Circulating Unmethylated Insulin DNA As a Biomarker of Human Beta Cell Death: A Multi-laboratory Assay Comparison

Context: There is an unmet need for biomarkers of pancreatic beta-cell death to improve early diagnosis of type 1 diabetes, enroll subjects into clinical trials, and assess treatment response. To address this need, several groups developed assays measuring insulin deoxyribonucleic acid (DNA) with unmethylated CpG sites in cell-free DNA. Unmethylated insulin DNA should be derived predominantly from beta-cells and indicate ongoing beta-cell death. Objective: To assess the performance of three unmethylated insulin DNA assays. Design and participants: Plasma or serum samples from 13 subjects undergoing total pancreatectomy and islet autotransplantation were coded and provided to investigators to measure unmethylated insulin DNA. Samples included a negative control taken post-pancreatectomy but pretransplant, and a positive control taken immediately following islet infusion. We assessed technical reproducibility, linearity, and persistence of detection of unmethylated insulin DNA for each assay. Results: All assays discriminated between the negative sample and samples taken directly from the islet transplant bag; 2 of 3 discriminated negative samples from those taken immediately after islet infusion. When high levels of unmethylated insulin DNA were present, technical reproducibility was generally good for all assays. Conclusions: The measurement of beta cell cell-free DNA, including insulin, is a promising approach, warranting further testing and development in those with or at-risk for type 1 diabetes, as well as in other settings where understanding the frequency or kinetics of beta cell death could be useful

Early Prognostic Indicators of Subsequent Hospitalization in Patients with Mild COVID-19

Comprehensive data on early prognostic indicators in patients with mild COVID-19 remains sparse. In this single center case series, we characterized the initial clinical presentation in 180 patients with mild COVID-19 and defined the earliest predictors of subsequent deterioration and need for hospitalization. Three broad patient phenotypes and four symptom clusters were characterized, differentiated by varying risk for adverse outcomes. Among 14 symptoms assessed, subjective shortness of breath (SOB) most strongly associated with adverse outcomes (odds ratio (OR) 21.3, 95% confidence interval (CI): 2.7–166.4; p < 0.0001). In combination, SOB and number of comorbidities were highly predictive of subsequent hospitalization (area under the curve (AUC) 92%). Additionally, initial lymphopenia (OR 21.0, 95% CI: 2.1–210.1; p = 0.002) and male sex (OR 3.5, 95% CI: 0.9–13.0; p = 0.05) were associated with increased risk of poor outcomes. Patients with known comorbidities, especially multiple, and those presenting with subjective SOB or lymphopenia should receive close monitoring and consideration for preemptive treatment, even when presenting with mild symptoms

JCEM ORourke et al Supplemental Materials 2022.pdf

This is the supplemental information for a manuscript from authors at the Benaroya Research Institute (O'Rourke et al), submitted to the Journal of Clinical Endocrinology and Metabolism in 2022.   The associated manuscript is entitled "Risk Modeling to Reduce Monitoring of an Autoantibody-Positive Population to Prevent DKA at Type 1 Diabetes Diagnosis." This file contains the detailed statistical methods used for data analysis, as well as code needed to reproduce our findings.</p

Early introduction of peanut reduces peanut allergy across risk groups in pooled and causal inference analyses

Background: The Learning Early About Peanut allergy (LEAP) study has shown the effectiveness of early peanut introduction in prevention of peanut allergy (PA). In the Enquiring About Tolerance (EAT) study, a statistically significant reduction in PA was present only in per-protocol (PP) analyses, which can be subject to bias. Objective: The aim of this study was to combine individual-level data from the LEAP and EAT trials and provide robust evidence on the bias-corrected, causal effect of early peanut introduction. Method: As part of the European Union-funded iFAAM project, this pooled analysis of individual pediatric patient data combines and compares effectiveness and efficacy estimates of oral tolerance induction among different risk strata and analysis methods. Results: An intention-to-treat (ITT) analysis of pooled data showed a 75% reduction in PA (p <.0001) among children randomized to consume peanut from early infancy. A protective effect was present across all eczema severity groups, irrespective of enrollment sensitization to peanut, and across different ethnicities. Earlier age of introduction was associated with improved effectiveness of the intervention. In the pooled PP analysis, peanut consumption reduced the risk of PA by 98% (p <.0001). A causal inference analysis confirmed the strong PP effect (89% average treatment effect relative risk reduction p <.0001). A multivariable causal inference analysis approach estimated a large (100%) reduction in PA in children without eczema (p =.004). Conclusion: We demonstrate a significant reduction in PA with early peanut introduction in a large group of pooled, randomized participants. This significant reduction was demonstrated across all risk subgroups, including children with no eczema. Furthermore, our results point to increased efficacy of the intervention with earlier age of introduction

Early introduction of peanut reduces peanut allergy across risk groups in pooled and causal inference analyses

