Role of humoral beta-cell autoimmunity in type 1 diabetes

Evolving epigenomics of immune cells in type 1 diabetes at single nuclei resolution

The appearance of diabetes-associated autoantibodies is the first detectable sign of the disease process leading to type 1 diabetes (T1D). Evidence suggests that T1D is a heterogenous disease, where the type of antibodies first formed imply subtypes. Here, we followed 49 children, who subsequently presented with T1D and 49 matched controls, profiling single-cell epigenomics at different time points of disease development. Quantitation of cell and nuclei populations as well as transcriptome and open-chromatin states indicated robust, early, replicable monocyte lineage differences between cases and controls, suggesting heightened pro-inflammatory cytokine secretion early among cases. The order of autoantibody emergence in cases showed variation across lymphoid and myeloid cells, potentially indicating cellular immune response divergence. The strong monocytic lineage representation in peripheral blood immune cells before seroconversion and the weaker differential coordination of these gene networks close to clinical diagnosis emphasizes the importance of early life as a critical phase in T1D development.

Viruses as a potential environmental trigger of type 1 diabetes mellitus (Review)

The etiopathogenesis of type 1 diabetes mellitus (T1DM) is a complex multifactorial process that involves an intricate network of genetic, epigenetic, immunological, and environmental factors. Despite the advances in recent years, some aspects of the mechanisms involved in triggering the disease are still unclear. Infections with certain viruses have been suggested as possible environmental triggers for the autoimmune process that leads to selective and progressive destruction of pancreatic β-cells and insufficiency of insulin production, which is its hallmark. In this review, advances in knowledge and evidence that suggest the participation of certain viruses in the mechanisms of disease initiation and progression are described. It has been accepted that environmental factors, including viruses, can initiate and possibly sustain, accelerate, or slow down the autoimmune process and consequently damage insulin-producing pancreatic β-cells. Although the role of these agents, especially human enteroviruses, has been exhaustively studied as the most likely triggers of the activation of autoimmunity that destroys pancreatic islets and leads to T1DM, certain doubts remain. Clinical epidemiological and experimental studies in humans and animals provide consistent and increasing evidence that persistent viral infections, especially with human enteroviruses and rotavirus infections, are associated with an increased risk of the disease in individuals genetically predisposed to autoimmunity.

Diagnostic value of anti-Kaiso autoantibody in axial spondyloarthritis

Objective

Axial spondyloarthritis (axSpA) is a chronic rheumatic disease predominantly characterized by inflammation and progressive structural damage. Patients are often diagnosed very late, which delays the optimal treatment period. Early diagnosis of axSpA, especially non-radiographic axSpA (nr-axSpA), remains a major challenge. This study aimed to investigate the diagnostic value of anti-Kaiso autoantibodies in axSpA and their correlation with clinical disease indicators.

Methods

Two pooled serum samples (seven patients with nr-axSpA and seven healthy controls) were profiled using HuProt arrays to investigate the diagnostic value of autoantibodies in nr-axSpA. Levels of anti-Kaiso autoantibodies in patients with axSpA and controls were determined using the Meso Scale Discovery assay system. Receiver operating characteristic curve analysis was performed to evaluate the diagnostic performance of anti-Kaiso autoantibodies in axSpA. Pearson's correlation was used to assess the correlation between anti-Kaiso autoantibodies and clinical parameters.

Results

Seven candidate autoantibodies were present in the serum of patients with nr-axSpA. The levels of anti-Kaiso autoantibodies were significantly higher in the nr-axSpA group than in the other groups. It can differentiate nr-axSpA from ankylosing spondylitis (AS), healthy controls, and rheumatoid arthritis. The level of early-stage AS among patients with nr-axSpA decreased when they progressed to the late stage. Of all patients with axSpA, serum anti-Kaiso autoantibody levels were positively correlated with the C-reactive protein level and the Bath Ankylosing Spondylitis Disease Activity Index score and negatively correlated with disease duration.

Conclusion

Anti-Kaiso autoantibody may be a valuable diagnostic biomarker for early-stage AS in the nr-axSpA period and may be a potential therapeutic target.

