Reduced morbidity at diagnosis and improved glycemic control in children previously enrolled in DiPiS follow-up.

AIMS/HYPOTHESIS: Children participating in longitudinal type 1 diabetes prediction studies were reported to have less severe disease at diabetes diagnosis. Our aim was to investigate children who from birth participated in the Diabetes Prediction in Skåne (DiPiS) study for metabolic status at diagnosis and then continued to be followed for 2 yr of regular clinical care. METHODS: Children, followed in DiPiS before diagnosis, were compared to children in the same birth cohort, who did not participate in follow-up. Metabolic status, symptoms at diagnosis as well as hemoglobin A1c (HbA1c) and doses of insulin at 3, 6, 12, and 24 months after diagnosis were compared. RESULTS: Children, followed in DiPiS and diagnosed at 2-12 yr of age, had 0.8% (9 mmol/mol) lower HbA1c at diagnosis than those who were not followed (p = 0.006). At diagnosis, fewer DiPiS children had symptoms (p = 0.014) and ketoacidosis at diagnosis were reduced (2% compared to 18%, p = 0.005). During regular clinical care, HbA1c levels for the DiPiS children remained lower both at 12 (0.4% (4 mmol/mol); p = 0.009) and 24 months (0.8% (9 mmol/mol) p < 0.001) after diagnosis, despite no difference in total daily insulin between the two groups. CONCLUSIONS: Participation in prospective follow-up before diagnosis of type 1 diabetes leads to earlier diagnosis with fewer symptoms, decreased incidence of ketoacidosis as well as better metabolic control up to 2 yr after diagnosis. Our data indicate that metabolic control at the time of diabetes diagnosis is important for early metabolic control possibly affecting the risk of long-term complications.

Glucose tolerance and beta-cell function in islet autoantibody-positive children recruited to a secondary prevention study.

AIMS: Children with type 1 diabetes (T1D) risk and islet autoantibodies are recruited to a secondary prevention study. The aims were to determine metabolic control in relation to human leukocyte antigen (HLA) genetic risk and islet autoantibodies in prepubertal children. METHODS: In 47 healthy children with GADA and at least one additional islet autoantibody, intravenous glucose tolerance test (IvGTT) and oral glucose tolerance test (OGTT) were performed 8-65 d apart. Hemoglobin A1c, plasma glucose as well as serum insulin and C-peptide were determined at fasting and during IvGTT and OGTT. RESULTS: All children aged median 5.1 (4.0-9.2) yr had autoantibodies to two to six of the beta-cell antigens GAD65, insulin, IA-2, and the three amino acid position 325 variants of the ZnT8 transporter. In total, 20/47 children showed impaired glucose metabolism. Decreased (≤ 30 µU/mL insulin) first-phase insulin response (FPIR) was found in 14/20 children while 11/20 had impaired glucose tolerance in the OGTT. Five children had both impaired glucose tolerance and FPIR ≤ 30 µU/mL insulin. Number and levels of autoantibodies were not associated with glucose metabolism, except for an increased frequency (p = 0.03) and level (p = 0.01) of ZnT8QA in children with impaired glucose metabolism. Among the children with impaired glucose metabolism, 13/20 had HLA-DQ2/8, compared to 9/27 of the children with normal glucose metabolism (p = 0.03). CONCLUSION: Secondary prevention studies in children with islet autoantibodies are complicated by variability in baseline glucose metabolism. Evaluation of metabolic control with both IvGTT and OGTT is critical and should be taken into account before randomization. All currently available autoantibody tests should be analyzed, including ZnT8QA.

Annual screening detects celiac disease in children with type 1 diabetes.

OBJECTIVE: To investigate the prevalence of celiac disease (CD) in a cohort of type 1 diabetes mellitus (T1DM) children and adolescents at the time of clinical diagnosis and to evaluate the screening procedure and possible role of human leukocyte antigen (HLA)-DQ during a 5-yr follow-up. RESEARCH DESIGN AND METHODS: The study group was a cohort of 300 newly diagnosed T1DM children and youths younger than 20 yr followed for 5 yr at six clinical centers for pediatric diabetes in the region Skåne in Sweden. Immunoglobulin A endomysium antibodies were used to screen the patients annually to be considered for an intestinal biopsy. All patients were analyzed for HLA-DQA1-B1 genotypes. RESULTS: While 0.7% (2/300) already had a diagnosed symptomatic CD, an additional 3% (10/300) had silent CD at the diagnosis of T1DM. During follow-up, another 6% (17/300) developed CD as follows: 10 after 1 yr, 5 after 2 yr, 1 after 3 yr, and 1 after 5 yr. Therefore, the cumulative frequency of CD confirmed by intestinal biopsies was 10% (29/300). HLA genotypes among T1DM patients developing CD were not different from those among patients with T1DM alone. CONCLUSIONS: Our study confirmed the low prevalence (0.7%) of diagnosed symptomatic CD at the time of clinical diagnosis but document by screening an increasing prevalence of silent CD during a 5-yr follow-up to reach an overall prevalence of 10%. We suggest that children with T1DM should be screened for CD at the onset of T1DM and annually for a minimum of at least 2 yr. HLA genotypes among T1DM patients developing CD were not different from those among patients with T1DM alone.

