Latent Autoimmune Diabetes In Adults Group Research Articles

The role of cholecalciferol deficiency in the development of latent autoimmune diabetes in adults

Background. Recently, a lot of information has appeared on the role of cholecalciferol deficiency in the development of the mechanisms of classical types of diabetes mellitus (DM) and its complications. However, there are currently almost no data regarding latent autoimmune diabetes in adults (LADA). The purpose of this study was to determine the effect of vitamin D deficiency on the compensation of carbohydrate metabolism in LADA. Materials and methods. The study included 56 patients with DM: 34 with LADA and 22 with classical type 1 DM (DM1), as well as 20 practically healthy individuals of the control group. According to the main phenotypes, patients with LADA were divided into 2 groups: LADA1 and LADA2. Cholecalciferol status was determined by the immunochemiluminescence method. Results. The fasting blood glucose level in LADA and DM1 group was significantly higher than in the controls, by 63.9 and 91.1 % (p < 0.001), respectively, and was also 16.6 % higher when comparing DM1/LADA groups (p < 0.05). The level of HbA1c in 66.1 % of patients of the experimental groups was more than 7 %, which indicates insufficient compensation of the disease. The content of vitamin D was significantly lower in the experimental groups compared to the controls; when comparing LADA/DM1 — by 43.7 % lower in case of classical DM1 (p < 0.05). Compensation of carbohydrate metabolism is worse in patients with LADA1 than in LADA2, and the lowest level of vitamin D was recorded in LADA1. According to the linear regression analysis of correlations in patients with LADA, negative correlations of medium strength were recorded between the level of cholecalciferol and fasting blood glucose (r = 0.487; p < 0.05), HbA1c (r = –0.593; p < 0.05); positive — between cholecalciferol and C-peptide (r = 0.412; p < 0.05). Conclusions. In patients with autoimmune diabetes, there is an insufficient supply of cholecalciferol. Low cholecalciferol content is observed in both groups of patients with LADA regardless of the disease phenotype and is associated with worse compensation of DM.

Plasma-derived exosomal miRNAs as potentially novel biomarkers for latent autoimmune diabetes in adults

AimTo characterize the exosomal miRNA profiles of latent autoimmune diabetes in adults (LADA) and evaluate the biomarker potential of selected miRNAs to distinguish LADA from type 2 diabetes (T2D). MethodsPlasma-derived exosomal miRNA expression profiles were measured in patients with LADA (N = 5) and control subjects (N = 5). Five differentially expressed miRNAs were selected to validate their expression levels and assess their diagnostic potential by quantitative real-time PCR (qRT–PCR) in a larger cohort. ResultsSeventy-five differentially expressed plasma-derived exosomal miRNAs were identified in LADA patients compared to healthy subjects. The expression levels of three exosomal miRNAs (hsa-miR-146a-5p, hsa-miR-223-3p and hsa-miR-21-5p) were significantly different between the LADA group and the T2D group. The three miRNAs exhibited areas under the receiver operating characteristic curves of 0.978, 0.96 and 0.809, respectively. ConclusionsThis study uncovers the miRNA profiles of plasma-derived exosomes from LADA patients and identifies exosomal miRNAs as potential biomarkers to discriminate LADA from T2D for the first time. Our data demonstrate the function of exosomal miRNAs in the development of LADA and contribute to an in-depth understanding of the precise mechanisms underlying the pathogenesis of LADA.

Thyroid autoantibody distribution in patients with latent autoimmune diabetes in youth: a multicenter, national survey.

