volagidemab produced a reduction in total daily insulin use at week 12 (35 mg volagidemab: -7.59 units (U) (95% confidence interval (CI) -11.79, -3.39; P = 0.040 versus placebo); 70 mg volagidemab: -6.64 U (95% CI -10.99, -2.29; P = 0.084 versus placebo); placebo: -1.27 U (95% CI -5.4, 2.9)) without meeting the prespecified significance level (P

BACKGROUND: Currently available semiautomated insulin-delivery systems require individualized insulin regimens for the initialization of therapy and meal doses based on carbohydrate counting for routine operation. In contrast, the bionic pancreas is initialized only on the basis of body weight, makes all dose decisions and delivers insulin autonomously, and uses meal announcements without carbohydrate counting. METHODS: In this 13-week, multicenter, randomized trial, we randomly assigned in a 2:1 ratio persons at least 6 years of age with type 1 diabetes either to receive bionic pancreas treatment with insulin aspart or insulin lispro or to receive standard care (defined as any insulin-delivery method with unblinded, real-time continuous glucose monitoring). The primary outcome was the glycated hemoglobin level at 13 weeks. The key secondary outcome was the percentage of time that the glucose level as assessed by continuous glucose monitoring was below 54 mg per deciliter; the prespecified noninferiority limit for this outcome was 1 percentage point. Safety was also assessed. RESULTS: A total of 219 participants 6 to 79 years of age were assigned to the bionic-pancreas group, and 107 to the standard-care group. The glycated hemoglobin level decreased from 7.9% to 7.3% in the bionic-pancreas group and did not change (was at 7.7% at both time points) in the standard-care group (mean adjusted difference at 13 weeks, -0.5 percentage points; 95% confidence interval [CI], -0.6 to -0.3; P

AIMS: To determine the effect of TTP399, a hepatoselective glucokinase activator, on the risk of ketoacidosis during insulin withdrawal in individuals with type 1 diabetes (T1D). MATERIALS AND METHODS: Twenty-three participants with T1D using insulin pump therapy were randomized to 800 mg TTP399 (n = 12) or placebo (n = 11) for 7 to 10 days. After the treatment period, an insulin withdrawal test (IWT) was performed, during which insulin pumps were removed to induce ketogenesis. The IWT was stopped after 10 hours or if blood glucose reached >399 mg/dL [22.1 mmol/L], if beta-hydroxybutyrate (BHB) was >3.0 mmol/L, or for patient discomfort. The primary endpoint was the proportion of participants who reached BHB concentrations of 1 mmol/L or greater. RESULTS: During the 7- to 10-day treatment period, mean fasting plasma glucose was significantly reduced ( -27.6 vs. -4.4 mg/dL [-1.5 vs. -0.2 mmol/L]; P = 0.03) and there were fewer adverse events, including hypoglycaemia, in the TTP399-treated arm. During the IWT, no differences were observed between TTP399 and placebo in mean serum BHB concentration, mean duration of IWT, or BHB at termination of IWT. However, serum bicarbonate was numerically higher and urine acetoacetate was quantitatively lower in the TTP399-treated participants. As a result of higher bicarbonate values, none of the TTP399-treated participants met the prespecified criteria for diabetic ketoacidosis (DKA), defined as BHB >3 mmol/L and serum bicarbonate

Individuals with type 1 diabetes have an impaired glucagon counterregulatory response to hypoglycemia. Sodium-glucose cotransporter (SGLT) inhibitors increase glucagon concentrations. We evaluated whether SGLT inhibition restores the glucagon counterregulatory hormone response to hypoglycemia. Adults with type 1 diabetes (n = 22) were treated with the SGLT2 inhibitor dapagliflozin (5 mg daily) or placebo for 4 weeks in a randomized, double-blind, crossover study. After each treatment phase, participants underwent a hyperinsulinemic-hypoglycemic clamp. Basal glucagon concentrations were 32% higher following dapagliflozin versus placebo, with a median within-participant difference of 2.75 pg/mL (95% CI 1.38-12.6). However, increased basal glucagon levels did not correlate with decreased rates of hypoglycemia and thus do not appear to be protective in avoiding hypoglycemia. During hypoglycemic clamp, SGLT2 inhibition did not change counterregulatory hormone concentrations, time to recovery from hypoglycemia, hypoglycemia symptoms, or cognitive function. Thus, despite raising basal glucagon concentrations, SGLT inhibitor treatment did not restore the impaired glucagon response to hypoglycemia. We propose that clinical reduction in hypoglycemia associated with these agents is a result of changes in diabetes care (e.g., lower insulin doses or improved glycemic variability) as opposed to a direct, physiologic effect of these medications on α-cell function.

