Gliadin, endomysial and thyroid antibodies in patients with latent autoimmune diabetes of adults (LADA)

Microbiota revolution: How gut microbes regulate our lives

The human intestine is a natural environment ecosystem of a complex of diversified and dynamic microorganisms, determined through a process of competition and natural selection during life. Those intestinal microorganisms called microbiota and are involved in a variety of mechanisms of the organism, they interact with the host and therefore are in contact with the organs of the various systems. However, they play a crucial role in maintaining host homeostasis, also influencing its behaviour. Thus, microorganisms perform a series of biological functions important for human well-being. The host provides the microorganisms with the environment and nutrients, simultaneously drawing many benefits such as their contribution to metabolic, trophic, immunological, and other functions. For these reasons it has been reported that its quantitative and qualitative composition can play a protective or harmful role on the host health. Therefore, a dysbiosis can lead to an association of unfavourable factors which lead to a dysregulation of the physiological processes of homeostasis. Thus, it has pre-viously noted that the gut microbiota can participate in the pathogenesis of autoimmune diseases, chronic intestinal inflammation, diabetes mellitus, obesity and atherosclerosis, neurological disorders (e.g., neurological diseases, autism, etc.) colorectal cancer, and more.

Antibodies against multiple post-translationally modified proteins aid in diagnosis of autoimmune hepatitis and associate with complete biochemical response to treatment

Background

(Auto)immune mediated and cholestatic liver disease (AILD) includes autoimmune hepatitis (AIH), primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC). Especially AIH is characterized by the presence of autoantibodies and elevated serum immunoglobulins. In rheumatoid arthritis, autoantibodies against post-translational modifications (PTMs) such as citrullination (Cit) and carbamylation (CarP) are used as diagnostic and prognostic markers, respectively. We studied the presence of six anti-PTM antibodies in patients with the three AILDs and non-AILD.

Methods

Antibodies against six PTMs (malondialdehyde-acetaldehyde adducts (MAA), advanced glycation end-products (AGE), CarP, acetylation (AL), Cit, and nitration (NT)) were tested in sera of patients with AILD (n = 106), non-AILD (n = 101) and compared with healthy controls (HC) (n = 100). Levels and positivity were correlated with clinical and biochemical features in a well-defined cohort of untreated AIH patients.

Results

Anti-PTM antibodies were more often detectable in sera from AILD patients compared with HCs (anti-MAA: 67.9% vs. 2.0%, anti-AGE: 36.8% vs. 4.0%, anti-CarP: 47.2% vs. 5.0% and anti-AL: 18.9% vs. 5.0%). In untreated AIH, time to complete biochemical response (CBR) was associated with anti-MAA, anti-AGE, anti-CarP and anti-AL antibodies. Significantly more patients with at least three anti-PTM antibodies attained CBR at 12  months of treatment (13 vs. 3 p = 0.01).

Conclusion

Anti-PTM antibodies are frequently present in AILD. The presence of anti-MAA, anti-AGE and anti-CarP antibodies correlates with the presence of AIH within this cohort. In AIH, harboring at least three anti-PTM antibody responses is positively associated with CBR. Determination of anti-PTM antibodies in liver disease may have diagnostic and prognostic value.

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.

Diabetic ketoacidosis as first presentation of latent autoimmune diabetes in adults in a patient with hashitoxicosis as first presentation of Hashimoto's thyroiditis: a case report

Background

Latent autoimmune diabetes in adults is an infrequent form of autoimmune diabetes mellitus, while Hashimoto’s thyroiditis, the most common thyroid disease in adults, rarely manifests as thyrotoxicosis. The concurrent initial presentation of these two autoimmune disorders is extremely rare.

Case presentation

A 29-year-old male of Albanian descent presented after being hospitalized owing to diabetic ketoacidosis. The diagnosis of type 1 diabetes mellitus was placed, and intensified insulin therapy was initiated. Medical history was not of significance except a 5 kg weight loss within 2 months. The patient presented with recurrent episodes of hypoglycemia, and the doses of preprandial and basal insulin were reduced. The differential diagnosis included type 1 diabetes mellitus “honeymoon” period or another type of diabetes mellitus. His serological tests only revealed positive autoantibodies against glutamic acid decarboxylase 65 and C-peptide. The diagnosis leaned toward latent autoimmune diabetes in adults, and the therapeutic approach involved cessation of preprandial insulin therapy, regulation, and subsequent discontinuation of basal insulin and introduction of metformin. Two years later, basal insulin was reintroduced along with a glucagon-like peptide-receptor agonist and metformin. Further physical examination during the initial visit disclosed upper limb tremor, lid lag, excessive sweating, increased sensitivity to heat, and tachycardia. Laboratory tests were indicative of hashitoxicosis (suppressed level of thyroid-stimulating hormone, high levels of total and free thyroid hormones, positive anti-thyroglobulin and anti-thyroid peroxidase, and negative anti-thyroid-stimulating hormone receptor). Thyroid-stimulating hormone level was spontaneously restored, but an increase was observed during follow-up. Levothyroxine was administrated for 2 years until the patient had normal thyroid function.