BackgroundA high seropositive rate of thyroid autoantibodies is often reported in patients with type 1 diabetes mellitus (T1DM), latent autoimmune diabetes in adults (LADA) and type 2 diabetes mellitus (T2DM). However, the positive rate of thyroid autoantibodies in latent autoimmune diabetes in youth (LADY) patients has not been reported in China. Thus, the purpose of the current study was to clarify the thyroid autoantibody distribution in patients with LADY to provide evidence for the clinical screening of autoimmune thyroid diseases (AITD).MethodsThis nationwide, multicenter and cross-sectional study included 1,723 younger patients (<30 years old) and 2,000 older patients (≥30 years old) aged 15 to 79 years. The patients were grouped into younger T1DM (n=281), LADY (n=130), younger T2DM (n=200), older T1DM (n=287), LADA (n=129), and older T2DM (n=200) groups. Autoantibodies against thyroid peroxidase (TPOA) and thyroglobulin (TGA) prevalence were analyzed in each group.ResultsThe prevalence of TGA or TPOA in LADY patients was similar to that in younger T1DM patients. The seropositive rate of TPOA in LADY patients was higher than that in LADA patients (36.2% vs. 23.3%, respectively; P=0.023); the risk of TPOA was higher in LADY patients than in LADA patients, even after adjusting for sex, glutamic acid decarboxylase (GADA)- and insulinoma-associated-2 (IA-2A)-positivity (OR =1.94, P=0.023). LADY patients with high GADA titers exhibited a higher frequency of thyroid autoantibodies than patients with low GADA titers did (TPOA, P=0.005; TGA, P=0.023; TPOA or TGA, P=0.004). Further analysis showed that only male patients showed a strong association between high GADA titers and thyroid autoantibodies positivity, and the association remained significant after adjustment for age (OR =11.14, P=0.025 for TGA; OR =4.99, P=0.011 for TPOA; OR =5.52, P=0.007 for TPOA or TGA).ConclusionsRoutine screening for thyroid autoantibodies is recommended in LADY patients, and special clinical attention should be paid to the thyroid autoantibodies status of male patients of LADY with high GADA titers to identify patients at high risk of developing AITD.

The frequency of arterial hypertension in young people with different types of diabetes mellitus

Objective. Arterial hypertension (AH) and diabetes mellitus (DM) are frequent comorbid diseases, which are associated with a high level of disability and mortality. According to the literature hypertension occurs in 50–80% of patients with type 2 diabetes (DM2) (which constitute more than 90% of the population with type 2 diabetes), compared with 30% of patients with type 1 diabetes (DM1). Comparative studies on the frequency of AH in young patients with different types of DM in the Siberian region have not been conducted. The aim of the research work was to study the frequency of AH and associations of AH with clinical and laboratory parameters in various types of DM diagnosed before the age of 45 years.Design and methods. 174 patients with the onset of DM from 18 to 45 years old were included. They were under observation at the Research Institute of Internal and Preventive Medicine — Branch of the Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences: in 20 patients DM1 was verified (group 1), in 80 — DM2 (group 2), 20 had HNF1A-MODY (Maturity-Onset Diabetes of the Young) (group 3), 36 had GCK-MODY (group 4), 18 had LADA (“latent autoimmune diabetes in adults”) (Group 5). All patients was done a clinical examination, determination of indicators of carbohydrate metabolism and basic biochemical parameters.Results. All groups were comparable in terms of gender, age, and duration of DM. AH of 1–2 degrees in group 1 was detected in 5 patients (25,0%), in 2 — in 20 people (25,0%), in 3 — in 5 (25,0%), in 4 — in 4 (11,1%), in 5 — in 4 (22,2%), significant differences were not identified. In different types of DM the development of AH is associated with various clinical and laboratory parameters. In DM1, the development of AH has a correlation with the age of the patient, with the level of low-density lipoprotein cholesterol; in DM2 — with the duration of diabetes, the patient’s age, body mass index, glucose level, lipid spectrum and diabetic complications; with HNF1A-MODY— with diabetic complications; with GCK-MODY — with the duration of diabetes, the age of the patient, with the level of total cholesterol, with the development of nephropathy; with LADA — with indicators of carbohydrate metabolism and triglycerides.Conclusions. It is necessary to screen for the presence of AH for any type of DM in young people. It is necessary to take into account the clinical and laboratory parameters associated with the AH depending on the type of DM.

