Glutamic Acid Decarboxylase Antibody Levels Research Articles

Does a prior diagnosis of infectious disease confer an increased risk of latent autoimmune diabetes in adults?

Infections are proposed risk factors for type 1 diabetes in children. We examined whether a diagnosis of infectious disease also confers an increased risk of latent autoimmune diabetes in adults (LADA). We used data from a population-based Swedish case-control study with incident cases of LADA (n=597) and matched controls (n=2386). The history of infectious disease was ascertained through national and regional patient registers. We estimated adjusted odds ratios (OR) with 95% confidence intervals for ≥1 respiratory (any/upper/lower), gastrointestinal, herpetic, other or any infectious disease episode, or separately, for 1 and ≥2 infectious disease episodes, within 0-1, 1-3, 3-5 and 5-10years before LADA diagnosis/matching. Stratified analyses were performed on the basis of HLA risk genotypes and Glutamic acid decarboxylase antibodies (GADA) levels. Individuals who developed LADA did not have a higher prevalence of infectious disease 1-10years before diabetes diagnosis. For example, OR was estimated at 0.87 (0.66, 1.14) for any versus no respiratory infectious disease within 1-3years. Similar results were seen for LADA with high-risk HLA genotypes (OR 0.95 [0.64, 1.42]) or high GADA levels (OR 1.10 [0.79, 1.55]), ≥2 episodes (OR 0.89 [0.56, 1.40]), and in infections treated using antibiotics (OR 1.03 [0.73, 1.45]). The only significant association was observed with lower respiratory disease the year preceding LADA diagnosis (OR 1.67 [1.06, 2.64]). Our findings do not support the idea that exposure to infections increases the risk of LADA. A higher prevalence of respiratory infection in the year before LADA diagnosis could reflect increased susceptibility to infections due to hyperglycemia.

Combination therapy with saxagliptin and vitamin D for the preservation of β-cell function in adult-onset type 1 diabetes: a multi-center, randomized, controlled trial

Disease modifying therapies aiming to preserve β-cell function in patients with adult-onset autoimmune type 1 diabetes are lacking. Here, we conducted a multi-centre, randomized, controlled trial to assess the β-cell preservation effects of saxagliptin alone and saxagliptin combined with vitamin D as adjunctive therapies in adult-onset autoimmune type 1 diabetes. In this 3-arm trial, 301 participants were randomly assigned to a 24-month course of the conventional therapy (metformin with or without insulin) or adjunctive saxagliptin or adjunctive saxagliptin plus vitamin D to the conventional therapy. The primary endpoint was the change from baseline to 24 months in the fasting C-peptide. The secondary endpoints included the area under the concentration-time curve (AUC) for C-peptide level in a 2-h mixed-meal tolerance test, glycemic control, total daily insulin use and safety, respectively. The primary endpoint was not achieved in saxagliptin plus vitamin D group (P = 0.18) and saxagliptin group (P = 0.26). However, compared with the conventional therapy, 2-h C-peptide AUC from 24 months to baseline decreased less with saxagliptin plus vitamin D (-276 pmol/L vs. -419 pmol/L; P = 0.01), and not to the same degree with saxagliptin alone (-314 pmol/L; P = 0.14). Notably, for participants with higher glutamic acid decarboxylase antibody (GADA) levels, the decline of β-cell function was much lower in saxagliptin plus vitamin D group than in the conventional therapy group (P = 0.001). Insulin dose was significantly reduced in both active treatment groups than in the conventional therapy group despite all groups having similar glycemic control. In conclusion, the combination of saxagliptin and vitamin D preserves pancreatic β-cell function in adult-onset autoimmune type 1 diabetes, an effect especially efficacious in individuals with higher GADA levels. Our results provide evidence for a novel adjunct to insulin and metformin as potential initial treatment for adult-onset type 1 diabetes. (ClinicalTrials.gov identifier: NCT02407899).

Evaluating the Prognostic Value of Islet Autoantibody Monitoring in Islet Transplant Recipients with Long-Standing Type 1 Diabetes Mellitus.

