Interferon autoantibodies associated with AIRE deficiency decrease the expression of IFN-stimulated genes.

Neutralizing autoantibodies to type I, but not type II, interferons (IFNs) are found at high titers in almost every patient with autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED), a disease caused by AIRE gene mutations that lead to defects in thymic T-cell selection. Combining genome-wide expression array with real time RT-PCR assays, we here demonstrate that antibodies against IFN-alpha cause highly significant down-regulation of interferon-stimulated gene expression in cells from APECED patients' blood by blocking their highly dilute endogenous IFNs. This down-regulation was lost progressively as these APECED cells matured in cultures without neutralizing autoantibodies. Most interestingly, a rare APECED patient with autoantibodies to IFN-omega but not IFN-alpha showed a marked increase in expression of the same interferon-stimulated genes. We also report unexpected increases in serum CXCL10 levels in APECED. Our results argue that the breakdown of tolerance to IFNs in AIRE deficiency is associated with impaired responses to them in thymus, and highlight APECED as another autoimmune disease with associated dysregulation of IFN activity.

Childhood obesity and insulin resistance.

Insulin resistance (IR) in childhood has importance to the understanding and prevention of the growing epidemic of insulin resistance syndrome (IRS) in adults with attendant obesity, type 2 diabetes (T2DM), atherosclerotic diseases, hypertension, gout, non-alcoholic, steato-hepatitis (NASH), gall bladder disease, nephropathy, polycystic ovarian disease (PCOS), infertility and premature senility. The severity of IR and its' complications in children unfortunately and usually progresses in their pubertal transition to adulthood; affected young children are more likely than adults to have underlying causal monogenic disorders; the sequence of natural history and events give insights into disease pathogeneses, and optimal life style choices that last are best made during the early formative years. Some features of IR in children discussed herein are: a strong tendency to low birth weight for gestational age, adverse effects of adrenarche and therapeutic steroid therapy, predisposition to premature pubarche, acanthosis nigricans, tall stature despite pituitary GH suppression, allergic diathesis, hyperandrogenism and PCOS, dyslipidemia and fatty liver disease, and diagnosis by clinical and biochemical markers of IR including insulin regulated hepatic hormonal binding proteins such as IGFBP-1. The national preoccupation with the "metabolic syndrome" T2DM and obesity, should be appropriately directed to an improved understanding of IR in children and their management, if the looming health crisis in affected adults is to be seriously addressed. The nation is facing its' first generation of children who will be less healthy and die younger than the previous generation (Marks (2005) Presentation to the American Association of Diabetes Educators 32nd Annual Meeting and Exhibition, August 10-13, Washington, DC).

Insulin-like growth factor binding protein-1 to screen for insulin resistance in children.

BACKGROUND: Diabetes and atherosclerosis are burgeoning health problems complicating obesity-associated insulin resistance (IR). Early detection of IR in children is a key to preventative strategies. Since peripheral insulin levels insensitively reflect hepatic insulin fluxes, we studied the insulin-regulated hepatic insulin-like growth factor binding proteins (IGFBPs)-1 and -3 as possible screening markers of childhood IR. METHODS: The tolbutamide-modified frequently sampled intravenous glucose tolerance test (FSIVGTT) and the oral glucose tolerance test (OGTT) were performed in 118 subjects < 21 years old with obesity. The relationships between insulin sensitivity index by minimal modeling (SiIVGTT), other Sis derived from fasting and OGTT insulin and glucose values, and the candidate serum markers were sought. RESULTS: Significant correlation was found between IGFBP-1 and SiIVGTT, similar to the correlations of insulin sensitivity indices with SiIVGTT. In children < or = 10 years old, correlation of IGFBP-1 with SiIVGTT was the strongest. All (100%) subjects with IR defined by SiIVGTT < 4.5 +/- 0.5 x 10(-4) min(-1) /(microIU/mL) had inappropriately low IGFBP-1 levels. IGFBP-3 was not correlated with SiIVGTT. CONCLUSIONS: IGFBP-1 levels decrease with obesity and IR. We propose that in young subjects, especially children under the age of 10 years, IGFBP-1 is a convenient and sensitive marker of IR, whereas elevated fasting insulin is less sensitive but more specific.

Insulin pump therapy from the time of diagnosis of type 1 diabetes.