Characteristics of the Gut Microbiota and Metabolism in Patients With Latent Autoimmune Diabetes in Adults: A Case-Control Study

Type 1 and type 2 diabetes are associated with gut dysbiosis. However, the relationship between the gut microbiota and latent autoimmune diabetes in adults (LADA), sharing clinical and metabolic features with classic type 1 and type 2 diabetes, remains unclear. Here, we used a multiomics approach to identify the characteristics of the gut microbiota and metabolic profiles in patients with LADA. This age- and sex-matched case-control study included 30 patients with LADA, 31 patients with classic type 1 diabetes, 30 patients with type 2 diabetes, and 29 healthy individuals. The gut microbiota profiles were identified through the 16S rRNA gene, and fecal and serum metabolites were measured through untargeted liquid chromatography-mass spectrometry. Patients with LADA had a significantly different structure and composition of the gut microbiota and their metabolites as well as a severe deficiency of short-chain fatty acid-producing bacteria. The gut microbiota structure of the patients with LADA was more similar to that of patients with type 1 diabetes who were positive for GAD antibody. We identified seven serum metabolite modules and eight fecal metabolite modules that differed between the LADA group and the other groups. The characteristic gut microbiota and related metabolites of patients with LADA are associated with autoantibodies, glucose metabolism, islet function, and inflammatory factors, which may contribute to the pathogenesis of LADA. Future longitudinal studies should explore whether modulating the gut microbiota and related metabolites can alter the natural course of autoimmune diabetes in the quest for new therapeutics.

Adult-onset autoimmune diabetes: comparative analysis of classical and latent presentation

IntroductionAdult-onset autoimmune diabetes (AID) has two different phenotypes: classic type 1 diabetes mellitus (T1DM), with insulin requirement just after diagnosis, and latent autoimmune diabetes in adults (LADA). The purpose of this study is to characterize patients with AID followed on a tertiary centre, comparing classic T1DM and LADA.MethodsWe collected data from patients with diabetes and positive islet autoantibodies, aged 30 years old and over at diagnosis. Patients who started insulin in the first 6 months were classified as T1DM and patients with no insulin requirements in the first 6 months were classified as LADA. Data regarding clinical presentation, autoantibodies, A1C and C-peptide at diagnosis, pharmacologic treatment and complications were analysed.ResultsWe included 92 patients, 46 with classic T1DM and 46 with LADA. The percentage of females was 50% in T1DM group and 52.1% in LADA group. The median age at diagnosis was 38 years (IQR–15) for T1DM and 42 years (IQR–15) for LADA (p = 0.057). The median time between diagnosis of diabetes and diagnosis of autoimmune aetiology was 0 months in T1DM group and 60 months in LADA group (p < 0.001). The mean BMI at diagnosis was 24.1 kg/m2 in T1DM group and 26.1 kg/m2 in LADA group (p = 0.042). In T1DM group, 67.4% of the patients had more than one positive autoantibody, comparing to 41.3% of LADA patients (p = 0.012). There was no statistical difference in what concerns to title of GAD autoantibodies, A1C and C-peptide at diagnosis of autoimmune aetiology. The presence of symptoms at diagnosis was associated with T1DM group (p < 0.001). The median daily insulin dose was 40 IU for T1DM (0.58 IU/kg) and 33.5 IU for LADA (0.57 IU/kg), with no statistical difference. LADA patients were more often under non-insulin antidiabetic drugs (p = 0.001). At 10 years follow up, 21.1% of T1DM patients and 63.3% of LADA patients had microvascular complications (p = 0.004). Diabetic nephropathy was present in 23.5% of T1DM patients and 53.3% of LADA patients (p = 0.047). At the last evaluation, 55.6% of T1DM and 82.6% of LADA patients had metabolic syndrome and this difference was independent of diabetes duration.ConclusionPatients with classic T1DM presented more often with symptoms, lower BMI and higher number of autoantibodies, which may be related to a more aggressive autoimmune process. Patients with LADA developed more frequently microvascular complications for the same disease duration, namely diabetic nephropathy, and had more often metabolic syndrome.

Bone mineral density spectrum in individuals with type 1 diabetes, latent autoimmune diabetes in adults, and type 2 diabetes