(1) Background: The correlation between titers of islet autoantibodies (IAbs) and the loss of transplanted islets remains controversial. We sought to evaluate the prognostic utility of monitoring IAbs in diabetic patients after islet transplantation (ITx); (2) Methods: Twelve patients with Type 1 diabetes mellitus and severe hypoglycemia underwent ITx. Serum concentration of glutamic acid decarboxylase (GAD), insulinoma antigen 2 (IA-2), and zinc transport 8 (ZnT8) autoantibodies was assessed before ITx and 0, 7, and 75 days and every 3 months post-operatively; (3) Results: IA-2A (IA-2 antibody) and ZnT8A (ZnT8 antibody) levels were not detectable before or after ITx in all patients (median follow-up of 53 months (range 24–61)). Prior to ITx, GAD antibody (GADA) was undetectable in 67% (8/12) of patients. Of those, 75% (6/8) converted to GADA+ after ITx. In 67% (4/6) of patients with GADA+ seroconversion, GADA level peaked within 3 months after ITx and subsequently declined. All patients with GADA+ seroconversion maintained long-term partial or complete islet function (insulin independence) after 1 or 2 ITx. There was no correlation between the presence of IAb-associated HLA haplotypes and the presence of IAbs before or after ITx; (4) Conclusions: There is no association between serum GADA trends and ITx outcomes. IA-2A and ZnT8A were not detectable in any of our patients before or after ITx.

Vitamin D status and risk of type 2 diabetes in the Norwegian HUNT cohort study: does family history or genetic predisposition modify the association?

IntroductionWe sought to investigate the relationship between serum 25-hydroxyvitamin D (25(OH)D) level and the risk of type 2 diabetes mellitus (T2DM) in adults who participated in the Trøndelag Health Study...

Investigating optimal β-cell-preserving treatment in latent autoimmune diabetes in adults: Results from a 21-month randomized trial.

To compare outcomes of glucagon-stimulated C-peptide tests (GSCTs) in people with latent autoimmune diabetes in adults (LADA) after a 21-month intervention with either insulin or the dipeptidyl peptidase-4 inhibitor sitagliptin. We included 64 glutamic acid decarboxylase (GAD) antibody-positive individuals, who were diagnosed with diabetes <3 years before the study, aged 30 to 70 years, and without clinical need for insulin treatment. We stratified participants by age and body mass index (BMI) and evaluated β-cell function by GSCT after a 48-hour temporary withdrawal of study medication. Age at randomization (mean 53 years), BMI (mean 27 kg/m2 ) and metabolic markers were similar between treatment arms. Glycated haemoglobin concentrations during intervention did not differ between arms. Fasting C-peptide concentrations after the intervention were similar, as were stimulated C-peptide levels (0.82 ± 0.63 nmol/L after insulin, 0.82 ± 0.46 nmol/L after sitagliptin; nonsignificant). Autoimmunity in the study population (estimated from GAD antibody titres and positivity/no positivity for zinc transporter 8 and islet antigen 2 antibodies) affected the evolution of the GSCT results significantly, which deteriorated in participants with high but not in those with low autoimmunity. Adjustment using analysis of covariance for the degree of autoimmunity did not alter the findings of no difference between treatment arms. β-cell function after intervention was similar in patients with insulin- and sitagliptin-treated LADA, regardless of the strength of autoimmunity. Further, participants with low levels of GAD antibodies did not experience progressive deterioration of β-cell function over a 21-month period. Taken together, these findings could be useful for clinicians' choices of treatment in people with LADA.

Correlation Between GAD Antibody Levels and Severity of Gastrointestinal Motility Dysfunction as Determined by Wireless Motility Capsule Testing

