Circulating Islet Cell Antibodies Research Articles

Descriptive and Retrospective Study on the Prevalence of Overweight and Obesity among Patients with Type 2 Diabetes Mellitus

Weight gain has been declared as one of the top 10 global health risks by the World Health Organization (WHO). In the past few decades, obesity has increased alarmingly around the world. Most patients with type 1 diabetes possess anti-insulin antibodies before receiving insulin therapy. About 80% of patients with type 1 diabetes have circulating islet cell antibodies. Both developed and developing countries are facing a medical disaster due to obesity. The incidence of type 2 diabetes is correlated with insulin resistance. Insulin resistance does not lead to hyperglycemia in most obese individuals. The purpose of this study is to determine whether Type 2 diabetes mellitus patients are overweight or obese, and to identify risk factors for such disease. Preventing diabetes complications and reducing its prevalence. A study was conducted to determine whether obesity increases the risk of diabetes. Identify dyslipidemia in Type 2 diabetics by studying its prevalence pattern. The age range of 40 to 70 years for type 2 diabetes mellitus patients. The study also excluded participants with dyslipidemia. Various metabolic parameters were measured as well as baseline anthropometric indices (BMI, WHR). We found 25 patients in normal weight category, 3 patients in underweight category, 50 patients in overweight category, and 53 patients in obese category among the patients aged 40-50 years. Developing appropriate and controlled strategies for improving nutrition and promoting weight loss is urgently needed to mitigate Type 2 diabetes patients' increasing health challenges.

Clinical Profile and Etiology of Diabetes Mellitus With Onset at Less Than 6 Months of Age

The aim of this study was to determine the clinical profile and etiology of diabetes mellitus (DM) with onset at < 6 months of age. All children aged < 6 months diagnosed with DM at a tertiary referral center between 2005 and 2008 were included in the study. Three cases of DM with onset at < 6 months of age were identified. All patients were female and of the same ethnic origin, with nonconsanguineous parents. Intrauterine growth retardation was noted in all three patients, and diabetic ketoacidosis and hypertriglyceridemia in two of the three. Blood samples from all three patients and their parents were analyzed for mutations in the KCNJ11 gene (inwardly-rectifying potassium channel, subfamily J, member 11 gene; OMIM 600937). A heterozygous de novo mutation in the KCNJ11 gene was detected in one patient, which confirmed the diagnosis of permanent neonatal DM. Neither C-peptide secretion nor circulating islet cell antibodies were detected in any patient during diagnosis, but C-peptide elevation was detected in the patient with permanent neonatal DM after treatment with sulfonylurea. One infant had clinical and immunological evidence of congenital cytomegalovirus infection while the diabetes in another case was postulated to be syndromic. DM within the first 6 months of life is a rare condition with various etiologies. The high prevalence of Kir6.2 mutations in neonatal diabetes means that all children < 6 months of age diagnosed with diabetes should be tested for Kir6.2 mutations at diagnosis.

Diabetes-Related Autoantibodies and Gestational Diabetes

Gestational diabetes mellitus (GDM) has long been recognized as a heterogeneous disorder (1,2), with autoimmunity against the β-cell contributing in a small subset of patients (3). Autoimmune diabetes is caused by the destruction of β-cells of pancreatic islets by an immune-mediated process, promoted by the interaction of genetic and environmental factors (4). Autoantibodies (AAs) against pancreatic β-cell antigens precede the clinical onset of type 1 diabetes (4). Circulating islet cell antibodies, originally described by indirect immunofluorescence in 1974 (5), have been demonstrated in the great majority of individuals with type 1 diabetes, both at the preclinical state and at the onset of clinically overt diabetes, and they persist in the circulation for a long time. Islet cell AAs include autoantibodies to islet cell cytoplasm (islet cell autoantibodies [ICAs]), to native insulin (insulin autoantibodies [IAAs]), to GAD (GADA) (6–8), and to tyrosine phosphatases (insulinoma-associated antigens IA-2A and IA-2β) (9,10). Age not only modifies the risk of autoimmune diabetes, but also the presence of AAs, the intensity of β-cell destruction, the rate of progression to overt diabetes, and the degree of residual insulin secretion. Approximately 30% of subjects with classic autoimmune diabetes (type 1A diabetes) present after age 35 years (11). Childhood autoimmune diabetes is associated with an increased prevalence of alleles DR3, DQB1*0201 and DR4, and DQB1*0302, with the proportion of heterozygotes declining with age at diagnosis (12). Children with the allele HLA DR2, DQB1*0602, almost never develop diabetes, whereas this allele confers a much lower protection for adult-onset autoimmune diabetes (13). Since the discovery of AAs against islet cell antigens, it has been recognized that a fraction of adults considered to have type 2 diabetes probably have autoimmune diabetes and that the presence of GADAs indicates a strong possibility of requiring …

Transfer of type 1 (insulin-dependent) diabetes mellitus associated autoimmunity to mice with severe combined immunodeficiency (SCID).

