Time dynamics of autoantibodies are coupled to phenotypes and add to the heterogeneity of autoimmune diabetes in adults: the HUNT study,Norway

Aims  

The aetiology of latent autoimmune diabetes in adults (LADA), assessed by autoimmune markers, is insufficiently clarified. We cross-sectionally investigated the prevalence and prospectively the prediabetic and postdiabetic presence of antibodies to glutamic acid decarboxylase (GADA), insulinoma-associated protein 2 and zinc transporter 8 in LADA and in type 1 diabetes.     

A clinically orientated approach increases the efficiency of screening for latent autoimmune diabetes in adults (LADA) in a large clinic-based cohort of patients with diabetes onset over 50 years.

AIMS: To assess if a clinically orientated approach improves screening for latent autoimmune diabetes in adults (LADA) in patients developing diabetes over age 50. METHODS: From a clinic-based cohort of 3327 patients with Type 2 DM diagnosed over age 50 we recruited those with at least one feature suggestive of insulin deficiency: (i) fasting blood glucose > or = 15 mmol/l and/or HbA(1c) > or = 10% in spite of adequate compliance to diet and treatment; (ii) decreasing body weight > or = 10% in the previous 3 months in spite of constant diet; (iii) BMI < 25 mg/kg(2). A control group of 240 patients not presenting any of the previous criteria was randomly selected from the out-patient clinic. RESULTS: We identified 220 (6.6%) patients, of whom 70 were positive for glutamic acid decarboxylase antibodies (GADA) and/or islet cell antibodies (ICA), giving a prevalence of LADA of 31.8% (95% CI 25.7-38.4). In contrast, no patient randomly selected from the remaining cohort had marker positivities. With respect to patients negative for both ICA and GADA, those who were positive had lower C-peptide values (0.53 +/- 0.51 vs. 0.88 +/- 0.42 nmol/l, P < 0.001); the lowest levels were found in patients in whom both antibodies were positive. In linear regression analysis, variables independently associated with fasting C-peptide were GADA (beta = -0.25, P < 0.001), ICA (beta = -0.15, P = 0.04), BMI (beta = 0.03, P < 0.001) and duration of diabetes (beta = -0.02, P < 0.001). CONCLUSION: This study shows that: (i) a clinically orientated approach increases the efficiency of a screening programme for LADA, so that one in three screened patients are classified correctly; (ii) ICA and GADA positivity were negatively associated with residual beta-cell function, independent of BMI and duration of the disease; (iii) positivity for both ICA and GADA identifies patients with the lowest residual beta-cell function.     

成年人迟发性自身免疫性糖尿病的临床特征

探讨成年人迟发性自身免疫性糖尿病的临床特征,以期早期识别。方法对４１８例临床诊断为２型糖尿病的患者通过ＩＣＡ和ＧＡＤ抗体测定,筛出ＬＡＤＡ５２例,与３０例成人速发型１型糖悄病和５０例健康人比较。结论目前简易可行的鉴别方法是检测免疫学指标ＩＣＡ和／或ＧＡＤ抗体,从２型糖尿病中筛查出ＬＡＤＡ。     

High titre of antiglutamic acid decarboxylase autoantibody is a strong predictor of the development of thyroid autoimmunity in patients with type 1 diabetes and latent autoimmune diabetes in adults