To assess bone mineral density (BMD) and associated clinical factors in patients with type 1 diabetes (T1D), latent autoimmune diabetes in adults (LADA), and type 2 diabetes (T2D) and in non-diabetic subjects. Total 108 age-, sex-, disease duration-, and postmenopausal ratio-matched patients with T1D, LADA, and T2D each and 216 age-, sex-, and postmenopausal ratio-matched non-diabetic controls. Anthropometric, biochemical, and BMD data were collected and analysed. BMD of total hip and lumbar spine of individuals in the LADA group was lower than those in the T2D and control groups but higher than those in the T1D group. After adjusting for body mass index (BMI), a significant difference in BMD in the lumbar spine was seen between groups. After adjustment for smoking, BMI, 25-(OH) vitamin D, calcium, haemoglobin A1c, and diabetic complication scores, BMD values of patients in LADA group were not significantly different from those of patients in T1D and T2D groups. Multiple stepwise regression analysis showed that BMD was (a) positively associated with weight and C-peptide, and negatively associated with age in patients with diabetes, (b) positively associated with C-peptide in the T1D and LADA groups. The proportion of patients with osteoporosis in the T1D, LADA, T2D, and control groups was 55.6%, 45.4%, 34.3%, and 26.9%, respectively. BMD values in T1D, LADA, and T2D were in an increasing order of mention. Patients with autoimmune diabetes were more susceptible to osteoporosis. A lower C-peptide level may be responsible for decreased BMD in individuals with autoimmune diabetes.

Altered peripheral nerve structure and function in latent autoimmune diabetes in adults

The present study was undertaken to investigate mechanisms of peripheral nerve dysfunction in latent autoimmune diabetes in adults (LADA). Participants with LADA (n = 15) underwent median nerve ultrasonography and nerve excitability to examine axonal structure and function, in comparison to cohorts of type 1 diabetes (n = 15), type 2 diabetes (n = 23) and healthy controls (n = 26). The LADA group was matched for diabetes duration, glycaemic control, and neuropathy severity with the type 1 and type 2 diabetes groups. A validated mathematical model of the human axon was utilized to investigate the pathophysiological basis of nerve dysfunction. The most severe changes in nerve structure and function were noted in the LADA group. The LADA cohort demonstrated a significant increase in nerve cross-sectional area compared to type 1 participants and controls. Compared to type 1 and 2 diabetes, measures of threshold electrotonus, which assesses nodal and internodal conductances, were significantly worse in LADA in response to both depolarising currents and hyperpolarising currents. In the recovery cycle, participants with LADA had a significant increase in the relative refractory period. Mathematical modelling of excitability recordings indicated the basis of nerve dysfunction in LADA was different to type 1 and 2 diabetes. Participants with LADA exhibited more severe changes in nerve function and different underlying pathophysiological mechanisms compared to participants with type 1 or 2 diabetes. Intensive management of risk factors to delay the progression of neuropathy in LADA may be required.

Identification of a distinct phenotype of elderly latent autoimmune diabetes in adults: LADA China Study 8.

Latent autoimmune diabetes in adults (LADA) exhibits significant clinical heterogeneity, but the underlying causes remain unclear. The aim of this study was to investigate whether age of onset of LADA contributes to the observed clinical heterogeneity by comparing the clinical, metabolic, and immunogenetic characteristics between elderly and young LADA patients. The cross-sectional study included a total of 579 patients with LADA which was further divided into elderly LADA (E-LADA) group (n=135, age of onset ≥60years) and young LADA (Y-LADA) group (n=444, age of onset <60years). Age-matched subjects with type 2 diabetes were served as control (E-T2D group, n=622). Clinical characteristics, serum autoantibodies, and HLA-DQ haplotypes were compared among these groups. Compared with patients with Y-LADA, patients with E-LADA have better residual beta-cell function and higher level of insulin resistance (both P<.01), more metabolic syndrome characteristics, similar proportion of islet autoantibody positivity, and strikingly different HLA-DQ genetic background. In comparison with E-T2D patients, E-LADA patients tend to have similar metabolic syndrome prevalence, comparable C-peptide levels, and insulin resistance levels and share similar HLA-DQ genetic characteristics. Elderly LADA differs phenotypically and genetically from Y-LADA but has a clinical and genetic profile more similar to that of E-T2D. These distinct phenotypes could potentially help physicians better manage patients with E-LADA.

Serum Sclerostin and Bone Turnover in Latent Autoimmune Diabetes in Adults.