ObjectiveTo quantify and contextualize the risk for coronavirus disease 2019 (COVID-19)-related hospitalization and illness severity in type 1 diabetes.Research design and methodsWe conducted a prospective cohort study to identify case subjects with COVID-19 across a regional health care network of 137 service locations. Using an electronic health record query, chart review, and patient contact, we identified clinical factors influencing illness severity.ResultsWe identified COVID-19 in 6,138, 40, and 273 patients without diabetes and with type 1 and type 2 diabetes, respectively. Compared with not having diabetes, people with type 1 diabetes had adjusted odds ratios of 3.90 (95% CI 1.75-8.69) for hospitalization and 3.35 (95% CI 1.53-7.33) for greater illness severity, which was similar to risk in type 2 diabetes. Among patients with type 1 diabetes, glycosylated hemoglobin (HbA1c), hypertension, race, recent diabetic ketoacidosis, health insurance status, and less diabetes technology use were significantly associated with illness severity.ConclusionsDiabetes status, both type 1 and type 2, independently increases the adverse impacts of COVID-19. Potentially modifiable factors (e.g., HbA1c) had significant but modest impact compared with comparatively static factors (e.g., race and insurance) in type 1 diabetes, indicating an urgent and continued need to mitigate severe acute respiratory syndrome coronavirus 2 infection risk in this community.

AimsTo use electronic health record data from real-world clinical practice to assess demographics, clinical characteristics and disease burden of adults with type 1 diabetes (T1D) in the United States.Materials and methodsRetrospective observational study of adults with T1D for ≥24 months at their first visit with a T1D diagnosis code ("index date") between July 2014 and June 2016 in the Optum Humedica database. Demographic characteristics, acute complications (severe hypoglycaemia [SH], diabetic ketoacidosis [DKA]), microvascular complications, cardiovascular (CV) events and health care resource utilization during the 12 months before the index date ("baseline period") were compared between patients with optimal versus suboptimal glycaemic control (glycated haemoglobin [HbA1c] 30 000 adults with T1D showed that individuals with suboptimal versus optimal glycaemic control differed significantly in terms of health care coverage, comorbidities, diabetes-related complications, health care utilization and CV risk factors. However, suboptimal control was not associated with increased risk of CV outcomes.

