Evaluation of the Diagnostic and Predictive Value of Glutamic Acid Decarboxylase, Zinc Transporter 8 Serum Levels in Alzheimer's Disease.

BACKGROUND: Identification of validated peripheral biomarkers for Alzheimer's Disease, leading to an early diagnosis of the disease, would be valuable for predicting progression and targeted therapeutics. In this regard, serum levels of GADA, ZnT8A, Zn, vitamin D, and leukocyte expression of brain-derived neurotrophic factor (BDNF) gene were investigated in Alzheimer's patients and control group. METHODS: Serum levels of GADA, ZnT8A, Zn, and vitamin D and leukocyte expression of the BDNF gene were evaluated in 40 AD patients and 40 control cases. The diagnostic value of investigated factors was examined with the receiver operating characteristic (ROC). RESULTS: The results showed significant differences of p < 0.0001, p < 0.0001, and p = 0.0006 between AD patients and control individuals in GADA, Zn, and ZnT8A serum levels, respectively. No significant difference was observed in the serum concentration of vitamin D between AD patients and control cases (p = 0.2993). The expression level of the BDNF gene in AD patients was different from control cases, but it was not statistically significant (p > 0.05). Moreover, ROC curve analysis disclosed a diagnostic potency for serum levels of GADA, Zn, and ZnT8A for AD with an area under the ROC curve of > 0.7 (p < 0.0001, p < 0.0001, and p = 0.0007, respectively). CONCLUSIONS: The results demonstrated the higher serum levels of GADA and ZnT8A and lower serum concentrations of Zn in the patient group. Therefore, these parameters can be discussed as possibly diagnostic in AD cases.

Clinical and demographic features among patients with type 1 diabetes mellitus in Henan, China.

BACKGROUND: The hallmark of type 1 diabetes (T1D) is an absolute lack of insulin. However, many studies showed a tendency to heterogeneity in TID. We aimed to investigate the demographic and clinical characteristics in T1D and the differences in young-onset and adult-onset patients. METHODS: This retrospective study was conducted among 1943 patients with clinically diagnosed T1D. Medical records on patients' demographics, anthropometric measurements, and clinical manifestation were collected. According to the age at onset, the newly diagnosed patients were divided into the young-onset group (< 18 years, 234 patients, mean age 11 years) and adult-onset group (≥ 18 years, 219 patients, mean age 27 years). Pancreatic ß-cell function was assessed by fasting C-peptide (FCP) and 2-h C-peptide (2-h CP). RESULTS: The median age of patients at disease onset was 22 years. The median duration of patients was 3 years. The overall median glycated hemoglobin (HbA1c) value was 10.3 % [89(mmol/mol)]. The prevalence of diabetic retinopathy was 25.1 %. The overall rate of DKA at onset in the new-onset patients was 59.6 %. The frequency of overall dyslipidemia was 37.8 %. The most frequent dyslipidemia was low high-density lipoprotein-cholesterol (HDL) (29 %). The proportion of patients with anti-glutamic acid decarboxylase (GADA), insulin antibody (IAA) and islet cell antibody (ICA) were 28.1 %, 6.4 % and 21.6 %, respectively. The mean HbA1c showed a downward trend with age. Increasing or decreasing trends of overweight and obesity in this population during the period 2012 to 2018 was not found. Compared with young-onset T1D, adult-onset patients comprised better islet function (FCP: 0.4 vs. 0.3 ng/ml, P < 0.001; 2-h CP: 0.9 vs. 0.7 ng/ml P < 0.001, respectively) and glycemic control [12.9 % (117mmol/mol) vs. 11.7 % (104mmol/mol), P < 0.001], higher prevalence of diabetes condition in the male gender (64.4 % vs. 51.3 %, P = 0.006), higher proportion of obesity or overweight (24.6 % vs. 9.5 %, P = 0.002), higher frequency of GADA (33.7 % vs. 23.3 %, P = 0.025), and lower frequency of diabetic ketoacidosis at disease onset (64.5 % vs. 43.5 %, P < 0.001). CONCLUSIONS: This population was characterized by poor overall blood glucose control, high prevalence of DKA, dyslipidemia and diabetic retinopathy, and low prevalence of islet-related antibodies, and overweight or obesity. Adult-onset patients with T1D were not uncommon and had better clinical manifestations than young-onset patients. Any findings related to body mass index (BMI) and autoantibodies should be considered strictly exploratory due to excessive missing data.

Structural network topology in limbic encephalitis is associated with amygdala enlargement, memory performance and serostatus.