Narcolepsy-A Neuropathological Obscure Sleep Disorder: A Narrative Review of Current Literature

Narcolepsy is a chronic, long-term neurological disorder characterized by a decreased ability to regulate sleep-wake cycles. Some clinical symptoms enter into differential diagnosis with other neurological diseases. Excessive daytime sleepiness and brief involuntary sleep episodes are the main clinical symptoms. The majority of people with narcolepsy experience cataplexy, which is a loss of muscle tone. Many people experience neurological complications such as sleep cycle disruption, hallucinations or sleep paralysis. Because of the associated neurological conditions, the exact pathophysiology of narcolepsy is unknown. The differential diagnosis is essential because relatively clinical symptoms of narcolepsy are easy to diagnose when all symptoms are present, but it becomes much more complicated when sleep attacks are isolated and cataplexy is episodic or absent. Treatment is tailored to the patient's symptoms and clinical diagnosis. To facilitate the diagnosis and treatment of sleep disorders and to better understand the neuropathological mechanisms of this sleep disorder, this review summarizes current knowledge on narcolepsy, in particular, genetic and non-genetic associations of narcolepsy, the pathophysiology up to the inflammatory response, the neuromorphological hallmarks of narcolepsy, and possible links with other diseases, such as diabetes, ischemic stroke and Alzheimer's disease. This review also reports all of the most recent updated research and therapeutic advances in narcolepsy. There have been significant advances in highlighting the pathogenesis of narcolepsy, with substantial evidence for an autoimmune response against hypocretin neurons; however, there are some gaps that need to be filled. To treat narcolepsy, more research should be focused on identifying molecular targets and novel autoantigens. In addition to therapeutic advances, standardized criteria for narcolepsy and diagnostic measures are widely accepted, but they may be reviewed and updated in the future with comprehension. Tailored treatment to the patient's symptoms and clinical diagnosis and future treatment modalities with hypocretin agonists, GABA agonists, histamine receptor antagonists and immunomodulatory drugs should be aimed at addressing the underlying cause of narcolepsy.

Heterogeneity in the presentation of clinical type 1 diabetes defined by the level of risk conferred by human leukocyte antigen class II genotypes

OBJECTIVES

The association between human leukocyte antigen (HLA) class II genotypes and susceptibility to type 1 diabetes (T1D) is well established. This study aimed at examining whether there are differences in the presentation of T1D depending on the HLA genotype.

RESEARCH DESIGN AND METHODS

We divided the study participants (N = 5798) in the Finnish Pediatric Diabetes Register into two groups based on the T1D risk conferred by their HLA genotype (high and moderate-risk genotypes, Group 1 vs. other genotypes, Group 2). We then examined differences in clinical, metabolic, and immunological characteristics. Children included in the study were 0-14-year-old and diagnosed between January 2003 and December 2019.

RESULTS

Participants in Group 1 were younger at the time of diagnosis (P < 0.001) and had more frequently family members affected by T1D (P < 0.001). Diabetic ketoacidosis (DKA) was more frequent among participants in Group 2 (P = 0.014) who also had a longer duration of symptoms before diagnosis (P < 0.001) and higher hemoglobin A1c (P = 0.001) at diagnosis. The HLA genotype was not, however, directly related to the DKA frequency. The frequency of islet cell antibodies (P < 0.003), insulin autoantibodies (P < 0.001), and islet antigen 2 autoantibodies (P < 0.001) was higher in Group 1 whereas glutamic acid decarboxylase autoantibodies were more frequent (P < 0.001) in Group 2. Group 1 had more participants with multiple autoantibodies (P = 0.027) whereas antibody negativity was more frequent in Group 2 (P = 0.003).

CONCLUSIONS

These findings indicate disease heterogeneity in relation to both clinical disease presentation and humoral autoimmunity, in particular. This heterogeneity is, at least partly, defined by HLA Class II genotypes.