Objective Type 1 diabetes mellitus (T1DM) is frequently associated with autoimmune thyroid diseases (AITD), but little is known about the risk of AITD in latent autoimmune diabetes in adults (LADA). We evaluated the genetic and immunological factors involved in the development of thyroid autoimmunity in patients with LADA and T1DM. Patients and measurements One hundred and ninety T1DM and 135 LADA patients were recruited in the study. Thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TGAb), glutamic acid decarboxylase antibody (GADA) and thyroid function were measured. The cytotoxic‐lymphocyte‐associated antigen‐4 (CTLA‐4) +49A/G and CT60 polymorphisms and the human leucocyte antigen (HLA)‐DQA1‐DQB1 genotype were determined. Results The prevalence of thyroid antibodies (TGAb and/or TPOAb) and thyroid dysfunction was 27·4% and 9·5% in patients with T1DM, and 21·5% and 11·1% in patients with LADA. Thyroid‐antibody‐positive T1DM patients had higher frequencies of GADA and HLA‐DQA1*03‐DQB1*0401 haplotypes than thyroid‐antibody negatives (P < 0·05). Thyroid‐antibody‐positive LADA patients had higher GADA titre, lower C‐peptide levels and higher frequencies of HLA‐DQA1*03‐DQB1*0401 haplotypes (P < 0·05). The CTLA‐4 +49A/G and CT60 polymorphism was associated with T1DM complicated with thyroid autoimmunity (OR = 2·33 and 2·54). Logistic regression revealed that only high‐titre GADA was associated with development of thyroid autoimmunity in patients with T1DM and LADA (OR = 3·50 and 3·10, respectively), and the presence of thyroid antibody predicted high risk for thyroid dysfunction in patients with T1DM and LADA (OR = 9·25 and 10·70, respectively). Conclusion Regular screening of thyroid antibody and function are recommended, especially in patients with T1DM and LADA with high GADA titre.     

GAD antibodies in probands and their relatives in a cohort clinically selected for Type 2 diabetes.

AIMS: A subset of patients who present as if they have Type 2 diabetes have positive pancreatic autoantibodies, and have been referred to as having latent autoimmune diabetes in adults (LADA). We assessed the prevalence and clinical characteristics of patients with glutamic acid decarboxylase antibodies (GADA) in a cohort clinically selected for Type 2 diabetes and determined the presence of diabetes and GADA in their first-degree relatives. METHODS: GADA were measured in 2059 subjects, not known to be related, and clinically selected as having Type 2 diabetes for genetic studies. Clinical characteristics were compared in GADA positive and GADA negative subjects. Diabetes and GAD antibody status were compared in 208 first-degree relatives of GADA positive and GADA negative probands. RESULTS: Of the subjects, 136 (7%) were GADA positive. Compared with the GADA negative subjects, they were slimmer (P < 0.001), diagnosed at a younger age (P = 0.011) and progressed to insulin faster (P < 0.001). Thirty-three per cent of GADA positive subjects had a first-degree relative with diabetes compared with 42% of GADA negative subjects (P = 0.034). The overall prevalence of GADA was similar in the first-degree relatives of GADA positive and GADA negative probands (4 v 5%), and 19 of 22 (86%) diabetic relatives of GADA positive probands were GADA negative. CONCLUSION: Despite clinically selecting a Type 2 diabetes cohort, 7% were GADA positive with an altered phenotype. These GADA positive patients had a strong family history of non-autoimmune diabetes. This suggests that, in this subgroup of patients, autoimmune pancreatic beta-cell destruction occurs on a background of Type 2 diabetes genetic susceptibility.     

谷氨酸脱羧酶抗体水平对两种成人隐匿性自身免疫糖尿病亚型的识别

目的　探讨不同谷氨酸脱羧酶 (GAD65)抗体水平的成人隐匿性自身免疫糖尿病(LADA)患者的临床特点 ,了解LADA患者中是否存在两种不同的亚型。方法　对 750例临床初诊为2型糖尿病 (T2DM)患者及其志愿参加进一步研究的 2 95例患者用放免法进行GAD65抗体 (GADA)测定 ,绘制GADA指数的频数分布图 ,进行各组间临床特点的比较。结果　 (1 )GADA在初诊 2型糖尿病中的阳性率为 9 7% ,高抗体水平者 (GADA指数≥ 0 5)占 2 8%。 (2 )LADA患者中抗体滴度较低(GADA指数 0 0 5～ <0 5)者在胰岛功能 (空腹C肽 50 0pmol/L比 50 4pmol/L ,P >0 0 5)、高血压比例(48 7%比 42 5 % ,P >0 0 5)及体重指数 (2 3 2kg/m2 比 2 2 3kg/m2 ,P >0 0 5)等方面与 2型糖尿病相似 ,即为LADA 2型 ;抗体滴度较高者 (GADA指数≥ 0 5)具有起病年龄小、胰岛功能差、更多使用胰岛素治疗 (P <0 0 1 )等特点 ,临床表现更类似经典的 1型糖尿病 ,即为LADA 1型。结论　LADA患者具有异质性 ,存在LADA 1和LADA 2两种亚型 ,LADA 1型的临床特点更类似于经典的 1型糖尿病     

