Fredda Ginsberg-Fellner

Cytotoxic Autoantibodies to Beta Cells in the Serum of Patients with Insulin-Dependent Diabetes Mellitus

We studied serum from 36 patients with insulin-dependent diabetes mellitus (IDDM) for the capacity to lyse beta cells. Immunofluorescence revealed an islet-cell cytoplasmic antibody (ICA) in 20 patients with IDDM and an islet-cell-surface antibody (ICSA) in 23. Neither ICA nor ICSA was found in any of 21 normal controls or 15 patients with non-insulin-dependent diabetes. In the presence of complement. ICSA-positive serum caused significant lysis as measured by release of 51Cr (50.1 +/- 8.8 per cent) from cultured rat islet cells, but ICSA-negative serum did not (17.7 +/- 7.3 per cent) (P < 0.001). Proof that ICSA-positive serum was lytic for beta cells was obtained by a double-fluorescence technique that identified lysed cells by their capacity to take up ethidium bromide and beta cells by their staining with fluorescein-conjugated antibody to insulin. These findings suggest that cytotoxic ICSA contributes to the pathogenesis of IDDM, but the mere presence of ICSA does not appear to be sufficient to produce diabetes; family studies showed that one fourth of the serum samples from nondiabetic first-degree relatives of diabetic probands were ICSA-positive and cytotoxic for beta cells.

Human monoclonal autoantibodies that react with multiple endocrine organs.

MANY human diseases have an autoimmune component. In some, such as myasthenia gravis1 and Hashimotos thyroiditis,2 the autoimmune response is predominantly organ-specific. In other diseases, such ...

The HLA System in Congenital Rubella Patients With and Without Diabetes

The HLA antigens of 173 patients with the congenital rubella syndrome (CR) are reported. Twenty-one of these patients are also clinically diabetic, and among them the frequencies of the HLA antigens DR2 and DR3 are significantly lower and higher, respectively, than in CR patients without diabetes or in controls. These data suggest that the genes that control susceptibility to type I or insulin-dependent diabetes mel-litus are necessary for the development of glucose intolerance in CR patients.

Anti-Insulin Antibodies in Children With Type I Diabetes Mellitus: Genetic Regulation of Production and Presence at Diagnosis Before Insulin Replacement

We evaluated the production of antibodies against insulin in a genetically well-defined population. In the first study, 124 young patients with type I diabetes for longer than 6 mo were included. Anti-insulin antibodies were detected by polyethyleneglycol (PEG) precipitation after incubation of acidified, charcoal-stripped sera with 125I-labeled pork insulin andwere expressed as microunits insulin bound per milliliter whole serum. For comparison, the patients were divided into six groups based on HLA DR antigens: 3/3, 3 /−, 4/4, 4 /− , 3/4, and − / − (– is non-DR3 or -DR4). The mean age of the patients was 14.7 ± 0.5 yr; the duration of diabetes was 5.8 ± 0.4 yr; and the glucose control, as measured byhemoglobin A1c was average (7.6 ± 0.2%). There were no significant differences in any of these parameters among the patients in any of the HLA DR groups. Patients expressing DR3/3 had significantly lower insulin binding than the rest of the groups (2.5 ± 0.4 vs. 13.6 ± 1.4 μU/ml, P < 0.0001). Patients with DR3/− did not differ in insulin-binding capacity from the other groups. The type of insulin used for replacement was not correlated with the serum insulin-binding capacity. In a second study, sera from 48 children, newlydiagnosed with type I diabetes, were examined for the presence of insulin binding before treatment with exogenous insulin and compared with sera from 80 children without diabetes or a family history of diabetes and from 103 unaffected HLA-identical or haploidentical siblings of a child withtype I diabetes. The sera from the newly diagnosed diabetics bound significantly more insulin in the assay (1.02 ± 0.06 μUsol;ml than the sera from either of the two control groups (0.52 ± 0.01 and 0.51 ± 0.02%, respectively, P = 0.0012). Sera from the newly diagnosed girls bound significantly more insulin than did those from the boys (1.13 ± 0.09 vs. 0.89 ± 0.07%, P < 0.02), and there was a highly significant (P = 0.0017) negative correlation between the age at onset of diabetes and the insulin bound by serum before insulin treatment. Finally, sera from six siblings of type I diabetics who became diabetic themselves were obtained when these children were metabolically normal and again just before insulin treatment was begun. Four of these children had a significant increase in their serum insulin binding from normal values to clearly elevated levels over intervals before metabolic decompensation. These data support the following conclusions. The reduced insulin binding previously observed in type I diabetics expressing HLA DR3 can be entirely attributed to the very low binding in individuals homozygous for this antigen. Thus, human antibody response to exogenous insulin is probably regulated by a dominant gene in negative linkage disequilibrium with HLA DR3. Most younger patients have detectable insulin binding at diagnosis of type I diabetes. The level of binding is reduced in older patients, suggesting either that younger children have a better response to insulin released from injured β-cells in a form that is antigenic or that younger children have animmaturity in the clearance of antigen-antibody complexes. Our preliminary data suggest that the elevation in insulin binding is a late event in the pathogenesis of type I diabetes, occurring soon before the symptoms are present.

