| 1. |
- Agardh, Daniel, et al.
(författare)
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HLA-DQB1*0201/0302 is associated with severe retinopathy in patients with IDDM
- 1996
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X. ; 39:11, s. 1313-1317
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Tidskriftsartikel (refereegranskat)abstract
- Some insulin-dependent diabetic (IDDM) patients develop severe forms of retinopathy. Putative risk factors such as hypertension, poor metabolic control, nephropathy and growth hormone levels do not fully explain the progress of retinopathy in these patients. It has been discussed whether there is a genetic marker, since some diabetic patients without any known predisposing risk factors develop severe retinopathy and others do not. In the present study, HLA-DR and DQ were compared in two patient groups with IDDM. One group consisted of patients with early-onset diabetes, with severe non-proliferative or proliferative retinopathy; the other group had no or only mild signs of retinopathy. High resolution HLA typing was carried out by polymerase chain reaction (PCR) and hybridization with allele specific probes. Alleles on the DR3-DQ2 haplotype, DRB1*0301, DQA1*0501 and DQB1*0201, were more frequent in patients with severe retinopathy. A difference was seen when combining certain alleles in the genotypes of DQA1*03/0501 (p > 0.05) and DQB1*0201/0302 (p < 0.01). The findings of the present study suggest that DQB1*0201/0302 is the strongest genetic marker for severe retinopathy and DRB1*0301/0401 only has a secondary influence when combined with this genotype. It seems as if IDDM patients who are positive for the genotype DR3-DQ2/DR4-DQ8 (DRB1*0301-DQA1*0501-DQB1*0201/DRB1*0401 -DQA1*03-DQB1*0302) are at greater risk of developing severe retinopathy.
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| 2. |
- Agardh, Daniel, et al.
(författare)
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Inverse relationship between GAD65 antibody levels and severe retinopathy in younger type 1 diabetic patients
- 1998
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Ingår i: Diabetes Research and Clinical Practice. - 1872-8227. ; 40:1, s. 9-14
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Tidskriftsartikel (refereegranskat)abstract
- Several risk factors for severe non-proliferative and proliferative retinopathy in type 1 diabetes mellitus have been proposed without explaining the rapid progression of retinopathy in some patients. Since GAD65 autoantibodies (GAD65Abs) are detected against glutamic acid decarboxylase (GAD), which is mainly expressed in islets and nervous tissue in type 1 diabetic patients, the aim of the present investigation was to test the hypothesis whether GAD65Abs are associated with rapidly progressing severe retinopathy. Patients with severe non-proliferative or proliferative retinopathy (n = 27) were compared with another group, which in spite of long diabetes duration had no or only mild signs of retinopathy (n = 28). GAD65Abs were analysed in a radioimmunoassay using in vitro translated human GAD65, and the levels were expressed as an index in relation to positive and negative reference samples. Using a cut-off level representing the 99th percentile of normals, 6/27 (22%) with and 9/28 (32%) without severe retinopathy were considered GAD65Ab positive. Although there was no difference in the number of GAD65Ab positive patients, the GAD65Ab levels were lower in patients with (0.30; 0.11-0.64) than without (0.68; 0.34-1.12) severe retinopathy (P = 0.03). The patients were also subjected to HLA-DR and DQ typing by PCR and hybridization with oligospecific probes. DQ2/8 was more common in patients with (56%) than without (29%) severe retinopathy (P = 0.05), but DQ2/8 could not account for the lower GAD65Ab levels in patients with severe retinopathy. It is concluded that GAD65Ab levels are inversely correlated with severe retinopathy in young type 1 diabetic patients.
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| 3. |
- Agardh, Carl-David, et al.
(författare)
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Clinical evidence for the safety of GAD65 immunomodulation in adult-onset autoimmune diabetes.