糖尿病的连续疾病谱学说

糖尿病连续疾病谱学说认为,从1型糖尿病、高滴度成人隐匿性自身免疫糖尿病（LADA）、低滴度LADA到2型 糖尿病,糖尿病表现为连续的疾病谱,中间存在多个过渡类型。该学说最早于2003年提出,随后经典遗传背景、胰岛 功能及衰退速度、胰岛自身免疫反应、其他自身免疫病、其他代谢特征、炎症细胞及因子等研究均证实这一学说。该学 说有助于深入理解糖尿病异质性的病因学机制,强调多维度、多指标指导临床分型与诊疗,进而推动精准分型的发展。     

Type 2 diabetes susceptibility gene variants predispose to adult-onset autoimmune diabetes

Aims/hypothesis

Latent autoimmune diabetes in adults (LADA) is phenotypically a hybrid of type 1 and type 2 diabetes. Genetically LADA is poorly characterised but does share genetic predisposition with type 1 diabetes. We aimed to improve the genetic characterisation of LADA and hypothesised that type 2 diabetes-associated gene variants also predispose to LADA, and that the associations would be strongest in LADA patients with low levels of GAD autoantibodies (GADA).

Methods

We assessed 41 type 2 diabetes-associated gene variants in Finnish (phase I) and Swedish (phase II) patients with LADA (n?=?911) or type 1 diabetes (n?=?406), all diagnosed after the age of 35 years, as well as in non-diabetic control individuals 40 years or older (n?=?4,002).

Results

Variants in the ZMIZ1 (rs12571751, p?=?4.1?×?10^?5) and TCF7L2 (rs7903146, p?=?5.8?×?10^?4) loci were strongly associated with LADA. Variants in the KCNQ1 (rs2237895, p?=?0.0012), HHEX (rs1111875, p?=?0.0024 in Finns) and MTNR1B (rs10830963, p?=?0.0039) loci showed the strongest association in patients with low GADA, supporting the hypothesis that the disease in these patients is more like type 2 diabetes. In contrast, variants in the KLHDC5 (rs10842994, p?=?9.5?×?10^?4 in Finns), TP53INP1 (rs896854, p?=?0.005), CDKAL1 (rs7756992, p?=?7.0?×?10^?4; rs7754840, p?=?8.8?×?10^?4) and PROX1 (rs340874, p?=?0.003) loci showed the strongest association in patients with high GADA. For type 1 diabetes, a strong association was seen for MTNR1B (rs10830963, p?=?3.2?×?10^?6) and HNF1A (rs2650000, p?=?0.0012).

Conclusions/interpretation

LADA and adult-onset type 1 diabetes share genetic risk variants with type 2 diabetes, supporting the idea of a hybrid form of diabetes and distinguishing them from patients with classical young-onset type 1 diabetes.     

Clinical and metabolic characteristics of patients with latent autoimmune diabetes in adults (LADA): Absence of rapid beta-cell loss in patients with tight metabolic control

Aim and methodsThe present study compared the clinical and metabolic characteristics of latent autoimmune diabetes in adults (LADA) with type 2 diabetes, as well as the residual beta-cell function and progression to insulin treatment, over a 2-year follow-up period, of antibody (Ab)-positive and Ab-negative patients who achieved tight glycaemic control (HbA_1c 7.0 ± 0.8% and 6.5 ± 0.9%, respectively, at the time of entry into the study).ResultsGlutamic acid decarboxylase antibodies (GADA) and/or islet cell antibodies (ICA) were detected in 10% of patients presenting with non-insulin-dependent diabetes. Around half of Ab-positive patients required insulin treatment during the follow-up. Ab-positive patients displayed lower stimulated C-peptide levels both at entry and during the follow-up compared with Ab-negative patients, although no significant decline in C-peptide levels was observed in either subgroup over two years. Nevertheless, Ab-positive patients progressed more frequently to insulin treatment, and stimulated C-peptide tended to decrease in LADA patients who subsequently required insulin, whereas it remained stable in those who were non-insulin-dependent. In those who progressed, the trend towards C-peptide decline persisted even after starting insulin treatment.ConclusionLADA patients demonstrate lower residual beta-cell function than do type 2 diabetes patients. However, those who achieve tight metabolic control do not present with a rapid decline in beta-cell function. Further studies are needed to determine the optimal treatment strategy in such patients.     