BACKGROUND: This study was designed to test the feasibility and efficacy of continuous subcutaneous insulin infusion (CSII) being instituted within 1 month of diagnosis of type 1 diabetes mellitus (T1DM). METHODS: Twenty-eight consecutive patients with newly diagnosed T1DM with a mean age of 12.1 +/- 6.2 years were placed on CSII, as early as within 1 day of their diagnosis. All accepted CSII when offered it, and none elected to discontinue CSII after follow-up periods of up to 3 years. RESULTS: Hemoglobin A1c levels declined from an initial mean of 10.5 +/- 2.4% to between 6.5% and 7.4% over the next 18 months, at a mean insulin requirement of 0.33 units/kg/day at 3 months, which gradually rose to 0.58 units/kg/day by 18 months. Endogenous insulin secretion, measured by C-peptide values, remained stable during the first 12 months after diagnosis. There was no significant weight gain for the duration of the study (20.7 kg/m(2) vs. a peak of 22.1 kg/m(2) at 12 months, P = 0.54). CONCLUSIONS: The study provided a positive experience with CSII as the initial insulin replacement therapy in newly diagnosed patients with T1DM with excellent clinical outcomes and apparent prolongations of the honeymoon period. It remains to be proven by random patient assignment whether endogenous insulin secretion is better preserved with CSII as an initial ongoing treatment modality and whether long-term complications are reduced by this approach.

Oral insulin therapy to prevent progression of immune-mediated (type 1) diabetes.

Repeated ingestion of insulin has been suggested as an immune tolerization therapy to prevent immune-mediated (type 1) diabetes. We performed a placebo-controlled, two-dose, oral insulin tolerance trial in newly diagnosed (< 2 years) diabetic patients who had required insulin replacement for less than 4 weeks and were found to have cytoplasmic islet cell autoantibodies (ICAs). No oral hypoglycemic agents were permitted during the trial. Endogenous insulin reserves were estimated at six-month intervals by plasma C-peptide responses to a mixed meal. Positive ICAs were found in 262 (31%) of the 846 patients screened. Of the 197 who agreed to participate, 187 could be followed for 6 to 36 months. Endogenous insulin retention was dependent upon initial stimulated C-peptide response, age at diabetes onset, and numbers of specific islet cell autoantibodies found. Oral insulin improved plasma C-peptide responses in patients diagnosed at ages greater than 20 years, best seen at the low (1 mg/day) over the high (10 mg/day) insulin dose (P = .003 and P = .01, respectively). In patients diagnosed before age 20 years, the 1 mg dose was ineffective, whereas the 10 mg dose actually accelerated C-peptide loss (P = .003). There were no adverse effects. If confirmed, these findings suggest that diabetic patients over age 20 years with ICA evidence of late-onset immune-mediated diabetes should be considered for oral insulin at 1 mg/day to better retain endogenous insulin secretion.

NKT cells and type-1 diabetes and the "hygiene hypothesis" to explain the rising incidence rates.

Immune-mediated (type-1) diabetes (IMD) is a multigenetic disease that is strongly influenced by the environment. Whereas the incidence rates are steadily rising worldwide, less than half of affected identical twins ever become concordant for IMD or even beta-cell autoimmunity. Worldwide, it is the tropical regions of the world that are replete in infectious and parasitic diseases that are the least affected. Repeated efforts to identify the putative inductive agents for beta-cell autoimmunity have proved unrewarding. Rather, we suggest that some environments are less protective than others and argue that it is the fall in incidences of infectious diseases and intestinal parasites that are likely responsible for the rise in autoimmune diseases like IMD in the West. Nonobese diabetic (NOD) mice reared in gnotobiotic environments have only worsened diabetes, while recent studies suggest that multiple defects in immune tolerance to self must be present before IMD can develop in the human or mouse. We speculate herein that the deficiency in natural killer T (NKT) cells in IMD in both species may be both genetic and environmentally influenced, predisposing to pancreatic beta-cell autoimmunity through a dysfunction of immunoregulatory T cells, with defective peripheral control of islet cell protein autoreactive cytotoxic CD8+ T cells. The encouraging results in NOD mice using alpha-galactosylceramide to stimulate NKT cells now warrant trials with this and other glycolipid NKT cell-stimulating agents in humans. Since it has become apparent that autoimmune diseases such as IMD are the result of an underlying immunodeficiency state, we strongly argue that its effective prevention will likely come through the use of immunostimulation and not through side effect-prone immunosuppression.

Whole-exome sequencing identifies novel LEPR mutations in individuals with severe early onset obesity.

OBJECTIVE: Obesity is a major public health problem that increases the risk for a broad spectrum of co-morbid conditions. Despite evidence for a strong genetic contribution to susceptibility to obesity, previous efforts to discover the relevant genes using positional cloning have failed to account for most of the apparent genetic risk variance. DESIGN AND METHODS: Deploying a strategy combining analysis of exome sequencing data in extremely obese members of four consanguineous families with segregation analysis, we screened for causal genetic variants. Filter-based analysis and homozygosity mapping were used to identify and prioritize putative functional variants. RESULTS: Two novel frameshift mutations in the leptin receptor in two of the families were identified. CONCLUSIONS: These results provide proof-of-principle that whole-exome sequencing of families segregating for extreme obesity can identify causal pathogenic mutations. The methods described here can be extended to additional families segregating for extreme obesity and should enable the identification of mutations in novel genes that predispose to obesity.

Basal insulin requirements on continuous subcutaneous insulin infusion during the first 12 months after diagnosis of type 1 diabetes mellitus.

