Early expression of antiinsulin autoantibodies of humans and the NOD mouse: Evidence for early determination of subsequent diabetes

Abstract

With the development of an insulin autoantibody (IAA) assay performed in 96-well filtration plates, we have evaluated prospectively the development of IAA in NOD mice (from 4 weeks of age) and children (from 7 to 10 months of age) at genetic risk for the development of type 1 diabetes. NOD mice had heterogeneous expression of IAA despite being inbred. IAA reached a peak between 8 and 16 weeks and then declined. IAA expression by NOD mice at 8 weeks of age was strongly associated with early development of diabetes, which occurred at 16 -18 weeks of age (NOD mice IAA ؉ at 8 weeks: 83% (5͞6) diabetic by 18 weeks versus 11% (1͞9) of IAA negative at 8 weeks; P < .01). In man, IAA was frequently present as early as 9 months of age, the first sampling time. Of five children found to have persistent IAA before 1 year of age, four have progressed to diabetes (all before 3.5 years of age) and the fifth is currently less than age 2. Of the 929 children not expressing persistent IAA before age 1, only one has progressed to diabetes to date (age onset 3), and this child expressed IAA at his second visit (age 1.1). In new onset patients, the highest levels of IAA correlated with an earlier age of diabetes onset. Our data suggest that the program for developing diabetes of NOD mice and humans is relatively ''fixed'' early in life and, for NOD mice, a high risk of early development of diabetes is often determined by 8 weeks of age. With such early determination of high risk of progression to diabetes, immunologic therapies in humans may need to be tested in children before the development of IAA for maximal efficacy.insulin autoantibodies ͉ radioassay ͉ type 1 diabetes T ype 1A diabetes mellitus, as defined by an expert panel of the American Diabetes Association, is characterized by the presence of antiislet autoantibodies (1). There has been tremendous progress in defining islet autoantigens and developing antiislet autoantibody assays (2-4). In the most recent Immunology of Diabetes Workshop, a series of antiislet autoantibody assays were compared (2). Although the GAD65 autoantibody (GAA) and ICA512 (IA-2) autoantibody (ICA512AA) assays showed good concordance between laboratories, the insulin autoantibody (IAA) assays were divergent, with marked differences between laboratories in sensitivity and specificity. In this workshop, many of the IAA assays utilizing Ͻ600 l of sera had sensitivities Ϸ1͞2 of those utilizing a larger volume of serum (2). It is likely that such marked differences in interlaboratory measurement of IAA and the technical difficulty of current assays contributes to differences in the reported importance of IAA for disease prediction.Despite the difficulties of IAA determination, a number of laboratories have routinely measured IAA with large sera volume assays for large series of patients followed to the development of diabetes. Studies from multiple countries have reported that IAA has an important role in diabetes prediction (5-8). Antiinsulin autoantibodies appear to be unique in that their levels are ...

Enhanced trafficking to the pancreatic lymph nodes and auto-antigen presentation capacity distinguishes peritoneal B lymphocytes in non-obese diabetic mice

“…Antigen presentation assay NOD and BALB/c mice were immunised subcutaneously on the hind flank with 50 μg insulin peptide (Insulin B [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]; Anaspec, San Jose, CA, USA). After 10 days, spleens were collected from these animals and splenic CD4 + T cells purified using CD4 MicroBeads (Miltenyi Biotec, Bergisch Gladbach, Germany).…”

“…The depletion of peritoneal B cells also protects NOD mice from type 1 diabetes [6]. Insulin autoantibodies measured by competitive radiobinding assays are typically of high affinity in humans and in NOD mice [8,9]. However, low-affinity insulin-binding autoantibodies that interact with multiple antigens have been reported in young NOD mice [10].…”

A new model of insulin-deficient diabetes: male NOD mice with a single copy of Ins1 and no Ins2

“…Insulin autoantibody (IAA) assay IAA was measured with a 96-well filtration plate micro-IAA assay as previously described [6] and expressed as an index. A value of 0.01 or greater is considered positive and exceeds the 99th percentile of normal controls.…”

In insulin-autoantibody-positive children from the general population, antibody affinity identifies those at high and low risk

“…Autoantibodies against islet beta cell antigens can appear early in life and predict the development of type 1 diabetes [1][2][3][4][5]. Autoantibodies against insulin (IAA) are often the first autoantibodies that are detected in childhood.…”