Bone formation is impaired in both type 1 diabetes and type 2 diabetes (T2D), whereas sclerostin, an antagonist of bone formation, is increased in T2D only. No data are available on latent autoimmune diabetes in adults (LADA), an autoimmune type of diabetes that may clinically resemble T2D at diagnosis. We evaluated serum sclerostin and bone turnover markers in LADA compared with those in T2D and whether metabolic syndrome (MetS) affects sclerostin in T2D or LADA. This cross-sectional study included 98 patients with T2D and 89 with LADA from the Action LADA and Non Insulin Requiring Autoimmune Diabetes cohorts. Patients were further divided according to MetS status. Nondiabetic participants (n = 53) were used as controls. Serum sclerostin, bone formation (pro-collagen type 1 N-terminal propeptide [P1NP]), and bone resorption (C-terminal telopeptide of type I collagen [CTX]) were analyzed. Patients with T2D had higher sclerostin than did those with LADA [P = 0.0008, adjusted for sex and body mass index (BMI)], even when analysis was restricted to patients with MetS (adjusted P = 0.03). Analysis of T2D and LADA groups separately showed that sclerostin was similar between those with and those without MetS. However, a positive trend between sclerostin and number of MetS features was seen with T2D (P for trend = 0.001) but not with LADA. Patients with T2D or LADA had lower CTX than did controls (P = 0.0003) and did not have significantly reduced P1NP. Sclerostin was unrelated to age or hemoglobin A1c but was correlated with BMI (ρ = 0.29; P = 0.0001), high-density lipoprotein (ρ = -0.23; P = 0.003), triglycerides (ρ = 0.19; P = 0.002), and time since diagnosis (ρ = 0.32; P < 0.0001). Patients with LADA presented lower bone resorption than did controls, similar to patients with T2D. Sclerostin is increased in T2D but not in LADA, suggesting possible roles on bone metabolism in T2D only.

Peripheral blood mononuclear cells of patients with latent autoimmune diabetes secrete higher levels of pro- & anti-inflammatory cytokines compared to those with type-1 diabetes mellitus following in vitro stimulation with β-cell autoantigens.

Background & objectives:Type-1 diabetes mellitus (T1DM) and latent autoimmune diabetes in adults (LADA) share similar pathological features but differ in age of onset and progression. There is a scarcity of information on differences in CD4+ T-cell responses, particularly, cytokine secretion, between the two forms of autoimmune diabetes. Here proliferative potential and concentration of pro- and anti-inflammatory cytokines secreted by peripheral blood mononuclear cells (PBMCs) of T1DM and LADA patients were compared, after in vitro stimulation with β-cell autoantigens.Methods:A total of 19 patients with LADA, 37 with T1DM and 20 healthy controls were compared on the basis of lymphocyte proliferation and secretion of pro- and anti-inflammatory cytokines belonging to different T-helper types after in vitro stimulation of PBMCs with insulin and glutamic acid decarboxylase 65 (GAD65).Results:Following insulin stimulation, LADA group secreted higher concentration of interleukin-17 (IL-17) (P=0.02) and had higher proportion of interferon gamma (IFN-γ) secretors (P<0.001) than T1DM group. Post-GAD65 stimulation, higher proportion of LADA patients secreted IL-23 than T1DM group (P=0.02). Proportion of responders, as well as levels of secreted IL-10, were significantly higher in LADA than T1DM group, following stimulation with both insulin (P=0.01) and GAD65 (P=0.03). A significant positive correlation was observed between body mass index and IL-17 levels (r=0.41, P=0.04) and fasting plasma C-peptide with IL-10 levels (r=0.37, P=0.04).Interpretation & conclusions:There are differences in the portfolio of cytokine secretion in diabetic subjects with varying rates of β-cell destruction as LADA subjects secrete higher levels of both pro- and anti-inflammatory cytokines on exposure to β-cell autoantigens, thus highlighting another distinguishing feature in the pathophysiology of the two forms of autoimmune diabetes.