BACKGROUND: Diabetes health care resource utilization (HCRU) studies tend to focus on patients with type 2 diabetes (T2D) or pool patients with T2D and type 1 diabetes (T1D). There is a paucity of recent data on the cost of treating patients with T1D in the United States. OBJECTIVES: To (a) estimate the per-patient per-year (PPPY) HCRU and costs, from a payer perspective, associated with treating U.S. adults with T1D and (b) compare these with the HCRU and costs for patients with T2D. METHODS: This retrospective cohort study used claims data from the Optum Clinformatics database between January 2015 and December 2017. Adults (aged ≥ 18 years) with a diagnosis of T1D were propensity score-matched to adults with T2D. Overall and nondiabetes-related HCRU and costs were assessed for T1D and T2D and compared between the 2 groups. RESULTS: Propensity scores were used to match 10,103 patient pairs from T1D and T2D cohorts (mean ages 54.4 and 56.9 years, respectively). In the T1D cohort, inpatient, emergency department (ED), outpatient, and prescription claims occurred in 14.0%, 17.3%, 85.5%, and 100% of patients, respectively, resulting in a mean total cost of U.S. $18,817 PPPY (diabetes-related = $11,002; nondiabetes-related = $7,816). The T1D cohort had significantly higher mean total costs than the T2D cohort ($18,817 vs. $14,148 PPPY; P < 0.001). When extrapolating these findings to a commercial health plan with 1 million covered lives, the estimated total direct medical costs of T1D would be $103.4 million. CONCLUSIONS: This study showed that the total annual cost of managing an adult with T1D is significantly higher than that of an adult with T2D. Nondiabetes costs accounted for 40% of the total per-patient cost, similar to patients with T2D, confirming that as patients with T1D live longer lives, they may also be at greater risk for cardiometabolic complications. DISCLOSURES: This study was funded by Sanofi U.S. and Lexicon Pharmaceuticals as part of a business partnership in a diabetes program at the time this study was conducted. Joish and Davies are employees and stockholders of Lexicon Pharmaceuticals. Zhou, Preblick, and Paranjape are employees and stockholders of Sanofi. Lin was a postdoctoral fellow at Sanofi through Rutgers University during this project. Deshpande provided consulting services through Communication Symmetry. Verma is an employee of Evidera, which was contracted by Sanofi for work on this study. Pettus is a consultant for Diasome, Insulet, Lexicon, Lilly, Mannkind, Novo Nordisk, Sanofi, and Senseonics.

The cytokine IL-7 is critical for T cell development and function. We performed a Phase Ib study in patients with type 1 diabetes (T1D) to evaluate how blockade of IL-7 would affect immune cells and relevant clinical responses. Thirty-seven subjects with T1D received s.c. RN168, a monoclonal antibody that blocks the IL -7 receptor α (IL7Rα) in a dose-escalating study. Between 90% and 100% IL-7R occupancy and near-complete inhibition of pSTAT5 was observed at doses of RN168 1 mg/kg every other week (Q2wk) and greater. There was a significant decline in CD4+ and CD8+ effector and central memory T cells and CD4+ naive cells, but there were fewer effects on CD8+ naive T cells. The ratios of Tregs to CD4+ or CD8+ effector and central memory T cells versus baseline were increased. RNA sequencing analysis showed downmodulation of genes associated with activation, survival, and differentiation of T cells. Expression of the antiapoptotic protein Bcl-2 was reduced. The majority of treatment-emergent adverse events (TEAEs) were mild and not treatment related. Four subjects became anti-EBV IgG+ after RN168, and 2 had symptoms of active infection. The immunologic response to tetanus toxoid was preserved at doses of 1 and 3 mg/kg Q2wk but reduced at higher doses. This trial shows that, at dosages of 1-3 mg/kg, RN168 selectively inhibits the survival and activity of memory T cells while preserving naive T cells and Tregs. These immunologic effects may serve to eliminate pathologic T cells in autoimmune diseases. NCT02038764. Pfizer Inc.

Background: Hypoglycemia rates usually increase when insulin treatment is intensified to improve glycemic control. We evaluated (post hoc) hypoglycemic rates in adult patients with type 1 diabetes (T1D) on sotagliflozin (a dual sodium-glucose cotransporter [SGLT] 1 and 2 inhibitor) in two phase 3, 52-week clinical trials (inTandem 1 and 2; NCT02384941 and NCT02421510). Materials and Methods: We analyzed rates of documented hypoglycemia (level 1, blood glucose ≥54 to

