Clinical features and immunotherapy outcomes of anti-glutamic acid decarboxylase 65 antibody-associated neurological disorders.

We described the clinical and neuroimaging characteristics of seven Chinese patients with anti-GAD65 antibody-associated neurological disorders of whom epileptic seizures were the initial and main symptoms. All patients were given immunotherapy and followed up monthly. The outcome demonstrates that immunotherapy is helpful for non-seizure manifestations of anti-GAD65-associated neurological autoimmunity and is less effective in the treatment of seizures, yet partial responses can still occur in the early stage. Taken together we suggest a trial with immunotherapy in all patients in the early stage of the disease, and in patients with non-epilepsy symptoms in the later stage.

Investigation into the antimicrobial activity of fumarate against Listeria monocytogenes and its mode of action under acidic conditions.

Organic acids such as fumarate are commonly used as antimicrobials in foods. Apart from the classical mechanism of intracellular dissociation, weak acids are active through important additional mechanisms which are not well-defined. Fumarate, based on its low dissociation constants is expected to have a low antimicrobial activity which is not the case, suggesting additional antimicrobial effects. Previously, fumarate has been shown to inhibit the GAD system of E. coli and therefore, we investigated for first time how it affects this system in Listeria monocytogenes. We found that fumarate is highly antimicrobial towards L. monocytogenes under acidic conditions. We also show that in cell lysates and similarly to E. coli, fumarate inhibits the GAD system of L. monocytogenes. However, despite the inhibition and in contrast to E. coli, L. monocytogenes is able to counteract this and achieve a higher extracellular GAD output (measured by GABA export) in the presence of fumarate compared to its absence. The latter is achieved by a dramatic 9.44-fold increase in the transcription of gadD2 which is the main component of the extracellular GAD system. Interestingly, although maleate, the cis-isomer of fumarate results in a more dramatic 48.5-fold gadD2 upregulation than that of fumarate, the final GADe output is lower suggesting that maleate might be a stronger inhibitor of the GAD system. In contrast, the GADe removes more protons in the presence of fumarate than in the presence of HCl at the same pH. All the above suggest that there are additional effects by fumarate which might be associated with the intracellular GAD system (GADi) or other acid resistance systems. We assessed the GADi output by looking at the intracellular GABA pools which were not affected by fumarate. However, there are multiple pathways (e.g. GABA shunt) that can affect GABAi pools and we cannot conclusively suggest that GADi is affected. Furthermore, similarly to maleate, fumarate is able to eliminate L. monocytogenes in biofilms under acidic conditions. Overall, fumarate is a good candidate for L. monocytogenes decontamination and biofilm removal which is not toxic compared to the toxic maleate.

Initial report of γ-aminobutyric acidergic locomotion regulatory system and its 3-mercaptopropionic acid-sensitivity in metamorphic juvenile of sea urchin, Hemicentrotus pulcherrimus.

The γ-aminobutyric acid (GABA) signal transmission system (GSTS) contributes to larval swimming through the regulation of ciliary beating. However, whether this system also contributes to the primary podia (PP)-generated motility of juveniles remained unclear. The present study aimed to elucidate the involvement of the GSTS in the motility of metamorphic juveniles (juveniles) (1) by immunohistochemically elucidating the location of molecular constituents of the PP, and (2) by inhibiting the activity of GΑΒΑ decarboxylase (GAD) with 3-mercaptopropionic acid (3-MPA). During metamorphosis, the echinus rudiment protrudes its PP out of the body surface in 8-arm plutei. The PP expresses immunopositive signal (-IS) of GAD, GABA, GABAA receptor and tropomyosin, and is constituted with the GABA-IS negative distal tip and the GABA/GAD-IS gaiter region. The latter radiates distal projections to the disc that contains a GAD-IS cellular network. The juvenile body cavity houses a GABA/ßIII-tubulin-IS Penta-radial ring (PrR) that extends branches into each PP and several bridges to the GAD/GABA-IS Penta-radial plate (PrP) on the oral side but does not reach to the gaiter region. 3-MPA reversibly inhibits the juvenile motility and GABA-IS expression in the PrR/PrP complex. This indicates that the complex is the major contributor to the GABAergic motility in juveniles.

Reference limits for GAD65 and IA-2 autoantibodies by chemiluminescence immunoassay in Northern European adults and children.