Introduction: There is an increasing body of evidence identifying an immune mediated role in the pathogenesis of both paraneoplastic and non-paraneoplastic gastrointestinal dysmotility. One such mechanism is an antibody mediated pathway involving Glutamic Acid Decarboxylase (GAD). Our objective in this study is to determine if the level of circulating GAD antibody correlates with the severity of gastrointestinal dysmotility, or the number of bowel segments impacted as determined by wireless motility capsule(WMC) testing. Methods: The study was conducted as a retrospective cohort analysis. We included all patients seen at The Cleveland Clinic who had a WMC study ordered between 2009 to 2017, and who also had positive Glutamic Acid Decarboxyase (GAD) antibodies. Patients were identified by CPT codes for WMC in the electronic medical record. Patients were excluded from the study if they failed the WMC due to technical failure. A total 304 completed WMT and also had GAD antibody measured. Of these patients, 35 had positive GAD antibodies (>5 IU/mL). Gastric emptying time (GET), Small Bowel Transit time (SBTT), and Large Bowel Transit time (LBTT) were measured using WMC data. The data from the WMC was compared to corresponding GAD antibody levels using pairwise correlation analysis after eliminating outliers. Additionally, the results were transformed to categorical data (abnormal or not) for evaluation of portions of the gastrointestinal tract involved. Abnormal measurements included a GET >4h, SBTT > 6h, or an LBTT >59h. Results: Results were calculated based on GET, SBTT and LBTT independently, as well as SLBTT and WGTT relative to the GAD antibodies. GAD antibody concentrations do not appear to correlate with the degree of gastrointestinal dysmotility as measured by WMC (Table 1). Conclusion: Based on this review of data, it seems that GAD antibody levels cannot be used as a predictor of disease severity, or to predict the location of gastrointestinal dysmotility. However, more research is needed. Empiric treatment with IVIg should not be used in patients with high GAD antibody levels in the absence of additional supportive data. A larger sample size is needed to confirm the findings of this study, and to identify further correlations.441 Figure 1. Correlation of emptying times and GAD levels

Zinc transporter 8 autoantibody (ZnT8A) by ELISA for diagnosing type 1 diabetes among Chinese people

This study aimed to evaluate the utility of enzyme-linked immunosorbent assay (ELISA) to measure ZnT8A for diagnosing type 1 diabetes among Chinese people. We recruited a group of 95 patients with type 1 diabetes, 130 patients with type 2 diabetes, and 110 subjects without diabetes. We measured ZnT8A level by ELISA and glutamic acid decarboxylase antibody (GADA) level by radioimmunoassay. We collected data on their history-based variables, body mass index (BMI), fasting blood glucose, glycosylated hemoglobin, and lipid levels. 24.2% were positive for ZnT8A in type 1 diabetics, compared to 0.0% in type 2 diabetics and 0.9% in the participants without diabetes (both p < 0.001). And the type 1 diabetics had higher ZnT8A level compared with the latter two groups (both p < 0.001). The frequency of ZnT8A in the “classical” type 1 diabetics was higher than that in patients with latent autoimmune diabetes in adults (45.0 vs. 18.7%, p < 0.05). The frequency/level of ZnT8A was higher in the youngest group (all p < 0.05). The ROC curve area was 0.892. The combination of ZnT8A and GADA increased the diagnostic sensitivity. The ZnT8A level was correlated with the GADA level. ZnT8A-positive type 1 diabetics had younger age at diagnosis (p = 0.022), lower BMI scores (p = 0.016), and more frequent ketosis (p = 0.034) and needed more insulin (p = 0.041) than ZnT8A-negative type 1 diabetics. This study demonstrated the value of ZnT8A in addition to GADA for the diagnosis of type 1 diabetes.

Cerebrospinal Fluid Level of Glutamic Acid Decarboxylase (GAD) Antibody in Patients with Encephalitis

