Inverse Relationship Between Organ-Specific Autoantibodies and Systemic Immune Mediators in Type 1 Diabetes and Type 2 Diabetes: Action LADA 11

Autoimmune diseases and the risk and prognosis of latent autoimmune diabetes in adults

AIMS/HYPOTHESIS

The aim of this study was to clarify the impact of autoimmune disease (AD) comorbidity on the risk and prognosis of latent autoimmune diabetes in adults (LADA).

METHODS

We used data from a Swedish study comprising newly diagnosed cases of LADA (n=586, stratified into LADAlow and LADAhigh by autoantibody levels), type 2 diabetes (n=2003) and matched control participants (n=2355). Information on 33 ADs and diabetic retinopathy was obtained by linkage to regional and national registers. We estimated the ORs for LADA and type 2 diabetes in relation to ADs before diabetes diagnosis, and the HRs for diabetic retinopathy after diabetes diagnosis. We performed functional pathway analyses to explore biological mechanisms driving the associations.

RESULTS

Individuals with ADs exhibit an increased susceptibility to LADA (OR 1.70; 95% CI 1.36, 2.13), particularly those with thyroid dysfunction (OR 1.88; 95% CI 1.38, 2.56), inflammatory bowel disease (OR 1.78; 95% CI 1.00, 3.16) or vitiligo (OR 3.91; 95% CI 1.93, 7.94), with stronger associations being observed for the LADAhigh phenotype. Only psoriasis was linked to type 2 diabetes (OR 1.47; 95% CI 1.08, 1.99). The biological pathways shared by LADA and ADs revolved around immune responses, including innate and adaptive immune pathways. The HRs for diabetic retinopathy in LADA patients with and without AD vs those with type 2 diabetes were 2.11 (95% CI 1.34, 3.32) and 1.68 (95% CI 1.15, 2.45), respectively.

CONCLUSIONS/INTERPRETATION

We confirm that several common ADs confer an excess risk of LADA, especially LADA with higher GADA levels, but having such a comorbidity does not appear to affect the risk of diabetic retinopathy.

Prognosis and outcome of latent autoimmune diabetes in adults: T1DM or T2DM?

Latent Autoimmune Diabetes in Adults (LADA) is a type of diabetes mellitus often overlooked in clinical practice for its dual resemblance to Type 1 Diabetes Mellitus (T1DM) in pathogenesis and to Type 2 Diabetes Mellitus (T2DM) in clinical presentation. To better understand LADA's distinctiveness from T1DM and T2DM, we conducted a comprehensive review encompassing etiology, pathology, clinical features, treatment modalities, and prognostic outcomes. With this comparative lens, we propose that LADA defies simple classification as either T1DM or T2DM. The specific treatments for the disease are limited and should be based on the therapies of T1DM or T2DM that address specific clinical issues at different stages of the disease. It is crucial to identify LADA cases potentially misdiagnosed as T2DM, warranting prompt screening for poor blood sugar control, short-term blood sugar deterioration, and other conditions. If the prognosis for LADA is similar to T2DM, it can be managed as T2DM. However, if the prognosis fundamentally differs, early LADA screening is crucial to optimize patient outcomes and enhance research on tailored treatments. The pathogenesis of LADA is clear, so the prognosis may be the key to determining whether it can be classified as T2DM, which is also the direction of future research. On the one hand, this paper aims to provide suggestions for the clinical screening and treatment of LADA based on the latest progress and provide worthy directions for future research on LADA.

Type 1 diabetes, celiac disease, and autoimmune thyroiditis autoantibodies in population-based type 2 diabetes patients

Aims

The study aims were to determine autoantibodies associated with type 1 diabetes (T1D), celiac disease (CD) and autoimmune thyroid disease (AITD) in individuals living with type 2 diabetes (T2D) compared to T1D and matched controls.

Methods

Individuals with T1D and T2D were randomly identified in health-care registers. Blood was collected through home-capillary sampling and autoantibodies associated with either T1D against glutamic acid decarboxylase (GADA), insulin (IAA), insulinoma antigen-2 (IA-2A), and zinc transporter 8 (ZnT8A), CD against tissue transglutaminase (tTGA) or AITD against thyroid peroxidase (TPOA) were determined in an automated, multiplex Antibody Detection by Agglutination-PCR (ADAP) assay.

Results

GADA were detected in 46 % (88/191) of T1D and increased to 6.2 % (23/372) in T2D compared to 2.6 % (7/259) of controls (p = 0.0367). tTGA was low (1.1-2.6 %) and not different in between the study cohorts, nonetheless, in T1D tTGA was associated to islet autoantibodies. TPOA was more frequent in T1D, 27.1 % (53/191), compared to either T2D, 14.8 % (55/372; p = 0.0002) or controls, 14.3 % (37/259) (p = 0.0004). Overall, TPOA was more frequent in GADA positive (34.8 %; 8/23) than negative (13.5 %; 47/349; p = 0.0053) T2D individuals.

Conclusion

It's suggested that analyzing GADA and TPOA may refine the autoimmune landscape in individuals clinically classified as T2D.