- 2005
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Ingår i: Journal of Diabetes and its Complications. - : Elsevier BV. - 1873-460X .- 1056-8727. ; 19:4, s. 238-246
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this Phase II study was to evaluate if alum-formulated human recombinant GAD65 is safe and does not compromise beta cell function. The study was conducted as a randomized, double blind, placebo-controlled, dose-escalation clinical trial in a total of 47 Latent Autoimmune Diabetes in Adults (LADA) patients who received either placebo or 4, 20, 100, or 500 μg Diamyd subcutaneously at Weeks 1 and 4. Safety evaluations, including neurology, beta cell function tests, diabetes status assessment, hematology, biochemistry, and cellular and humoral immunological markers, were repeatedly assessed over 24 weeks. None of the patients had significant study-related adverse events (AE). Fasting c-peptide levels at 24 weeks were increased compared with placebo (P=.0015) in the 20 μg but not in the other dose groups. In addition, both fasting (P=.0081) and stimulated (P=.0236) c-peptide levels increased from baseline to 24 weeks in the 20 μg dose group. GADA log levels clearly increased (P=.0002) in response to 500 μg Diamyd. The CD4+CD25+/CD4+CD25− cell ratio increased (P=.0128) at 24 weeks in the 20 μg group. No sudden increase in HbA1c or plasma glucose or decrease in beta cell function was observed in any of the dose groups. These positive findings for clinical safety further support the clinical development of Diamyd as a therapeutic to prevent autoimmune diabetes.
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| 4. |
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| 5. |
- Agardh, Carl-David, et al.
(författare)
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GAD65 vaccination: 5 years of follow-up in a randomised dose-escalating study in adult-onset autoimmune diabetes.
- 2009
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X. ; 52, s. 1363-1368
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Tidskriftsartikel (refereegranskat)abstract
- AIMS/HYPOTHESIS: The aim of this study was to ascertain whether treatment of GAD65 autoantibody (GADA)-positive diabetic patients with alum-formulated recombinant GAD65 (GAD-alum) is safe and does not compromise beta cell function. METHODS: This Phase 2, placebo-controlled, dose-escalation clinical trial, which was randomized through a central office, was performed in 47 GADA-positive type 2 diabetic patients, who received subcutaneous injections of GAD-alum (4 [n = 9], 20 [n = 8], 100 [n = 9] or 500 [n = 8] mug) or placebo (n = 13) at weeks 1 and 4 of the trial. Participants and caregivers were blinded to group assignments. The primary outcome was safety as assessed by neurological tests, medications and beta cell function evaluated over 5 years, representing the end of the trial. RESULTS: No severe study-related adverse events occurred during the 5 year follow-up. None of the dose groups was associated with an increased risk of starting insulin treatment compared with the placebo group. The use of oral hypoglycaemic agents did not differ between the dose groups. After 5 years, fasting C-peptide levels declined in the placebo group (-0.24; 95% CI -0.41 to -0.07 log(10) nmol/l; p = 0.01) and the 500 microg dose group (-0.37; 95% CI -0.57 to -0.17 log(10) nmol/l; p = 0.003), but not in the 4 microg (-0.10; 95% CI -0.28 to 0.07 log(10) nmol/l; p = 0.20), 20 microg (0.04; 95% CI -0.12 to 0.19 log(10) nmol/l; p = 0.58) and 100 microg (0.00; 95% CI -0.20 to -0.20 log(10) nmol/l; p = 0.98) dose groups. CONCLUSIONS/INTERPRETATION: The primary outcome of safety was achieved, since no severe study-related adverse events occurred. TRIAL REGISTRATION: Because the study was initiated before 1 July 2005, the protocol was not registered in a registry. FUNDING: This trial was funded by the National Institutes of Health (grant numbers DK26190 and DK53004), the Swedish Research Council (grant number 72X-14064) and Diamyd Therapeutics (Stockholm, Sweden).
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| 6. |
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| 7. |
- Bekris, L. M., et al.