Limbic encephalitis (LE) forms a spectrum of autoimmune diseases involving temporal lobe epilepsy and memory impairment. Imaging features of LE are known to depend on the associated antibody and to occur on the brain network level. However, first studies investigating brain networks in LE have either focused on one distinct antibody subgroup or on distinct anatomical regions. In this study, brain graphs of 17 LE patients with autoantibodies against glutamic acid decarboxylase 65 (GAD-LE), four LE patients with autoantibodies against leucine-rich glioma-inactivated 1, five LE patients with autoantibodies against contactin-associated protein-like 2, 26 age- and gender-matched healthy control subjects, and 20 epilepsy control patients with hippocampal sclerosis were constructed based on T1-weighted structural magnetic resonance imaging scans and diffusion tensor imaging. GAD-LE showed significantly altered global network topology in terms of integration and segregation as compared to healthy controls and patients with hippocampal sclerosis (P < .01, analysis of variance with Tukey-Kramer post hoc tests). Linear regression linked global network measures with amygdala volume and verbal memory performance (P < .05). Alterations of local network topology show serotype dependence in hippocampus, amygdala, insula, and various cortical regions. Our findings reveal serotype-dependent patterns of structural connectivity and prove the relevance of in silico network measures on clinical grounds.

Reduced display of conformational epitopes in the N-terminal truncated GAD65 isoform: relevance for people with stiff person syndrome or DQ8/8-positive Type 1 diabetes mellitus.

AIMS: To investigate whether the N-terminal truncated glutamic acid decarboxylase 65 (GAD65) isoform is as well recognized by people with stiff person syndrome as it is by people with Type 1 diabetes, and whether conformational GAD65 antibody epitopes are displayed properly by the isoform. METHODS: GAD65 antibody-positive healthy individuals (n=13), people with stiff-person syndrome (n=15) and children with new-onset Type 1 diabetes (n=654) were analysed to determine binding to full-length GAD65 and the N-terminal truncated GAD65 isoform in each of these settings. GAD65 autoantibody epitope specificity was correlated with binding ratios of full-length GAD65/N-terminal truncated GAD65. RESULTS: The N-terminal truncated GAD65 isoform was significantly less recognized in GAD65Ab-positive people with stiff-person syndrome (P=0.002) and in healthy individuals (P=0.0001) than in people with Type 1 diabetes. Moreover, at least two specific conformational GAD65Ab epitopes were not, or were only partially, presented by the N-terminal truncated GAD65 isoform compared to full-length GAD65. Finally, an N-terminal conformational GAD65Ab epitope was significantly less recognized in DQ8/8 positive individuals with Type 1 diabetes (P=0.02). CONCLUSIONS: In people with stiff person syndrome preferred binding to the full-length GAD65 isoform over the N-terminal truncated molecule was observed. This binding characteristic is probably attributable to reduced presentation of two conformational epitopes by the N-terminal truncated molecule. These findings support the notion of disease-specific GAD65Ab epitope specificities and emphasize the need to evaluate the applicability of novel assays for different medical conditions.

Role of plasma exchange in stiff person syndrome.

OBJECTIVE: Stiff person syndrome (SPS) is commonly associated with antibodies directed against 65-kDa glutamic acid decarboxylase (GAD65). Therapeutic Plasma Exchange (TPE) has been used as an adjunct therapy in patients who do not respond well to conventional treatment, which includes immunosuppression therapies, anti-anxiety medications, muscle relaxants, anticonvulsants, and pain relievers. METHODS: We retrospectively analyzed the clinical data and outcomes of ten patients with the clinical diagnosis of anti-GAD65 positive SPS in which TPE was employed to improve symptoms refractory to conventional treatment during an eight-year period. RESULTS: TPE was initiated as complementary therapy in patients with worsening of symptoms characteristic of SPS. Six patients underwent chronic treatment with TPE following an initial course, of which the frequency of TPE was guided by the clinical response. Two patients only had transient improvements with further disease progression. Four patients developed a relapse of symptoms when the interval between procedures was increased. One of the four patients dependent on TPE had worsening of symptoms following complete cessation of TPE due to lack of insurance coverage. Four patients underwent only an acute hospitalized course of treatment with TPE; one demonstrated complete resolution of symptoms; one had a partial response; and two experienced no improvement. CONCLUSION: Our study supports previous reports that TPE may be beneficial for the management of patients with anti-GAD65 positive SPS, both for acute exacerbations and long-term maintenance, either as an adjunct therapy, or in lieu of treatment with disease modifying agents.

Relationship of four vitamin D receptor gene polymorphisms with type 1 diabetes mellitus susceptibility in Kuwaiti children.