Background: The Learning Early About Peanut allergy (LEAP) study has shown the effectiveness of early peanut introduction in prevention of peanut allergy (PA). In the Enquiring About Tolerance (EAT) study, a statistically significant reduction in PA was present only in per-protocol (PP) analyses, which can be subject to bias. Objective: The aim of this study was to combine individual-level data from the LEAP and EAT trials and provide robust evidence on the bias-corrected, causal effect of early peanut introduction. Method: As part of the European Union-funded iFAAM project, this pooled analysis of individual pediatric patient data combines and compares effectiveness and efficacy estimates of oral tolerance induction among different risk strata and analysis methods. Results: An intention-to-treat (ITT) analysis of pooled data showed a 75% reduction in PA (p &lt;.0001) among children randomized to consume peanut from early infancy. A protective effect was present across all eczema severity groups, irrespective of enrollment sensitization to peanut, and across different ethnicities. Earlier age of introduction was associated with improved effectiveness of the intervention. In the pooled PP analysis, peanut consumption reduced the risk of PA by 98% (p &lt;.0001). A causal inference analysis confirmed the strong PP effect (89% average treatment effect relative risk reduction p &lt;.0001). A multivariable causal inference analysis approach estimated a large (100%) reduction in PA in children without eczema (p =.004). Conclusion: We demonstrate a significant reduction in PA with early peanut introduction in a large group of pooled, randomized participants. This significant reduction was demonstrated across all risk subgroups, including children with no eczema. Furthermore, our results point to increased efficacy of the intervention with earlier age of introduction

High residual C-peptide likely contributes to glycemic control in type 1 diabetes

BACKGROUND Residual C-peptide is detected in many people for years following the diagnosis of type 1 diabetes; however, the physiologic significance of low levels of detectable C-peptide is not known. METHODS We studied 63 adults with type 1 diabetes classified by peak mixed-meal tolerance test (MMTT) C-peptide as negative (0.200–0.400; n = 15), or high (>0.400; n = 17). We compared the groups’ glycemia from continuous glucose monitoring (CGM), β cell secretory responses from a glucose-potentiated arginine (GPA) test, insulin sensitivity from a hyperinsulinemic-euglycemic (EU) clamp, and glucose counterregulatory responses from a subsequent hypoglycemic (HYPO) clamp. RESULTS Low and intermediate MMTT C-peptide groups did not exhibit β cell secretory responses to hyperglycemia, whereas the high C-peptide group showed increases in both C-peptide and proinsulin (P ≤ 0.01). All groups with detectable MMTT C-peptide demonstrated acute C-peptide and proinsulin responses to arginine that were positively correlated with peak MMTT C-peptide (P < 0.0001 for both analytes). During the EU-HYPO clamp, C-peptide levels were proportionately suppressed in the low, intermediate, and high C-peptide compared with the negative group (P ≤ 0.0001), whereas glucagon increased from EU to HYPO only in the high C-peptide group compared with negative (P = 0.01). CGM demonstrated lower mean glucose and more time in range for the high C-peptide group. CONCLUSION These results indicate that in adults with type 1 diabetes, β cell responsiveness to hyperglycemia and α cell responsiveness to hypoglycemia are observed only at high levels of residual C-peptide that likely contribute to glycemic control. FUNDING Funding for this work was provided by the Leona M. and Harry B. Helmsley Charitable Trust, the National Center for Advancing Translational Sciences, and the National Institute of Diabetes and Digestive and Kidney Diseases

Airway Epithelial Gene Expression Differs Across Urban Childhood Asthma Phenotypes

Rationale: Children living in low-income urban environments experience high asthma morbidity. Prior phenotyping of these children has identified a subgroup with low levels of allergy (T2-low) but highly symptomatic asthma. Assessment of the airway epithelium in these children can provide important mechanistic insights into disease pathogenesis. Methods: We performed RNA-sequencing of nasal brush samples from 123 children in the Asthma Phenotypes in the Inner City (APIC) cohort. These children were previously clustered into 5 phenotypes according to metrics of T2 biomarkers, lung function, rhinitis and asthma symptoms, and asthma severity. Differential gene expression was assessed by modular analysis. Results: The cluster of children characterized by T2-low highly-symptomatic asthma and rhinitis had significantly increased expression of a module of 875 genes. This module was highly enriched for Neuroactive ligand-receptor interaction genes (KEGG; FDR=2.3E-5), Olfactory transduction genes (KEGG; FDR=2.6E-4) and Extracellular matrix genes (UniProtKB; FDR=8.6E-12), the latter of which included multiple collagen and ADAM (a disintegrin and metalloproteinase) genes. This expression module also included a small number of cytokine/receptor pathway genes notable for IL23R, IL26, and IL2 and an absence of canonical T2 genes. This pathway was upregulated 1.5-fold over the cluster of children with T2-low mild asthma, and 2.4-fold over the cluster of children with highly symptomatic T2-high asthma (FDRs \u3c0.05). Conclusions: Our results demonstrate a unique nasal gene expression profile characteristic of urban children with highly symptomatic asthma and rhinitis but with minimal allergy, most notable for numerous genes related to neuronal signaling and components of Th17 signaling, suggesting unique molecular mechanisms of disease