Conclusions

The prevalence of thyroid autoantibodies in patients with latent autoimmune diabetes in adults ranges from 20% to 30%. This correlation can be attributed to genetic involvement as well as disorders of immune tolerance to autoantigens. Hence, this report gives prominence to the holistic approach and consideration of comorbidities in patients with diabetes mellitus.

Prevalence of Latent Autoimmune Diabetes in Adult Based on the Presence of GAD 65 Antibodies in North-Eastern Uttar Pradesh, India

Objective The objective of this paper was (1) to study the prevalence of latent autoimmune diabetes in adult (LADA) in the region of north-eastern Uttar Pradesh, India, based on the positivity for glutamic acid decarboxylase 65 (GAD65) antibodies and (2) to compare the glycemic profile between GAD65-positive and GAD65-negative subjects.

Materials and Methods The subjects were of more than 30 years of age, with either recently diagnosed pre-diabetes/diabetes presenting with the hemoglobin A1c (HbA1c) level of ≥5.7% or already diagnosed cases of type 2 diabetes mellitus (T2DM) who had no requirement of insulin therapy for at least 6 months from the time of their diagnosis. All the patients were natives of north-eastern Uttar Pradesh. The GAD65 test was done by the enzyme-linked immunosorbent assay. Further, the glycemic status of GAD-positive and GAD-negative subjects were compared on the basis of fasting blood sugar (FBS), fasting insulin (FI), and homeostatic model assessment for insulin resistance (HOMA-IR).

Statistical Analysis The “unpaired t-test” was used to compare and assess the significance of differences between the glycemic profile of GAD65-positive and GAD65-negative subjects using the GraphPad Prism Scientific Software, San Diego, CA, United States. The p-value of <0.05 was considered to be significant.

Results A total of 77 patients were included in the study, with the age group ranging from 30 to 75 years (47.81 ± 12.9 years) with the male–female ratio of 1:2.6. The prevalence of LADA was found to be 51.95%. On comparing GAD65-positive and GAD65-negative groups, a higher value of HbA1c levels and FBS were found in the former, whereas FI and HOMA-IR were found to be higher in the latter. On testing for significance of difference, only FI and HbA1c values were significant (p-value <0.0001).

Conclusion LADA can no longer be considered a rare type of diabetes mellitus, with the present study showing a high prevalence of LADA in this north eastern region of Uttar Pradesh. Identification of adult-onset diabetics accurately as LADA or true T2DM is very crucial for the appropriate treatment, as LADA patients require insulin inevitably and much earlier than true T2DM patients, who can be managed mostly on oral hypoglycemic agents with seldom requirement of insulin.

Associated autoimmunity in Type 1 Diabetes and latent autoimmune diabetes of adults: The role of glutamic-acid decarboxylase autoantibodies

AIMS

To determine the prevalence of Associated Autoimmune Diseases (AADs) in Latent Autoimmune Diabetes of Adults (LADA) versus autoimmune Type 1 Diabetes (T1D) and the role of glutamic-acid decarboxylase antibodies (GADA) and other factors.

METHODS

Adults with autoimmune diabetes mellitus (DM) were recruited from the Diabetes Center of Nikaia-Piraeus Hospital. Demographic and clinical parameters were recorded and anti-pancreatic and organ-specific antibodies were measured.

RESULTS

Of 160 patients, 33.75% had one AAD and 24.37% had two or more. Patients with LADA had higher overall prevalence of AADs, mainly autoimmune thyroiditis and gastritis. Celiac disease was present only in T1D. GADA positive patients had higher prevalence of AADs and multiple autoimmunity, especially thyroiditis and gastritis. Patients with LADA had higher rates of positive GADA or islet-cell antibodies (ICA). After controlling for LADA, GADA remained a significant predictor of AADs. Female gender and chronological age were also significant predictors of AADs.

CONCLUSIONS

AADs were present in 58.13% of patients. Patients with LADA were more prone to a generalized autoimmune disorder than those with T1D. AADs development was significantly associated with female sex, older age and positive GADA, which proved an independent marker of associated autoimmunity.