Background: Assaying the Glutamic Acid Decarboxylas( GAD) antibody in patients with encephalitis in cerebrospinal fluid and blood serum and its role in autoimmune encephalitis in children. Objective: This study Aimed at screening for GAD antibody in CSF of children presenting with acute encephalitis with non bacterial cause mostly autoimmune.Participants and methods: study is a pilot prospective study, conducted in the Pediatric department, Children’s Hospital, Ain Shams University.Fifty patients diagnosed with encephalitis exhibited at least one sign of parenchymatous brain dysfunction such as altered consciousness personality or behavior change, seizure, paresis, or ataxia. Encephalitis was defined as the presence of encephalopathy plus at least two of four findings: (1) fever (body temperature>38C); (2) abnormal cerebrospinal fluid examination (pleocytosis>5 white blood cells/mL and/or increased protein content>40 mg/dL) with negative cerebrospinal fluid culture; (3) abnormal electroencephalography findings compatible with encephalitis such as diffuse or focal slow activity, or periodic lateralized epileptiform discharges; and (4)abnormal results of neuroimaging, including computed tomography and magnetic resonance imaging (10), ,with age ranged from 6-144 Months; followed up In the period from September 2014 till March 2016.Basic clinical evaluation and laboratory investigations were done, GAD antibody level was measured in CSF and blood serum. Results: GAD receptor antibody titer was done in CSF which range from (36 -368 ng/l) with median of 64.83 (57.93-74.48), while in serum it range from (42.76-900) ng/l) with median 89.5(58.62-154.5).It was found that 6/50 (12%) patients had high GAD receptor antibody titer were high in CSF. The other 44/50 (88%) patients had low GAD antibody titer. In serum samples of twinty patients we had 8/20 (40%) patients had high GAD antibody titer and the rest were low GAD antibody titer 12/20 (60%).Significant occurrence of DCL, hospitalization plus mechanical ventilation and long term sequel were detected in patients with high GAD antibody titer. EEG findings; Two patients showed generalized epileptogenic activity, one patient had diffuse cortical dysfunction and two patient had multifocal epileptiform discharge and the rest of patients had normal finding. Eighty six precent had normal MRI findings,While 7 patients (14%) had non specific findings;3 patients had transient cortical meningeal enhancment,2 patients had high intensity in medial temporal lobe,one had abnormal signal intensity in medial temporal lobe and one patient had global brain atrophy. Conclusion: GAD Abs are directed against an intracellular antigen. The proposed pathogenic mechanisms of neurological disease in patients with antibodies directed against intracellular proteins is not clear. The present study emphasizes the importance of studying the CSF of patients with encephalitis suspected to be mediated by GAD autoimmunity.Both serum and CSF level must be assessed simultaneously as CSF level may change rapidly with fluctuation of disease. There are great efforts to be done to define the role of these GAD antibodies and to determine how they affect central nervous system function. These studies must be carried out so that appropriate treatments can be provided for the growing number of patients with possible antibody-mediated conditions.

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.

A Novel Graphene Modified Electrochemical Sensor for Ultrasensitive Detection of T1D Serum Autoantibody

Recently, autoantibody biomarkers have been reported for early diagnosis of type 1 diabetes (T1D) also known as insulin-dependent diabetes mellitus or juvenile diabetes. Our objective is to design an electrochemical immunosensor to detect glutamic acid decarboxylase antibodies (GADA) from serum as a diagnostic measure for T1D. The sensor is designed on a screen printed eight electrode array (AuSPE) made of gold working electrodes, gold counter electrode, and a silver pseudo reference electrode. Protein A/G coated magnetic beads were used to capture the GADA spiked in 5% human serum samples. The antibody-captured by the magnetic beads were allowed to bind with the surface antigen (GAD-65) immobilized onto the carboxylated graphene oxide modified working electrode surface by carbodiimide chemistry. Both differential pulse voltammetry and Faradaic electrochemical impedance techniques were able to detect ultra-low levels of GADA. Acknowledgements: We are grateful for the financial support by the National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health under Award Number R15DK103386.

Evaluation of Glutamic Acid Decarboxylase Antibody Levels in Patients with Juvenile Myoclonic Epilepsy and Mesial Temporal Lobe Epilepsy with Hippocampal Sclerosis.

Several clinical studies have been conducted to investigate the role of autoantibodies and immunological mechanisms in the etiology of treatment-resistant epilepsy in recent years. Some immunological treatments have been suggested as a result of these studies. In this study, we aimed to investigate the role of autoimmunity in partial and idiopathic generalized epilepsy and determine the relationship between drug resistance and autoimmune antibodies. Twenty-eight patients (24 treatment-responsive and 4 treatment-resistant) with juvenile myoclonic epilepsy (JME), 26 patients with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLEHS) resistant to antiepileptic drug treatment, and 26 age-matched healthy control subjects were included in a two-year cross sectional study. Glutamic acid decarboxylase antibody (GADA) levels were measured with a radioimmunoassay method in the serum of the included subjects. High GADA titers were detected in 2 patients with JME (7.1%), 1 patient with MTLEHS (3.8%), and 1 healthy subject (3.8%). There was no statistically significant difference among the groups regarding the serum GADA level. Although a limited number of drug-resistant patients with JME our study did not show relationships among anti-GADAs, both epileptic syndromes and drug resistance. Because we did not determine any significant relationship between GADA levels and JME or MTLEHS, we do not recommend analysis of serum GADA levels in routine examinations where there is no evidence to suggest risk factors for autoimmunity.

Clinical and Laboratory Characteristics of Childhood Diabetes Mellitus: A Single-Center Study from 2000 to 2013.