BACKGROUND: The incidence of type 1 diabetes mellitus (T1DM) in Kuwait is amongst the highest in the world. Vitamin D is considered to be involved in immune modulation and its deficiency contribute to autoimmune destruction of insulin producing beta cells in T1DM patients. Vitamin D has been shown to exert its effects via a nuclear vitamin D receptor (VDR) and therefore, VDR gene may be considered a candidate for T1DM susceptibility. METHODS: The genotypes of four VDR gene polymorphisms were determined in 253 Kuwaiti Arab T1DM patients and 214 healthy controls by PCR-RFLP analysis. Serum concentrations of three autoantibodies i.e. ICA (Islet cell autoantibody), GADA (Glutamic acid decarboxylase) and INS (Insulin autoantibody) were determined by radio-immunoassays. RESULTS: Statistically significant differences were detected between the genotypes of two VDR gene polymorphisms (FokI, C > T, rs10735810 and TaqI, C > T, rs731236) between T1DM patients and controls (P < 0.0001). In both, the frequency of variant alleles was considerably high in T1DM than in the controls. In contrast, the VDR gene ApaI (G > T, rs7975232) and BsmI (A > G, rs1544410) polymorphisms did not show association with T1DM. The homozygous variant genotypes of FokI, ApaI and TaqI polymorphisms show significant differences between various age-of-onset subgroups while no such association was detected in the case of BsmI polymorphism. Significant differences were also noted between heterozygous genotypes of all four polymorphisms especially between 4-6y and > 6y age-of-onset subgroups of T1DM patients. Three autoantibodies, ICA (Islet cell), GADA (glutamate decarboxylase) and INS (insulin) were positively associated to, varying degrees, with T1DM in Kuwaiti Arabs harboring different VDR gene polymorphism genotypes. CONCLUSIONS: Our results demonstrate a significant effect of two VDR gene polymorphisms (FokI and TaqI) and three autoantibodies on genetic susceptibility of T1DM in Kuwaiti Arabs along with other factors.

Electrochemical and Surface-Plasmon Correlation of a Serum-Autoantibody Immunoassay with Binding Insights: Graphenyl Surface versus Mercapto-Monolayer Surface.

We present here the correlation of picomolar affinities between surface-plasmon and electrochemical immunoassays for the binding of serum glutamic acid decarboxylase 65 autoantibody (GADA), a biomarker of type 1 diabetes (T1D), to its antigen GAD-65. Carboxylated (∼5.0%)-graphene-modified immunoassembly on a gold surface-plasmon chip or on an electrochemical array provided significantly larger binding affinity, higher sensitivity, and lower detection limits than a self-assembled monolayer surface of mercaptopropionic acid (MPA). Estimation of the relative surface -COOH groups by covalent tagging of an electroactive aminoferrocene showed that the graphenyl surface displayed a greater number of -COOH groups (9-fold) than the MPA surface. X-ray-photoelectron-spectroscopy analysis showed more C-O and C═O functionalities on the graphene-COOH surface than on the MPA surface. The graphene-COOH coating on gold exhibited ∼5.5-fold enhancement of plasmon signals compared with a similar coating on a plain glass surface. In summary, this article provides a quantitative comparison of carboxylated graphene with a mercapto-monolayer immunoassembly. Additionally, we propose that the binding-constant value can be useful as a quality-control checkpoint for reproducible and reliable production of large-scale biosensors for clinical bioassays.

'25-Hydroxyvitamin D, Autoantigenic and Total Antibody Concentrations: Results from a Danish Case-control Study of Newly Diagnosed Patients with Childhood Type 1 Diabetes and their Healthy Siblings'.

B cells have recently entered the stage as an important accessory player in type 1 diabetes (T1D) etiopathogenesis. Experimental studies suggest regulatory functions of vitamin D on B cells. However, only a few human studies, with considerable methodological limitations, have been conducted within this field. Our objective was to investigate whether higher 25-hydroxyvitamin D (25(OH)D) concentrations were inversely associated with ß-cell autoantigens glutamic acid decarboxylase (isoform 65) (GADA) and insulinoma-associated antigen-2A (IA-2A). Further, we also wanted to examine the relationship between 25(OH)D and total antibody concentrations. We randomly selected 500 patients with newly diagnosed T1D and 500 siblings for 25(OH)D, antibody and genetic analysis from the population-based Danish Registry of Childhood and Adolescent Diabetes. The relative change (RC) in the mean concentration of GADA, IA-2A and antibody isotypes by a 10 nmol/l increase in 25(OH)D concentration was modelled by a robust log-normal regression model. We found no association between 25(OH)D and GADA [adjusted RC per 10 nmol/l increase: 1.00; 95% confidence interval (CI): 0.98-1.02] and IA-2A [adjusted RC per 10 nmol/l increase: 0.92; CI: 0.76-1.12]. Further, 25(OH)D was not associated with the total concentration of antibody isotypes [immunoglobulin (Ig)A, IgE, IgG and IgM]. All null findings were unaltered after adjustment for genetic variation in the vitamin D pathway. Physiological concentrations of 25(OH)D are unlikely to have a clinically important effect on antibody concentrations in a paediatric population of newly diagnosed patients with T1D and their healthy siblings.

Glutamic Acid Decarboxylase Antibody in a Patient with Myelitis: A Retrospective Study.