Methanolic Extract of Sambucus ebulus Ameliorates Clinical Symptoms in Experimental Type 1 Diabetes through Anti-Inflammatory and Immunomodulatory Actions

Objective

Sambucus ebulus (SE), a famous traditional Iranian medicine, is grown in the north of Iran. As a traditional medicine with anti-inflammatory effects, SE has been utilized against inflammatory joint diseases, insect bites, infectious wounds, edema, and eczema. Type1 diabetes, is an autoimmune disease, characterized by the destruction of pancreatic beta cells by the immune system. For the first time, we investigated the effect of methanolic extract of SE on CD4+, CD8+ and regulatory T cells in experimental type 1 diabetes (T1D).

Materials and Methods

In this experimental study, fifty-six C57BL\6 mice in 8 groups (G1-G8), were enrolled. Diabetes was induced by a multiple low-dose streptozotocin (MLDS) protocol and mice were daily treated with SE extract at 200 and 400 mg/kg doses, for 35 days. Fasting blood glucose was weekly measured by a glucometer. Islets insulin content was analyzed by immunohistochemistry. Percentage of CD4+, CD8+ and regulatory T cells and cytokines production levels were evaluated by flow cytometer and ELISA, respectively.

Results

The clinical symptoms of diabetes were significantly alleviated in G2 group mice which received 400 mg/ kg SE extract. Immunohistochemistry analysis showed that the insulin content of islets increased in G2 group mice. Immunophenotyping analysis indicated that the percentage of CD4+ and CD8+ T cells in G2 group mice was significantly decreased. SE extract significantly increased the percentage of regulatory T cells. The extract in G2 and G4 groups mice significantly decreased IFN-γ and IL-17levels. The extract significantly increased IL-10 in G2 group mice.

Conclusion

The protective effect of SE extract in MLDS-induced diabetes could be partly due to a decrease of CD4+ and CD8+ T cells and an increase of Treg cells resulting in an inflammation reduction in the pancreatic islets.

Clinical features, biochemistry, and HLA-DRB1 status in youth-onset type 1 diabetes in Sudan

OBJECTIVE

To further understand clinical and biochemical features, and HLA-DRB1 genotypes, in new cases of diabetes in Sudanese children and adolescents.

RESEARCH DESIGN AND METHODS

Demographic characteristics, clinical information, and biochemical parameters (blood glucose, HbA1c, C-peptide, autoantibodies against glutamic acid decarboxylase 65 [GADA] and insulinoma-associated protein-2 [IA-2A], and HLA-DRB1) were assessed in 99 individuals <18 years, recently (<18 months) clinically diagnosed with T1D. HLA-DRB1 genotypes for 56 of these Arab individuals with T1D were compared to a mixed control group of 198 healthy Arab (75%) and African (25%) individuals without T1D.

RESULTS

Mean ± SD age at diagnosis was 10.1 ± 4.3 years (range 0.7-17.6 years) with mode at 9-12 years. A female preponderance was observed. Fifty-two individuals (55.3%) presented in diabetic ketoacidosis (DKA). Mean ± SD serum fasting C-peptide values were 0.22 ± 0.25 nmol/L (0.66±0.74 ng/ml). 31.3% were autoantibody negative, 53.4% were GADA positive, 27.2% were IA-2A positive, with 12.1% positive for both autoantibodies. Association analysis compared to 198 controls of similar ethnic origin revealed strong locus association with HLA-DRB1 (p < 2.4 × 10-14 ). Five HLA-DRB1 alleles exhibited significant T1D association: three alleles (DRB1*03:01, DRB1*04:02, and DRB1*04:05) were positively associated, while three (DRB1*10:01, DRB1*15:02, and DRB1*15:03) were protective. DRB1*03:01 had the strongest association (odds ratio = 5.04, p = 1.7 × 10-10 ).

CONCLUSIONS

Young Sudanese individuals with T1D generally have similar characteristics to reported European-origin T1D populations. However, they have higher rates of DKA and slightly lower autoantibody rates than reported European-origin populations, and a particularly strong association with HLA-DRB1*03:01.