Background: Adjunct therapy can help patients with type 1 diabetes achieve glycemic goals while potentially mitigating some of the side effects of insulin. In this study, we used a patient survey to identify the unmet needs in type 1 diabetes therapy, patient views of treatment benefit-risk trade-offs, and patient preferences for the use of an adjunct therapy. Methods: A quantitative survey was sent to 2084 adults with type 1 diabetes in November 2017. "Jobs-to-be-done" and conjoint analyses were performed on survey responses to identify unmet needs and the importance of treatment-associated benefits and risks to patients. A 5-point Likert scale measured the importance and satisfaction with patients' current therapy, and with gaps relating to unmet needs. In the conjoint analysis, patients were asked to choose between "packages" of attributes of two doses of adjunct therapy (200 and 400 mg) and placebo, based on established benefits and side effects. Results: A total of 1313 patients (63%) responded. The greatest unmet needs identified were simplifying treatment, lowering/maintaining glycated hemoglobin (HbA1c), reducing mental effort, and increasing time in range (TIR). Conjoint analysis showed that reductions in body weight and TIR had the highest attribute importance (25% and 18%, respectively). The majority (93%) of patients had a preference for the adjunct therapy (either dose) over placebo. Conclusions: This survey highlights the importance of measures beyond HbA1c, such as treatment simplification and TIR, and patient preference for adjunct therapies that help address unmet needs in type 1 diabetes treatment.

Sodium-glucose cotransporter (SGLT) inhibitors are new oral antidiabetes medications shown to effectively reduce glycated hemoglobin (A1C) and glycemic variability, blood pressure, and body weight without intrinsic properties to cause hypoglycemia in people with type 1 diabetes. However, recent studies, particularly in individuals with type 1 diabetes, have demonstrated increases in the absolute risk of diabetic ketoacidosis (DKA). Some cases presented with near-normal blood glucose levels or mild hyperglycemia, complicating the recognition/diagnosis of DKA and potentially delaying treatment. Several SGLT inhibitors are currently under review by the U.S. Food and Drug Administration and European regulatory agencies as adjuncts to insulin therapy in people with type 1 diabetes. Strategies must be developed and disseminated to the medical community to mitigate the associated DKA risk. This Consensus Report reviews current data regarding SGLT inhibitor use and provides recommendations to enhance the safety of SGLT inhibitors in people with type 1 diabetes.

Type 1 diabetes (T1D) is an autoimmune disease characterized by the destruction of insulin-producing b-cells in the pancreas. This destruction leads to chronic hyperglycemia, necessitating lifelong insulin therapy to manage blood glucose levels. Typically diagnosed in children and young adults, T1D can, however, occur at any age. Ongoing research aims to uncover the precise mechanisms underlying T1D and to develop potential interventions. These include efforts to modulate the immune system, regenerate b-cells, and create advanced insulin delivery systems. Emerging therapies, such as closed-loop insulin pumps, stem cell-derived b-cell replacement and disease-modifying therapies (DMTs), offer hope for improving the quality of life for individuals with T1D and potentially moving towards a cure. Currently, there are no disease-modifying therapies approved for stage 3 T1D. Preserving b-cell function in stage 3 T1D is associated with better clinical outcomes, including lower HbA1c and decreased risk of hypoglycemia, neuropathy, and retinopathy. Tumor Necrosis Factor alpha (TNFa) inhibitors have demonstrated efficacy at preserving b-cell function by measurement of C-peptide in two clinical trials in people with stage 3 T1D. However, TNF-a inhibitors have yet to be evaluated in a pivotal trial for T1D. To address the promising clinical findings of TNF-a inhibitors in T1D, Breakthrough T1D convened a panel of key opinion leaders (KOLs) in the field. The workshop aimed to outline an optimal clinical path for moving TNF-a inhibitors to a pivotal clinical trial in T1D. Here, we summarize the evidence for the beneficial use of TNF-a inhibitors in T1D and considerations for strategies collectively identified to advance TNF-a inhibitors beyond phase 2 clinical studies for stage 3 T1D. [ABSTRACT FROM AUTHOR]

BackgroundGlycated hemoglobin (HbA1c) and measures of short-term glycemia do not fully capture daily patterns in plasma glucose dynamics. This study evaluated 24-h glycemic profiles in patients with type 2 diabetes (T2D) initiated on dapagliflozin treatment using continuous glucose monitoring (CGM).MethodsThis randomized double-blind placebo-controlled multicenter parallel-design 4-week study compared dapagliflozin (10 mg/d; n = 50) with placebo (n = 50) in adult patients with T2D uncontrolled (HbA1c 7.5%-10.5%) on either stable doses of metformin monotherapy (≥1500 mg/d) or insulin (≥30 U/d with or without up to two oral antidiabetes drugs). CGM was used to measure 24-h glycemic profiles for 7 days pretreatment and during week 4 of treatment. The primary outcome was change from baseline in 24-h mean glucose (MG) at week 4.ResultsThe 24-h MG decreased 18.2 mg/dL with dapagliflozin and increased 5.8 mg/dL with placebo (P

