Gun Forsander

GAD Treatment and Insulin Secretion in Recent-Onset Type 1 Diabetes

BACKGROUND The 65-kD isoform of glutamic acid decarboxylase (GAD) is a major autoantigen in patients with type 1 diabetes mellitus. This trial assessed the ability of alum-formulated GAD (GAD-alum) to reverse recent-onset type 1 diabetes in patients 10 to 18 years of age. METHODS We randomly assigned 70 patients with type 1 diabetes who had fasting C-peptide levels above 0.1 nmol per liter (0.3 ng per milliliter) and GAD autoantibodies, recruited within 18 months after receiving the diagnosis of diabetes, to receive subcutaneous injections of 20 microg of GAD-alum (35 patients) or placebo (alum alone, 35 patients) on study days 1 and 30. At day 1 and months 3, 9, 15, 21, and 30, patients underwent a mixed-meal tolerance test to stimulate residual insulin secretion (measured as the C-peptide level). The effect of GAD-alum on the immune system was also studied. RESULTS Insulin secretion gradually decreased in both study groups. The study treatment had no significant effect on change in fasting C-peptide level after 15 months (the primary end point). Fasting C-peptide levels declined from baseline levels significantly less over 30 months in the GAD-alum group than in the placebo group (-0.21 vs. -0.27 nmol per liter [-0.62 vs. -0.81 ng per milliliter], P=0.045), as did stimulated secretion measured as the area under the curve (-0.72 vs. -1.02 nmol per liter per 2 hours [-2.20 vs. -3.08 ng per milliliter per 2 hours], P=0.04). No protective effect was seen in patients treated 6 months or more after receiving the diagnosis. Adverse events appeared to be mild and similar in frequency between the two groups. The GAD-alum treatment induced a GAD-specific immune response. CONCLUSIONS GAD-alum may contribute to the preservation of residual insulin secretion in patients with recent-onset type 1 diabetes, although it did not change the insulin requirement. (ClinicalTrials.gov number, NCT00435981.)

Glycaemic control and diabetes care utilization in young adults with Type 1 diabetes.

Objectives  To explore how glycaemic control in young adults is related to diabetes care utilization during the transition to adult diabetes care and if these variables differ between males and females.

Influence of the initial management regimen and family social situation on glycemic control and medical care in children with type I diabetes mellitus.

It is well known that social family factors are of importance in diabetes care, but it is not clear whether the initial management regimen can buffer these factors. In a prospective, randomized intervention study, 36 children with diabetes mellitus (type I) were followed, the aim being to study if a family psychosocial intervention at diagnosis could improve glycemic control and minimize hospital admissions. The control group was treated initially in a hospital ward, while the study group received problem‐based learning and family‐therapeutic and social support in an out‐hospital training apartment. A number of family social variables were evaluated at the time of diagnosis and 6, 12 and 24 mo later. Family function was assessed using the self‐estimated Family Climate Test at these same time‐points. HbA1c values and information concerning in‐ and out‐hospital visits to the pediatric clinic were collected for the 5‐y period following diagnosis. We found no association between the offered management regimen and glycemic control or rate of readmission. In the study group only, both parents reported a significant improvement of the family climate. An increased risk for poor glycemic control was recorded in children living in one‐parent families (p= 0.03) or in families where the father had a low level of education (p= 0.04). Younger age (p= 0.05), a single‐parent family (p= 0.05) and poor glycemic control (p= 0.02) were associated with more days of rehospitalization. The rate of divorce in the whole group was at least as high as in the normal population but, surprisingly, maternal dysfunction was associated with lower HbA1c value.

Type 1 diabetes patients born to immigrants to Sweden increase their native diabetes risk and differ from Swedish patients in HLA types and islet autoantibodies.

Delli AJ, Lindblad B, Carlsson A, Forsander G, Ivarsson S‐A, Ludvigsson J, Marcus C, Lernmark Å; for the Better Diabetes Diagnosis (BDD) Study Group. Type 1 diabetes patients born to immigrants to Sweden increase their native diabetes risk and differ from Swedish patients in HLA types and islet autoantibodies.