Association of autoimmune thyroid disease with type 1 diabetes mellitus and its ultrasonic diagnosis and management

As a common hyperglycemic disease, type 1 diabetes mellitus (T1DM) is a complicated disorder that requires a lifelong insulin supply due to the immune-mediated destruction of pancreatic β cells. Although it is an organ-specific autoimmune disorder, T1DM is often associated with multiple other autoimmune disorders. The most prevalent concomitant autoimmune disorder occurring in T1DM is autoimmune thyroid disease (AITD), which mainly exhibits two extremes of phenotypes: hyperthyroidism [Graves' disease (GD)] and hypo-thyroidism [Hashimoto's thyroiditis, (HT)]. However, the presence of comorbid AITD may negatively affect metabolic management in T1DM patients and thereby may increase the risk for potential diabetes-related complications. Thus, routine screening of thyroid function has been recommended when T1DM is diagnosed. Here, first, we summarize current knowledge regarding the etiology and pathogenesis mechanisms of both diseases. Subsequently, an updated review of the association between T1DM and AITD is offered. Finally, we provide a relatively detailed review focusing on the application of thyroid ultrasonography in diagnosing and managing HT and GD, suggesting its critical role in the timely and accurate diagnosis of AITD in T1DM.

Reclassification of type 2 diabetes to type 1 diabetes in Asturias (Spain) between 2011 and 2020

BACKGROUND

Differentiating between type 1 diabetes (T1D) and type 2 diabetes (T2D) can be difficult in adults. The aim of this study was to determine the frequency of diagnostic reclassification from T2D to T1D, the characteristics of the patients and the impact on the management of the disease.

METHODS

Observational and descriptive study including patients diagnosed with T1D in Asturias (Spain) between 2011 and 2020 who had been considered as T2D for at least 12 months.

RESULTS

A total of 205 patients were included, representing 45.3% of those diagnosed with T1D over 30 years of age. Median time of evolution as T2D was 7,8 years. The age was 59.1 ± 12.9 years. BMI was > 25 kg/m² in 46.8% of patients. HbA1c was 9.1 ± 2.1%, 77 ± 22 mmol/mol, and 56.5% were using insulin. Pancreatic antibodies were present in 95.5%, the most frequent being GAD, 82.6%. At 6 months, basal insulin use increased from 46.9 to 86.3%, and HbA1c decreased, 9.2 ± 2.0%vs7.7 ± 1.2%, 77 ± 22vs60 ± 13 mmol/mol; p < 0.0001.

CONCLUSIONS

Diagnosis as T2D in patients with T1D in adults is common. Age, BMI, insulin use and other clinical features are not definitely discriminatory. GAD is the antibody of choice in case of diagnostic suspect. Reclassification has important implications for metabolic control.

Diagnostic Dilemmas and Current Treatment Approaches in Latent Onset Autoimmune Diabetes in Adults: A Concise Review

Latent Onset Autoimmune Diabetes in Adults (LADA) is an autoimmune disorder between T1DM and T2DM and is often misdiagnosed as T2DM due to its late-onset. The disease is characterized by β-cell failure and slow progression to insulin dependence. Early diagnosis is significant in limiting disease progression. C-peptide levels and autoantibodies against β-cells are the most critical diagnostic biomarkers in LADA. The review aims to provide an overview of the biomarkers used to diagnose LADA, and the following treatment approaches. We have summarized LADA's pathophysiology and the autoantibodies involved in the condition, diagnostic approaches, and challenges. There are clear shortcomings concerning the feasibility of autoantibody testing. Finally, we have explored the treatment strategies involved in the management of LADA. In conclusion, the usual management includes treatment with metformin and the addition of low doses of insulin. Newer oral hypoglycaemic agents, such as GLP-1RA and DPP-4 inhibitors, have been brought into use. Since the disease is not entirely understood at the research level and in clinical practice, we hope to encourage further research in this field to assess its prevalence. Large randomized controlled trials are required to compare the efficacy of different available treatment options.

Latent autoimmune diabetes in adults in China

Latent autoimmune diabetes in adults (LADA) is a type of diabetes caused by slow progression of autoimmune damage to pancreatic beta cells. According to the etiological classification, LADA should belong to the autoimmune subtype of type 1 diabetes (T1D). Previous studies have found general immune genetic effects associated with LADA, but there are also some racial differences. Multicenter studies have been conducted in different countries worldwide, but it is still unclear how the Chinese and Caucasian populations differ. The epidemiology and phenotypic characteristics of LADA may vary between Caucasian and Chinese diabetic patients as lifestyle, food habits, and body mass index differ between these two populations. The prevalence of LADA in China has reached a high level compared to other countries. The prevalence of LADA in China has reached a high level compared to other countries, and the number of patients with LADA ranks first in the world. Previous studies have found general immune genetic effects associated with LADA, but some racial differences also exist. The prevalence of LADA among newly diagnosed type 2 diabetes patients over the age of 30 years in China is 5.9%, and LADA patients account for 65% of the newly diagnosed T1D patients in the country. As a country with a large population, China has many people with LADA. A summary and analysis of these studies will enhance further understanding of LADA in China. In addition, comparing the similarities and differences between the Chinese and the Caucasian population from the perspectives of epidemiology, clinical, immunology and genetics will help to improve the understanding of LADA, and then promote LADA studies in individual populations.

Small RNAs are differentially expressed in autoimmune and non-autoimmune diabetes and controls

OBJECTIVE

Diabetes is a heterogeneous disease and a precise diagnosis of diabetes subgroups is necessary to initiate proper early treatment and clinical management of the disease. Circulating small RNAs (sRNAs) are potentially diagnostic biomarkers in diseases, including diabetes. Here we aimed to examine whether profiles of circulating sRNAs differed between patients with autoimmune and non-autoimmune diabetes and non-diabetic controls.

DESIGN

This cross-sectional case-control study included participants from the third survey of the HUNT study.

METHODS

We performed sRNA sequencing in serum from adult-onset type 1 diabetes (n = 51), type 2 diabetes (n = 50) and latent autoimmune diabetes in adult (LADA, n = 51), as well as non-diabetic HUNT3 participants as control group (n = 51). Differential expression analysis of the sRNAs was performed in R using limma-voom.