(författare)
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GAD65 autoantibody epitopes in adult patients with latent autoimmune diabetes following GAD65 vaccination
- 2007
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Ingår i: Diabetic Medicine. - : Wiley. - 1464-5491 .- 0742-3071. ; 24:5, s. 521-526
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Tidskriftsartikel (refereegranskat)abstract
- Aims Subcutaneous injection of recombinant human GAD65 (rhGAD65) in patients with latent autoimmune diabetes in adults (LADA) correlates with an increase in C-peptide levels. In this study we analysed the effect of rhGAD65 administration on the GAD65-specific autoimmune response. Methods Longitudinal serum samples obtained from LADA patients (n = 47) who received 4, 20, 100 or 500 mu g alum-formulated rhGAD65 or placebo by subcutaneous injection twice (4 weeks apart) were analysed for their epitope recognition using GAD65-specific recombinant Fab and GAD65/67 fusion proteins. Results Overall, minor changes in the epitope pattern were observed using either approach. Only in the 500-mu g dosage group was an increase in GAD65Ab level associated with a significant increase in the binding to a conformational epitope located at the middle part of GAD65. Conclusions Our data suggest that the apparent beneficial effects of 20 mu g alum-formulated recombinant human GAD65 is not explained by changes in the GAD65Ab epitope pattern.
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| 8. |
- Krause, Stephanie, et al.
(författare)
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GAD Autoantibody Affinity in Adult Patients With Latent Autoimmune Diabetes, the Study Participants of a GAD65 Vaccination Trial
- 2014
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Ingår i: Diabetes Care. - : American Diabetes Association. - 1935-5548 .- 0149-5992. ; 37:6, s. 1675-1680
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE Patients with latent autoimmune diabetes in adults (LADA) express autoantibodies against the 65-kDa isoform of GAD (GADA). Intervention with recombinant human GAD65 formulated with aluminium hydroxide (GAD-alum) given twice subcutaneously to LADA patients at intervals of 4 weeks was safe and did not compromise beta-cell function in a Phase II clinical trial. GADA affinity has been shown to predict progression to type 1 diabetes. Here, we asked whether GADA affinity was affected by the GAD65 antigen-specific vaccination and/or associated with beta-cell function in participants of this trial. RESEARCH DESIGN AND METHODS GADA affinity was measured in sera of 46 LADA patients obtained prior to the first week and 20 weeks after the second injection with GAD-alum or placebo using competitive binding experiments with [I-125]-labeled and unlabeled human GAD65. RESULTS At baseline, GADA affinities ranged from 1.9 X 10(7) to 5.0 X 10(12) L/mol (median 2.8 X 10(19) L/mol) and were correlated with GADA titers (r = 0.47; P = 0.0009), fasting (r = 0.37; P = 0.01) and stimulated (r = -0.40; P = 0.006) C-peptide concentrations, and HbA(1c) (r = 0.39; P = 0.007). No significant changes in affinity were observed from baseline to week 24. Patients with GADA affinities in the lower first quartile (<4 X 10(9) L/mol) had better preserved fasting C-peptide concentrations at baseline than those with higher affinities (mean 1.02 vs. 0.66 nmol/L; P = 0.004) and retained higher concentrations over 30 months of follow-up (mean 1.26 vs. 0.62 nmol/L; P = 0.01). CONCLUSIONS Intervention with GAD-alum in LADA patients had no effect on GADA affinity. Our data suggest that patients with low GADA affinity have a prolonged preservation of residual beta-cell function.
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| 9. |
- Ortqvist, E, et al.
(författare)
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Changes in GAD65Ab-Specific Antiidiotypic Antibody Levels Correlate with Changes in C-Peptide Levels and Progression to Islet Cell Autoimmunity.