The prevalence and characteristics of latent autoimmune diabetes in adults (LADA) and its relation with chronic complications in a clinical department of a university hospital in Korea

Few studies were performed to evaluate the prevalence of latent autoimmune diabetes in adults (LADA) and the difference of chronic complications between LADA, T1DM, and T2DM in Korean. The aim of this study is to establish the prevalence of LADA in a diabetic clinic of Soonchunhyang University hospital and to compare the phenotypic characteristics according to DM classification based on positivity of glutamic acid decarboxylase antibodies (GADA). Also, another important point concerns the occurrence of diabetes chronic microvascular complications in LADA. 323 patients who were checked GADA among diabetic patients admitted at Soonchunhyang University hospital were recruited. Twenty-eight patients (8.7%) were identified as positive for GADA. 11.5% (n = 37) were diagnosed with T1DM and 5.3% (n = 17) were diagnosed with LADA. GADA titer showed significant negative correlation with age of onset, total cholesterol (TC), triglyceride (TG), fasting C-peptide, stimulated C-peptide, BMI, and positive correlation with HbA1C and HDL-C. Compared with those that tested negative for GADA, patients with GADA positive had lower values of onset age, BMI, TC, TG, LDL-C, fasting, and stimulated C-peptide levels and higher values of HbA1C. A significant gradual increase of values was observed for the onset age, BMI, SBP, DBP, fasting, and stimulated C-peptide across the T1DM, LADA, and T2DM subgroups. Concerning the chronic complications there was no difference in prevalence of retinopathy, neuropathy and nephropathy between three groups. Of LADA patients, 12 patients were receiving insulin treatment and mean time to insulin initiation was about 37 months. In conclusion, because our study suggests LADA subgroups in Korea appear to have a faster decline in C-peptide levels, it is worth detecting the patients with LADA early and effort to preserve beta cell function. Furthermore, our results showed that the prevalence of microvascular complication was comparable between the subgroups.     

The clinical characteristics of latent autoimmune diabetes in adults and its relation with chronic complications in metabolically poor controlled Turkish patients with Type 2 diabetes mellitus

It has been reported that some patients with Type 2 diabetes mellitus (DM) have latent autoimmune diabetes in adults (LADA) and may show different clinical characteristics than those with Type 2 DM. We aimed to determine the ratio and clinical features of LADA in patients with diagnosed initially as Type 2 DM. We measured glutamic acid decarboxylase antibodies (GADA) in 54 patients, diagnosed clinically with Type 2 DM. Of 54 patients, 17 (31%) were GADA positive. GADA-positive patients had significantly earlier diabetes onset age (P<.001), lower BMI (P<.05), and lower serum C-peptide value (P<.001) than did those who were GADA negative. A higher proportion of the GADA-positive patients were receiving insulin therapy (P<.01). With respect to the duration of DM, familial history of DM, and the levels of blood pressures, fasting plasma glucose, and HbA1c, there was no difference between the two groups. Nephropathy and retinopathy were more frequent in GADA-positive than in GADA-negative patients. The prevalence of neuropathy was comparable between the two groups. GADA was negatively associated with BMI, C-peptide levels, and diabetes-onset age, but positively related to retinopathy, nephropathy, and insulin treatment. This study indicated that the important portion of the patients who were initially diagnosed as Type 2 DM may have LADA. In Type 2 diabetic patients who have lower BMI and diagnosis of diabetes in relatively younger age, the possibility of LADA should be taken into consideration. The higher prevalence of nephropathy and retinopathy in GADA-positive patients also suggests the importance of early diagnosis and strict metabolic control in these patients.     