Gestational diabetes: Impact of home glucose monitoring on neonatal birth weight

Two groups of 58 gestational diabetic women matched for age, prepregnancy weight, height, and parity were studied. The home glucose monitoring study group performed fasting and 1-hour postprandial capillary blood glucose testing after every meal. The control group was followed by conventional treatment. The incidence of macrosomia (birth weight of greater than or equal to 4000 gm) and large (greater than or equal to 90%) for gestational age infants was significantly reduced in the home glucose monitoring group. The mean birth weight of the study group was 3231 +/- 561 gm, while that of the control group was 3597 +/- 721 gm (p less than 0.002). Significantly more patients in the home glucose monitoring group were receiving insulin therapy (50% versus 21%). We believe that intensive home glucose monitoring will allow for the early identification of those gestational diabetic patients needing insulin and thus reduce the incidence of macrosomia and large for gestational age infants.

Ischemia and sensory nerve conduction in diabetes mellitus

Sensory conduction along the median nerve was evaluated during 30 minutes of ischemia in patients with diabetes mellitus. There was abnormal persistence of the sensory evoked potential in 19 of 22 diabetic patients, but not in normal controls, patients with nonmetabolic neuropathies, or 5 of 6 patients with motor neuron diseases. There was an excellent correlation between ischemic resistance and effective control of glucose metabolism, as manifested by Hb A1C levels. These data suggest that abnormal ischemic resistance in diabetes may be the most sensitive indicator of peripheral neural dysfunction even when there are no other electrophysiologic or clinical abnormalities.

HLA Antigens, Cytoplasmic Islet Cell Antibodies, and Carbohydrate Tolerance in Families of Children with Insulin-dependent Diabetes Mellitus

Cytoplasmic pancreatic islet cell antibodies were found in 21﹪ of 244 unaffected first degree relatives of type I diabetic patients. Twenty-five percent of HLA-identical, 35﹪ of HLA-haploidentical, 16﹪ of HLA-nonidentical siblings, and 14﹪ of parents were ICA-positive. In the HLA-identical sibs, irrespective of ICA, and in the 18 ICA-positive parents but not the other groups, increased plasma glucose levels were observed after the administration of glucose. In most children, these were associated with reduced insulin levels, while in the adults elevated insulin responses were noted. In 48﹪ of the ICA-positive children and 84﹪ of the ICA-positive parents, other evidence of “autoimmunity” was obtained either by history or by testing for specific autoantibodies. Two of the originally unaffected HLA-identical and ICA-positive siblings developed diabetes during the course of the study. These findings, plus previously reported data in families with two diabetic sibs demonstrating that the empiric risk for developing IDDM is of the order of 30﹪ for HLA-identical sibs but < 5﹪ for those that are HLA-haploidentical, suggest that HLA-identity may be a useful predictor of potential type I diabetes. The presence of ICA may, at times, portend the need for future antidiabetic therapy but prospective studies must be continued to fully elucidate this relationship.