RESULTS

We identified differences in sRNA expression between autoimmune (type 1 diabetes and LADA) and non-autoimmune diabetes (type 2 diabetes) and between patients with diabetes and non-diabetic controls. Focusing on miRNA, we identified 10 differentially expressed mature miRNAs and 30 differentially expressed miRNA variants (isomiRs). We also identified significant changes within other sRNA classes, including a pronounced downregulation of a tRNA fragment in patients with diabetes compared to non-diabetic controls. We created cross-validated sRNA signatures based on the significant sRNAs that distinguished patients with diabetes from non-diabetic controls, and autoimmune from non-autoimmune diabetes, with high specificity and sensitivity. sRNA profiles did not distinguish between type 1 diabetes and LADA.

CONCLUSIONS

Circulating sRNAs are differentially expressed between patients with diabetes and non-diabetic controls and between autoimmune and non-autoimmune diabetes.

Islet autoantibody positivity in an adult population with recently diagnosed diabetes in Uganda

Aims

This study aimed to investigate the frequency of islet autoantibody positivity in adult patients with recently diagnosed diabetes in Uganda and its associated characteristics.

Methods

Autoantibodies to glutamic acid decarboxylase-65 (GADA), zinc transporter 8 (ZnT8-A), and tyrosine phosphatase (IA-2A) were measured in 534 adult patients with recently diagnosed diabetes. Islet autoantibody positivity was defined based on diagnostic thresholds derived from a local adult population without diabetes. The socio-demographic, clinical, and metabolic characteristics of islet autoantibody-positive and negative participants were then compared. The differences in these characteristics were analysed using the x² test for categorical data and the Kruskal Wallis test for continuous data. Multivariate analysis was performed to identify predictors of islet autoantibody positivity.

Results

Thirty four (6.4%) participants were positive for ≥1 islet autoantibody. GADA, IA-2A and ZnT8-A positivity was detected in 17 (3.2%), 10 (1.9%), and 7 (1.3%) participants, respectively. Compared with those negative for islet autoantibodies, participants positive for islet autoantibodies were more likely to live in a rural area (n = 18, 52.9% Vs n = 127, 25.5%, p = 0.005), to be initiated on insulin therapy (n = 19, 55.9% Vs n = 134, 26.8%, p<0.001), to have a lower median waist circumference (90 [80–99] cm Vs 96 [87–104.8], p = 0.04), waist circumference: height ratio (0.55 [0.50–0.63] vs 0.59 [0.53–0.65], p = 0.03), and fasting C-peptide concentration (0.9 [0.6–1.8] Vs 1.4 [0.8–2.1] ng/ml, p = 0.01). On multivariate analysis, living in a rural area (odds ratio or OR 3.62, 95%CI 1.68–7.80, p = 0.001) and being initiated on insulin therapy (OR 3.61, 95% CI 1.67–7.83, p = 0.001) were associated with islet autoantibody positivity.

Conclusion

The prevalence of islet autoantibody positivity was relatively low, suggesting that pancreatic autoimmunity is a rare cause of new-onset diabetes in this adult Ugandan population. Living in a rural area and being initiated on insulin therapy were independently associated with islet autoantibody positivity in this study population.

Innate immunity in latent autoimmune diabetes in adults

Latent autoimmune diabetes in adults (LADA) is an autoimmune disease that shares some genetic, immunological and clinical features with both type 1 diabetes and type 2 diabetes. Immune cells including CD4⁺ T cells, CD8⁺ T cells, B cells, macrophages and dendritic cells (DCs) have been detected in the pancreas of patients with LADA and a rat model of LADA. Therefore, similar to type 1 diabetes, the pathogenesis of LADA may be caused by interactions between islet β-cells and innate and adaptive immune cells. However, the role of the immunity in the initiation and progression of LADA remains largely unknown. In this review, we have summarized the potential roles of innate immunity and immune-modulators in LADA development. Furthermore, we have examined the evidence and discussed potential innate immunological reasons for the slower development of LADA compared with type 1 diabetes. More in-depth mechanistic studies are needed to fully elucidate the roles of innate immune-associated genes, molecules and cells in their contributions to LADA pathogenesis. Undertaking these studies will greatly enhance the development of new strategies and optimization of current strategies for the diagnosis and treatment of the disease.

Adult-Onset Type 1 Diabetes: Current Understanding and Challenges

Recent epidemiological data have shown that more than half of all new cases of type 1 diabetes occur in adults. Key genetic, immune, and metabolic differences exist between adult- and childhood-onset type 1 diabetes, many of which are not well understood. A substantial risk of misclassification of diabetes type can result. Notably, some adults with type 1 diabetes may not require insulin at diagnosis, their clinical disease can masquerade as type 2 diabetes, and the consequent misclassification may result in inappropriate treatment. In response to this important issue, JDRF convened a workshop of international experts in November 2019. Here, we summarize the current understanding and unanswered questions in the field based on those discussions, highlighting epidemiology and immunogenetic and metabolic characteristics of adult-onset type 1 diabetes as well as disease-associated comorbidities and psychosocial challenges. In adult-onset, as compared with childhood-onset, type 1 diabetes, HLA-associated risk is lower, with more protective genotypes and lower genetic risk scores; multiple diabetes-associated autoantibodies are decreased, though GADA remains dominant. Before diagnosis, those with autoantibodies progress more slowly, and at diagnosis, serum C-peptide is higher in adults than children, with ketoacidosis being less frequent. Tools to distinguish types of diabetes are discussed, including body phenotype, clinical course, family history, autoantibodies, comorbidities, and C-peptide. By providing this perspective, we aim to improve the management of adults presenting with type 1 diabetes.