- 2010
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Ingår i: The Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 1945-7197 .- 0021-972X. ; 95, s. 310-318
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Tidskriftsartikel (refereegranskat)abstract
- Context: The previously reported absence of 65-kDa glutamate decarboxylase antibody (GAD65Ab)-specific antiidiotypic antibodies (anti-Id) in type 1 diabetes (T1D) patients at clinical onset could be due to an inability to mount an antibody response to GAD65Ab or a longitudinal decline in anti-Id levels. Objective and Design: We investigated anti-Id levels in longitudinal samples obtained from T1D patients (n = 41) (clinical diagnosis - 12 months), and latent autoimmune diabetes in adults (LADA) patients (n = 32) who received alum-formulated human recombinant GAD65 (baseline - 12 months). We also determined anti-Id levels in a small cohort of Type 2 diabetes patients during their development of autoimmune T cell responses. Results: At clinical onset T1D patients presented no or low anti-Id levels. However, 22/41 T1D patients showed >/=50% increase in GAD65Ab-specific anti-Id levels during follow-up; peaking at 3 (n = 1), 6 (n = 10), 9 (n = 10), or 12 (n = 1) months. Increasing anti-Id levels marked patients who experienced a temporary increase in C-peptide levels. Anti-Id levels correlated significantly with glycated hemoglobin and C-peptide levels at 6 and 9 months (P values ranged from <0.001 to <0.05). In LADA patients receiving placebo, anti-Id levels declined in seven of nine patients, whereas four of five patients receiving 20 mug alum-formulated human recombinant GAD65 showed increasing anti-Id levels. Changes in anti-Id and C-peptide levels closely correlated (P < 0.0001). The significant decline in anti-Id levels (P = 0.03) in T2D patients developing T cell autoimmune responses supports our hypothesis that declining anti-Id levels are associated with developing islet autoimmunity. Conclusions: The close association between GAD65Ab-specific anti-Id levels and beta-cell function may provide a novel marker for the progression of autoimmune diabetes.
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| 10. |
- Papadopoulou, Anastasia, et al.
(författare)
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Gestational diabetes mellitus is associated with TCF7L2 gene polymorphisms independent of HLA-DQB1*0602 genotypes and islet cell autoantibodies.
- 2011
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Ingår i: Diabetic Medicine. - : Wiley. - 1464-5491 .- 0742-3071. ; 28:9, s. 1018-1027
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Tidskriftsartikel (refereegranskat)abstract
- Aims: To test whether the TCF7L2 gene was associated with gestational diabetes, whether the association between TCF7L2 and gestational diabetes was independent of HLA-DQB1*0602 and islet cell autoantibodies, as well as maternal age, number of pregnancies, family history of diabetes and the HLA-DQB1 genotypes, and to test whether the distribution of HLA-DQB1 alleles was affected by country of birth. Methods: We genotyped the rs7903146, rs12255372 and rs7901695 single nucleotide polymorphisms of the TCF7L2 gene in 826 mothers with gestational diabetes and in 1185 healthy control subjects in the Diabetes Prediction in Skåne Study. The mothers were also typed for HLA-DQB1 genotypes and tested for islet cell autoantibodies against GAD65, insulinoma-associated antigen-2 and insulin. Results: The heterozygous genotypes CT, GT and TC of the rs7903146 (T is risk for Type 2 diabetes), rs12255372 (T is risk for Type 2 diabetes) and rs7901695 (C is risk for Type 2 diabetes), respectively, as well as the homozygous genotypes TT, TT and CC of the rs7903146, rs12255372 and rs7901695, respectively, were strongly associated with gestational diabetes (P < 0.0001). These associations remained statistically significant after adjusting for maternal age, number of pregnancies, family history of diabetes and HLA-DQ genotypes and were independent of the presence of islet cell autoantibodies. No interaction was observed between TCF7L2 and HLA-DQB1*0602, which was shown to be negatively associated with gestational diabetes in mothers born in Sweden (P = 0.010). Conclusions: The TCF7L2 was associated with susceptibility for gestational diabetes independently of the presence of HLA-DQB1*0602 and islet cell autoantibodies and other factors such as maternal age, number of pregnancies, family history of diabetes and other HLA-DQ genotypes. The HLA-DQB1*0602 was negatively associated with gestational diabetes in mothers born in Sweden.
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