OBJECTIVE: The aim of this study was to evaluate the positive rate of serum glutamic acid decarboxylase (GAD) autoantibody in patients with myelitis and to describe the clinical findings in patients with positive GAD antibody. METHODS: Serum samples were collected from 390 patients with myelitis, including 210 patients positive for aquaporin 4 (AQP4) antibody and 180 patients negative for AQP4. GAD65 antibody was measured by an indirect immunofluorescence assay. RESULTS: Only 1 serum and cerebral spinal fluid sample from 390 patients (0.26%) was positive for anti-GAD antibodies. The patient was a female with relapsing myelitis and a thymic mass. Thymic resection was undertaken, and pathological examination revealed a benign thymic cyst. Extensive infiltration of lymphocytes positive for CD3, CD4, CD8 and CD20 was found. Immunohistochemistry showed positive expression of GAD65 in the cyst. CONCLUSIONS: Although serum GAD65 antibodies were present in a patient, it is not recommended to routinely screen for GAD65 antibodies in patients with myelitis because of their rare occurrence. However, screening for GAD65 antibodies should be considered in patients who have been diagnosed with cancer or a thymic abnormality.

Anti-GAD antibodies in a cohort of neuropsychiatric patients.

OBJECTIVE: Antiglutamate decarboxylase (anti-GAD) antibodies are associated with several neurological manifestations, like epilepsy and movement disorders. However, in daily neurological practice, it remains hard to define when to test for anti-GAD antibodies in patients with neurologic and/or psychiatric symptoms. Therefore, here, we report the patient characteristics of a large retrospective cohort of patients tested for anti-GAD antibodies in clinical practice and compare the characteristics of anti-GAD positive and anti-GAD negative patients. METHODS: We blindly assessed relevant clinical symptoms and comorbidities and functional outcome with the modified Rankin Scale (mRS) in a retrospective observational cohort of all patients in which the decision to assess anti-GAD levels had been made based solely on the presence of possible associated neurological and/or psychiatric symptoms (N=119). RESULTS: Out of 119 patients, 17 (14.3%) were anti-GAD positive. The anti-GAD positive patients had a median age of 30years (range: 3-64; 2 children). They all had epilepsy, with 8 (47%) patients reporting cognitive complaints. Psychiatric symptoms were less prevalent in anti-GAD positive patients, only 1 anti-GAD positive patient (6%) versus 34 anti-GAD negative patients (33%) reported psychiatric symptoms (p=0.021). The most frequent comorbidity of anti-GAD positive patients was diabetes mellitus type 1 (n=8). Twelve (71%) and 13 (78%) of the anti-GAD positive patients were functionally independent at the time of diagnosis and after one year, respectively (mRS score: 0 to 2). There was no significant difference in functional status at any time during follow-up compared with the anti-GAD negative group. CONCLUSION: Antiglutamate decarboxylase (anti-GAD) antibodies relate to epilepsy with or without cognitive complaints. However, psychiatric symptoms were almost absent in anti-GAD positive patients, and the presence of anti-GAD antibodies contributed little to the prognosis in our cohort.

Post-ganglionic autonomic neuropathy associated with anti-glutamic acid decarboxylase antibodies.

PURPOSE: Antibodies to glutamic acid decarboxylase (GAD-Abs) have been associated with several conditions, rarely involving the autonomic nervous system. Here, we describe two patients complaining of autonomic symptoms in whom a post-ganglionic autonomic neuropathy has been demonstrated in association with significantly elevated serum and CSF GAD-Abs levels. METHODS: Patients underwent nerve conduction studies, sympathetic skin response testing, evaluation of autonomic control of the cardiovascular system and skin biopsy. Also, serum screening to exclude predisposing causes of peripheral neuropathy was performed. Anti-GAD65 antibodies were evaluated in serum and CSF. RESULTS: GAD-Abs titer was increased in both serum and CSF in both patients. Sympathetic skin response was absent and skin biopsy revealed a non-length-dependent small-fiber neuropathy with sympathetic cholinergic and adrenergic post-ganglionic damage in both patients. Nerve conduction studies and evaluation of autonomic control of the cardiovascular system were normal in both patients. Both patients were treated with steroids with good, but partial, (patient 2) recovery of the autonomic dysfunctions. CONCLUSIONS: Although the pathophysiological mechanisms involved are not fully defined, GAD-abs positivity in serum and CSF should be searched in patients with autonomic neuropathy when no other acquired causes are evident. This positivity may help to clarify autoimmune etiology and, subsequently, to consider immunomodulatory treatment.

A case of autoimmune polyendocrine syndrome type I with strong positive GAD antibody titer, followed up with glucose tolerance measured by oral glucose tolerance test.