Novel autoantibodies to the β-cell surface epitopes of ZnT8 in patients progressing to type-1 diabetes

Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by autoimmune destruction of insulin-producing β-cells in pancreatic islets. Seroconversions to islet autoantibodies (IAbs) precede the disease onset by many years, but the role of humoral autoimmunity in the disease initiation and progression are unclear. In the present study, we identified a new IAb directed to the extracellular epitopes of ZnT8 (ZnT8ec) in newly diagnosed patients with T1D, and demonstrated immunofluorescence staining of the surface of human β-cells by autoantibodies to ZnT8ec (ZnT8ecA). With the assay specificity set on 99th percentile of 336 healthy controls, the ZnT8ecA positivity rate was 23.6% (74/313) in patients with T1D. Moreover, 30 children in a longitudinal follow up of clinical T1D development were selected for sequential expression of four major IAbs (IAA, GADA, IA-2A and ZnT8icA). Among them, 10 children were ZnT8ecA positive. Remarkably, ZnT8ecA was the earliest IAb to appear in all 10 children. The identification of ZnT8ec as a cell surface target of humoral autoimmunity in the earliest phase of IAb responses opens a new avenue of investigation into the role of IAbs in the development of β-cell autoimmunity.

The Potential Causes of Cystic Fibrosis-Related Diabetes

Cystic fibrosis (CF) is a genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator gene (CFTR). Cystic fibrosis-related diabetes (CFRD) is the most common comorbidity, affecting more than 50% of adult CF patients. Despite this high prevalence, the etiology of CFRD remains incompletely understood. Studies in young CF children show pancreatic islet disorganization, abnormal glucose tolerance, and delayed first-phase insulin secretion suggesting that islet dysfunction is an early feature of CF. Since insulin-producing pancreatic β-cells express very low levels of CFTR, CFRD likely results from β-cell extrinsic factors. In the vicinity of β-cells, CFTR is expressed in both the exocrine pancreas and the immune system. In the exocrine pancreas, CFTR mutations lead to the obstruction of the pancreatic ductal canal, inflammation, and immune cell infiltration, ultimately causing the destruction of the exocrine pancreas and remodeling of islets. Both inflammation and ductal cells have a direct effect on insulin secretion and could participate in CFRD development. CFTR mutations are also associated with inflammatory responses and excessive cytokine production by various immune cells, which infiltrate the pancreas and exert a negative impact on insulin secretion, causing dysregulation of glucose homeostasis in CF adults. In addition, the function of macrophages in shaping pancreatic islet development may be impaired by CFTR mutations, further contributing to the pancreatic islet structural defects as well as impaired first-phase insulin secretion observed in very young children. This review discusses the different factors that may contribute to CFRD.

Modeling Type 1 Diabetes Using Pluripotent Stem Cell Technology

Induced pluripotent stem cell (iPSC) technology is increasingly being used to create in vitro models of monogenic human disorders. This is possible because, by and large, the phenotypic consequences of such genetic variants are often confined to a specific and known cell type, and the genetic variants themselves can be clearly identified and controlled for using a standardized genetic background. In contrast, complex conditions such as autoimmune Type 1 diabetes (T1D) have a polygenic inheritance and are subject to diverse environmental influences. Moreover, the potential cell types thought to contribute to disease progression are many and varied. Furthermore, as HLA matching is critical for cell-cell interactions in disease pathogenesis, any model that seeks to test the involvement of particular cell types must take this restriction into account. As such, creation of an in vitro model of T1D will require a system that is cognizant of genetic background and enables the interaction of cells representing multiple lineages to be examined in the context of the relevant environmental disease triggers. In addition, as many of the lineages critical to the development of T1D cannot be easily generated from iPSCs, such models will likely require combinations of cell types derived from in vitro and in vivo sources. In this review we imagine what an ideal in vitro model of T1D might look like and discuss how the required elements could be feasibly assembled using existing technologies. We also examine recent advances towards this goal and discuss potential uses of this technology in contributing to our understanding of the mechanisms underlying this autoimmune condition.

Extended family history of type 1 diabetes in HLA-predisposed children with and without islet autoantibodies

OBJECTIVE

The aim of this study was to explore the extended family history of type 1 diabetes in children at genetic risk and define the impact of a positive family history on the development of islet autoimmunity and type 1 diabetes.