Increased spontaneous CCL2 (MCP-1) and CCL5 (RANTES) secretion in vitro in LADA compared to type 1 diabetes and type 2 diabetes: Action LADA 14

AIMS

Immune-mediated type 1 diabetes (T1D) in adulthood and latent autoimmune diabetes in adults (LADA) share similar pathological mechanisms but differ clinically in disease progression. The aim of this study was to acquire insights into spontaneous and stimulated chemokine secretion of immune cells in different diabetes types.

MATERIALS AND METHODS

We investigated in vitro spontaneous, mitogen (PI) and antigen (HSP60, p277, pGAD, pIA2) stimulated chemokine secretion of leucocytes from patients with T1D (n = 32), LADA (n = 22), type 2 diabetes (T2D; n = 49), and glucose-tolerant individuals (n = 13). Chemokine concentration in supernatants was measured for CCL2 (MCP-1), CXCL10 (IP10) and CCL5 (RANTES) using a multiplex bead array assay.

RESULTS

Spontaneous secretion of CCL2 and CCL5 were higher in LADA compared to T1D and T2D (all p < 0.05) while CXCL10 was similar in the groups. Mitogen-stimulated secretion of CCL2 in LADA was lower compared to T1D and T2D (all p < 0.05) while CXCL10 and CCL5 were similar in all groups. Upon stimulation with pIA2 the secretion of CCL2 in LADA was lower compared to T2D (p < 0.05). Spontaneous CXCL10 secretion in LADA was positively associated with body mass index (r²  = 0.35; p = 0.0035) and C-peptide (r²  = 0.30; p = 0.009).

CONCLUSIONS

Chemokine secretion is altered between different diabetes types. Increased spontaneous secretion of CCL2 and CCL5 and decreased secretion of CCL2, upon stimulation with PI and pIA2, in LADA compared to T1D and T2D could reflect altered immune responsiveness in LADA patients in association with their slower clinical progression compared to insulin dependence.

Management of Latent Autoimmune Diabetes in Adults: A Consensus Statement From an International Expert Panel

A substantial proportion of patients with adult-onset diabetes share features of both type 1 diabetes (T1D) and type 2 diabetes (T2D). These individuals, at diagnosis, clinically resemble T2D patients by not requiring insulin treatment, yet they have immunogenetic markers associated with T1D. Such a slowly evolving form of autoimmune diabetes, described as latent autoimmune diabetes of adults (LADA), accounts for 2-12% of all patients with adult-onset diabetes, though they show considerable variability according to their demographics and mode of ascertainment. While therapeutic strategies aim for metabolic control and preservation of residual insulin secretory capacity, endotype heterogeneity within LADA implies a personalized approach to treatment. Faced with a paucity of large-scale clinical trials in LADA, an expert panel reviewed data and delineated one therapeutic approach. Building on the 2020 American Diabetes Association (ADA)/European Association for the Study of Diabetes (EASD) consensus for T2D and heterogeneity within autoimmune diabetes, we propose "deviations" for LADA from those guidelines. Within LADA, C-peptide values, proxy for β-cell function, drive therapeutic decisions. Three broad categories of random C-peptide levels were introduced by the panel: 1) C-peptide levels <0.3 nmol/L: a multiple-insulin regimen recommended as for T1D; 2) C-peptide values ≥0.3 and ≤0.7 nmol/L: defined by the panel as a "gray area" in which a modified ADA/EASD algorithm for T2D is recommended; consider insulin in combination with other therapies to modulate β-cell failure and limit diabetic complications; 3) C-peptide values >0.7 nmol/L: suggests a modified ADA/EASD algorithm as for T2D but allowing for the potentially progressive nature of LADA by monitoring C-peptide to adjust treatment. The panel concluded by advising general screening for LADA in newly diagnosed non-insulin-requiring diabetes and, importantly, that large randomized clinical trials are warranted.

Pancreas Pathology of Latent Autoimmune Diabetes in Adults (LADA) in Patients and in a LADA Rat Model Compared With Type 1 Diabetes

Approximately 10% of patients with type 2 diabetes suffer from latent autoimmune diabetes in adults (LADA). This study provides a systematic assessment of the pathology of the endocrine pancreas of patients with LADA and for comparison in a first rat model mimicking the characteristics of patients with LADA. Islets in human and rat pancreases were analyzed by immunohistochemistry for immune cell infiltrate composition, by in situ RT-PCR and quantitative real-time PCR of laser microdissected islets for gene expression of proinflammatory cytokines, the proliferation marker proliferating cell nuclear antigen (PCNA), the anti-inflammatory cytokine interleukin (IL) 10, and the apoptosis markers caspase 3 and TUNEL as well as insulin. Human and rat LADA pancreases showed differences in areas of the pancreas with respect to immune cell infiltration and a changed ratio between the number of macrophages and CD8 T cells toward macrophages in the islet infiltrate. Gene expression analyses revealed a changed ratio due to an increase of IL-1β and a decrease of tumor necrosis factor-α. IL-10, PCNA, and insulin expression were increased in the LADA situation, whereas caspase 3 gene expression was reduced. The analyses into the underlying pathology in human as well as rat LADA pancreases provided identical results, allowing the conclusion that LADA is a milder form of autoimmune diabetes in patients of an advanced age.