We examined the clinical and laboratory characteristics of children newly diagnosed with diabetes mellitus (DM) in a single-center study. We retrospectively reviewed the data of 155 children with DM between January 2000 and December 2013. Of 155 diabetic children, 87 (56.1%) were diagnosed with type 1 DM (T1DM) and 68 (43.9%) with type 2 DM (T2DM). Mean ages at diagnosis were 8.95±3.89 years (T1DM) and 13.76±2.23 years (T2DM), respectively (p<0.001). There were significant differences in HbA1c, C-peptide, and glutamic acid decarboxylase antibody levels between the T1DM and T2DM groups. Annual numbers of children with DM have increased, and since 2011 the number of children with T2DM has surpassed the number with T1DM. The most common clinical symptom in T1DM was polyuria, and 26.4% of children with T1DM presented initially with diabetic ketoacidosis. In contrast, 60.3% of T2DM children showed glucosuria in a school urine screening, and only 19.1% presented with polydipsia. The rate of positivity for at least more than one islet autoantibody was 77.1% in T1DM and 26.3% in T2DM. Serum C-peptide levels in T2DM were increased up to 12 months after onset and remained >3.59 ng/mL for 36 months. However, serum C-peptide levels in T1DM were slightly increased up to 6 months after onset and gradually decreased to 0.32 ng/mL for 36 months. The prevalence of children with DM has increased over the last 14 years, and the proportion of T2DM patients has rapidly increased since 2009. Because childhood DM is associated with several metabolic and cardiovascular complications, children should be screened for early detection of DM, especially asymptomatic T2DM in children and adolescents.

Stiff-Person Syndrome and Graves' Disease: A Pediatric Case Report.

A 9-year-old female child presented with a history of falls, weight loss, diffuse leg pain, and progressive gait disorder, following 1 previous event described as a tonic–clonic seizure. She had increased thyroid volume, brisk symmetric reflexes, abnormal gait, and painful spasms of the paraspinal musculature. Thyroid function tests indicated biochemical hyperthyroidism, and thyrotropin receptor antibodies were positive. Her electromyography showed continuous activation of normal motor units of the paraspinal and proximal lower extremity muscles. The patient had a diagnosis of Graves’ disease with associated stiff-person syndrome, with elevated anti–glutamic acid decarboxylase antibody levels. After intravenous immunoglobulin therapy, her ambulation was substantially improved and the symptoms of stiff-person syndrome decreased dramatically.

Alcohol and the risk for latent autoimmune diabetes in adults: results based on Swedish ESTRID study.

ObjectiveModerate alcohol consumption is associated with a reduced risk of type 2 diabetes. Our aim was to investigate whether alcohol consumption is associated with the risk of latent autoimmune diabetes in adults (LADA), an autoimmune form of diabetes with features of type 2 diabetes.DesignA population-based case–control study was carried out to investigate the association of alcohol consumption and the risk of LADA.MethodsWe used data from the ESTRID case–control study carried out between 2010 and 2013, including 250 incident cases of LADA (glutamic acid decarboxylase antibodies (GADAs) positive) and 764 cases of type 2 diabetes (GADA negative), and 1012 randomly selected controls aged ≥35. Logistic regression was used to estimate the odds ratios (ORs) of diabetes in relation to alcohol intake, adjusted for age, sex, BMI, family history of diabetes, smoking, and education.ResultsAlcohol consumption was inversely associated with the risk of type 2 diabetes (OR 0.95, 95% CI 0.92–0.99 for every 5-g increment in daily intake). Similar results were observed for LADA, but stratification by median GADA levels revealed that the results only pertained to LADA with low GADA levels (OR 0.85, 95% CI 0.76–0.94/5 g alcohol per day), whereas no association was observed with LADA having high GADA levels (OR 1.00, 95% CI 0.94–1.06/5 g per day). Every 5-g increment of daily alcohol intake was associated with a 10% increase in GADA levels (P=0.0312), and a 10% reduction in homeostasis model assessment of insulin resistance (P=0.0418).ConclusionsOur findings indicate that alcohol intake may reduce the risk of type 2 diabetes and type 2-like LADA, but has no beneficial effects on diabetes-related autoimmunity.

Coffee consumption and the risk of latent autoimmune diabetes in adults--results from a Swedish case-control study.