Role of anti-GAD, anti-IA2 antibodies and C-peptide in differentiating latent autoimmune diabetes in adults from type 2 diabetes mellitus

Latent autoimmune diabetes in adults (LADA) is a form of autoimmune diabetes affecting adult patients who do not require insulin at diagnosis, positive for circulating islet autoantibodies and characterized by slower beta cell destruction. The study was aimed to identify and characterize LADA patients from clinically diagnosed type 2 diabetes mellitus (DM). We estimated anti-glutamic acid decarboxylase (anti-GAD), anti-tyrosine phosphatase-like insulinoma antigen 2 (anti-IA2) antibodies, fasting connecting peptide (C-peptide) and other clinical and biochemical parameters in 297 clinically diagnosed type 2 DM patients. The diagnosis of LADA was made by the presence of at least one pancreatic autoantibody, and thereafter LADA groups were compared with those of autoantibody-negative type 2 DM groups. The prevalence of LADA was found to be 15.2 % among patients presumed to have type 2 DM. There was significant difference concerning age of patients (p < 0.001), body mass index (p < 0.001), serum levels of C-peptide (p < 0.001), insulin (p < 0.001), total cholesterol (p < 0.001), triglycerides (p = 0.025), high-density lipoprotein cholesterol (HDL-C; p = 0.004), low-density lipoprotein cholesterol (LDL-C; p = 0.001) as well as insulin resistance (p < 0.001) between LADA group and type 2 DM patients. In conclusion, anti-GAD antibody and C-peptide level determination can be considered as confirmatory diagnostic markers for LADA, along with anti-IA2 assay, while other clinical and biochemical parameters can be useful for further characterizing LADA patients.

Preproinsulin specific CD8 + T cells in subjects with latent autoimmune diabetes show lower frequency and different pathophysiological characteristics than those with type 1 diabetes

Latent autoimmune diabetes in adults (LADA) resembles type 1 diabetes (T1D) in disease presentation except that its onset is slow. We compared pathophysiological characteristics of CD8+ T cells recognizing preproinsulin (PPI) derived epitopes in both disease groups using MHC-I dextramers (DMRs) in peripheral blood and after in-vitro stimulation with PPI. Subjects with T1D harbored higher frequency of DMR+ CD8+ T cells with relatively higher frequency of effector T cell subsets. Following stimulation with PPI, an increase in DMR+ CD8+ T cells, particularly the central-memory subset was observed in T1D group, whereas no significant change in DMR+ CD8+ T cell subsets was observed in LADA group. Intracellular expression of Granzyme-B and Perforin in DMR+ CD8+ T cells was comparable in both the groups. In conclusion, lower frequency and inferior proliferative potential on account of a relatively restrained central-memory subset of PPI specific CD8+ T cells are associated with slow rate of disease progression in LADA.

The association of cytotoxic T-lymphocyte antigen-4 + 49A/G and CT60 polymorphisms with type 1 diabetes and latent autoimmune diabetes in Chinese adults.

The aim of this study was to investigate the association of cytotoxic T-lymphocyte antigen-4 (CTLA-4) + 49A/G and CT60 polymorphisms with latent autoimmune diabetes in adults (LADA) and the genetic differences between LADA, type 1 diabetes (T1DM), and type 2 diabetes (T2DM) in a Chinese population. A total of 231 LADA, 402 T1DM, and 330 T2DM patients as well as 482 nondiabetic controls were recruited in the study. CTLA-4 + 49A/G and CT60 polymorphisms were analyzed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). The level of glutamic acid decarboxylase antibodies (GADAs) was detected by a radioligand binding assay. The CTLA-4 + 49A/G risk genotype GG was most frequent in T1DM patients (45.3%), followed by LADA patients (44.2%) and T2DM patients (38.8%). Significantly higher frequencies of the risk genotype GG were observed in the T1DM (OR = 1.532, 95% CI 1.168-2.010, P = 0.002) and LADA patients (OR = 1.464, 95% CI 1.063-2.017, P = 0.019). The frequencies of the CTLA-4 CT60 risk genotype GG were 65.2, 61.9, 58.5, and 56.4% in the T1DM, LADA, T2DM, and control groups, respectively. The CTLA-4 CT60 GG risk genotypes were only associated with T1DM (OR = 1.445, 95% CI 1.1-1.898, P = 0.008). Compared with controls, patients having a high titer of GADA (GADA ≥ 180 IU/ml) had higher frequencies of the GG risk genotype of CTLA-4 + 49 A/G (49.4% vs. 35.1% OR = 1.807, 95% CI 1.125-2.903, P = 0.014), but there was no difference between patients having a low titer of GADA and controls. The CTLA-4 + 49 A/G polymorphism confers genetic susceptibility to LADA and T1DM, while the CTLA-4 CT60 polymorphism is only associated with T1DM in Chinese population. The CTLA-4 + 49 A/G genotype distribution in LADA is associated with the GADA level.