Latent Autoimmune Diabetes in Adults: A Review of Clinically Relevant Issues

Latent autoimmune diabetes in adults (LADA) is still a poorly characterized entity. However, its prevalence may be higher than that of classical type 1 diabetes. Patients with LADA are often misclassified as type 2 diabetes. The underlying autoimmune process against β-cell has important consequences for the prognosis, comorbidities, treatment choices and even patient-reported outcomes with this diabetes subtype. However, there is still an important gap of knowledge in many areas of clinical relevance. We are herein focusing on the state of knowledge of relevant clinical issues than may help in the diagnosis and management of subjects with LADA.

Past, present and future of latent autoimmune diabetes in adults

Latent autoimmune diabetes in adults (LADA) is the most common form of autoimmune diabetes diagnosed in adults. Similar to type 1 diabetes, the prevalence of LADA is impacted by ethnicity and geography. LADA is characterized by β cell loss due to autoimmunity and insulin resistance and has highly heterogeneous clinical features, autoimmunity, and genetics in a glutamic acid decarboxylase antibody (GADA) titre-dependent manner, suggesting LADA is part of a continuum spectrum between type 1 and type 2 diabetes. Although LADA is the most frequent form of autoimmune diabetes diagnosed in adults, clinical trials involving LADA are scarce. Here we review the recent advancements in LADA epidemiology, clinical features, pathogenesis, and interventions. We also highlight the environmental factors that are thought to play an important role in addition to genetics in the pathogenesis of LADA. In the future, high-throughput molecular profiles might shed light on the nature of LADA among the wide spectrum of diabetes and offer new opportunities to identify novel LADA-specific biomarkers.

Long-term risk of cardiovascular disease in individuals with latent autoimmune diabetes in adults (UKPDS 85)

AIMS

Latent autoimmune diabetes in adults (LADA) is diagnosed in up to 12% of adults with clinically diagnosed type 2 diabetes (T2D). LADA tends to have healthier cardiovascular (CV) risk profiles than T2D, but it remains uncertain whether the risk of CV events differs between the two. We examined the risk of CV events in patients enrolled in the United Kingdom Prospective Diabetes Study (UKPDS) according to LADA status.

MATERIALS AND METHODS

Diabetes autoantibodies (AAb) were measured in 5062 UKPDS participants. The incidence of major adverse CV events (MACE), defined as CV death, non-fatal myocardial infarction or non-fatal stroke, was compared in those with LADA (≥1 AAb test positive) and those without LADA (AAb negative).

RESULTS

There were 567 participants (11.2%) with LADA. Compared with participants with T2D, they were younger, with higher mean HbA1c and HDL-cholesterol values, and with lower body mass index and total cholesterol and systolic blood pressure values (all P < 0.01). After a median (25th, 75th percentile) 17.3 (12.6-20.7) years of follow-up, MACE occurred in 157 (17.4 per 1000 person-years) participants with LADA and in 1544 (23.5 per 1000 person-years) participants with T2D (HR, 0.73; 95% confidence interval [CI], 0.62-0.86; P < 0.001). However, after adjustment for confounders, this difference was no longer significant (HR_adj , 0.90; 95% CI, 0.76-1.07; P = 0.22).

CONCLUSIONS

In adults thought to have newly diagnosed T2D, the long-term risk of MACE was lower in those with LADA. However, this did not differ after adjustment for traditional CV risk factors, suggesting that measurement of AAb in addition to traditional CV risk factors will not aid in stratification of CV risk in clinically diagnosed T2D.

Identification of autoimmune type 1 diabetes and multiple organ-specific autoantibodies in adult-onset non-insulin-requiring diabetes in China: A population-based multicentre nationwide survey

AIMS

To investigate the prevalence of adult-onset autoimmune diabetes (ADM) and predisposition to autoimmune diseases by quantifying serum organ-specific autoantibodies in people with phenotype of type 2 diabetes (T2D).

MATERIALS AND METHODS

We included a nationally representative sample of 46 239 adults aged ≥20 years from 14 provinces, of whom 4671 had diabetes, plus 1000 control subjects with normal glucose tolerance (NGT). Participants were screened centrally for autoantibodies to glutamic acid decarboxylase (GAD), islet antigen 2 (IA2) and zinc transporter isoform-8 (Znt8) and were defined as having ADM where positive for these antibodies. We then assayed thyroid peroxidase (TPO), tissue transglutaminase (tTG) and 21-hydroxylase (21-OH) autoantibodies in randomly selected participants with ADM and in age-matched, sex-matched and non-ADM controls with T2D plus controls with NGT.

RESULTS

Post-normalization, the standardized prevalence rate of ADM was 6.0% (95% confidence interval [CI] 5.3-6.8) in initially non-insulin-requiring participants with ADM, corresponding to six million adults in China, in whom adjusted antibody positivity was: TPO autoantibodies 16.3% (95% CI 10.8-21.8), tTG autoantibodies 2.1% (95% CI 0.0-4.2), and 21-OH autoantibodies 1.8% (95% CI -0.2 to 3.8). Those participants with ADM who were GAD autoantibody-positive had high risk of TPO autoantibody positivity (odds ratio [OR] 2.39, P = 0.0031) and tTG autoantibody positivity (OR 6.98, P = 0.027), while those positive for IA2 autoantibodies had a high risk of tTG autoantibody positivity (OR 19.05, P = 0.001).

CONCLUSIONS

A proportion of people with phenotype of T2D in China have ADM, with diabetes-associated autoantibodies, and may be at risk of developing other organ-specific autoimmune diseases; therefore, it may be clinically relevant to consider screening such Chinese populations.