The GAD65 and IA-2 antibodies (Abs) are biomarkers of the development of type 1 diabetes mellitus (T1DM) in both children and adults. The upper reference limit for the autoantibodies made by the manufacture was established on an adult Chinese population. Here, we established upper reference limits for Northern European adults and children in accordance with the Clinical and Laboratory Standards Institute (CLSI) guidelines. Serum samples from healthy Danish children (0-18 years) and adults (18-70 years) were analysed for GAD65Ab and IA-2Ab using MAGLUMI 800 Chemiluminescence Immunoassay (CLIA). The Kruskal-Wallis test was used for evaluating differences between gender and age groups. No gender or age differences were found for neither GAD65Ab nor IA-2Ab, and a combined upper reference limit for both children and adults could be established. An upper reference limit of 5.1 IU/mL was defined for GAD65Ab and 11.5 U/mL for IA-2Ab. Our results showed a substantial discrepancy with the reference limits established by the manufacturer.

Ascorbic Acid Supplementation Prevents the Detrimental Effects of Prenatal and Postnatal Lead Exposure on the Purkinje Cell and Related Proteins in the Cerebellum of Developing Rats.

We investigated the effects of lead (Pb) and ascorbic acid co-administration on rat cerebellar development. Prior to mating, rats were randomly divided into control, Pb, and Pb plus ascorbic acid (PA) groups. Pregnant rats were administered Pb in drinking water (0.3% Pb acetate), and ascorbic acid (100 mg/kg) via oral intubation until the end of the experiment. Offspring were sacrificed at postnatal day 21, the age at which the morphology of the cerebellar cortex in developing pups is similar to that of the adult brain. In the cerebellum, Pb exposure significantly reduced Purkinje cells and ascorbic acid prevented their reduction. Along with the change of the Purkinje cells, long-term Pb exposure significantly reduced the expression of the synaptic marker (synaptophysin), γ-aminobutyric acid (GABA)-synthesizing enzyme (glutamic acid decarboxylase 67), and axonal myelin basic protein while ascorbic acid co-treatment attenuated Pb-mediated reduction of these proteins in the cerebellum of pups. However, glutamatergic N-methyl-D-aspartate receptor subtype 1 (NMDAR1), anchoring postsynaptic density protein 95 (PSD95), and antioxidant superoxide dismutases (SODs) were adversely changed; Pb exposure increased the expression of NMDAR1, PSD95, and SODs while ascorbic acid co-administration attenuated Pb-mediated induction. Although further studies are required about the neurotoxicity of the Pb exposure, the results presented here suggest that developmental Pb exposure disrupted normal development of Purkinje cells by increasing glutamatergic and oxidative stress in the cerebellum. Additionally, ascorbic acid co-treatment is beneficial in attenuating prenatal and postnatal Pb exposure-induced maldevelopment of Purkinje cells in the developing cerebellum.

Fulminant onset of insulin-dependent diabetes with positive anti-GAD antibody titers during treatment with nivolumab in a patient with NSCLC.

Programmed cell death-1 (PD-1) and programmed cell death-ligand-1 (PD-L1) inhibitors have been highlighted in the field of cancer treatment. The interaction between PD-1 and PD-L1 is thought to play an important role in the regulation of the self-immune tolerance mechanism, so blocking these molecules may cause serious immune-related adverse events (IrAE), including fulminant insulin-dependent (type 1) diabetes. Here, we describe a patient with fulminant type 1 diabetes induced by nivolumab, an anti-PD-1 antibody. The patient, a 78-year-old man, was being treated with nivolumab as a third-line treatment for squamous cell carcinoma of the lung. After three cycles, he experienced an abrupt flare-up of the blood glucose within half a day. His blood glucose further increased without clinical symptoms until his hospital visit. Laboratory data showed the complete exhaustion of intrinsic insulin and the elevation of serum antibody titer to glutamic acid decarboxylase (GAD). Although the patient was previously diagnosed with non-insulin-dependent (type 2) diabetes, his disease activity had been well controlled with oral medication and low-dose insulin therapy until just before the flare-up. Because of the laboratory findings and the extremely rapid onset of hyperglycemia, a diagnosis of fulminant, rather than the rapid onset, type 1 diabetes related to nivolumab therapy was strongly suspected. Our case study indicates that fulminant hyperglycemia can occur extremely rapidly. The blood glucose of patients receiving PD-1 antibody therapy should be closely monitored.