Amyloids in Site-Specific Autoimmune Reactions and Inflammatory Responses

Amyloid deposition is a histological hallmark of common human disorders including Alzheimer's disease (AD) and type 2 diabetes. Although some reports highlight that amyloid fibrils might activate the innate immunity system via pattern recognition receptors, here, we provide multiple lines of evidence for the protection by site-specific amyloid protein analogs and fibrils against autoimmune attacks: (1) strategies targeting clearance of the AD-related brain amyloid plaque induce high risk of deadly autoimmune destructions in subjects with cognitive dysfunction; (2) administration of amyloidogenic peptides with either full length or core hexapeptide structure consistently ameliorates signs of experimental autoimmune encephalomyelitis; (3) experimental autoimmune encephalomyelitis is exacerbated following genetic deletion of amyloid precursor proteins; (4) absence of islet amyloid coexists with T-cell-mediated insulitis in autoimmune diabetes and autoimmune polyendocrine syndrome; (5) use of islet amyloid polypeptide agonists rather than antagonists improves diabetes care; and (6) common suppressive signaling pathways by regulatory T cells are activated in both local and systemic amyloidosis. These findings indicate dual modulation activity mediated by amyloid protein monomers, oligomers, and fibrils to maintain immune homeostasis. The protection from autoimmune destruction by amyloid proteins offers a novel therapeutic approach to regenerative medicine for common degenerative diseases.

Elevated TPOAb is a Strong Predictor of Autoimmune Development in Patients of Type 2 Diabetes Mellitus and Non-Alcoholic Fatty Liver Disease: A Case-Control Study

OBJECTIVE

The aim of this study was to assess the prevalence of thyroid autoimmunity in T2DM with NAFLD, furthermore explore the relationship between elevated TPOAb titer and the severity of NAFLD.

METHODS

A total of 400 patients with T2DM were divided into two groups according to NAFLD. Thyroid function and other metabolic indicators were measured.

RESULTS

There were more TPOAb-positive patients in both groups, and the prevalence of TPOAb positive was significantly different in two groups (17% vs 6.9%, p< 0.01). FT4 was significantly lower in patients with T2DM with NAFLD (median FT4 0.89 vs 1.08, p < 0.001), while TSH was increased (median TSH 2.85 vs 2.28, p < 0.05). In patients with T2DM with NAFLD, the proportion of women in the thyroid autoimmune-positive group was significantly higher than the negative (71.1% vs 46%, p < 0.01). Similarly, thyroid autoimmune-positive T2DM and NAFLD patients had lower FT4 levels (median FT4 0.59 vs 0.92, p < 0.001), higher TSH levels (median TSH 3.65 vs 2.67, p < 0.001), and much higher TPOAb/TGAb (median TPOAb/TGAb 6.8 vs 1.46, p < 0.001). The increase of TPOAb was significantly correlated with the severity of fatty liver. HbA1c, TC, TG, TSH, TPOAb/TGAb and severity of fatty liver were risk factors of thyroid autoimmunity.

CONCLUSION

Autoimmune thyroid disease is more common in patients with T2DM complicated with NAFLD. Elevated TPOAb titer is closely related to fatty liver, suggesting that elevated TPOAb titer is a predictor of autoimmune development in T2DM with NAFLD.

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.

Zinc transporter 8 autoantibodies (ZnT8-ab) are associated with higher prevalence of multiple diabetes-related autoantibodies in adults with type 1 diabetes

AIM

The study aimed to assess the prevalence of zinc transporter 8 autoantibodies (ZnT8-ab), other diabetes-related autoantibodies and clinical manifestation of type 1 diabetes in adults, depending on age of the onset of disease.

METHODS

119 patients with type 1 diabetes, 66 at age <35 years (T1DM < 35) and 53 T1DM at age ≥35 years (T1DM ≥ 35). We assessed clinical features, GAD-ab, IA2-ab, ICA, ZnT8-ab and thyroid peroxidase antibodies (ATPO).

RESULTS

In T1DM < 35 lower initial serum C-peptide concentration was observed and diabetes ketoacidosis (DKA) was more common. ATPO positivity was more prevalent in T1DM ≥ 35 (35.8 vs 21.2%, p = 0.04). The prevalence of GAD-ab, IA2-ab and ZnT8-ab was similar in both groups, the titres of IA2-ab and ICA were higher in T1DM < 35 but titre of ZnT8-ab was higher in T1DM ≥ 35. The majority of T1DM < 35 patients were positive for three autoantibodies (40.9%), while T1DM ≥ 35 subjects most often presented with only one (30.2%) antibody, most commonly GAD-ab (81.2%). 45% T1DM < 35 and 34% T1DM ≥ 35 subjects were positive for ZnT8-ab. ZnT8-ab positive patients had higher titre and more frequent occurrence of multiple diabetes-related autoantibodies than ZnT8-ab negative patients.