Subclinical inflammation and depressive symptoms in patients with type 1 and type 2 diabetes

Depression is a frequent comorbidity of type 1 diabetes (T1D) and type 2 diabetes (T2D). Depression and diabetes are linked by a bidirectional relationship, but the underlying mechanisms are still incompletely understood. Experimental, observational and intervention studies showed that inflammatory processes contribute to the development of depression in animal models and humans. Given the high risk of morbidity and mortality in patients with the double burden of diabetes and depression, this review provides an overview of epidemiological studies that addressed the relationship between biomarkers of inflammation and depressive symptoms or depression in diabetes patients. In patients with T1D, there is some evidence that higher levels of high-sensitivity C-reactive protein (hsCRP), IL-6, IL-1 receptor antagonist (IL-1RA) and sICAM-1 may be related to depressive symptoms or (for hsCRP) lower treatment response. For T2D, hsCRP, IL-1RA, CCL2 and adiponectin or its isoforms were associated with depressive symptoms in at least two studies, whereas positive associations of IL-1β, IL-6 and IL-18 with depressive symptoms or depression were reported from single cohorts. However, the number of studies is too low for any meaningful meta-analysis. Prospective life course studies including both patients with T1D and T2D, a comprehensive assessment of systemic inflammation and repeated assessment of depressive symptoms should represent a future research priority to clarify to what extent subclinical inflammation affects the risk of depression in patients with diabetes. A better understanding of the role of inflammatory processes may help to identify subtypes of depression with partly different pathogenesis, which could have consequences with respect to therapeutic options including immunomodulation.

Type 1 Diabetes-related Autoantibodies in Different Forms of Diabetes

Autoantibodies against Glutamic Acid Decarboxylase (GADA), insulinoma antigen-2 (IA- 2A), insulin (IAA) and the most recently Zinc Transporter 8 (ZnT8A) are one of the most reliable biomarkers for autoimmune diabetes in both children and adults. They are today the only biomarkers that can distinguish Latent Autoimmune Diabetes in Adults (LADA) from phenotypically type 2 diabetes. As the frequency of autoantibodies at diagnosis in childhood type 1 diabetes depends on age, GADA is by far the most common in adult onset autoimmune diabetes, especially LADA. Being multiple autoantibody positive have also shown to be more common in childhood diabetes compared to adult onset diabetes, and multiple autoantibody positivity have a high predictive value of childhood type 1 diabetes. Autoantibodies have shown inconsistent results to predict diabetes in adults. Levels of autoantibodies are reported to cause heterogeneity in LADA. Reports indicate that individuals with high levels of autoantibodies have a more type 1 diabetes like phenotype and individuals with low levels of autoantibody positivity have a more type 2 diabetes like phenotype. It is also well known that autoantibody levels can fluctuate and transient autoantibody positivity in adult onset autoimmune diabetes have been reported to affect the phenotype.

Evidence of diabetes-specific autoimmunity in obese subjects with normal glucose tolerance

BACKGROUND

Recently, significant attention has been paid to the possible activation of an autoimmune response in the presence of obesity. The aim of this study was to evaluate and compare the frequencies of autoantibodies typical of autoimmune diabetes in obese patients with normal glucose tolerance (NGT), obese patients with type 2 diabetes (T2D) and controls. We also evaluated the presence of immunoreactivity to Hashimoto's thyroiditis and autoimmune gastritis.

MATERIALS AND METHODS

Consecutive sera from obese patients, 444 with NGT, 322 with T2D, and 212 controls were analysed by radioimmunoassay or enzyme-linked immunosorbent assay for glutamic acid decarboxylase, protein tyrosine phosphatase islet antigen-2 (IA-2)_IC and IA-2_(256-760) , islet beta-cell zinc cation transporter (ZnT8), thyroid peroxidase, and anti-parietal cell autoantibodies.

RESULTS

Altogether the presence of organ-specific autoantibodies was significantly more frequent in obese patients with NGT (128/444, 28.5%) and obese with T2D (79/322, 24.5%) than in controls (36/212, 17%; P = 0.002). Thyroid peroxidase immunoreactivity was prevalent in all groups of subjects investigated. The frequencies of diabetes-specific autoantibodies were slightly higher in obese patients with NGT (20/444, 4.5%) than in obese with T2D (12/322, 3.7%) and controls (4/212, 1.9%). The anti IA-2_(256-760) was the most frequent islet autoantibody in obese subjects with NGT (14/20, 70%).

CONCLUSIONS

We observed significant evidence of immunoreactivity specific to diabetes, thyroid, and gastric-parietal cells in obese patients with NGT. The relatively higher frequency of the diabetes-related IA-2_(256-760) autoantibodies in obese patients with NGT may suggest that this autoantibody could be associated with obesity the presence of obesity itself.

Clinical Management of Epilepsy With Glutamic Acid Decarboxylase Antibody Positivity: The Interplay Between Immunotherapy and Anti-epileptic Drugs

Background: There is scanty guidance in the literature on the management of patients with glutamic acid decarboxylase (GAD65) antibody associated autoimmune epilepsy (GAD-epilepsy). GAD-epilepsy is a rare distinct neurological syndrome with a wide clinical spectrum. We describe six GAD-epilepsy patients with special emphasis on the treatment timing and the relationship between immunologic and anti-epileptic therapy.

Methods: Six patients diagnosed with GAD-epilepsy in Tampere University Hospital who had received immunotherapy from 2013 to 2017 were retrospectively analyzed from patient records. Data about symptom onset, including antibody levels, magnetic resonance imaging (MRI), electroencephalograms, immunotherapy and anti-epileptic treatment timing and treatment responses were collected and analyzed. Kruskall-Wallis test was used in the statistical evaluation.