A novel approach in acidic disinfection through inhibition of acid resistance mechanisms; Maleic acid-mediated inhibition of glutamate decarboxylase activity enhances acid sensitivity of Listeria monocytogenes.

Here it is demonstrated a novel approach in disinfection regimes where specific molecular acid resistance systems are inhibited aiming to eliminate microorganisms under acidic conditions. Despite the importance of the Glutamate Decarboxylase (GAD) system for survival of Listeria monocytogenes and other pathogens under acidic conditions, its potential inhibition by specific compounds that could lead to its elimination from foods or food preparation premises has not been studied. The effects of maleic acid on the acid resistance of L. monocytogenes were investigated and found that it has a higher antimicrobial activity under acidic conditions than other organic acids, while this could not be explained by its pKa or Ka values. The effects were found to be more pronounced on strains with higher GAD activity. Maleic acid affected the extracellular GABA levels while it did not affect the intracellular ones. Maleic acid had a major impact mainly on GadD2 activity as also shown in cell lysates. Furthermore, it was demonstrated that maleic acid is able to partly remove biofilms of L. monocytogenes. Maleic acid is able to inhibit the GAD of L. monocytogenes significantly enhancing its sensitivity to acidic conditions and together with its ability to remove biofilms, make a good candidate for disinfection regimes.

Primary islet autoantibody at initial seroconversion and autoantibodies at diagnosis of type 1 diabetes as markers of disease heterogeneity.

OBJECTIVE: The relationship between patterns of islet autoantibodies at diagnosis and specificity of the first islet autoantibody at the initiation of autoimmunity was analyzed with the aim of identifying patterns informative of the primary autoantibodies. METHODS: Information about a single first autoantibody at seroconversion and autoantibody data at diagnosis were available for 128 children participating in the follow-up cohort of the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) study. Autoantibody data at diagnosis and genotyping results were also obtained from children in the Finnish Pediatric Diabetes Register (FPDR). RESULTS: Insulin autoantibodies (IAA) were the most common primary antibodies (N = 68), followed by those for glutamic acid decarboxylase (GADA; N = 38), IA-2 antigen (IA-2A; N = 13), and zinc transporter 8 (ZnT8A; N = 9), whereas at diagnosis, IA-2A were most frequent (N = 103), followed by IAA (N = 78), ZnT8A (N = 73), and GADA (N = 71). Accordingly, the presence of many specific autoantibodies at diagnosis was due to the secondary antibodies appearing after primary antibodies, and in some cases, the primary autoantibody, most often IAA, had already disappeared at the time of diagnosis. Many of the autoantibody combinations present at diagnosis could be assembled into groups associated with either IAA or GADA as first autoantibodies. These combinations, in children diagnosed below the age of 10 years in the FPDR, were found to be strongly associated with risk genotypes in either INS (IAA first) or IKZF4-ERBB3 (GADA first) genes. CONCLUSIONS: Autoantibody patterns at diagnosis may be informative on primary autoantibodies initiating autoimmunity in young children developing type 1 diabetes.

High Prevalence of Autoimmune Diabetes and Poor Glycaemic Control among Adults in Madagascar: A Brief Report from a Humanitarian Health Campaign in Ambanja.

Madagascar is a geographically isolated country considered a biodiversity hotspot with unique genomics. Both the low-income and the geographical isolation represent risk factors for the development of diabetes. During a humanitarian health campaign conducted in Ambanja, a rural city in the northern part of Madagascar, we identified 42 adult subjects with diabetes and compared their features to 24 randomly enrolled healthy controls. 42.9% (n = 18) of diabetic subjects showed HbA1c values ≥ 9.0%. Unexpectedly, waist circumference and BMI were similar in people with diabetes and controls. Different from the healthy controls, diabetic subjects showed a low prevalence of obesity (5.7% versus 30%, p = 0.02). Accordingly, we found a high prevalence of autoimmune diabetes as 12% of people with diabetes showed positivity for the autoantibody against glutamic acid decarboxylase. Diabetic subjects with positive autoantibody had higher HbA1c values (11.3 ± 4.1% versus 8.3 ± 2.6%, p = 0.03) compared to diabetic subjects with negative autoantibody. In conclusion, here we describe the presence of diabetes and its features in a rural area of Northern Madagascar, documenting poor glycaemic control and a high prevalence of autoimmune diabetes. These data highlight that the diabetes epidemic involves every corner of the world possibly with different patterns and features.