METHODS

The subjects were participants in The Finnish Type 1 Diabetes Prediction and Prevention (DIPP) study and carried increased HLA-conferred risk for type 1 diabetes. The case children (N = 343) were positive for at least one islet autoantibody, and the control children (N = 343) matched by age, gender and class II HLA genotype were negative for islet autoantibodies at the time of data collection. Extended family history of type 1 diabetes was obtained by using a structured questionnaire.

RESULTS

Among children who were autoantibody positive and progressed to type 1 diabetes 62.2% (28/45) had at least one relative with type 1 diabetes. Interestingly, 57.8% of these children (26/45) had such a relative outside the nuclear family compared to 30.7% of children with no autoantibodies (P = .001), 35.2% of those with only classical islet cell antibodies (P = .006), and 35.2% of non-progressors with biochemical autoantibodies (P = 0.011). A positive history of type 1 diabetes in the paternal extended family was more common in children with multiple biochemical autoantibodies compared to those with only one biochemical autoantibody (P = .010). No association between the specificity of the first appearing autoantibody and family history of the disease was found.

CONCLUSIONS

Type 1 diabetes in relatives outside the nuclear family is a significant risk factor for islet autoimmunity and progression to clinical disease in HLA susceptible children.

Atypical juvenile hereditary hemochromatosis onset with positive pancreatic islet autoantibodies diabetes caused by novel mutations in HAMP and overall clinical management

Background

Atypical clinical symptoms of juvenile hereditary hemochromatosis (JHH) often leads to misdiagnosis and underdiagnosis bringing ominous outcomes, even death.

Methods

The whole exome was sequenced and interpreted. A literature review assisted to analyze and verify the phenotype–genotype relationships. We revealed the entire process of diagnosis, treatments, and outcome of two diabetic onset of JHH families to provide new insights for genotype–phenotype relation with novel compound heterozygous mutations in the hepcidin antimicrobial peptide (HAMP, OMIM: 606464).

Results

Two probands were diagnosed and treated as type 1 diabetes initially because of specific symptoms and positive islet autoantibodies. Poor control of hyperglycemia and progressive symptoms occurred. Sequencing informed that the compound heterozygous and homozygous mutations c.166C>G and c.223C>T in HAMP caused type 1 diabetic‐onset JHH. The two patients accessed irregular phlebotomy treatments, and then, experienced poor prognosis. We summarized the process of overall clinical management of reported 26 cases comparing to our novel atypical diabetic onsets Juvenile Hereditary Hemochromatosis cases.

Conclusion

It was first reported that positive pancreatic islet autoantibodies diabetes onset of JHH resulted from loss‐of‐function mutations of HAMP, of which the atypical JHH should be differentially diagnosed with type 1 diabetes at the onset. Early administration of phlebotomy and vital organs protection and surveillance might be important for the treatment of atypical JHH.

The Role of β Cell Stress and Neo-Epitopes in the Immunopathology of Type 1 Diabetes

Due to their secretory function, β cells are predisposed to higher levels of endoplasmic reticulum (ER) stress and greater sensitivity to inflammation than other cell types. These stresses elicit changes in β cells that alter their function and immunogenicity, including defective ribosomal initiation, post-translational modifications (PTMs) of endogenous β cell proteins, and alternative splicing. Multiple published reports confirm the presence of not only CD8+ T cells, but also autoreactive CD4+ T cells within pancreatic islets. Although the specificities of T cells that infiltrate human islets are incompletely characterized, they have been confirmed to include neo-epitopes that are formed through stress-related enzymatic modifications of β cell proteins. This article summarizes emerging knowledge about stress-induced changes in β cells and data supporting a role for neo-antigen formation and cross-talk between immune cells and β cells that provokes autoimmune attack - leading to a breakdown in tissue-specific tolerance in subjects who develop type 1 diabetes.