Elevated hemoglobin A1c and low-density lipoprotein cholesterol levels in thiazide-treated diabetic patients.

Despite the well-known hyperglycemic effect of thiazide diuretics, these agents are often administered to diabetic patients. This study compared 89 insulin-treated diabetic patients receiving hydrochlorothiazide, 57 receiving furosemide, and 255 receiving no diuretic. Hemoglobin A1c level was 7.2 +/- 1.8 percent (mean +/- SD) with hydrochlorothiazide, significantly higher than the levels of 5.9 +/- 2.3 percent with furosemide and 6.4 +/- 2.0 percent with no diuretic. Low-density lipoprotein cholesterol level was 154 +/- 43 mg/dl with hydrochlorothiazide, but 134 +/- 42 mg/dl with furosemide and 130 +/- 42 mg/dl with no diuretic. Multivariate analysis showed that the associations remained significant after adjustment for age, sex, race, type and duration of diabetes, body mass index, blood pressure, serum potassium level, insulin dose, and treatment with other medications. These findings suggest that treatment with thiazide diuretics in the diabetic population may increase low-density lipoprotein cholesterol and hemoglobin A1c levels.

C-peptide reserve in insulin-dependent diabetes

SummaryResidual beta cell secretory capacity was assessed in short term (2 months to 2 years) and long term (5 to 8 years) insulin-dependent diabetics by measurement of serum C-peptide immunoreactivity during three provocative tests: glucose, tolbutamide, and glucagon. Minimal C-peptide secretion could be detected in only one out of seven long term diabetics by the stimulatory tests. All seven short-term diabetics responded to at least one provocative test of beta cell reserve, although these responses were blunted. The greatest C-peptide responses occurred after glucagon administration (mean increase 0.62 pmol/ml) in short-term responders. Patients who responded to one test did not necessarily respond to another stimulus. There was no correlation between basal C-peptide levels and the ability to provoke further C-peptide secretion by any of the three tests. C-peptide responses did not correlate with % Haemoglobin A1c, mean fasting blood glucose levels, or mean blood glucose concentrations during an oral glucose tolerance test. The data indicate that stimulation tests are only useful in assessing endogenous beta cell reserve in patients with diabetes of less than 5 years duration. In diabetics of longer duration there is little insulin reserve above basal levels.

Cytotoxic Islet Cell Surface Antibodies (ICSA) in Patients with Type I Diabetes and Their First-degree Relatives

We describe a nonradioactive microcytotoxicity assay for ICSA using a cloned rat insulinoma cell line. This assay system had good reproducibility (r = 0.93) and was suitable for the study of large numbers of samples. The following results were obtained by testing the sera of 111 patients with IDDM (type I diabetes) and all of their first-degree relatives. (1) Thirty-five percent of IDDM patients had ICSA, as compared with only 2% of healthy controls. (2) ICSA was found more frequently in patients within 2 yr of onset (45%) than in those with disease for longer than 2 yr (27%) (P < 0.05). (3) The prevalence of ICSA was associated with the presence of cytoplasmic islet cell antibodies (ICA) (P < 0.05). (4) No association was found between the prevalence of ICSA and specific HLA-DR aileles. Association with the HLA haplotypes in families with ICSA-positive probands, on the other hand, is suggested although not proven by these data. (5) Among the nondiabetic relatives of IDDM patients, 5% of the parents and 14% of the sibs had ICSA. Increased prevalence of ICSA occurred in the unaffected sibs of ICSA-positive probands (31%) but not in those of ICSA-negative probands (4%) (P < 0.001); in fact, therelatives of ICSA-negative probands had ICSA with a frequency not higher than in unrelated controls. (6) Female relatives of ICSA-positive probands were more often ICSA-positive than males, but no such difference was found among probands. (7) In multiplex sibships, ICSA were not associated with disease in the sibs. These results suggest that the persistent presence of ICSA in relativesof IDDM patients is determined by a combination of environmental and genetic factors, including sex.