Inhibition of glutamate decarboxylase (GAD) by ethyl ketopentenoate (EKP) induces treatment-resistant epileptic seizures in zebrafish.

Epilepsy is a chronic brain disorder characterized by recurrent seizures due to abnormal, excessive and synchronous neuronal activities in the brain. It affects approximately 65 million people worldwide, one third of which are still estimated to suffer from refractory seizures. Glutamic acid decarboxylase (GAD) that converts glutamate into GABA is a key enzyme in the dynamic regulation of neural network excitability. Importantly, clinical evidence shows that lowered GAD activity is associated with several forms of epilepsy which are often treatment resistant. In the present study, we synthetized and explored the possibility of using ethyl ketopentenoate (EKP), a lipid-permeable GAD-inhibitor, to induce refractory seizures in zebrafish larvae. Our results demonstrate that EKP evoked robust convulsive locomotor activities, excessive epileptiform discharges and upregulated c-fos expression in zebrafish. Moreover, transgenic animals in which neuronal cells express apoaequorin, a Ca2+-sensitive bioluminescent photoprotein, displayed large luminescence signals indicating strong EKP-induced neuronal activation. Molecular docking data indicated that this proconvulsant activity resulted from the direct inhibition of both gad67 and gad65. Limited protective efficacy of tested anti-seizure drugs (ASDs) demonstrated a high level of treatment resistance of EKP-induced seizures. We conclude that the EKP zebrafish model can serve as a high-throughput platform for novel ASDs discovery.

The Mechanism of Regulation of Pantothenate Biosynthesis by the PanD-PanZ·AcCoA Complex Reveals an Additional Mode of Action for the Antimetabolite N-Pentyl Pantothenamide (N5-Pan).

The antimetabolite pentyl pantothenamide has broad spectrum antibiotic activity but exhibits enhanced activity against Escherichia coli. The PanDZ complex has been proposed to regulate the pantothenate biosynthetic pathway in E. coli by limiting the supply of ß-alanine in response to coenzyme A concentration. We show that formation of such a complex between activated aspartate decarboxylase (PanD) and PanZ leads to sequestration of the pyruvoyl cofactor as a ketone hydrate and demonstrate that both PanZ overexpression-linked ß-alanine auxotrophy and pentyl pantothenamide toxicity are due to formation of this complex. This both demonstrates that the PanDZ complex regulates pantothenate biosynthesis in a cellular context and validates the complex as a target for antibiotic development.

Glutamic acid decarboxylase and islet antigen 2 antibody profiles in people with adult-onset diabetes mellitus: a comparison between mixed ethnic populations in Singapore and Germany.

AIM: To gain insight into the presence of islet cell autoimmunity in an ethnic Asian compared with a white European population. METHODS: For this cross-sectional study we recruited people with adult-onset diabetes (age of diagnosis 20-60 years), at tertiary referral centres in Germany (n=1020) and Singapore (n=1088). Glutamic acid decarboxylase and islet antigen 2 antibodies were measured according to Islet Autoantibody Standardization Program protocols. RESULTS: The prevalence of glutamic acid decarboxylase antibody positivity was 13.9% (95% CI 12.1-16.0; P<0.001) in the white European cohort compared with 6.8% (95% CI 5.5-8.4; P<0.001) in the Asian cohort. Glutamic acid decarboxylase antibody positivity was 11.4% (95% CI 7.7-16.6) in Indian, 6.0% (95% CI 3.6-9.9) in Malay and 5.8% (95% CI 4.3-7.7; P<0.001) in Chinese participants. In the white European participants, the prevalence of islet antigen 2 antibody positivity was 7.8% (95% CI 6.4-9.4) compared with 14.8% (95% CI 12.8-17.0; P<0.001) in the Asian cohort as a whole, and among the three ethnicities in the Asian cohort it was 12.4% (95% CI 8.6-17.7) in Indian, 16.8% (95% CI 12.6-22.2) in Malay and 15.7% (95% CI 13.2-18.6) in Chinese participants. Double antibody positivity was seen in 5.7% (95% CI 4.5-7.1) of white European participants compared with 1.6% (95% CI 1.0-2.5; P<0.01) of Asian participants. In the white European cohort, those who were glutamic acid decarboxylase autoantibody-positive had a lower BMI than those who were autoantibody-negative, but this trend was absent in the Asian cohort. CONCLUSIONS: A marked prevalence of islet cell autoimmunity was observed in people with adult-onset diabetes. While glutamic acid decarboxylase antibodies were more frequent in the European cohort, islet antigen 2 antibody positivity was highest in the three ethnic groups in Singapore, suggesting ethnic-specific differences in antibody profiles.