High levels of antigen-specific islet antibodies predict future beta-cell failure in patients with onset of diabetes in adult age.

It is unclear whether high levels of antigen-specific islet antibodies [GADA (glutamic acid decarboxylase 65 antibodies) and IA2-ab (protein tyrosine phosphatase-like protein antibodies)] predict beta-cell failure in patients with onset of diabetes in adult age. Therefore, GADA and IA2-ab levels at the diagnosis of diabetes were related to fasting plasma C-peptide levels 5 yr later in 148 patients with diabetes onset in adult age (age at onset, 20-77 yr; median, 57 yr). Classical islet cell antibodies (ICA) were also determined. Complete beta-cell failure (undetectable fasting plasma C-peptide) was only present in 4 patients at diagnosis of diabetes, but in 21 patients 5 yr thereafter. At diagnosis, ICA were detected in 20 of 21 (95%) patients with beta-cell failure after 5 yr and in only 7 of 127 (5%) without, whereas GADA and/or IA2-ab (>97.5 percentile of healthy controls) were detected in all 21 (100%) with but also in 23 of 127 (18%) patients without beta-cell failure after 5 yr. Thus, ICA had a higher positive predictive value (74%) than GADA and/or IA2-ab (47%; P < 0.05). With high cutoff values for GADA and IA2-ab, however, GADA and/or IA2-ab were detected in 19 of 21 (90%) patients with beta-cell failure vs. only in 5 of 127 (4%) without, giving a positive predictive value of 79%. Slightly elevated GADA levels in IA2-ab-negative patients were associated with progressive but not complete beta-cell failure within the study period. Hence, high GADA and/or IA2-ab levels predict a future complete beta-cell failure, whereas low GADA levels predict slowly progressive beta-cell insufficiency.     

成人迟发自身免疫性糖尿病与1、2型糖尿病临床表现的比较

目的：探讨成人迟发自身免疫性糖尿病（LADA）的临床特征，方法：评价谷氨酸脱羧酶抗体（GADA）、胰岛细胞抗体（ICA）阳性LADA患者各种急性和慢性并发症的患病率，并与速发型1和2型糖尿病（DM）相比较。结果：LADA患者的年龄，BMI，空腹及餐后C肽水平介于1和2型DM之间，LADA组29％患者有酮症，再次酮症的频率与1型相似，但至首次酮症的时间较长。视网膜病变患病率为19．5％，与1型DM相似；白内障患病率为48．8％，与2型DM相似；冠心病患病率与2型DM相似，高血压患病率介于1、2型DM之间。LADA组有微量白蛋白尿者较少，3组间显性肾病变。周围神经病变和高脂血症的患病率相似。结论：LADA的临床特征及急性和慢性并发症的患病率与1和2型DM有所不同。     

IgG4-subclass of glutamic acid decarboxylase antibody is more frequent in latent autoimmune diabetes in adults than in type 1 diabetes

Aims/hypothesis Glutamic acid decarboxylase autoantibodies (GADA) are the most frequent beta-cell-specific autoantibodies in type 1 diabetes and in latent autoimmune diabetes in adults (LADA). The autoimmune attack on pancreatic islet cells is associated with a T helper 1 cell (T_h1) response, mainly represented by IgG₁-subclass in humans. It has been proposed that the presence of IgG₄ may be associated with a T_h2 response. The aim of our study was to compare the GADA IgG-subclass distribution between adult patients with type 1 diabetes and LADA.Methods Patients with type 1 diabetes (n=45) and patients with LADA (n=60) were included. Radioimmunoprecipitation assay with IgG-subclass specific Sepharose (IgG₁, IgG₂, IgG₃ and IgG₄) was used to precipitate the antibody/antigen-complex.Results We only detected IgG₄-subclass of GADA in subjects with LADA (26.7%; p<0.001). IgG₁ was the most common GADA-subclass in both groups, however IgG₁ as the solely expressed subclass was more common among type 1 diabetic patients (77.8%; p<0.05). The rank order of the frequencies of IgG-subclasses in type 1 diabetes was IgG₁>IgG₃>IgG₂>IgG₄ and in LADA patients IgG₁>IgG₄>IgG₂>IgG₃.Conclusions/interpretation The difference in GADA IgG-subclasses could indicate a different immune response, possibly an altered balance between T_h1 and T_h2 cytokine profile in pancreatic islets. This difference could contribute to the slower rate of beta cell destruction in LADA patients, as reflected by a higher C-peptide level at clinical onset.     