Coffee consumption is associated with a reduced risk of Type2 diabetes. Our aim was to investigate if coffee intake may also reduce the risk of latent autoimmune diabetes in adults, an autoimmune form of diabetes with features of Type2 diabetes. We used data from a population-based case-control study with incident cases of adult onset (≥35years) diabetes, including 245 cases of latent autoimmune diabetes in adults (glutamic acid decarboxylase antibody positive), 759 cases of Type2 diabetes (glutamic acid decarboxylase antibody negative), together with 990 control subjects without diabetes, randomly selected from the population. Using questionnaire information on coffee consumption, we estimated the odds ratio of latent autoimmune diabetes in adults and Type2 diabetes adjusted for age, sex, BMI, smoking, physical activity, alcohol, education and family history of diabetes. Coffee intake was inversely associated with Type2 diabetes (odds ratio0.92, 95%CI 0.87-0.98 per cup/day). With regard to latent autoimmune diabetes in adults, the general trend was weak (odds ratio1.04, 95%CI 0.96-1.13), but stratification by degree of autoimmunity (median glutamic acid decarboxylase antibody levels) suggested that coffee intake may be associated with an increased risk of high glutamic acid decarboxylase antibody latent autoimmune diabetes in adults (odds ratio1.11, 95%CI 1.00-1.23 per cup/day). Furthermore, for every additional cup of coffee consumed per day, there was a 15.2% (P=0.0268) increase in glutamic acid decarboxylase antibody levels. Our findings confirm that coffee consumption is associated with a reduced risk of Type2 diabetes. Interestingly, the findings suggest that coffee may be associated with development of autoimmunity and possibly an increased risk of more Type1-like latent autoimmune diabetes in adults.

Comparison of Adults with Insulin Resistance (IR) in Latent Autoimmune Diabetes Versus IR in Glutamic Acid Decarboxylase Antibody-negative Diabetes

Insulin resistance in latent autoimmune diabetes in adults (LADA) patients is controversial. The aim of this study was to evaluate insulin resistance and its related factors (metabolic syndrome parameters) among subjects with LADA and glutamic acid decarboxylase antibodies (GADA) negative diabetes, as well as the impact of these factors on insulin resistance. GADA levels were investigated in 1140 diabetic patients aged between 30 and 70 years. Insulin resistance and metabolic syndrome parameters were assessed in LADA and GAD-negative diabetic patients by general linear model. In addition, the impact of metabolic syndrome factors on insulin resistance was assessed in LADA and glutamic acid decarboxylase (GAD)-negative diabetic patients. LADA was diagnosed in 33 subjects from 1140 Malaysian diabetic patients (prevalence = 2.9%). The results showed that LADA patients had higher insulin resistance and high density lipoprotein cholesterol (HDLc) (P = 0.003 and 0.00017 respectively) and lower body mass index (BMI) (P = 0.007) compared to GAD-negative diabetic patients. The HDLc was associated with decreased insulin resistance in LADA patients (P = 0.041), whereas HbA1c, triacylglycerides (TG) and waist were associated with increased insulin resistance in GAD-negative diabetic patients (P = 3.6×10⁻¹², 1.01×10⁻⁵ and 0.004 respectively). HbA1c was highly associated with decreasing β-cell function in both LADA (P = 0.009) and GAD-negative diabetic subjects (P = 2.2×10⁻²⁸). Insulin resistance is significantly higher in LADA than GAD-negative diabetic Malaysian subjects.

Non-Convulsive Status Epilepticus Associated With Glutamic Acid Decarboxylase Antibody

Autoimmune encephalitis associated with glutamic acid decarboxylase antibodies (GAD-Ab) often presents with treatment-resistant partial seizures, as well as other central nervous system symptoms. In contrast to several other well-characterized autoantibodies, GAD-Ab has very rarely been associated with status epilepticus. We report a 63-year-old woman initially admitted with somnolence and psychiatric findings. The EEG findings, of generalized and rhythmical slow spike-wave activity over the posterior regions of both hemispheres, together with the clinical deterioration in responsiveness, led to the diagnosis of non-convulsive status epilepticus. Investigation of a broad panel of autoantibodies, revealed only increased serum GAD-Ab levels. Following methylprednisolone and intravenous immunoglobulin treatments, the patient's neurological symptoms improved, EEG findings disappeared and GAD-Ab levels significantly decreased. GAD-Ab should be added to the list of anti-neuronal antibodies associated with non-convulsive status epilepticus. Disappearance of clinical findings and seroreversion after immunotherapy suggest that GAD-Ab might be involved in seizure pathogenesis.