A 26-year-old Japanese woman presented with adrenal insufficiency, and treatment was started with cortisone and fludrocortisone in 1975. A few years later, she presented with hypoparathyroidism and was diagnosed with autoimmune polyendocrine syndrome type I (APS I), and treatment with calcium and alfacalcidol was started. She was found to have subacute thyroiditis and relative adrenal failure in 2006. Her condition remained stable under treatment with cortisone, fludrocortisone, levothyroxine, calcium lactate, precipitated calcium carbonate and alfacalcidol. While antibodies against pancreatic glutamic acid decarboxylase (GAD) were strongly positive (7,690 U/ml), fasting glucose level was 4.9 mmol/L and HbA1c was 6.3% on admission. As GAD antibody showed a high-titer of >10,000 U/ml and fasting plasma glucose level showed a rising trend, we performed 75-g oral glucose tolerance test (OGTT) 6 years after discharge. Whereas OGTT in 2012 showed impaired glucose tolerance, glucose tolerance had reverted to normal in 2014. A patient with a high-titer GAD antibody does not always have progressive glucose intolerance. GAD antibody positivity is common in not only type 1 diabetes, but also APS I and stiff-person syndrome (SPS). There are differences in recognized epitopes among the three disorders. Epitopes for GAD65 antibody associated with type 1 diabetes are located in the middle region and the COOH-terminal of the GAD65 protein, whereas epitopes associated with SPS reside in the NH2-terminal in addition to the middle region and COOH-terminal. The present case suggests that these differences in epitopes may be related to various pathogenic mechanisms including glucose intolerance.

[Comparison of effects between IL-2 and IL-7 on glutamic acid decarboxylase 65 reactive T cell responses in patients with Type 1 diabetes].

OBJECTIVE: To explore the type of cytokine (IL-2 or IL-7) and its most optimal concentration regarding the improvement of the signal-to-noise ratio of glutamic acid decarboxylase 65 (GAD65) in enzyme-linked immunospot (ELISPOT) assay in Type 1 diabetic (T1DM) patients.
 Methods: Twenty T1DM patients (Group A) and sixteen healthy controls matched with age and sex (Group B) were enrolled in our study, and their peripheral blood mononuclear cells (PBMCs) were isolated by Ficoll method. GAD65, internal control and Pediacel served as "five-for-one" vaccine were selected as the stimulating antigen. Different concentrations of IL-2 [0 U/mL (Group 1), 0.5 U/mL (Group 2), 2.5 U/mL (Group 3) and 12.5 U/mL (Group 4)] were added to the culture system. The CD4+ T cells of secreting interferon-gamma (IFN-γ) in the above groups were determined by ELISPOT. The spots number, net values and stimulating index (SI) were compared in GAD65 (signal) and internal control (background). Next, another 21 T1DM patients (Group C)and 12 healthy controls matched with age and sex (Group D) were enrolled, and the specific T cell response to the GAD65 antigen was detected. The net values and SI were compared between the best optimal concentration of IL-2 (2.5 U/mL, Group 5) and IL-7 (0.5 ng/mL, Group 6).
 Results: 1) After adding IL-2 into the Group A, the amount of GAD65 reactive T cells in different groups increased compared with Group A1, while the background in the internal control also increased gradually with the increased concentration of IL-2. There was no significant difference in net value (signal-noise) in the different concentration between the Group A3 and the Group A4 (P>0.05). The SI in the Group A3 (2.8), the highest one, was significantly higher than that in the Group B3 (1.3) (P<0.05). 2) Although the number of GAD65 spots in the Group C6 and the Group D6 were slightly higher than that in the Group C5 and the Group D5, respectively, the background in the Group C6 and the Group D6 also increased, without statistical significance (P>0.05). The mean net value spot and SI in the Group C5 (net value: 5.5; SI: 2.8) were both significantly higher than those in the Group C6 (net value: 4.3; SI: 1.8) (both P<0.05).
 Conclusion: The concentration of 2.5 U/mL for IL-2 is proved to be the best optimal concentration for GAD65 specific T-cell responses in ELISPOT in patients with T1DM. IL-2 is much better than IL-7 in improvement of the SI in the ELISPOT.

Seizure control and cognitive improvement via immunotherapy in late onset epilepsy patients with paraneoplastic versus GAD65 autoantibody-associated limbic encephalitis.

OBJECTIVE: To determine the efficacy of immunotherapy in limbic encephalitis (LE) associated epilepsies with autoantibodies against intracellular antigens in the forms of paraneoplastic autoantibodies versus glutamic acid decarboxylase 65 (GAD)-autoantibodies. METHODS: Eleven paraneoplastic-antibodies+ and eleven age- and gender-matched GAD-antibodies+ patients with LE were compared regarding EEG, seizure frequency, MRI volumetry of the brain, and cognition. All patients received immunotherapy with corticosteroids add-on to antiepileptic therapy. A few patients underwent additional interventions like immunoglobulins or immunoadsorption. RESULTS: Immunotherapy led to a significantly greater proportion of seizure-free patients in the paraneoplastic antibodies+(55%) as compared to GAD-antibodies+(18%) patients (p<0.05). Impaired cognition was evident initially (total cognitive performance score based on attentional-executive function, figural/verbal memory and word fluency) in 100% of the paraneoplastic-antibodies+ and 73% of the GAD-antibodies+ group. After therapy, cognition improved significantly in the paraneoplastic-antibodies+, but not in the GAD-antibodies+ patients (p<0.05). Cognitive change did not correlate with the change in the number of antiepileptic drugs over time. MRI showed larger and unchanged volumes of the amygdala, presubiculum and subiculum in GAD-antibodies+as compared to paraneoplastic-antibodies+patients (p<0.05) over time. CONCLUSIONS: Our data provide evidence of a beneficial effect of immunotherapy added to antiepileptic drugs on seizure frequency and cognition only in the paraneoplastic-antibodies+ subgroup of LE presenting autoantibodies against intracellular antigens.