Effect of simultaneous vaccination with H1N1 and GAD-alum on GAD<Subscript>65</Subscript>-induced immune response

Aims/hypothesis

A European Phase III trial of GAD formulated with aluminium hydroxide (GAD-alum) failed to reach its primary endpoint (preservation of stimulated C-peptide secretion from baseline to 15 months in type 1 diabetes patients), but subgroup analysis showed a clinical effect when participants from Nordic countries were excluded, raising concern as to whether the mass vaccination of the Swedish and Finnish populations with the Pandemrix influenza vaccine could have influenced the study outcomes. In the current study, we aimed to assess whether Pandemrix vaccination affects the specific immune responses induced by GAD-alum and the C-peptide response.

Methods

In this secondary analysis, we analysed data acquired from the Swedish participants in the Phase III GAD-alum trial who received subcutaneous GAD-alum vaccination (two doses, n = 43; four doses, n = 46) or placebo (n = 48). GAD autoantibodies (GADA) and H1N1 autoantibodies, GAD₆₅-induced cytokine secretion and change in fasting and stimulated C-peptide levels from baseline to 15 months were analysed with respect to the relative time between H1N1 vaccination and the first injection of GAD-alum.

Results

GADA levels at 15 months were associated with the relative time between GAD-alum and Pandemrix administration in participants who received two doses of the GAD-alum vaccine (p = 0.015, r = 0.4). Both in participants treated with two doses and four doses of GAD-alum, GADA levels were higher when the relative time between vaccines was ≥210 days (p < 0.05). In the group that received two doses of GAD-alum, levels of several GAD₆₅-induced cytokines were higher in participants who received the H1N1 vaccination and the first GAD-alum injection at least 150 days apart, and the change in fasting and stimulated C-peptide at 15 months was associated with the relative time between vaccines. Neither of these effects were observed in individuals who received four doses of GAD-alum.

Conclusions/interpretation

In individuals who received two doses of GAD-alum, receiving the Pandemrix vaccine closer to the first GAD-alum injection, i.e. <150 days, seemed to affect both GAD₆₅-induced immune response and C-peptide preservation.

Trial registration:

ClinicalTrials.gov NCT00723411.

     

Fatty fish consumption and risk of latent autoimmune diabetes in adults

Objective:

It has been suggested that intake of fatty fish may protect against both type 1 and type 2 diabetes. Hypotheses rest on the high marine omega-3 fatty acid eicosapentaenoic acid+docosahexaenoic acid (EPA+DHA) and vitamin D contents, with possible beneficial effects on immune function and glucose metabolism. Our aim was to investigate, for the first time, fatty fish consumption in relation to the risk of latent autoimmune diabetes in adults (LADA).

Methods:

Analyses were based on data from a Swedish case–control study with incident cases of LADA (n=89) and type 2 diabetes (n=462) and randomly selected diabetes-free controls (n=1007). Diabetes classification was based on the onset of age (⩾35), glutamic acid decarboxylase autoantibodies, and C-peptide. A validated food frequency questionnaire was used to derive information on previous intake of fish, polyunsaturated long-chain omega-3 fatty acids (n-3 PUFA) and supplementation of fish oil and vitamin D. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using logistic regression, adjusted for age, gender, body mass index (BMI), family history of diabetes, physical activity, smoking, education, and consumption of alcohol, fruit, vegetables and red meat.