INTRODUCTION: While the endogenous first-phase insulin response has disappeared by the time of diagnosis of type 1 diabetes mellitus (T1DM), anecdotal evidence suggests that these patients can continue to have a second-phase insulin response during the first 12 months after diagnosis. We hypothesized that patients who are started on continuous subcutaneous insulin infusion (CSII) at the time of diagnosis of T1DM would have a lower basal insulin requirement than the 40-60% usually expected. METHODS: We analyzed 38 patients with T1DM, age 9.9 +/- 6.4 years, 71% male, who were started on CSII within the first month of diagnosis. RESULTS: Average basal insulin requirements were 47-49% of total daily dose during the first 12 months after diagnosis and decreased from 0.30 U/kg/day at diagnosis to 0.20 U/kg/day by 12 months. Baseline percentage of basal insulin was significantly correlated with hemoglobin A1c at baseline and at six months. The percentage of basal insulin requirement at 12 months after diagnosis was significantly correlated with baseline body mass index (BMI) and current BMI. No other correlations between percentage of basal insulin requirements and any other factors were seen. CONCLUSION: Our data suggest that, even though some endogenous insulin production remains during the first year after diagnosis of T1DM, the distribution of basal versus total daily insulin requirements remains the same as in the general population of people with diabetes. There may be benefits to starting patients on a higher basal rate at time of diagnosis for overall glycemic control during the first six months. Further research is needed to optimize starting insulin doses to maximize their potential in preserving beta-cell function.

Guidelines and recommendations for laboratory analysis in the diagnosis and management of diabetes mellitus.

BACKGROUND: Multiple laboratory tests are used in the diagnosis and management of patients with diabetes mellitus. The quality of the scientific evidence supporting the use of these assays varies substantially. APPROACH: An expert committee drafted evidence-based recommendations for the use of laboratory analysis in patients with diabetes. An external panel of experts reviewed a draft of the guidelines, which were modified in response to the reviewers' suggestions. A revised draft was posted on the Internet and was presented at the AACC Annual Meeting in July, 2000. The recommendations were modified again in response to oral and written comments. The guidelines were reviewed by the Professional Practice Committee of the American Diabetes Association. CONTENT: Measurement of plasma glucose remains the sole diagnostic criterion for diabetes. Monitoring of glycemic control is performed by the patients, who measure their own plasma or blood glucose with meters, and by laboratory analysis of glycated hemoglobin. The potential roles of noninvasive glucose monitoring, genetic testing, autoantibodies, microalbumin, proinsulin, C-peptide, and other analytes are addressed. SUMMARY: The guidelines provide specific recommendations based on published data or derived from expert consensus. Several analytes are of minimal clinical value at the present time, and measurement of them is not recommended.

HLA-DR3 and DR4 and their relation to the incidence and progression of diabetic retinopathy.

PURPOSE: Cross-sectional data from the Wisconsin Epidemiologic Study of Diabetic Retinopathy indicated that patients with HLA-DR4, but not DR3, were more likely to have prevalent proliferative retinopathy than those without both antigens. We describe the relation of HLA-DR3 and DR4 antigens to the 14-year incidence and progression of diabetic retinopathy and macular edema in this cohort. DESIGN: A population-based cohort study. PARTICIPANTS: A probability sample of male and female patients receiving primary care for diabetes in 11 counties of southern Wisconsin. METHODS: Participants were invited for a baseline examination in 1980 to 1982, with follow-up examinations at 4, 10, and 14 years later. At the 4-year examination, a random sample of participants (n = 428) diagnosed with diabetes before the age of 30 and taking insulin were selected for HLA-DR typing. MAIN OUTCOME MEASURES: Fourteen-year incidence and progression of diabetic retinopathy and macular edema based on masked stereoscopic fundus photographic grading. RESULTS: There was no relation between HLA-DR3 and DR4 status with the 14-year incidence and progression of diabetic retinopathy, progression to proliferative retinopathy, and incidence of macular edema. Patients with either HLA-DR3 or DR4 were less likely to progress to proliferative retinopathy compared with those who were negative for both, although these relations were not statistically significant. The associations did not vary after adjusting for hypertension status, baseline retinopathy, and glycosylated hemoglobin levels, or after stratifying by duration of diabetes (less than 10 years vs. 10 years or more) and age at diagnosis of diabetes (less than 15 years vs. 15 years or more). Furthermore, 10-year mortality and 14-year nephropathy rates did not differ by HLA-DR3 or DR4 status, suggesting that selective mortality did not explain the pattern of associations seen. CONCLUSIONS: In contrast to the initial cross-sectional findings, these data suggest that HLA-DR3 or DR4 status is unrelated to 14-year incidence and progression of diabetic retinopathy. The discrepancy may be related to increasing homogeneity of retinopathy and diminishing power to detect small differences, but it may also reflect the uncertain and inconsistent effects of HLA-DR3 or DR4 on the development and progression of diabetic retinopathy.