Results: All patients were female aged 9–54 at symptom onset. Three had hypothyroidism, none had diabetes, two had migraine. Five patients had very high (>2,000 IU/ml) and one had high (52–251 IU/ml) GAD65 antibody titers. All patients presented with seizure disorders. Patients who received early initiation of immunotherapy (3–10 months) responded well to treatment; patients in whom the immunotherapy was started later (15–87 months) did not respond (p = 0.0495). The first patient was seizure-free after 1 year of regular intravenous immunoglobulin and one antiepileptic drug (AED). The second patient developed unilateral temporal lobe T2 signal changes in MRI; she responded well to immunotherapy, experiencing a significant reduction in seizure frequency and resolution of MRI abnormalities. However, seizures continued despite trials with several AEDs. The third patient responded well to immunoadsorption and rituximab with one AED, with lowering of GAD65 titers (from >2,000 to 300). There was a long delay in the diagnosis of GAD-epilepsy in the three patients who had developed refractory epilepsy, one with hippocampal sclerosis. They all received immunotherapy but none responded. However, AED modification or vagus nerve stimulation reduced the seizure frequency in two patients. Epilepsy surgery was ineffective.

Conclusions: These results highlight the importance of early detection of GAD65 antibodies in refractory epilepsy as immunotherapy can be effective if administered in the early stages of the disease when it can prevent permanent brain tissue damage.

Longitudinal associations between biomarkers of inflammation and changes in depressive symptoms in patients with type 1 and type 2 diabetes

BACKGROUND

Depressive disorders represent a frequent comorbidity of type 1 diabetes (T1D) and type 2 diabetes (T2D). Subclinical inflammation increases the risk of depressive symptoms in the general population, but the relationship appears complex and bidirectional, and longitudinal data from patients with diabetes are lacking. Therefore, this study aimed to analyse associations between changes in depressive symptoms and changes in biomarkers of inflammation in patients with T1D and T2D and to investigate the hypothesis that higher baseline levels of biomarkers of inflammation are related to a less pronounced reduction of depressive symptoms over time.

METHODS

Depressive symptoms and systemic levels of six biomarkers of inflammation were assessed in 168 individuals with T1D and 103 individuals with T2D who participated in baseline and 1-year follow-up examinations. Data were obtained from two matching randomised controlled trials addressing diabetes distress and depressive symptoms. Longitudinal associations between biomarkers and depressive symptoms were estimated using linear regression models adjusting for multiple confounders.

RESULTS

In patients with T2D, reductions in depressive symptoms were associated with reductions in high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-18 and IL-1 receptor antagonist (IL-1RA) (P ≤ 0.016), whereas no associations were seen for IL-6, CCL2 and adiponectin. Higher CCL2 levels at baseline were associated with lower subsequent reduction in depressive symptoms (P = 0.018). Neither baseline levels nor changes in biomarkers in subclinical inflammation were associated with changes in depressive symptoms in patients with T1D.

CONCLUSIONS

Reductions of depressive symptoms were longitudinally associated with reductions in biomarkers of inflammation in patients with T2D. Higher baseline CCL2 levels were related with lower reduction of depressive symptoms in this group. No such associations were observed in patients with T1D, suggesting that risk factors and pathomechanisms linking inflammation and depression may differ between diabetes types.

Low-grade Inflammatory Marker Profile May Help to Differentiate Patients With LADA, Classic Adult-Onset Type 1 Diabetes, and Type 2 Diabetes

OBJECTIVE

To test whether differences in serum concentrations of adiposity-related low-grade inflammatory mediators could help to differentiate patients with latent autoimmune diabetes in adults (LADA), classic adult-onset type 1 diabetes, and type 2 diabetes.

RESEARCH DESIGN AND METHODS

This cross-sectional study involved 75 patients with LADA, 67 with classic adult-onset type 1 diabetes, and 390 with type 2 diabetes. Serum concentrations of adiponectin, soluble tumor necrosis factor-α receptor 2 (sTNFRII), interleukin-6, hs-CRP, and total leukocyte number were measured. To evaluate the differences of these markers among diabetes types, we performed logistic regression models and evaluated area under the receiver-operating characteristic curve (AUC_ROC) values.

RESULTS

The profile of innate immunity-related inflammatory markers correlated with metabolic syndrome components. LADA versus classic adult-onset type 1 diabetes was independently related to sTNFRII (odds ratio [OR] 1.9 [95% CI 1.01-3.97]; P = 0.047) and hs-CRP levels (OR 0.78 [95% CI 0.62-0.96]; P = 0.019), and a higher number of total leukocytes lowered the risk of LADA compared with type 2 diabetes (OR 0.98 [95% CI 0.97-0.99]; P = 0.036). The logistic regression model including explanatory biomarkers explained 35% of the variation for LADA versus classic adult-onset type 1 diabetes (AUC_ROC 0.83 [95% CI 0.74-0.92]; P < 0.001) and 15% of the variation for LADA versus type 2 diabetes (AUC_ROC 0.73 [95% CI 0.70-0.80]; P < 0.001).

CONCLUSIONS

Inflammatory, adiposity, and immune-related markers could help to differentiate a LADA diagnosis from that of classic adult-onset type 1 diabetes, and also LADA from that of type 2 diabetes, along with islet autoantibody positivity.

Islet Autoantibody Patterns in Patients With Type 2 Diabetes Aged 60 and Higher: A Cross-Sectional Study in a Chinese Hospital

BACKGROUND

Some elderly citizens with a clinical diagnosis of type 2 diabetes had evidence of positive islet autoantibodies. We aimed to discover their islet autoantibody patterns and independent correlative factors that might lead to a better understanding of significance of islet autoimmunity in the progression of elderly diabetes.