Exogenous γ-aminobutyric acid treatment affects citrate and amino acid accumulation to improve fruit quality and storage performance of postharvest citrus fruit.

The loss of organic acids during postharvest storage is one of the major factors that reduces the fruit quality and economic value of citrus. Citrate is the most important organic acid in citrus fruits. Molecular evidence has proved that γ-aminobutyric acid (GABA) shunt plays a key role in citrate metabolism. Here, we investigated the effects of exogenous GABA treatment on citrate metabolism and storage quality of postharvest citrus fruit. The content of citrate was significantly increased, which was primarily attributed to the inhibition of the expression of glutamate decarboxylase (GAD). Amino acids, including glutamate, alanine, serine, aspartate and proline, were also increased. Moreover, GABA treatment decreased the fruit rot rate. The activities of antioxidant enzymes and the content of energy source ATP were affected by the treatment. Our results indicate that GABA treatment is a very effective approach for postharvest quality maintenance and improvement of storage performance in citrus production.

Cytosolic Accumulation of L-Proline Disrupts GABA-Ergic Transmission through GAD Blockade.

Proline dehydrogenase (PRODH), which degrades L-proline, resides within the schizophrenia-linked 22q11.2 deletion suggesting a role in disease. Supporting this, elevated L-proline levels have been shown to increase risk for psychotic disorders. Despite the strength of data linking PRODH and L-proline to neuropsychiatric diseases, targets of disease-relevant concentrations of L-proline have not been convincingly described. Here, we show that Prodh-deficient mice with elevated CNS L-proline display specific deficits in high-frequency GABA-ergic transmission and gamma-band oscillations. We find that L-proline is a GABA-mimetic and can act at multiple GABA-ergic targets. However, at disease-relevant concentrations, GABA-mimesis is limited to competitive blockade of glutamate decarboxylase leading to reduced GABA production. Significantly, deficits in GABA-ergic transmission are reversed by enhancing net GABA production with the clinically relevant compound vigabatrin. These findings indicate that accumulation of a neuroactive metabolite can lead to molecular and synaptic dysfunction and help to understand mechanisms underlying neuropsychiatric disease.

Validation of a rapid type 1 diabetes autoantibody screening assay for community-based screening of organ donors to identify subjects at increased risk for the disease.

The Network for Pancreatic Organ donors with Diabetes (nPOD) programme was developed in response to an unmet research need for human pancreatic tissue obtained from individuals with type 1 diabetes mellitus and people at increased risk [i.e. autoantibody (AAb)-positive] for the disease. This necessitated the establishment of a type 1 diabetes-specific AAb screening platform for organ procurement organizations (OPOs). Assay protocols for commercially available enzyme-linked immunosorbent assays (elisas) determining AAb against glutamic acid decarboxylase (GADA), insulinoma-associated protein-2 (IA-2A) and zinc transporter-8 (ZnT8A) were modified to identify AAb-positive donors within strict time requirements associated with organ donation programmes. These rapid elisas were evaluated by the international islet AAb standardization programme (IASP) and used by OPO laboratories as an adjunct to routine serological tests evaluating donors for organ transplantation. The rapid elisas performed well in three IASPs (2011, 2013, 2015) with 98-100% specificity for all three assays, including sensitivities of 64-82% (GADA), 60-64% (IA-2A) and 62-68% (ZnT8A). Since 2009, nPOD has screened 4442 organ donors by rapid elisa; 250 (5·6%) were identified as positive for one AAb and 14 (0.3%) for multiple AAb with 20 of these cases received by nPOD for follow-up studies (14 GADA+, two IA-2A(+) , four multiple AAb-positive). Rapid screening for type 1 diabetes-associated AAb in organ donors is feasible, allowing for identification of non-diabetic, high-risk individuals and procurement of valuable tissues for natural history studies of this disease.