Zinc Transporter 8 Autoantibodies and Their Association With SLC30A8 and HLA-DQ Genes Differ Between Immigrant and Swedish Patients With Newly Diagnosed Type 1 Diabetes in the Better Diabetes Diagnosis Study

We examined whether zinc transporter 8 autoantibodies (ZnT8A; arginine ZnT8-RA, tryptophan ZnT8-WA, and glutamine ZnT8-QA variants) differed between immigrant and Swedish patients due to different polymorphisms of SLC30A8, HLA-DQ, or both. Newly diagnosed autoimmune (≥1 islet autoantibody) type 1 diabetic patients (n = 2,964, <18 years, 55% male) were ascertained in the Better Diabetes Diagnosis study. Two subgroups were identified: Swedes (n = 2,160, 73%) and immigrants (non-Swedes; n = 212, 7%). Non-Swedes had less frequent ZnT8-WA (38%) than Swedes (50%), consistent with a lower frequency in the non-Swedes (37%) of SLC30A8 CT+TT (RW+WW) genotypes than in the Swedes (54%). ZnT8-RA (57 and 58%, respectively) did not differ despite a higher frequency of CC (RR) genotypes in non-Swedes (63%) than Swedes (46%). We tested whether this inconsistency was due to HLA-DQ as 2/X (2/2; 2/y; y is anything but 2 or 8), which was a major genotype in non-Swedes (40%) compared with Swedes (14%). In the non-Swedes only, 2/X (2/2; 2/y) was negatively associated with ZnT8-WA and ZnT8-QA but not ZnT8-RA. Molecular simulation showed nonbinding of the relevant ZnT8-R peptide to DQ2, explaining in part a possible lack of tolerance to ZnT8-R. At diagnosis in non-Swedes, the presence of ZnT8-RA rather than ZnT8-WA was likely due to effects of HLA-DQ2 and the SLC30A8 CC (RR) genotypes.

A novel triple mix radiobinding assay for the three ZnT8 (ZnT8-RWQ) autoantibody variants in children with newly diagnosed diabetes.

BACKGROUND AND AIMS Autoantibodies against the zinc transporter 8 (ZnT8A) are common in type 1 diabetes (T1D). ZnT8A analyses are complicated by the fact that there are three variants of the autoantigen at amino acid position 325 representing ZnT8-R (Arginine), ZnT8-W (Tryptophan) and ZnT8-Q (Glutamin). The aims of the study were: 1) to develop an autoantigen triple mix Radio-Binding Assay (RBA) for ZnT8A; 2) to identify the individual ZnT8-R,-W,-QA reactivity and 3) to validate the triple mix ZnT8A RBA in children with newly diagnosed T1D. METHODS Serum samples were obtained from 2664 (56% males, n=1436) patients in the Swedish nationwide Better Diabetes Diagnosis (BDD) study representing patients with T1D (97%, n=2582), T2D (1.7%, n=46), MODY (1.0%, n=28) and secondary diabetes (0.3%, n=8). cDNA coding for the C-terminal end of each variant was prepared by site-directed mutagenesis and subcloned into a high efficiency in vitro transcription translation vector. The ZnT8 variants were labeled with 35S-methionine and used in a standard RBA separating free from autoantibody-bound autoantigen with Protein A-Sepharose. RESULTS ZnT8-TripleA was detected in 1678 (65%) patients with T1D, 4 (9%) T2D, 3 (11%) MODY and in none (0%) of the patients with secondary diabetes. Among the T1D patients ZnT8-RA was detected in 1351 (52%) patients, ZnT8-WA in 1209 (47%) and ZnT8-QA in 790 (31%) demonstrating that 1661 (64%) had one or several ZnT8A. The ZnT8-TripleA assay showed a false positive rate of 1.9% (n=49). Only 1.2% (n=32) of the T1D patients were false negative for ZnT8-TripleA compared to 0/46 (0%) of the T2D patients. The precision (intra assay CV) and reproducibility (inter assay CV) of the ZnT8-TripleA assay did not differ from the RBA of the individual ZnT8 variants. CONCLUSION We conclude that the ZnT8-TripleA assay had low false positive and false negative rates. The ZnT8-TripleA assay would therefore be highly suitable not only to analyze patient with newly diagnosed diabetes but also for screening the general population since this assay demonstrated high sensitivity and very high specificity.

Triple specificity of ZnT8 autoantibodies in relation to HLA and other islet autoantibodies in childhood and adolescent type 1 diabetes.