CONCLUSIONS

Adults with T1DM < 35 and T1DM ≥ 35 differ in the severity of autoimmune response at diagnosis. ZnT8-ab positivity is related to higher titre and more frequent occurrence of multiple diabetes-related autoantibodies.

The Clinical Significance of Glycoprotein Phospholipase D Levels in Distinguishing Early Stage Latent Autoimmune Diabetes in Adults and Type 2 Diabetes

Autoantibodies have been widely used as markers of latent autoimmune diabetes in adults (LADA); however, the specificity and sensitivity of autoantibodies as markers of LADA are weak compared with those found in type 1 diabetes (T1DM). In this study, we aimed to identify other plasma proteins as potential candidates that can be used effectively to determine early stage LADA and type 2 diabetes (T2DM) to facilitate early diagnosis and treatment. These issues were addressed by studying new-onset ‘classic’ T1DM (n = 156), LADA (n = 174), T2DM (n = 195) and healthy cohorts (n = 166). Plasma samples were obtained from the four cohorts. We employed isobaric tag for relative and absolute quantitation (iTRAQ) together with liquid chromatography tandem mass spectrometry (LC-MS) to identify plasma proteins with significant changes in LADA. The changes were validated by Western blot and ELISA analyses. Among the four cohorts, 311 unique proteins were identified in three iTRAQ runs, with 157 present across the three data sets. Among them, 49/311 (16.0%) proteins had significant changes in LADA compared with normal controls, including glycoprotein phospholipase D (GPLD1), which was upregulated in LADA. Western blot and ELISA analyses showed that GPLD1 levels were higher in both LADA and T1DM cohorts than in both T2DM and healthy cohorts, while there were no significant differences in the plasma concentrations of GPLD1 between the LADA and T1DM cohorts. GPLD1 is implicated as a potential candidate plasma protein for determining early stage LADA and T2DM.

Common autoimmune biomarkers, thyroid hormonal abnormalities, and beta cells dysfunction in patients with latent autoimmune diabetes in adults with type II diabetes mellitus

AIM

Latent autoimmune diabetes in adults (LADA) is autoimmune diabetes with a slow progression characterized by the presence of antibodies associated with Type I diabetes. The present study aimed to assess autoimmune characteristics in patients with LADA in Iran. We attempted to obtain a clear view of autoimmune conditions in LADA among our population.

METHODS

This study was sourced from the population-based survey of KERCARDS aiming assessment of cardiovascular risk factors among a great sample of Iranian population who were resident in Kerman, a great province in southern Iran. Among all diabetic patients who were negative for Anti Glutamic Acid Decarboxylase (GAD) antibody test, 120 were selected as the controls and among 80 patients who were positive for this test diagnosed as LADA, the recorded files of 57 patients were complete considered as the cases.

RESULTS

The level of thyroxin is significantly lower in patients with LADA compared with the controls so 73.7% and 45% of patients had normal level of thyroxin, respectively. Also, those with LADA had considerably lower levels of both thyroid peroxydaseantibody (TPO-Ab) and C-peptide when compared with non-LADA group. Using multivariate analyses and with the presence of baseline variables including gender, age, and duration of disease, the diagnosis of LADA was associated with lower serum levels of Anti-TPO, C-peptide, and thyroxin, but not associated with the level of Anti-TTG in serum.

CONCLUSION

LADA patients may face with lower serum levels of C-peptide and thyroid-specific antibodies indicating insulin therapy requirement and authoimmune fundaments of the disease, respectively.

Serological markers of enterocyte damage and apoptosis in patients with celiac disease, autoimmune diabetes mellitus and diabetes mellitus type 2

Impairment of mucosal barrier integrity of small intestine might be causative in immune-mediated gastrointestinal diseases. We tested the markers of epithelial apoptosis - cytokeratin 18 caspase-cleaved fragment (cCK-18), and enterocyte damage - intestinal fatty acid-binding protein (I-FABP) and soluble CD14 (sCD14) in sera of patients with untreated celiac disease (CLD), those on gluten-free diet (CLD-GFD), patients with autoimmune diabetes mellitus (T1D), T1D with insulitis (T1D/INS), and diabetes mellitus type 2 (T2D). We found elevated levels of cCK-18 (P<0.001), I-FABP (P<0.01) and sCD14 (P<0.05) in CLD when compared to healthy controls. However, the levels of cCK-18 (P<0.01) and I-FABP (P<0.01) in CLD-GFD were higher when compared with controls. Interestingly, elevated levels of cCK-18 and I-FABP were found in T2D and T1D (P<0.001), and T1D/INS (P<0.01, P<0.001). Twenty-two out of 43 CLD patients were seropositive for cCK-18, 19/43 for I-FABP and 11/43 for sCD14; 9/30 of T2D patients were positive for cCK-18 and 5/20 of T1D/INS for sCD14, while in controls only 3/41 were positive for cCK-18, 3/41 for I-FABP and 1/41 for sCD14. We documented for the first time seropositivity for sCD14 in CLD and potential usefulness of serum cCK-18 and I-FABP as markers of gut damage in CLD, CLD-GFD, and diabetes.