Use of Dried Capillary Blood Sampling for Islet Autoantibody Screening in Relatives: A Feasibility Study.

BACKGROUND: Islet autoantibody testing provides the basis for assessment of risk of progression to type 1 diabetes. We set out to determine the feasibility and acceptability of dried capillary blood spot-based screening to identify islet autoantibody-positive relatives potentially eligible for inclusion in prevention trials. MATERIALS AND METHODS: Dried blood spot (DBS) and venous samples were collected from 229 relatives participating in the TrialNet Pathway to Prevention Study. Both samples were tested for glutamic acid decarboxylase, islet antigen 2, and zinc transporter 8 autoantibodies, and venous samples were additionally tested for insulin autoantibodies and islet cell antibodies. We defined multiple autoantibody positive as two or more autoantibodies in venous serum and DBS screen positive if one or more autoantibodies were detected. Participant questionnaires compared the sample collection methods. RESULTS: Of 44 relatives who were multiple autoantibody positive in venous samples, 42 (95.5%) were DBS screen positive, and DBS accurately detected 145 of 147 autoantibody-negative relatives (98.6%). Capillary blood sampling was perceived as more painful than venous blood draw, but 60% of participants would prefer initial screening using home fingerstick with clinic visits only required if autoantibodies were found. CONCLUSIONS: Capillary blood sampling could facilitate screening for type 1 diabetes prevention studies.

Effects of chronic inhibition of GABA synthesis on attention and impulse control.

BACKGROUND: Cortical GABA regulates a number of cognitive functions including attention and working memory and is dysregulated in a number of psychiatric conditions. In schizophrenia for example, changes in GABA neurons [reduced expression of glutamic acid decarboxylase (GAD), parvalbumin (PV) and the GABA reuptake transporter (GAT1)] suggest reduced cortical GABA synthesis and release; these changes are hypothesized to cause the cognitive deficits observed in this disorder. The goals of this experiment were to determine whether chronically reducing GAD function within the rat PFC causes attention deficits and alterations in PV and GAT1 expression. METHODS: Male Sprague Dawley rats were trained on the 5-choice serial reaction time task (5CSRTT, a task of attention) until they reached criterion performance and then were implanted with a bilateral cannula aimed at the medial PFC. Cannulae were connected to osmotic minipumps that infused the GAD inhibitor l-allylglycine (LAG, 3.2µg/0.5µl/h) for 13days. Following a 5-day recovery from surgery rats were tested on the standard 5CSRTT for 5 consecutive days and then tested on two modifications of the 5CSRTT. Finally, locomotor activity was assessed and the rats sacrificed. Brains were rapidly extracted and flash frozen and analyzed for the expression of GAD67, PV, GAT1 and the obligatory NMDA receptor subunit NR1. RESULTS: Chronic LAG infusions transiently impaired attention, persistently impaired impulse control and increased locomotor activity. Behavioral changes were associated with an upregulation of GAD67, but no change in PV, GAT1 or NR1 expression. SUMMARY: Chronic inhibition of GABA synthesis within the medial PFC, increased impulsive behavior and locomotion, but did not impair attention; results consistent with previous research following acute inhibition of GABA synthesis. Moreover, our data do not support the hypothesis that decreasing GABA synthesis and release is sufficient to cause changes in other GABA-related proteins.

Glutamic acid decarboxylase autoantibody-positivity post-partum is associated with impaired ß-cell function in women with gestational diabetes mellitus.