[Autoimmune insulitis in patients with type 2 diabetes mellitus A randomized clinical trial in hospitalized patients]. / Autoimunitná inzulítída u pacientov s diabetes mellitus 2. typu. Randomizovaný klinický prieskum u hospitalizovaných pacientov.

BACKGROUND: It is not always easy to classify diabetes (DM) diagnosed in adults, with a significant group of patients initially classified and treated for type 2 diabetes mellitus (DM2T) presenting signs indicating the presence of autoimmune insulitis (AI), which is characteristic of type 1 diabetes mellitus (DM1T), or latent autoimmune diabetes mellitus in adults (LADA). GOAL: Identify the proportion of patients entered with DM2T who present AI signs, and the number of patients of that proportion, who at the same time present low insulin secretion, and what clinical and laboratory manifestations could be used to differentiate between these patients.Cohort and methods: A randomized clinical trial with a pre-determined set of assessed parameters for n = 625 patients, who were hospitalized during the first 6 months of 2016 at the National Endocrinology and Diabetology Institute (NEDU), Lubochna. Apart from the standard parameters, C-peptide (CP) and autoantibodies to glutamic acid decarboxylase (GADA) were examined for each patient. GADA positive (GADA+) patients were compared to GADA negative (GADA-) patients in the following parameters: gender, age, age at the time of dia-gnosing DM, duration of DM, HbA1c, incidence of hypoglycemia, lipidogram, fasting C-peptide levels, BMI, waist circumference, incidence of hypoglycemias, presence of microvascular and macrovascular complications, treatment of dia-betes and incidence of other endocrinopathies. GADA+ with low CP were subsequently compared to GADA+ patients with normal CP. RESULTS: Of 625 patients originally classified and treated as DM2T, 13 % were GADA+. 31 % of them had low CP (< 0.2 nmol/l) and 28 % had CP levels within the intermediary range (0.2-0.4 nmol/l). Females made up a larger proportion of GADA+ patients, with a lower BMI, smaller waist circumference, lower CP, higher HDL cholesterol levels, a greater incidence of hypoglycemias and lower total daily dose of insulin. GADA+ patients with low CP differed from GADA+ patients with normal CP in higher HDL cholesterol levels, lower triglyceride levels and earlier need of insulin thera-py. The testing for GADA and CP levels with regard to the other relevant characteristics led to re-classification, or more precisely adding of DM1T/LADA (as the main, or parallel cause of DM) for 2.9 % of all the patients included and a clinically significant proportion of AI could be assumed in 6.1 % of the patients. SUMMARY: The results of our study show that the pathogenesis of DM in patients initially diagnosed and registered with DM2T and with concurrent presence of GADA includes mechanisms characteristic of both DM2T (insulin resistance) and DM1T (autoimmune insulitis) acting in parallel, with different intensity, in differing proportions and time sequence as a fluid continuum, which also accounts for the differences between individual patients. The characteristics highlighting the presence and role of AI based on our results include high titre of GADA+, low CP levels, early need of insulin therapy, presence of thyroid disorder, higher HDL cholesterol levels and lower triglyceride levels. The characteristics highlighting the dominance of mechanisms characteristic of DM2T (insulin resistance) included higher BMI and waist circumference values, normal CP levels, low HDL cholesterol levels, higher triglyceride levels, higher blood pressure and borderline titre of GADA. KEY WORDS: autoimmune diabetes mellitus - C-peptide - GADA - HDL-cholesterol - classification.

Biomarkers related to severe hypoglycaemia and lack of good glycaemic control in ACCORD.