An Increased Diagnostic Sensitivity of Truncated GAD65 Autoantibodies in Type 1 Diabetes May Be Related to HLA-DQ8.

N-terminally truncated (96-585) GAD65 (tGAD65) autoantibodies may better delineate type 1 diabetes than full-length GAD65 (fGAD65) autoantibodies. We aimed to compare the diagnostic sensitivity and specificity between fGAD65 and tGAD65 autoantibodies for type 1 diabetes in relation to HLA-DQ. Sera from children and adolescents with newly diagnosed type 1 diabetes (n = 654) and healthy control subjects (n = 605) were analyzed in radiobinding assays for fGAD65 (fGADA), tGAD65 (tGADA), and commercial 125I-GAD65 (RSRGADA) autoantibodies. The diagnostic sensitivity and specificity in the receiver operating characteristic curve did not differ between fGADA and tGADA. At the optimal cutoff, the diagnostic sensitivity for fGADA was lower than tGADA at similar diagnostic specificities. In 619 patients, 64% were positive for RSRGADA compared with 68% for fGADA and 74% for tGADA. Using non-DQ2/non-DQ8 patients as reference, the risk of being diagnosed with fGADA and tGADA was increased in patients with DQ2/2 and DQ2/8. Notably, logistic regression analysis suggested that DQ8/8 patients had an increased risk to be diagnosed with tGADA (P = 0.003) compared with fGADA (P = 0.09). tGADA had a higher diagnostic sensitivity for type 1 diabetes than both fGADA and RSRGADA. As DQ8/8 patients represent 10-11% of patients with newly diagnosed type 1 diabetes <18 years of age, tGADA analysis should prove useful for disease classification.

Relationship between Ljungan virus antibodies, HLA-DQ8, and insulin autoantibodies in newly diagnosed type 1 diabetes children.

Environmental factors, including viral infections, may explain an increasing and fluctuating incidence of childhood type 1 diabetes (T1D). Ljungan virus (LV) isolated from bank voles have been implicated, but it is unclear whether LV contributes to islet autoimmunity, progression to clinical onset, or both, of T1D. The aim was to test whether LV antibodies (LVAb) were related to HLA-DQ and islet autoantibodies in newly diagnosed T1D patients (n=676) and controls (n=309). Patients, 0-18 years of age, diagnosed with T1D in 1996-2005 were analyzed for LVAb, HLA-DQ genotypes, and all seven known islet autoantibodies (GADA, IA-2A, IAA, ICA, ZnT8RA, ZnT8WA, and ZnT8QA). LVAb at 75(th) percentile, defined as cut off, was 90 (range 6-3936) U/mL and 4(th) quartile LVAb were found in 25% (170/676) of which 64% were <10 (n=108, p<0.0001), and 27% were<5 (n=45; p<0.0001) years old. The 4(th) quartile LVAb in children <10 years of age correlated to HLA DQ2/8, 8/8, and 8/X (p<0.0001). Furthermore, in the group with 4(th) quartile LVAb, 55% were IAA positive (p=0.01) and correlation was found between 4(th) quartile LVAb and IAA in children <10 years of age (p=0.035). It is concluded that 1) LVAb were common among the young T1D patients and LVAb levels were higher in the younger age groups; 2) 4(th) quartile LVAb correlated with IAA; and 3) there was a correlation between 4(th) quartile LVAb and HLA-DQ8, particularly in the young patients. The presence of LVAb supports the notion that prior exposure to LV may be associated with T1D.

Genetic and perinatal factors as risk for childhood type 1 diabetes.

The mechanisms by which gestational infections, blood incompatibility, birth weight, mother's age and other prenatal or neonatal events increase the risk for type 1 diabetes are not understood. Studies so far have been retrospective, and there is a lack of population-based prospective studies. The possibility of identifying children at type 1 diabetes risk among first-degree relatives has resulted in prospective studies aimed at identifying postnatal events associated with the appearance of autoantibody markers for type 1 diabetes and a possible later onset of diabetes. However, the majority (85%) of new onset type 1 diabetes children do not have a first-degree relative with the disease. Population-based studies are therefore designed to prospectively analyse pregnant mothers and their offspring. One such study is DiPiS (Diabetes Prediction in Skåne), which is examining a total of about 10,000 pregnancies expected every year in the Skåne (Scania) region of Sweden that has 1.1 million inhabitants. Blood samples from all mothers in this region are obtained during pregnancy and at the time of delivery. Cord blood is analysed for HLA high-risk alleles and for autoantibodies against the 65 kD isoform of glutamic acid decarboxylase (GADA), the protein tyrosine phosphatase-related IA-2 antigen (IA-2A) and insulin (IAA) as a measure of prenatal autoimmune exposure. Identifying high-risk children by genetic, autoimmune and gestational risk factors followed by prospective analyses will make it possible to test the hypothesis that gestational events may trigger beta cell autoimmunity as a prerequisite for childhood type 1 diabetes.