Antinuclear antibodies and glutamic acid decarboxylase antibodies in children with refractory epilepsy

BackgroundIncreased prevalence of antinuclear antibodies (ANA) and auto glutamic acid decarboxylase antibodies (GADA) ratio have been reported in patients with epilepsy. Anti-GAD antibodies (GADA) were first implicated in the pathogenesis of some neurological diseases including epilepsy. The aim of the studyTo determine the occurrence of GADA and ANA in the serum of children with refractory epilepsy. Patients and methodsForty children with refractory epilepsy 25 males and 15 females, mean age 9.17±3.4years were selected for this study. Patients with refractory epilepsy had recurrent seizures for more than 18months with no more than a 3-month seizure free period during those 18months and failure of at least two appropriate AEDs with proper doses, good compliance and within normal therapeutic range. Twenty children with controlled idiopathic epilepsy 15 males and 5 females newly diagnosed as suffering from various types of seizures generalized and partial types, mean age 10.1±3.1years were also included in this study. These children with idiopathic epilepsy were included in this study for comparison with children with refractory epilepsy as regard to the serum ANA and GADA. ResultsChildren with refractory epilepsy had high-serum levels of GADA and ANA in comparison to children with idiopathic epilepsy (P<0.001), also there was a significant correlation between the duration of seizures and the serum levels of ANA and GADA in children with refractory epilepsy. ConclusionChildren with refractory epilepsy had high-titer of GADA and ANA. The finding confirmed the association between high GADA, ANA and refractory epilepsy suggesting an immunologic origin of refractory epilepsy.

Autoantibodies to glutamic acid decarboxylase in patients with epilepsy are associated with low cortical GABA levels

Antibodies to glutamic acid decarboxylase (GAD), the major pathway for the synthesis of c-aminobutyric acid(GABA) in humans, are found at elevated levels in a subgroup of patients with chronic epilepsy. To test whether the antibodies were associated with changes in cortical GABA levels we used magnetic resonance spectroscopy. Four patients with epilepsy and high serum GAD antibody levels (107-6,200 units/ml) and 10 healthy controls were recruited. A 3T GABA-optimized spectrum was obtained from a reproducible voxel in the cortex. Compared to the control group, the patient group had significantly lower GABA concentrations within the cortex. Demonstration of an association between high serum GAD antibodies and low cortical GABA levels in patients with epilepsy suggests that GAD antibodies are, at least, a marker of a specific disease process and support a role for immune-mediated GABAergic dysfunction.

Clinical significance of glutamic acid decarboxylase antibodies in patients with epilepsy

Glutamic acid decarboxylase antibodies (GADAs) have been detected in patients with epilepsy, but the clinical determinants of epilepsy associated with GADA have not been defined. We analyzed GADA with a radioimmunoassay in sera of 253 well-characterized patients with epilepsy and 200 control subjects. The positive samples were confirmed by immunohistochemistry and western blotting (WB). Sera were screened for other autoantibodies. GADA were detected in 15 patients (5.9%) and in three control subjects (1.5%) (p = 0.026). Seven patients (2.8%) had high GADA titers [>or=1,000 relative units (RUs)/ml], six of whom had temporal lobe epilepsy (TLE). All three GADA-positive control subjects had low titers. Two of the five patients with high GADA titers and available cerebrospinal fluid (CSF) samples had intrathecal synthesis (IS) of GADA; one patient had CSF oligoclonal bands. The prevalence of increased levels of GADA tended to be higher in patients with TLE than in patients with extra-TLE [odds ratio (OR) 1.32, 95% confidence interval (CI) 0.39-4.42; p = 0.657]. The patients with high GADA titers had significantly higher number of other autoantibodies compared to the patients with low GADA titers (p = 0.001) and the patients with normal GADA (p < 0.001). High GADA titers were present in a subgroup of patients; close to 90% had TLE. The immunologic profile of these patients suggests that the most probable origin of their epilepsy is autoimmune. A positive IS of GADA may be a marker of an ongoing immune response that could identify those patients in whom a trial with immunosuppressive therapy might be warranted.