AIMS/HYPOTHESIS: In patients with diabetes, intensive glycaemic control reduces microvascular complications. However, severe hypoglycaemia frequently complicates intensive glycaemic control. Blood biomarkers that predict successful intensification of glycaemic control in patients with type 2 diabetes without the development of severe hypoglycaemia would advance patient care. In patients who received intensive treatment for type 2 diabetes from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study, we hypothesised that insulin deficiency and islet autoantibodies would be associated with severe hypoglycaemia and failure to achieve near-normal glycaemia (HbA1c <6.0% [42 mmol/mol]). METHODS: A nested case-control design was used. Cases (n = 326) were defined as participants having severe hypoglycaemia and failure to achieve an HbA1c level of <6.0% (42 mmol/mol) prior to the ACCORD transition or death. Controls (n = 1,075) were those who achieved an HbA1c level of <6.0% (42 mmol/mol) prior to the ACCORD transition or death without severe hypoglycaemia. Each case was matched (for race, age and BMI) by up to four controls. Baseline insulin deficiency (fasting C-peptide ≤0.15 nmol/l) and islet autoantibodies (glutamic acid decarboxylase [GAD], tyrosine phosphatase-related islet antigen 2 [IA2], insulin [IAA] and zinc transporter 8 [ZnT8]) were measured. Conditional logistic regression with and without adjustment for age, BMI and diabetes duration was used on the full cohort and after removal of patients who died and their respective controls. RESULTS: Severe hypoglycaemia accompanied by an inability to achieve an HbA1c level of <6.0% (42 mmol/mol) was associated with insulin deficiency (adjusted OR 23.2 [95% CI 9.0, 59.5], p < 0.0001), the presence of IAA autoantibodies or baseline insulin use (adjusted OR 3.8 [95% CI 2.7, 5.3], p < 0.0001), GAD autoantibodies (OR 3.9 [95% CI 2.5, 6.0], p < 0.0001), IA2 autoantibodies (OR 16.7 [95% CI 3.9, 71.6], p = 0.0001) and ZnT8 autoantibodies (adjusted OR 3.9 [95% CI 1.2, 12.4], p = 0.02). CONCLUSIONS: C-peptide and islet autoantibodies may serve as biomarkers to predict the risk of severe hypoglycaemia during intensification of type 2 diabetes treatment. TRIAL REGISTRATION: ClinicalTrials.gov NCT00000620 (original ACCORD study).

Relationship between serum GAD-Ab and the genetic polymorphisms of GAD2 and type 2 diabetes mellitus.

In this study, we investigated the relationship between serum glutamic acid decarboxylase (GAD) autoantibody (Ab) levels and single nucleotide polymorphisms (SNPs) of the glutamic acid de-carboxylase 2 (GAD2) 5'-untranslated region and the susceptibility to type 2 diabetes in the Han population. The distributions of patients with SNPs in the GAD2 5'-untranslated region (rs2236418, rs185649317, and rs8190590) and type 2 diabetes and that of the healthy group were genotyped and analyzed using Sequenom MassArray SNP genotyp-ing. GAD-Ab levels were also detected. The frequency distributions of the AA, AG, and GG genotypes in the polymorphic site rs2236418 in the diabetes GAD-Ab-positive group were 45.9, 42.8, and 11.4%, respectively, whereas those in the control group were 36.6, 43.7, and 19.8%, respectively. The difference between the 2 groups was statis-tically significant (P < 0.05). Unlike the GG genotype, the AA and AA + AG genotypes increased the risk of GAD-Ab (odds ratios (95% confidence intervals) = 2.623 (1.351-4.937) and 2.152 (1.375-4.202), respectively). The associations of the 3 SNPs of the GAD2 gene 5'-un-translated region polymorphisms with susceptibility to type 2 diabe-tes in the Chongqing Han population were significant. The SNP of rs2236418 in the Chongqing Han population of diabetic patients with serum GAD-Ab levels was significantly correlated with the SNPs rs185649317 and rs8190590.

Clinical & immunological profile of newly diagnosed patients with youth onset diabetes mellitus.

BACKGROUND & OBJECTIVES: There has been a rise in the incidence of diabetes mellitus in the younger population of India. There are limited data available on the immunological profile of youth onset diabetes mellitus (DM) especially in type 2. Therefore, this study was undertaken to evaluate the clinical and immunological profile of youth onset DM in north India. METHODS: Fifty one consecutive patients of 8-35 yr of age with diabetes mellitus attending the Lok Nayak Hospital, Maulana Azad Medical College, New Delhi, and Hormone Care and Research Center at Ghaziabad, Uttar Pradesh, India, were included in the study. All subjects were tested for glutamic acid decarboxylase (GAD), an islet cell antigen ICA512/IA2, and insulin antibodies. GAD and ICA512/IA2 were done by ELISA and insulin autoantibodies were tested by radioimmunoassay (RIA) method. These patients were also screened for hepatitis A to E, cytomegalovirus (CMV) and Epstein-Barr virus (EBV) as trigger factors for onset of type 1 DM. RESULTS: o0 f the total 51 patients, 38 were men and 13 were women. The mean age and BMI of the subjects was 19.7 (±7) years and 21 (± 5) kg/m [2] , respectively. Twenty patients were below the age of 18 yr and their height was more than 75 th percentile of Indian standards. All patients were symptomatic and 12 of these presented with ketoacidosis. Only 48 per cent (n=24) were positive for GAD, 14 per cent (n=7) for ICA512/IA-2, and 28% (n=14) were positive for insulin antibody. Five of these patients had evidence of hepatitis E virus infection. None of the subjects had evidence of active CMV or EBV infection. INTERPRETATION & CONCLUSIONS: About half of the youth onset diabetes mellitus patients from north India had presence of pancreatic autoimmunity in the form of GAD, ICA512/IA2, and insulin antibodies or a combination of antibodies suggestive of having type 1 DM. Further studies need to be done on a large sample size in different parts of the country.