AimsTo evaluate the effect of concomitant dipeptidyl peptidase IV inhibitor (DPPIVi) use on efficacy and safety of insulin glargine 300 U/mL (Gla-300) versus glargine 100 U/mL (Gla-100) in people with type 2 diabetes on oral antihyperglycaemic drugs.MethodsA post hoc patient-level meta-analysis was performed using data from EDITION 2 (basal insulin [N = 811]) and EDITION 3 (insulin-naïve [N = 878]), multicentre, randomised, open-label, parallel-group, phase 3a trials of similar design. Endpoints analysed included HbA1c, hypoglycaemia and adverse events, investigated in subgroups of participants with and without concomitant DPPIVi use.ResultsOf 1689 participants randomised, 107 (13%, Gla-300) and 133 (16%, Gla-100) received DPPIVi therapy. The least squares mean change in HbA1c (baseline to month 6) was comparable between treatment groups, irrespective of DPPIVi use (no evidence of heterogeneity of treatment effect across subgroups, p = 0.753), although group sizes were unbalanced. The cumulative mean number of confirmed (≤3.9 mmol/L [≤70 mg/dL]) or severe hypoglycaemic events, and the risk and annualised rate of such events, were consistently lower for Gla-300 than Gla-100 during the night (between 00:00 and 05:59 h) or at any time of day (24 h period), irrespective of DPPIVi use. Severe hypoglycaemia occurred in 8/838 and 10/844 participants in the Gla-300 and Gla-100 groups, respectively, and was not affected by DPPIVi use. The adverse event profile was similar between treatment groups and DPPIVi subgroups.ConclusionsGlycaemic control with Gla-300 was comparable to Gla-100, with less hypoglycaemia during the night and at any time of day (24 h), irrespective of concomitant DPPIVi use.Trial registrationClinicalTrials.gov NCT01499095; NCT01676220.

The clinical benefits of real time continuous glucose monitoring (rtCGM) use have been well demonstrated in both CSII- and MDI-treated individuals in large clinical trials. However, recommendations for patient use of rtCGM in everyday life situations are lacking. This article provides guidance to clinicians and patients with type 1 diabetes (T1D) in effective use of rtCGM data, including glucose rate of change (ROC) arrows, for insulin dosing adjustments and other treatment decisions. The recommendations presented here are based on our own clinical experiences as endocrinologists, our personal experiences living with T1D using rtCGM, and findings from a recent survey of T1D patients who have successfully used rtCGM in their self-management. It is important that both clinicians and people with diabetes understand the utility and limitations of rtCGM. Maintaining a collaborative clinician-user relationship remains an important factor in safe, successful rtCGM use.

OBJECTIVE: To determine how diabetes technologies, including continuous glucose monitoring (CGM) and automated insulin delivery (AID) systems, impact glycemic metrics, prevalence of severe hypoglycemic events (SHEs), and impaired awareness of hypoglycemia (IAH) in people with type 1 diabetes in a real-world setting within the U.S. RESEARCH DESIGN AND METHODS: In this retrospective, observational study with cross-sectional elements, participants aged ≥18 years were enrolled from the T1D Exchange Registry/online community. Participants completed a one-time online survey describing glycemic metrics, SHEs, and IAH. The primary objective was to determine the proportions of participants who reported achieving glycemic targets (assessed according to self-reported hemoglobin A1c) and had SHEs and/or IAH. We performed additional subgroup analyses focusing on the impact of CGM and insulin delivery modality. RESULTS: A total of 2,074 individuals with type 1 diabetes were enrolled (mean ± SD age 43.0 ± 15.6 years and duration of type 1 diabetes 26.3 ± 15.3 years). The majority of participants (91.7%) were using CGM, with one-half (50.8%) incorporating AID. Despite high use of diabetes technologies, only 57.7% reported achieving glycemic targets (hemoglobin A1c <7%). SHEs and IAH still occurred, with ∼20% of respondents experiencing at least one SHE within the prior 12 months and 30.7% (95% CI 28.7, 32.7) reporting IAH, regardless of CGM or AID use. CONCLUSIONS: Despite use of advanced diabetes technologies, a high proportion of people with type 1 diabetes do not achieve glycemic targets and continue to experience SHEs and IAH, suggesting an ongoing need for improved treatment strategies. [ABSTRACT FROM AUTHOR]