METHODS

A total of 541 inpatients of clinically diagnosed type 2 diabetes aged 60 and over were recruited. Three islet autoantibodies including insulin autoantibody (IAA), islet cell antibody (ICA), and glutamic acid decarboxylase antibody (GADA) as well as clinical and biochemical characteristics were tested and collected in Huashan Hospital. Associations between these antibodies and clinical features were analyzed by Spearman correlation and binary logistic analyses.

RESULTS

In our current study, total positive rate of islet autoantibodies (IAA, ICA, and GADA) was 35.67% with 26.62% for individual IAA, 5.55% for ICA, and 5.91% for GADA, in elderly with type 2 diabetes. None of combinations of such autoantibodies were observed, with the exception of IAA + ICA (0.74%, n = 4), IAA + GADA (1.48%, n = 8), and ICA + GADA (0.18%, n = 1). Compared with GADA negative group, patients in positive group tended to have lower level of fasting and postprandial C peptide, fasting blood glucose (FBG), and body mass index (BMI). After adjusted for the BMI, FBG, and postprandial C peptide, fasting C peptide seemed to be an independent factor related to GADA positivity (OR = 0.52, p = 0.02). As for patients with positive IAA, they were more likely to have insulin treatment with longer duration of diabetes, higher level of BMI, and lower level of postprandial C peptide. After adjusted for the duration of diabetes, BMI, and postprandial C peptide, insulin treatment was a significant predictor for IAA positivity (OR = 5.20, p < 0.0001). Furthermore, hs-CRP was positively related to ICA positivity, and hs-CRP appeared to be an independent indicator for ICA (OR = 3.43, p = 0.008).

CONCLUSION

In elderly with type 2 diabetes, high prevalence rate of IAA was frequently accompanied with insulin treatment, while ICA and GADA were more closely associated with the systemic inflammation and beta-cell failure, respectively.

Preclinical carotid atherosclerosis in patients with latent autoimmune diabetes in adults (LADA), type 2 diabetes and classical type 1 diabetes

BACKGROUND

LADA is probably the most prevalent form of autoimmune diabetes. Nevertheless, there are few data about cardiovascular disease in this group of patients. The aim of this study was to investigate the frequency of carotid atherosclerotic plaques in patients with LADA as compared with patients with classic type 1 diabetes and type 2 diabetes.

METHODS

Patients with LADA were matched for age and gender in different proportions to patients with type 2 diabetes, and classic type 1 diabetes. None of the patients had clinical cardiovascular disease. All subjects underwent B-mode carotid ultrasound to detect atheroma plaques. Demographics were obtained from all subjects.

RESULTS

We included 71 patients with LADA, 191 patients with type 2 diabetes and 116 patients with type 1 diabetes. Carotid atherosclerosis was more frequent in patients with LADA compared with type 2 diabetes (73.2% vs. 56.9%, P = 0.0018) and classic type 1 diabetes (57.1%, P = 0.026); these changes occurred despite healthier macrovascular risk profiles in the former. Age (P < 0.001), smoking (P = 0.003) and hypertension (P = 0.019) were independently associated with carotid atherosclerosis. Multiple plaques were also more frequent in patients with LADA as compared with classic type 1 diabetes and type 2 diabetes (45.1% and 33.6% vs. 27.2%, respectively, P = 0.022). The frequency of carotid plaques increased with increasing diabetes duration in LADA patients compared with type 2 diabetes (85.7% vs. 58.8%, inverse OR 5.72 [1.5-21.8]; P = 0.009).

CONCLUSIONS

LADA patients do not present with less carotid atherosclerosis than patients with type 1 and type 2 diabetes. Their macrovascular risk occurs despite a healthier macrovascular risk profile than those patients with type 2 diabetes.

Family history of type 1 and type 2 diabetes and risk of latent autoimmune diabetes in adults (LADA)

BACKGROUND

A family history of diabetes (FHD) is a strong predictor of diabetes risk, yet has rarely been investigated in latent autoimmune diabetes in adults (LADA). This study therefore investigated the risk of LADA and type 2 diabetes (T2D) in relation to FHD, taking into account the type of diabetes in relatives.

METHODS

Data from a population-based study were used, including incident cases of LADA [glutamic acid decarboxylase antibody (GADA)-positive, n=378] and T2D (GADA-negative, n=1199), and their matched controls (n=1484). First-degree relatives with disease onset at age<40 years and taking insulin treatment were classified as type 1 diabetes (T1D) or, if otherwise, as T2D. Odds ratios (ORs) were adjusted for age, gender, BMI, education and smoking. Cases were genotyped for high- and low-risk HLA genotypes.

RESULTS

Both FHD-T1D (OR: 5.8; 95% CI: 3.2-10.3) and FHD-T2D (OR: 1.9; 95% CI: 1.5-2.5) were associated with an increased risk of LADA, whereas the risk of T2D was associated with FHD-T2D (OR: 2.7; 95% CI: 2.2-3.3), but not FHD-T1D. In LADA patients, FHD-T1D vs FHD-T2D was associated with higher GADA but lower C-peptide levels, lower prevalence of low-risk HLA genotypes (5.0% vs 28.6%, respectively; P=0.038) and a tendency for higher prevalence of high-risk genotypes (90.0% vs 69.1%, respectively; P=0.0576).

CONCLUSION

The risk of LADA is substantially increased with FHD-T1D but also, albeit significantly less so, with FHD-T2D. This supports the idea of LADA as a mix of both T1D and T2D, but suggests that the genes related to T1D have greater impact. LADA patients with FHD-T1D had more T1D-like features, emphasizing the heterogeneity of LADA.