LADA prevalence estimation and insulin dependency during follow‐up

Latent autoimmune diabetes in adults (LADA) is a form of autoimmune-mediated diabetes in adults, usually defined by GAD autoantibody positivity. Few epidemiological surveys on LADA in Asians did not come to a conclusive answer regarding prevalence and incidence, because of different criteria used in patient ascertainment. We estimated LADA prevalence in a recent type 2 diabetes cohort by the positivity of circulating autoantibodies to pancreatic islet cell antigens (GAD, IA-2 and zinc transporter 8 (ZnT8)) applying a comparable Caucasian criteria. We then observed the development of insulin dependency prospectively for 36 months. Applying the European NIRAD LADA group criteria, we found a high prevalence of LADA (4.4%) in Korean patients with phenotypic type 2 diabetes. This high prevalence of LADA in Korea is noteworthy since the previous population-based LADA prevalence survey reported low prevalence (1.7%). When we consider the low-titre GAD antibodies and the low prevalence of multiple autoantibodies, however, increased LADA prevalence does not necessarily mean increase in future insulin dependency. After 36 months of follow-up, only 3 of 39 patients who were initially classified as LADA have become insulin-dependent. Those three were all positive for multiple autoantibodies (GAD, IA-2 and zinc transporter 8 antibody). Other features of insulin secretion or insulin resistance did not determine future insulin necessity. Although the LADA prevalence estimated by anti-GAD positivity appeared to increase, the true insulin dependency evidenced by multiple antibody positivity did not increase in Korea.

Autoimmune diabetes in adults: lessons from the UKPDS

Latent autoimmune diabetes in adults (LADA) is characterised by a relatively mild diabetes onset, autoantibody positivity and eventual requirement for insulin therapy. Twelve per cent of newly diagnosed, UK Prospective Diabetes Study (UKPDS) patients were positive for autoantibodies to GAD65 (GADA) and/or insulinoma-associated antigen-2A (IA-2A) and managed as if they had Type 2 diabetes according to the UKPDS protocol. Here, we compare data from UKPDS LADA patients with that from other cohorts. In common with other groups, UKPDS LADA patients required insulin therapy earlier post-diagnosis than non-LADA patients. Reduction of islet function was similar in UKPDS LADA groups randomised to oral glucose-lowering agents or insulin replacement therapy, contesting the current hypothesis of reduced decline of insulin secretion in LADA by immediate insulin therapy. Disease progression was not predicted by post-diagnosis GADA levels or epitope specificities as has been suggested. Slowly progressing insulitis and pancreatic beta-cell loss at post-mortem are consistent with sustained retention of residual C-peptide secretion in LADA. Genetic association patterns at the human leucocyte antigen (HLA) and insulin gene (INS) regions are similar in UKPDS LADA patients and individuals with adult and childhood-onset Type 1 diabetes. The combined evidence suggests that LADA is an adult-onset form of Type 1 diabetes, rather than a separate condition or an intermediate state in a continuum of phenotype from Type 1 to Type 2 diabetes.

HLA DRB1, DQB1 and insulin promoter VNTR polymorphisms: interactions and the association with adult‐onset diabetes mellitus in Czech patients