Autoimmunity and the gut

Autoimmune diseases have increased dramatically worldwide since World War II. This is coincidental with the increased production and use of chemicals both in industrial countries and agriculture, as well as the ease of travel from region to region and continent to continent, making the transfer of a pathogen or pathogens from one part of the world to another much easier than ever before. In this review, triggers of autoimmunity are examined, principally environmental. The number of possible environmental triggers is vast and includes chemicals, bacteria, viruses, and molds. Examples of these triggers are given and include the mechanism of action and method by which they bring about autoimmunity.

Are zinc transporter type 8 antibodies a marker of autoimmune thyroiditis in non-obese adults with new-onset diabetes?

OBJECTIVE

The diagnosis of autoimmune diabetes in non-obese adults is based on the detection of glutamic acid decarboxylase autoantibodies (GADA), islet cell antibodies (ICA) and antibodies to tyrosine phosphatase (IA-2A). Zinc transporter 8 (ZnT8) has been identified as a new autoantigen in patients with type 1 diabetes mellitus. The coincidence of autoimmune thyroiditis (AITD) with diabetes is common; therefore, screening of TSH and thyroid peroxidase antibodies (ATPO) is recommended during the diagnosis of diabetes. In this study, we determined whether the occurrence of islet autoantibodies is associated with a positive titre of ATPO in newly diagnosed adult-onset autoimmune diabetic patients.

DESIGN AND METHODS

THE STUDY INVOLVED 80 NON-OBESE ADULTS AGED 44 (INTERQUARTILE RANGE (IQR): 37-51) years with a BMI of 24.0 (IQR: 22.2-26.0) kg/m(2) and new-onset diabetes. The markers of autoimmune diabetes (GADA, ICA, IA-2A and ZnT8A), TSH and thyroid peroxidase antibodies (ATPO) were evaluated.

RESULTS

IN THE STUDY POPULATION, 70% (N=56) OF THE SUBJECTS WERE POSITIVE FOR AT LEAST ONE OF THE FOUR ASSESSED MARKERS OF AUTOIMMUNE DIABETES (83.9% GADA, 62.5% ICA, 42.8% IA-2A AND 33% ZNT8A) AND 37.5% OF THE SUBJECTS WERE POSITIVE FOR ATPO. THE ZNT8A-POSITIVE SUBJECTS HAD HIGHER ATPO TITRES THAN THE ZNT8A-NEGATIVE SUBJECTS (172.7 (IQR: 0.36-410.4) vs 92.4 (IQR: 0-23.7) IU/ml, P=0.001). Based on the assessed islet autoantibodies, the occurrence of positive ZnT8A and GADA was found to be related to a positive titre of ATPO using logistic regression (OR=5.48, 95% CI: 1.65-18.14, P=0.006 and OR=3.42, 95% CI: 1.09-10.71, P=0.03 respectively).

CONCLUSIONS

In non-obese adults with new-onset diabetes, the presence of GADA and especially ZnT8 autoantibodies increases the risk of AITD.

GADA titer-related risk for organ-specific autoimmunity in LADA subjects subdivided according to gender (NIRAD study 6)

CONTEXT

Latent autoimmune diabetes in adults (LADA) includes a heterogeneous population wherein, based on glutamic acid decarboxylase antibody (GADA) titer, different subgroups of subjects can be identified.

OBJECTIVE

The aim of the present study was to evaluate GADA titer-related risk for β-cell and other organ-specific autoimmunity in LADA subjects.

METHODS

Adult-onset autoimmune diabetes subjects (n=236) and type 2 diabetes (T2DM) subjects (n=450) were characterized for protein tyrosine phosphatase (IA-2IC and IA-2(256-760)), zinc transporter 8 (ZnT8), thyroid peroxidase, (TPO), steroid 21-hydroxylase (21-OH), tissue transglutaminase (tTG), and antiparietal cell (APC) antibodies.