AIMS: To investigate whether the presence of glutamic acid decarboxylase (GAD) autoantibodies post-partum in women with prior gestational diabetes mellitus was associated with changes in metabolic characteristics, including ß-cell function and insulin sensitivity. METHODS: During 1997-2010, 407 women with gestational diabetes mellitus were offered a 3-month post-partum follow-up including anthropometrics, serum lipid profile, HbA1c and GAD autoantibodies, as well as a 2-h oral glucose tolerance test (OGTT) with blood glucose, serum insulin and C-peptide at 0, 30 and 120 min. Indices of insulin sensitivity and insulin secretion were estimated to assess insulin secretion adjusted for insulin sensitivity, disposition index (DI). RESULTS: Twenty-two (5.4%) women were positive for GAD autoantibodies (GAD+ve) and the remainder (94.6%) were negative for GAD autoantibodies (GAD-ve). The two groups had similar age and prevalence of diabetes mellitus. Women who were GAD+ve had significantly higher 2-h OGTT glucose concentrations during their index-pregnancy (10.5 vs. 9.8 mmol/l, P = 0.001), higher fasting glucose (5.2 vs. 5.0 mmol/l, P = 0.02) and higher 2-h glucose (7.8 vs. 7.1 mmol/l, P = 0.05) post-partum. Fasting levels of C-peptide and insulin were lower in GAD+ve women compared with GAD-ve women (520 vs. 761 pmol/l, P = 0.02 and 33 vs. 53 pmol/l, P = 0.05) Indices of insulin sensitivity were similar in GAD+ve and GAD-ve women, whereas all estimates of DI were significantly reduced in GAD+ve women. CONCLUSION: GAD+ve women had higher glucose levels and impaired insulin secretion adjusted for insulin sensitivity (DI) compared with GAD-ve women. The combination of OGTT and GAD autoantibodies post-partum identify women with impaired ß-cell function. These women should be followed with special focus on development of Type 1 diabetes.

Novel therapy for insulin-dependent diabetes mellitus: infusion of in vitro-generated insulin-secreting cells.

Insulin-dependent diabetes mellitus (IDDM) is a metabolic disease usually resulting from autoimmune-mediated ß-cell destruction requiring lifetime exogenous insulin replacement. Mesenchymal stem cells (MSC) hold promising therapy. We present our experience of treating IDDM with co-infusion of in vitro autologous adipose tissue-derived MSC-differentiated insulin-secreting cells (ISC) with hematopoietic stem cells (HSC). This was an Institutional Review Board approved prospective non-randomized open-labeled clinical trial after informed consent from ten patients. ISC were differentiated from autologous adipose tissue-derived MSC and were infused with bone marrow-derived HSC in portal, thymic circulation by mini-laparotomy and in subcutaneous circulation. Patients were monitored for blood sugar levels, serum C-peptide levels, glycosylated hemoglobin (Hb1Ac) and glutamic acid decarboxylase (GAD) antibodies. Insulin administration was made on sliding scale with an objective of maintaining FBS < 150 mg/dL and PPBS around 200 mg/dL. Mean 3.34 mL cell inoculums with 5.25 × 10(4) cells/µL were infused. No untoward effects were observed. Over a mean follow-up of 31.71 months, mean serum C-peptide of 0.22 ng/mL before infusion had sustained rise of 0.92 ng/mL with decreased exogenous insulin requirement from 63.9 international units (IU)/day to 38.6 IU/day. Improvement in mean Hb1Ac was observed from 10.99 to 6.72%. Mean GAD antibodies were positive in all patients with mean of 331.10 IU/mL, which decreased to mean of 123 IU/mL. Co-infusion of autologous ISC with HSC represents a viable novel therapeutic option for IDDM.

Similar weight-adjusted insulin secretion and insulin sensitivity in short-duration late autoimmune diabetes of adulthood (LADA) and type 2 diabetes: Action LADA 9 [corrected].

AIMS: To explore insulin sensitivity and insulin secretion in people with latent autoimmune diabetes in adulthood (LADA) compared with that in people with type 2 diabetes. METHODS: A total of 12 people with LADA, defined as glutamic acid decarboxylase (GAD) antibody positivity and > 1 year of insulin independency (group A) were age-matched pairwise to people with type 2 diabetes (group B) and to six people with type 2 diabetes of similar age and BMI (group C). ß-Cell function (first-phase insulin secretion and assessment of insulin pulsatility), insulin sensitivity (hyperinsulinemic-euglycemic clamp) and metabolic response during a mixed meal were studied. RESULTS: Both first-phase insulin secretion and insulin release during the meal were greater (P = 0.05 and P = 0.009, respectively) in type 2 diabetes as compared with LADA; these differences were lost on adjustment for BMI (group C) and could be explained by BMI alone in a multivariate analysis. Neither insulin pulsatility, incretin secretion nor insulin sensitivity differed among the groups. CONCLUSIONS: We found no evidence that LADA and type 2 diabetes were distinct disease entities beyond the differences explained by BMI.