To establish the diagnostic sensitivity of and the relationships between autoantibodies to all three Zinc transporter 8 (Zinc transporter 8 autoantibody to either one, two, or all three amino acid variants at position 325, ZnT8A) variants to human leukocyte antigen (HLA)‐DQ and to autoantibodies to glutamic acid decarboxylase (GADA), insulinoma‐associated protein 2 (IA‐2A), and insulin (IAA).

Metabolic control in children with insulin-dependent diabetes mellitus 5 y after diagnosis. Early detection of patients at risk for poor metabolic control.

Children (n= 38) aged 3‐15 y were randomly chosen, at the time of diabetes diagnosis, for conventional management at a hospital ward, or for treatment partly in a training apartment where the family was offered problem‐based education and special therapeutic support. HbA1c, blood glucose stability, urinary C‐peptide excretions and incidence of hypoglycaemic attacks and diabetes ketoacidosis (DKA) were monitored and some standardized, self‐estimated psychological tests were performed during the first 2 y after diagnosis. During the 3 y thereafter, HbA1c, presence of DKA, microalbuminuria, retinopathy and hypertension were monitored. None of the patients demonstrated signs of diabetes microangiopathy or DKA. The overall mean HbA1c level was 7.2% 5 y after diagnosis and 30% of the children had HbA1c values < 6.3%. There were no differences in the HbA1c values for the patients treated by the different management regimens. Blood glucose variability (SD) was also similar, with 75% of the values in the range of 3–10 mmol/l. Patients with poor glycaemic control (mean HbA1c >8.3%) year 5 after diagnosis had already the second year after diagnosis significantly higher HbA1c values and blood glucose variability. The fathers of these patients demonstrated a higher degree of maladjustment. On the basis of increasing HbA1c values, high blood glucose variability and psychosocial risk factors such as their fathers’emotional responses, patients at risk for poor metabolic control in the future can be identified within 2 y after diagnosis. Efforts and resources can thus be focused at an early stage on this group.

C-peptide in the classification of diabetes in children and adolescents.

Ludvigsson J, Carlsson A, Forsander G, Ivarsson S, Kockum I, Lernmark Å, Lindblad B, Marcus C, Samuelsson U. C‐peptide in the classification of diabetes in children and adolescents.

Low risk HLA-DQ and increased body mass index in newly diagnosed type 1 diabetes children in the Better Diabetes Diagnosis study in Sweden

Objective:Type 1 diabetes and obesity has increased in childhood. We therefore tested the hypothesis that type 1 diabetes human leukocyte antigen DQ (HLA-DQ) risk genotypes may be associated with increased body mass index (BMI).Design:The type 1 diabetes high-risk HLA-DQ A1*05:01-B1*02:01/A1*03:01-B1*03:02 genotype along with lower risk DQ genotypes were determined at the time of clinical onset by PCR and hybridization with allele-specific probes. BMI was determined after diabetes was stabilized.Subjects:A total of 2403 incident type 1 diabetes children below 18 years of age were ascertained in the Swedish national Better Diabetes Diagnosis (BDD) study between May 2005 to September 2009. All children classified with type 1 diabetes, including positivity for at least one islet autoantibody, were investigated.Results:Overall, type 1 diabetes HLA-DQ risk was negatively associated with BMI (P<0.0008). The proportion of the highest risk A1*05:01-B1*02:01/A1*03:01-B1*03:02 genotype decreased with increasing BMI (P<0.0004). However, lower risk type 1 diabetes DQ genotypes were associated with an increased proportion of patients who were overweight or obese (P<0.0001). Indeed, the proportion of patients with the low-risk A1*05:01-B1*02:01/A1*05:01-B1*02:01 genotype increased with increasing BMI (P<0.003). The magnitude of association on the multiplicative scale between the A1*05:01-B1*02:01/A1*05:01-B1*02:01 genotype and increased BMI was significant (P<0.006). The odds ratio in patients with this genotype of being obese was 1.80 (95% confidence interval 1.21–2.61; P<0.006). The increased proportion of overweight type 1 diabetes children with the A1*05:01-B1*02:01 haplotype was most pronounced in children diagnosed between 5 and 9 years of age.Conclusions:Susceptibility for childhood type 1 diabetes was unexpectedly found to be associated with the A1*05:01-B1*02:01/A1*05:01-B1*02:01 genotype and an increased BMI. These results support the hypothesis that overweight may contribute to the risk of type 1 diabetes in children positive for HLA-DQ A1*05:01-B1*02:01.