RESULTS

High GADA titer compared to low GADA titer showed a significantly higher prevalence of IA-2IC, IA-2(256-760), ZnT8, TPO, and APC antibodies (P≤0.04 for all comparison). 21-OH antibodies were detected in 3.4% of high GADA titer. A significant decreasing trend was observed from high GADA to low GADA and to T2DM subjects for IA-2(256-760), ZnT8, TPO, tTG, and APC antibodies (P for trend≤0.001). TPO was the only antibody showing a different prevalence between gender; low GADA titer and T2DM female patients had a higher frequency of TPO antibody compared to males (P=0.0004 and P=0.0006, respectively), where the presence of high GADA titer conferred an odds ratio of 8.6 for TPO compared to low GADA titer. After subdividing high and low GADA titer subjects according to the number of antibodies, we observed that 73.3% of high GADA titer subjects were positive for at least one or more antibodies, compared to 38.3% of low GADA titer (P<0.0001).

CONCLUSIONS

In LADA subjects, high GADA titer was associated with a profile of more severe autoimmunity and, in male gender, specifically predisposed to thyroid autoimmunity. A regular screening for other antibodies is recommended in LADA patients according to GADA titer and gender.

Epitope analysis of GAD65 autoantibodies in adult-onset type 1 diabetes and latent autoimmune diabetes in adults with thyroid autoimmunity

This study aimed at determining which GAD65 epitopes the spontaneous antibodies recognized and whether the epitope-specific GAD65Abs could be associated with the development of thyroid autoimmunity in Chinese adult-onset type 1 diabetes (T1DM) and latent autoimmune diabetes in adults (LADA). The levels of GAD65Abs and their reactivities to N-terminal (GAD65-N), middle (GAD65-M) and C-terminal (GAD65-C) regions of human GAD65 were measured by radioligand assay in 109 patients with adult-onset T1DM and 107 with LADA. TPOAb, TGAb and the genotypes of HLADQA1-DQB1 were determined. The percentage of LADA patients with GAD65-NAb was significantly higher than that of adult-onset T1DM patients (21.5% vs. 11.0%, P = 0.037), but LADA patients with GAD65-CAb less than T1DM patients (47.7% vs. 70.6%, P = 0.001). LADA patients with both GAD65-M and GAD65-CAb (GAD65-M + CAb) appeared to be at higher risk for the development of thyroid autoimmunity, lower serum C-peptide level and the requirement for insulin therapy (P < 0.05). More frequent T1DM patients with HLADQA1*03-DQB1*0303 developed GAD65-M + CAb (55.8% vs. 35.1%, P = 0.008). In comparison with those without thyroid autoimmunity, more frequent T1DM patients and LADA patients with thyroid autoimmunity displayed GAD65-M + CAbs (44.0% vs.16.9% and 53.1% vs. 17.3%, P = 0.002 and <0.001, respectively) with a diagnostic specificity of 83.1 or 82.7% for thyroid autoimmunity, respectively. LADA patients with GAD65-M + CAbs had clinical features similar to T1DM patients. Adult-onset T1DM and LADA patients with GAD65-M + CAbs are at an increased risk for the development of thyroid autoimmunity.

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.

The role of gut microbiota (commensal bacteria) and the mucosal barrier in the pathogenesis of inflammatory and autoimmune diseases and cancer: contribution of germ-free and gnotobiotic animal models of human diseases

Metagenomic approaches are currently being used to decipher the genome of the microbiota (microbiome), and, in parallel, functional studies are being performed to analyze the effects of the microbiota on the host. Gnotobiological methods are an indispensable tool for studying the consequences of bacterial colonization. Animals used as models of human diseases can be maintained in sterile conditions (isolators used for germ-free rearing) and specifically colonized with defined microbes (including non-cultivable commensal bacteria). The effects of the germ-free state or the effects of colonization on disease initiation and maintenance can be observed in these models. Using this approach we demonstrated direct involvement of components of the microbiota in chronic intestinal inflammation and development of colonic neoplasia (i.e., using models of human inflammatory bowel disease and colorectal carcinoma). In contrast, a protective effect of microbiota colonization was demonstrated for the development of autoimmune diabetes in non-obese diabetic (NOD) mice. Interestingly, the development of atherosclerosis in germ-free apolipoprotein E (ApoE)-deficient mice fed by a standard low-cholesterol diet is accelerated compared with conventionally reared animals. Mucosal induction of tolerance to allergen Bet v1 was not influenced by the presence or absence of microbiota. Identification of components of the microbiota and elucidation of the molecular mechanisms of their action in inducing pathological changes or exerting beneficial, disease-protective activities could aid in our ability to influence the composition of the microbiota and to find bacterial strains and components (e.g., probiotics and prebiotics) whose administration may aid in disease prevention and treatment.