Both the human leucocyte antigen (HLA) DRB1 and the HLA DQB1 gene loci play a role in the development and progression of autoimmune diabetes mellitus (T1DM). Similarly, the insulin promoter variable number tandem repeats (INS-VNTR) polymorphism is also involved in the pathogenesis of diabetes mellitus (DM). We studied the association between each of these polymorphisms and DM diagnosed in patients older than age 35 years. Furthermore, we analysed possible interactions between HLA DRB1/DQB1 and INS-VNTR polymorphisms. Based on C-peptide and GADA levels we were able to distinguish three types of diabetes: T1DM, latent autoimmune diabetes in adults (LADA) and T2DM. INS-VNTR was genotyped indirectly by typing INS-23HphI A/T polymorphism. The genotype and allele frequencies of INS-23HphI did not differ between each of the diabetic groups and group of healthy subjects. We did, however, observe an association between the INS-23HphI alleles, genotypes and C-peptide secretion in all diabetic patients: A allele frequency was 86.2% in the C-peptide-negative group vs. 65.4% in the C-peptide-positive group (P(corr.) < 0.005); AA genotype was found to be 72.4% in the C-peptide-negative group vs. 42.6% in the C-peptide-positive groups (P(corr.) < 0.01). The HLA genotyping revealed a significantly higher frequency of HLA DRB1*03 allele in both T1DM and LADA groups when compared to healthy subjects: T1DM (25.7%) vs. control group (10.15%), odds ratio (OR) = 3.06, P < 0.05; LADA (27.6%) vs. control (10.15%), OR = 3.37, P < 0.01. The simultaneous presence of both HLA DRB1*04 and INS-23HphI AA genotype was detected in 37.5% of the T1DM group compared to only 9.2% of the healthy individuals group (OR = 5.9, P(corr.) < 0.007). We summarize that in the Central Bohemian population of the Czech Republic, the INS-23HphI A allele appears to be associated with a decrease in pancreatic beta cell secretory activity. HLA genotyping points to at least a partial difference in mechanism, which leads to T1DM and LADA development as well as a more diverse genetic predisposition in juvenile- and adult-onset diabetes. The simultaneous effect of HLA and INS-VNTR alleles/genotypes predispose individuals to an increased risk of diabetes development.

Cytotoxic Preproinsulin-specific CD8 T Cells in Type 1 Diabetes in Man

Latent autoimmune diabetes in adults (LADA) resembles type 1 diabetes (T1D) in disease presentation except that its onset is slow. We compared pathophysiological characteristics of CD8 + T cells recognizing preproinsulin (PPI) derived epitopes in both disease groups using MHC-I dextramers (DMRs) in peripheral blood and after in-vitro stimulation with PPI. Subjects with T1D harbored higher frequency of DMR + CD8 + T cells with relatively higher frequency of effector T cell subsets. Following stimulation with PPI, an increase in DMR + CD8 + T cells, particularly the central-memory subset was observed in T1D group, whereas no significant change in DMR + CD8 + T cell subsets was observed in LADA group. Intracellular expression of Granzyme-B and Perforin in DMR + CD8 + T cells was comparable in both the groups. In conclusion, lower frequency and inferior proliferative potential on account of a relatively restrained central-memory subset of PPI specific CD8 + T cells are associated with slow rate of disease progression in LADA.

The role of C-peptide levels in screening for latent autoimmune diabetes in adults.

Early detection of latent autoimmune diabetes in adults (LADA) is important in that the earlier insulin therapy is initiated, the greater the preservation of pancreatic beta cells. This study assessed whether a random C-peptide level is an effective screening test for LADA. Random C-peptide levels were measured in 39 subjects with LADA and 39 subjects with type 2 diabetes who were matched for age, race, gender, and duration of diabetes. LADA was definitively diagnosed by the presence of antiglutamic acid decarboxylase antibodies. The mean C-peptide level in the LADA group was 1.0 +/- 0.2 ng/mL and 5.1 +/- 0.4 ng/mL in the group with type 2 diabetes. Only 1 LADA subject had a C-peptide level above the normal range, and all subjects with type 2 diabetes had a C-peptide level within or above the normal range. LADA can be ruled out in adult-onset diabetes by the presence of elevated C-peptide. The more expensive testing for anti-GAD antibodies to definitively diagnose LADA should be reserved for patients who on screening have a low or normal random C-peptide level.

Clinical and Genetic Heterogeneity of Latent Autoimmune Diabetes in Adults

We read with interest the comments of Fukui et al. (1) in this issue of Diabetes Care regarding our recent article (2). They claim that patients with latent autoimmune diabetes in adults (LADA) are heterogeneous in their clinical attributes and that the LADA patients in our study represented the LADA type 1 subgroup. Because of this, we observed that their clinical and genetic characteristics resembled patients having rapidly progressive adult-onset type 1 diabetes. We agree that LADA patients may show heterogeneous clinical features, but we feel that our patients with LADA are representative of the whole LADA group: 25% of our LADA patients belonged to the overweight category based on their BMI, and the same percentage of patients had lipid abnormalities. The median of the insulin-free period after the diagnosis of diabetes was 3.0 years (1.0–6.0), despite the fact that we initiated insulin therapy in 23 of our …