Prediction and prevention of type 1 diabetes in children

Type 1 diabetes (T1D) is a chronic T-cell mediated autoimmune disease characterized by destruction of beta cells. Although new data have better defined the complex etiology underling the interrelation of genetic and environmental factors in the natural history of T1D, relevant pieces of the puzzle still are missing. Genetic predisposition is mainly associated to some histocompatibility leukocyte antigen (HLA) alleles; however, recent data suggest that new as well as still unknown genes might better define the complex multigenetic risk of the disease. In addition to the genetic effects, the concordance in familial aggregation in T1D indicates a pivotal role of environmental factors in the course of the disease, facilitating autoantibodies production. JDRF has recently proposed a new early stage of T1D according to which the detection of two or more autoantibodies in the blood, might describe those children at increased risk of developing T1D during the following years. In contrast to the improvements reached by prediction models, to date primary, secondary and tertiary prevention have still failed to achieve a safe and efficacious intervention strategies. Anyway, the most recent progresses in this field pave the way for future studies, with the aim of preventing T1D in children.

High prevalence of humoral autoimmunity in first-degree relatives of Mexican type 1 diabetes patients

AIMS

To assess the prevalence of autoantibodies (Aab) to insulin (IAA), glutamic acid decarboxylase 65 (GADA) and insulinoma antigen 2 (IA-2A), as well as human leukocyte antigen (HLA) class II alleles, in first degree relatives (FDR) of Mexican patients with type 1 diabetes (T1D), and to explore whether these parameters mirror the low incidence of T1D in the Mexican population.

METHODS

Aab titers were determined by ELISA in 425 FDR, 234 siblings, 40 offspring and 151 parents of 197 patients with T1D. Typing of HLA-DR and -DQ alleles was performed in 41 Aab-positive FDR using polymerase chain reaction with allele-specific oligotyping.

RESULTS

Seventy FDR (16.47%) tested positive for Aab. The siblings (19.2%) and the offspring (25%) had significantly higher prevalence of Aab than the parents (9.9%). GADA was the most frequent Aab. Almost half of the Aab-positive FDR had two different Aab (45.7%), and none tested positive for three Aab. The highest prevalence of Aab was found among women in the 15-29 years age group. Moreover, the positivity for two Aab was significantly more frequent among females. A considerable number of FDR (48.8%) carried the susceptible HLA-DR3, -DR4, -DQB1*0201 or -DQB1*0302 alleles, but almost none had the high risk genotype HLA-DR3/DR4.

CONCLUSIONS

FDR of Mexican T1D patients have high prevalence of islet Aab, comparable to countries with the highest incidence of T1D. However, Aab positivity does not seem to be associated with HLA risk genotypes, which may have an impact on the low incidence of T1D in Mexico.

The Better Diabetes Diagnosis (BDD) study - A review of a nationwide prospective cohort study in Sweden

The incidence of type 1 diabetes (T1D) in Sweden is one of the highest in the world. However, the possibility of other types of diabetes must also be considered. In addition, individuals with T1D constitute a heterogeneous group. A precise classification of diabetes is a prerequisite for optimal outcome. For precise classification, knowledge on the distribution of genetic factors, biochemical markers and clinical features in individuals with new onset of diabetes is needed. The Better Diabetes Diagnosis (BDD), is a nationwide study in Sweden with the primary aim to facilitate a more precise classification and diagnosis of diabetes in order to enable the most adequate treatment for each patient. Secondary aims include identification of risk factors for diabetes-related co-morbidities. Since 2005, data on almost all children and adolescents with newly diagnosed diabetes in Sweden are prospectively collected and including heredity of diabetes, clinical symptoms, levels of C peptide, genetic analyses and detection of autoantibodies. Since 2011, analyses of HLA profile, autoantibodies and C peptide levels are part of clinical routine in Sweden for all pediatric patients with suspected diagnosis of diabetes. In this review, we present the methods and main results of the BDD study so far and discuss future aspects.

Autoantibodies against zinc transporter 8 are related to age and metabolic state in patients with newly diagnosed autoimmune diabetes

AIMS

To assess the prevalence of ZnT8-ab and its correlation to other autoimmune markers and diabetic ketoacidosis occurrence in children and adults with T1DM onset.