Results:

Weekly fatty fish consumption (⩾1 vs <1 serving per week), was associated with a reduced risk of LADA but not type 2 diabetes (OR 0.51, 95% CI 0.30–0.87, and 1.01, 95% CI 0.74–1.39, respectively). Similar associations were seen for estimated intake of n-3 PUFA (⩾0.3 g per day; LADA: OR 0.60, 95% CI 0.35–1.03, type 2 diabetes: OR 1.14, 95% CI 0.79–1.58) and fish oil supplementation (LADA: OR 0.47, 95% CI 0.19–1.12, type 2 diabetes: OR 1.58, 95% CI 1.08–2.31).

Conclusions:

Our findings suggest that fatty fish consumption may reduce the risk of LADA, possibly through effects of marine-originated omega-3 fatty acids.     

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.     

Type 1 diabetes islet associated antibodies in subjects infected by echovirus 16

Aims/hypothesis To determine whether the emergent infection by echovirus 16 that occurred in Cuba during the year 2000 was related to the presence of Type 1 diabetes associated autoantibodies.Methods The presence of ICA, IAA, GADA, IA2 antibodies and neutralizing antibodies (NtAb) to echovirus 16 were determined in sera from 38 infected children and adolescents and 80 control subjects, matched in sex, age, local residence and time of sample collection.Results The occurrence of a large-scale echovirus 16 epidemic was associated with the appearance of humoral autoimmune markers of Type 1 diabetes, especially for ICA, IAA and GADA. In the convalescent stage, ICA, IAA and GADA seroconversion was shown in 92.1%, 44.7% and 28.9% of echovirus 16 infected subjects. None of the 80 uninfected subjects had ICA or IAA, while one was GADA positive. ICA, IAA and GADA frequency was higher in the convalescent than in the acute stage (p<0.0005). A strong positive correlation was found between the NtAb to echovirus 16 and ICA titres in both acute and convalescent stage (r=0.91; p<0.0001, r=0.55; p=0.0003 respectively).Conclusion/interpretation This work provides evidence of an association between echovirus 16 infection and the presence of Type 1 diabetes related antibodies (ICA, IAA and GADA). Our data show that the echovirus 16 infection might be capable of inducing a process of autoimmune beta-cell damage and support the hypothesis that enterovirus infections are important risk factors for the development of Type 1 diabetes.Abbreviations EV echovirus - ICA islet cell antibodies - IAA insulin autoantibodies - GADA glutamic acid decarboxylase antibodies - IA2A tyrosine phosphatase antibodies - NtAb neutralizing antibodies - TMA thyroid microsomal antibodies - PGA parietal gastric cells antibodies - JDF juvenile diabetes foundation - CVB4 coxsackie virus B4 - CVB5 coxsackie virus B5     

Latent autoimmune diabetes in adults (LADA) in South Wales: incidence and characterization

Aim To define the incidence and characteristics of latent autoimmune diabetes in adults (LADA). Methods We estimated the incidence of LADA by examining the incidence of Type 2 diabetes and calculating the proportion that were antibody positive. The incidence of Type 2 diabetes was calculated by analysis of computer records of 35 out of 36 general practices in Swansea. In addition, thirty‐two practices participated in recruiting people with Type 2 diabetes to have glutamic acid decarboxylase (GAD) antibody testing. Results The crude proportion of Type 2 patients testing positive for GAD antibodies (GADA) was 4.0% (28/683). This figure did not change when we analysed only the practices that tested more than 60% of all eligible patients. In these practices, 79% (387/487) of all eligible patients were GADA tested and 14/387 [3.6% (95% confidence interval: 2.1–6.1%)] were classified as having LADA. This gives an incidence of LADA of 9 per 100 000 (95% confidence interval: 4.4–17.8 per 100 000) people per year registered with a general practitioner. Patients testing positive for GADA were more likely to have a lower body mass index, other antibodies, to present with acute symptoms and to have higher glycated haemoglobin. Conclusions This is the first study of the incidence of LADA in primary care. People with LADA make up a significant proportion of people with apparent Type 2 diabetes. Patients with LADA are likely to be symptomatic, have poorer glycaemic control and have other autoimmune antibodies.     

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

BackgroundA 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.MethodsData 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.ResultsBoth 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).ConclusionThe 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.