Diabetes classification: grey zones, sound and smoke: Action LADA 1

Diseases gain identity from clinical phenotype as well as genetic and environmental aetiology. The definition of type 1 diabetes is clinically exclusive, comprising patients who are considered insulin dependent at diagnosis, whilst the definition of type 2 diabetes is inclusive, only excluding those who are initially insulin dependent. Ketosis-prone diabetes (KPD) and latent autoimmune diabetes in adults (LADA) are each exclusive forms of diabetes which are, at least initially, clinically distinct from type 2 diabetes and type 1 diabetes, and each have a different natural history from these major types of diabetes.KPD can be diagnosed unequivocally as diabetes presenting with the categorical clinical feature, ketoacidosis. In contrast, LADA can be diagnosed by the co-occurrence of three traits, not one of which is categorical or exclusive to the condition: adult-onset non-insulin-requiring diabetes, an islet autoantibody such as glutamic acid decarboxylase autoantibodies (GADA) or cytoplasmic islet cell autoantibodies (ICA), and no need for insulin treatment for several months post-diagnosis. But while some would split diabetes into distinct subtypes, there is a strong case that these subtypes form a continuum of varying severity of immune and metabolic dysfunction modified by genetic and non-genetic factors. This article discusses the nature of disease classification in general, and KPD and LADA in particular, emphasizing the potential value and pitfalls in classifying diabetes and suggesting a need for more research in this area.

Diabetes and diarrhea in an elderly woman

Between 5 and 10% of adults initially diagnosed with type 2 diabetes mellitus.(DM) actually have adult-onset autoimmune diabetes. Given the large number of patients diagnosed with DM type 2, the entity called latent autoimmune diabetes in adults (LADA) by some authors could represent half of all diabetics with type 1A diabetes. We report the case of a 75-year-old woman, with a history of brittle diabetes and irritable bowel syndrome, who was finally diagnosed with autoimmune diabetes and celiac disease.

Diabetes auto-imune latente do adulto ou diabetes melito tipo 2 magro?

A prevalência do diabetes auto-imune latente do adulto (LADA) varia em virtude da população estudada, dos critérios usados e dos anticorpos avaliados. Em 256 pacientes com menos de 25 anos, encontramos 26 (10,2%) com anticorpos anti-GAD (GADA) positivos, dos quais 16 (6,3%) evoluíram sem necessidade de insulina inicialmente. Embora exista controvérsias, sugere-se como critérios diagnósticos de LADA: idade entre 25 e 65 anos; ausência de cetoacidose ou hiperglicemia sintomática no diagnóstico ou imediatamente após, sem necessidade de insulina por 6 a 12 meses; e presença de auto-anticorpos (especialmente GADA). A auto-imunidade e a resistência insulínica coexistem no LADA, e a contribuição desses fatores parece estar refletida nos títulos de GADA. Um subgrupo similar aos diabéticos tipo 2, fenotipicamente e na progressão para necessidade de insulina, parece ser melhor identificado pela presença de baixos títulos de GADA, sobretudo isolados. Por outro lado, indivíduos com altos títulos de GADA e múltiplos anticorpos apresentam fenótipo mais próximo do diabetes melito do tipo 1 (DM1) clássico e são de maior risco para falência prematura das células-beta. Comparados aos diabéticos GADA-negativos, pacientes com LADA apresentam maior prevalência de outros auto-anticorpos (anti-TPO, anti-21-hidroxilase e associados à doença celíaca) e maior freqüência de genótipos e haplótipos de risco para DM1. Pacientes com altos títulos de GADA podem ser beneficiados, retardando a falência das células-beta, com a insulinização precoce e evitando-se o uso de sulfoniluréias. Em oposição, pacientes com baixos títulos de GADA aparentemente não teriam prejuízos em serem conduzidos da mesma forma que pacientes portadores de diabetes melito tipo 2 (DM2) (GADA-negativos).

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.

The islet autoantibody titres: their clinical relevance in latent autoimmune diabetes in adults (LADA) and the classification of diabetes mellitus

Latent autoimmune diabetes in the adult (LADA) is a slowly progressive form of autoimmune diabetes, characterized by diabetes-associated autoantibody positivity. A recent hypothesis proposes that LADA consists of a heterogeneous population, wherein several subgroups can be identified based on their autoimmune status. A systematic review of the literature was carried out to appraise whether the clinical characteristics of LADA patients correlate with the titre and numbers of diabetes-associated autoantibodies. We found that the simultaneous presence of multiple autoantibodies and/or a high-titre anti-glutamic acid decarboxylase (GAD)--compared with single and low-titre autoantibody--is associated with an early age of onset, low fasting C-peptide values as a marker of reduced pancreatic B-cell function, a high predictive value for future insulin requirement, the presence of other autoimmune disorders, a low prevalence of markers of the metabolic syndrome including high body mass index, hypertension and dyslipidaemia, and a high prevalence of the genotype known to increase the risk of Type 1 diabetes. We propose a more continuous classification of diabetes mellitus, based on the finding that the clinical characteristics gradually change from classic Type 1 diabetes to LADA and finally to Type 2 diabetes. Future studies should focus on determining optimal cut-off points of anti-GAD for differentiating clinically relevant diabetes mellitus subgroups.