METHODS

The study included 367 patients (218 children; 149 adults) at the T1DM onset. Selected diabetes-related autoantibodies such as GAD-ab, IA2-ab, ZnT8-ab were tested before the initiation of insulin therapy. Diabetic ketoacidosis was defined as glucose concentration > 13.9 mmol/l, pH < 7.30, concentration of HCO₃ < 15 mmol/l, presence of ketone bodies in the blood and urine.

RESULTS

The autoantibodies pattern differs in both study groups. Children were mostly positive for two (37.8%) and three (49.5%) autoantibodies, whereas adults for one (32.2%) and two (30.7%). The most frequently detected autoantibodies in youth were ZnT8-ab (81.1%) and IA2-ab (80.7%), while in adults GAD-ab (74.8%). ZnT8-ab (p < 0.0001) titers were significantly higher in children, but adults had higher titer of GAD-ab (p < 0.0001) and IA2-ab (p < 0.0001). Children developed more frequently diabetic ketoacidosis (28.4 vs. 10.7%, p = 0.0002). ZnT8-ab (p = 0.002) and IA2-ab (p = 0.008) were reported mostly in individuals with ketoacidosis. A correlation between the number of positive antibodies and the severity of ketoacidosis was observed (R_s - 0.129 p = 0.014). ZnT8-ab were associated with a greater risk of ketoacidosis independent of gender, age group and the autoantibodies number [OR = 2.44 (95% CI 1.0-5.94), p = 0.04].

CONCLUSIONS

Children are at greater risk of ketoacidosis at the diagnosis of diabetes. ZnT8-ab and IA2-ab are commonly detected in children, while adults have frequently higher titer of GAD-ab. ZnT8-ab are associated with more acute diabetes onset.

Knip M, Åkerblom HK, Al Taji E, Becker D, Bruining J, Castano L, Danne T, de Beaufort C, Dosch HM, Dupre J, Fraser WD, Howard N, Ilonen J, Konrad D, Kordonouri O, Krischer JP, Lawson ML, Ludvigsson J, Madacsy L, Mahon JL, Ormisson A, Palmer JP, Pozzilli P, Savilahti E, Serrano-Rios M, Songini M, Taback S, Vaarala O, White NH, Virtanen SM, Wasikowa R. Effect of Hydrolyzed Infant Formula vs Conventional Formula on Risk of Type 1 Diabetes: The TRIGR Randomized Clinical Trial

IMPORTANCE

Early exposure to complex dietary proteins may increase the risk of type 1 diabetes in children with genetic disease susceptibility. There are no intact proteins in extensively hydrolyzed formulas.

OBJECTIVE

To test the hypothesis that weaning to an extensively hydrolyzed formula decreases the cumulative incidence of type 1 diabetes in young children.

DESIGN, SETTING, AND PARTICIPANTS

An international double-blind randomized clinical trial of 2159 infants with human leukocyte antigen-conferred disease susceptibility and a first-degree relative with type 1 diabetes recruited from May 2002 to January 2007 in 78 study centers in 15 countries; 1081 were randomized to be weaned to the extensively hydrolyzed casein formula and 1078 to a conventional formula. The follow-up of the participants ended on February 28, 2017.

INTERVENTIONS

The participants received either a casein hydrolysate or a conventional adapted cow's milk formula supplemented with 20% of the casein hydrolysate. The minimum duration of study formula exposure was 60 days by 6 to 8 months of age.

MAIN OUTCOMES AND MEASURES

Primary outcome was type 1 diabetes diagnosed according to World Health Organization criteria. Secondary outcomes included age at diabetes diagnosis and safety (adverse events).

RESULTS

Among 2159 newborn infants (1021 female [47.3%]) who were randomized, 1744 (80.8%) completed the trial. The participants were observed for a median of 11.5 years (quartile [Q] 1-Q3, 10.2-12.8). The absolute risk of type 1 diabetes was 8.4% among those randomized to the casein hydrolysate (n = 91) vs 7.6% among those randomized to the conventional formula (n = 82) (difference, 0.8% [95% CI, -1.6% to 3.2%]). The hazard ratio for type 1 diabetes adjusted for human leukocyte antigen risk group, duration of breastfeeding, duration of study formula consumption, sex, and region while treating study center as a random effect was 1.1 (95% CI, 0.8 to 1.5; P = .46). The median age at diagnosis of type 1 diabetes was similar in the 2 groups (6.0 years [Q1-Q3, 3.1-8.9] vs 5.8 years [Q1-Q3, 2.6-9.1]; difference, 0.2 years [95% CI, -0.9 to 1.2]). Upper respiratory infections were the most common adverse event reported (frequency, 0.48 events/year in the hydrolysate group and 0.50 events/year in the control group).