Family history of Type 1 diabetes affects insulin secretion in patients with 'Type 2' diabetes.

AIMS: The aim was to evaluate the impact of family history of diabetes on the phenotype of patients diagnosed with Type 2 diabetes and the frequency of susceptibility genotypes. METHODS: Patients with Type 2 diabetes with family history for both Type 1 and Type 2 diabetes (FH(MIX, n) = 196) or Type 2 diabetes only (FH(T2), n = 139) matched for age, sex, BMI and age at diagnosis, underwent an oral glucose tolerance test and a combined glucagon test and insulin tolerance test. Glutamic acid decarboxylase (GAD) antibodies and major Type 1 and Type 2 diabetes susceptibility gene variants were analysed. Patients were stratified into groups according to family history or GAD antibody positivity (GADA+, GADA-) or a combination of these (GADA+/FH(MIX), GADA+/FH(T2), GADA-/FH(MIX), GADA-/FH(T2)). RESULTS: Compared with other patients, those with FH(MIX) more often had GAD antibodies (14.3 vs. 4.3%, P = 0.003), and those with both FH(MIX) and GAD antibodies had the highest frequency of insulin deficiency (stimulated serum C-peptide < 0.7 nmol/l, GADA+/FH(MIX) 46.4% vs. GADA-/FH(MIX) 9.5% (P < 0.00001), GADA-/FH(T2) 4.5% (P < 0.00001), GADA+/FH(T2) 0%). Patients with GADA+/FH(MIX) more often had HLA-DQB1 risk genotypes compared with patients with GADA-/FH(MIX) or GADA-/FH(T2D) (47 vs. 23 or 14%, P = 0.05 and P < 0.00001, respectively). In logistic regression analyses, FH(MIX), GAD antibody positivity and HLA risk genotypes were independently associated with insulin deficiency. CONCLUSION: A family history for both type 1 and type 2 diabetes was associated with higher prevalence of GAD antibodies and HLA-DQB1 risk genotypes than a family history of type 2 diabetes only, and was associated with earlier and more severe development of insulin deficiency, which was only partially explained by GAD antibodies and HLA.

Glutamic acid decarboxylase (anti-GAD) & tissue transglutaminase (anti-TTG) antibodies in patients with thyroid autoimmunity.

BACKGROUND & OBJECTIVES: Several autoimmune disorders have been reported to be associated with autoimmune thyroiditis and may coexist with other organ-specific autoantibodies. The aim of the present study was to evaluate the presence of tissue transglutaminase (anti-TTG) and glutamic acid decarboxylase (anti-GAD) antibodies in patients suffering from autoimmune thyroiditis as diagnosed by anti-thyroid peroxidase (anti-TPO) antibodies, which may indicate high risk for developing celiac disease or type 1 diabetes mellitus. METHODS: Five thousand children and 2800 adults were screening as part of a general health examination done on a voluntary basis in four different parts of Delhi. A total of 577 subjects positive for anti-TPO antibody constituted the cases. Equal number of age and sex matched anti-TPO antibody negative controls were randomly selected from the same cohort to form paired case control study. The cases and controls were further divided into two groups as follows: group-1 (children and adolescent <18 yr), group-2 (adults >18 yr). Serum samples of cases and controls were analysed for thyroid function test (FT3, FT4, and TSH), anti-TTG and anti-GAD antibodies. RESULTS: A total of 1154 subjects (577 cases and 577 controls) were included in this study. Hypothyroidism was present in 40.2 per cent (232) cases compared to only 4.7 per cent (27) in controls (P<0.001). Anti-TTG and anti-GAD antibodies were present in 6.9 and 12.5 per cent subjects among cases compared to 3.5 per cent (P=0.015) and 4.3 per cent (P=0.001) in controls, respectively. Only anti-GAD antibody were significantly positive in cases among children and adolescents (P =0.0044) and adult (P=0.001) compared to controls. Levels of anti-TTG and anti-GAD antibodies increased with increasing titre of anti-TPO antibody. INTERPRETATION & CONCLUSIONS: Our findings showed high positivity of anti-GAD and anti-TTG antibodies among subjects with thyroid autoimmunity. It is, therefore, important to have high clinical index of suspicion for celiac disease or type 1 diabetes mellitus in patients with autoimmune thyroiditis.