A recent study examined the prevalence of cannabis use among adults with diabetes in the United States. The study found that 9.0% of adults with diabetes reported using cannabis in the past month, with an increase from 7.7% in 2021 to 10.3% in 2022. Factors associated with cannabis use among adults with diabetes included residing in states where cannabis is legal, a history of hepatitis, past-year major depressive episode, past-year emergency department use, past-month tobacco use, binge drinking, opioid misuse, and stimulant misuse. The study emphasizes the need for further research on the effects of cannabis use on the health of patients with diabetes and suggests comprehensive substance use screenings in diabetes care. However, the study acknowledges limitations such as self-reporting and the lack of distinction between types of diabetes and cannabinoid products used. Clinicians are advised to discuss the potential harms of cannabis use with their patients with diabetes. [Extracted from the article]

The article discusses the ongoing debate surrounding time spent in specific glycemic ranges for patients with type 1 diabetes, particularly focusing on the transition from time in range (TIR) to time in tight range (TITR) as a potential new metric for glycemic control, highlighting the challenges and implications of adopting TITR as a new standard in diabetes management.

The article discusses research by R.L.T., J.M.G., and J.H.P., reported in the Diabetes Care issue, focusing on topics such as the association between increased exposure to hypoglycemia and reduced epinephrine response, the implications of recurrent hypoglycemia on cardiovascular complications in type 1 diabetes (T1D), and the potential impact of strict avoidance of hypoglycemia on autonomic response and hypoglycemia awareness.

The endocrine pancreas is one of the most inaccessible organs of the human body. Its autoimmune attack leads to type 1 diabetes (T1D) in a genetically susceptible population and a lifelong need for exogenous insulin replacement. Monitoring disease progression by sampling peripheral blood would provide key insights into T1D immune-mediated mechanisms and potentially change preclinical diagnosis and the evaluation of therapeutic interventions. This effort has been limited to the measurement of circulating anti-islet antibodies, which despite a recognized diagnostic value, remain poorly predictive at the individual level for a fundamentally CD4 T cell–dependent disease. Here, peptide–major histocompatibility complex tetramers were used to profile blood anti-insulin CD4 T cells in mice and humans. While percentages of these were not directly informative, the state of activation of anti-insulin T cells measured by RNA and protein profiling was able to distinguish the absence of autoimmunity versus disease progression. Activated anti-insulin CD4 T cell were detected not only at time of diagnosis but also in patients with established disease and in some at-risk individuals. These results support the concept that antigen-specific CD4 T cells might be used to monitor autoimmunity in real time. This advance can inform our approach to T1D diagnosis and therapeutic interventions in the preclinical phase of anti-islet autoimmunity. Editor's summary: Type 1 diabetes (T1D) is an autoimmune disease mediated by autoreactive CD4 T cells attacking insulin-producing islet cells in the pancreas. Although T1D is driven by aberrant T cell responses, anti-islet antibodies have been used as a diagnostic marker but are not always an effective predictor of disease progression. Sharma et al. now describe the use of peptide-major histocompatibility complex tetramers to profile anti-insulin CD4 T cells in peripheral blood. This method detected activated anti-insulin CD4 T cells at the time of diagnosis as well as in genetically at-risk individuals and those with established disease. These findings provide critical insights into the features of CD4 T cells associated with disease onset and can inform improvements in T1D diagnosis and therapeutics development.—Christiana Fogg [ABSTRACT FROM AUTHOR]