CONCLUSIONS AND RELEVANCE

Among infants at risk for type 1 diabetes, weaning to a hydrolyzed formula compared with a conventional formula did not reduce the cumulative incidence of type 1 diabetes after median follow-up for 11.5 years. These findings do not support a need to revise the dietary recommendations for infants at risk for type 1 diabetes.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00179777.

Early life origin of type 1 diabetes

Type 1 diabetes (T1D) is perceived as a chronic immune-mediated disease with a subclinical prodromal period characterized by selective loss of insulin-producing beta cells in the pancreatic islets in genetically susceptible subjects. The incidence of T1D has increased manifold in most developed countries after World War II in parallel with a series of other immune-mediated diseases. T1D results from gene-environmental interactions. The appearance of disease-associated autoantibodies into the peripheral circulation is the first detectable sign of the initiation of the disease process leading to clinical T1D. The first autoantibodies may appear already before the age of 6 months and the seroconversion rate peaks during the second year of life. This implies that exogenous factors involved in the pathogenesis of T1D must be operative in early life, some of them most likely already during pregnancy. Here, we discuss putative endogenous factors that may contribute to the development of T1D during fetal and early postnatal life. Many environmental factors operative in early life have been implicated in the pathogenesis of T1D, but relatively few have been firmly confirmed.

Antibodies to post-translationally modified insulin as a novel biomarker for prediction of type 1 diabetes in children

AIMS/HYPOTHESIS

We have shown that autoimmunity to insulin in type 1 diabetes may result from neoepitopes induced by oxidative post-translational modifications (oxPTM). Antibodies specific to oxPTM-insulin (oxPTM-INS-Ab) are present in most newly diagnosed individuals with type 1 diabetes and are more common than autoantibodies to native insulin. In this study, we investigated whether oxPTM-INS-Ab are present before clinical onset of type 1 diabetes, and evaluated the ability of oxPTM-INS-Ab to identify children progressing to type 1 diabetes.

METHODS

We used serum samples collected longitudinally from the 'All Babies in Southeast Sweden (ABIS)' cohort tested for the gold standard islet autoantibodies to insulin (IAA), GAD (GADA), tyrosine phosphatase 2 (IA-2A) and zinc transporter 8 (ZnT8A). We studied 23 children who progressed to type 1 diabetes (progr-T1D) and 63 children who did not progress to type 1 diabetes (NP) after a median follow-up of 10.8 years (interquartile range 7.7-12.8). Of the latter group, 32 were positive for one or more islet autoantibodies (NP-AAB⁺). oxPTM-INS-Ab to insulin modified by ^•OH or HOCl were measured by our developed ELISA platform.

RESULTS

Antibodies to at least one oxPTM-INS were present in 91.3% of progr-T1D children. oxPTM-INS-Ab co-existed with GADA, IA-2A, IAA or ZnT8A in 65.2%, 56.5%, 38.9% and 33.3% progr-T1D children, respectively. In addition, oxPTM-INS-Ab were present in 17.4%, 26.1%, 38.9% and 41.6% of progr-T1D children who were negative for GADA, IA-2A, IAA and ZnT8A, respectively. ^•OH-INS-Ab were more common in progr-T1D children than in NP-AAB⁺ children (82.6% vs 19%; p < 0.001) and allowed discrimination between progr-T1D and NP-AAB⁺ children with 74% sensitivity and 91% specificity. None of the NP-AAB^- children were positive for oxPTM-INS-Ab.

CONCLUSIONS/INTERPRETATION

oxPTM-INS-Ab are present before the clinical onset of type 1 diabetes and can identify children progressing to type 1 diabetes.