Familial aggregation of LADA and juvenile type 1 diabetes in a French Caucasian family

We describe here the unusual aggregation of diabetes cases in a family of 10 subjects. Among them, three adult siblings presented with LADA and one child presented with juvenile type 1 diabetes. Although the exact pathogenesis of LADA is unknown and questions the role of autoimmunity in beta cell failure, the familial aggregation of these two forms of diabetes underlines the existence of common roots, i.e. immune mechanisms and genetic susceptibility. This report clearly illustrates the differences in terms of autoimmunity (prevalence and titer of GAD and IA2 antibodies) and HLA class II genotype between patients with LADA and those with juvenile type 1 diabetes.

The thyroid and urticaria

PURPOSE OF REVIEW

Although it is generally accepted that thyroid autoimmunity is more prevalent in patients with chronic urticaria than in the general population, the importance of this finding is unclear. In addition, there are reports that chronic urticaria remits in some but not all patients who have evidence of thyroid autoimmunity and are treated with l-thyroxine. This review will summarize the history of this controversy and suggest a possible role for thyroid autoimmunity in the pathophysiology of chronic urticaria.

RECENT FINDINGS

Important subsets of patients with chronic urticaria have autoantibodies to the high-affinity receptor for IgE (FcepsilonRI), anti-IgE, and antithyroid antibodies. Patients with chronic urticaria and biochemical evidence of thyroid autoimmunity may have active thyroid disease or may be clinically euthyroid. These patients are often poorly responsive to conventional therapy of urticaria and may have more chronic disease. New findings on the pathogenic effects of anti-FcepsilonRI auto-antibodies and of antithyroid antibodies have revealed a role for complement activation.

SUMMARY

Currently, there are no compelling arguments to decide whether or not thyroid autoimmunity plays a significant role in the pathogenesis of chronic urticaria. New developments concerning a role for complement activation in the pathogenesis of chronic urticaria may, however, lead to better understanding of this phenomenon in the future.

Latent autoimmune diabetes in adults: definition, prevalence, beta-cell function, and treatment

Latent autoimmune diabetes in adults (LADA) is a disorder in which, despite the presence of islet antibodies at diagnosis of diabetes, the progression of autoimmune beta-cell failure is slow. LADA patients are therefore not insulin requiring, at least during the first 6 months after diagnosis of diabetes. Among patients with phenotypic type 2 diabetes, LADA occurs in 10% of individuals older than 35 years and in 25% below that age. Prospective studies of beta-cell function show that LADA patients with multiple islet antibodies develop beta-cell failure within 5 years, whereas those with only GAD antibodies (GADAs) or only islet cell antibodies (ICAs) mostly develop beta-cell failure after 5 years. Even though it may take up to 12 years until beta-cell failure occurs in some patients, impairments in the beta-cell response to intravenous glucose and glucagon can be detected at diagnosis of diabetes. Consequently, LADA is not a latent disease; therefore, autoimmune diabetes in adults with slowly progressive beta-cell failure might be a more adequate concept. In agreement with proved impaired beta-cell function at diagnosis of diabetes, insulin is the treatment of choice.

Latent autoimmune diabetes in adults (LADA) should be less latent

'Latent autoimmune diabetes in adults' (LADA) is the term coined to describe adults who have a slowly progressive form of autoimmune or type 1 diabetes that can be treated initially without insulin injections. The diagnosis of LADA is currently based on three clinical criteria: (1) adult age at onset of diabetes; (2) the presence of circulating islet autoantibodies, which distinguishes LADA from type 2 diabetes; and (3) insulin independence at diagnosis, which distinguishes LADA from classic type 1 diabetes. The prevalence of LADA in adults presenting with non-insulin-requiring diabetes is approximately 10%. Recognition of LADA expands the concept and prevalence of autoimmune diabetes, but LADA remains poorly understood at both a clinical and research level. In this perspective, we review the nomenclature, diagnostic criteria, genetics, pathology and therapy of LADA, to arrive at recommendations that might advance knowledge and management of this form of diabetes.