Pancreatic beta-cell destruction and development of Type 1 (insulin-dependent) diabetes mellitus are associated with circulating islet cell antibodies. Mice with severe combined immunodeficiency (SCID mice) were reconstituted with peripheral blood mononuclear cells from Type 1 diabetic patients, one who was antibody positive and one antibody negative, and from healthy individuals. Reconstituted mice were subsequently immunized with rat islets in incomplete Freunds adjuvant or adjuvant alone. Seventeen mice received peripheral blood mononuclear cells obtained at three different time points from the islet cell antibody positive patient. Before immunization with rat islets two mice developed antibodies to glutamic acid decarboxylase, a major target for antibodies in Type 1 diabetes, whereas none were positive for cytoplasmic islet cell antibodies. Following immunization with rat islets, glutamic acid decarboxylase antibodies were detected by immunoprecipitation in three additional mice, two of which also became positive for cytoplasmic islet cell antibodies. Of 22 mice which received peripheral blood mononuclear cells from either the islet cell antibody negative patient (n = 5) or from two healthy individuals (n = 17), none were positive for islet cell autoantibodies before or after immunization. None of the islet cell antibody positive mice became hyperglycaemic, showed impaired glucose tolerance or islet cell damage when studied 40 days after immunization (i.e. 100 days after reconstitution). In conclusion these results show that human B lymphocytes producing diabetes-associated autoantibodies can be transferred to SCID mice and remain antigen sensitive, but also that autoantibodies alone are not sufficient to induce beta-cell destruction.

Human monoclonal islet cell antibodies from a patient with insulin-dependent diabetes mellitus reveal glutamate decarboxylase as the target antigen.

The autoimmune phenomena associated with destruction of the beta cell in pancreatic islets and development of type 1 (insulin-dependent) diabetes mellitus (IDDM) include circulating islet cell antibodies. We have immortalized peripheral blood lymphocytes from prediabetic individuals and patients with newly diagnosed IDDM by Epstein-Barr virus transformation. IgG-positive cells were selected by anti-human IgG-coupled magnetic beads and expanded in cell culture. Supernatants were screened for cytoplasmic islet cell antibodies using the conventional indirect immunofluorescence test on cryostat sections of human pancreas. Six islet cell-specific B-cell lines, originating from a patient with newly diagnosed IDDM, could be stabilized on a monoclonal level. All six monoclonal islet cell antibodies (MICA 1-6) were of the IgG class. None of the MICA reacted with human thyroid, adrenal gland, anterior pituitary, liver, lung, stomach, and intestine tissues but all six reacted with pancreatic islets of different mammalian species and, in addition, with neurons of rat cerebellar cortex. MICA 1-6 were shown to recognize four distinct antigenic epitopes in islets. Islet cell antibody-positive diabetic sera but not normal human sera blocked the binding of the monoclonal antibodies to their target epitopes. Immunoprecipitation of 35S-labeled human islet cell extracts revealed that a protein of identical size to the enzyme glutamate decarboxylase (EC 4.1.1.15) was a target of all MICA. Furthermore, antigen immunotrapped by the MICA from brain homogenates showed glutamate decarboxylase enzyme activity. MICA 1-6 therefore reveal glutamate decarboxylase as the predominant target antigen of cytoplasmic islet cell autoantibodies in a patient with newly diagnosed IDDM.

Glucose‐induced Insulin Response is Reduced and Proinsulin Response Increased in Healthy Siblings of Type 1 Diabetic Patients

Glucose-stimulated insulin and proinsulin responses, and insulin sensitivity, were studied in 30 HLA identical, 38 HLA haplo-identical, and 25 HLA non-identical, healthy islet-cell-antibody negative siblings of Type 1 diabetic patients. The results were compared with 41 age- and sex-matched healthy subjects with no diabetes in the family. The proinsulin-corrected insulin response to an intravenous glucose infusion test was significantly lower among siblings when insulin sensitivity was taken into account (1.65 (inter-quartile range 1.20-2.64) vs 2.18 (1.65-3.28) nmol mmol-1 min, p = 0.04). Proinsulin values were consistently higher among siblings than among control subjects (peak values 50.0 vs 38.0 pmol l-1 (p = 0.004)). When proinsulin release was corrected for individual insulin sensitivity this difference remained. The results suggest disturbed islet B-cell function, unrelated to HLA identity or the presence of circulating islet cell antibodies.

Islet cell autoimmunity in type I diabetic patients after HLA-mismatched pancreas transplantation.

The aim of this study was to investigate a possible reenhancement of islet cell autoimmunity in type I (insulin-dependent) diabetic patients who received HLA-mismatched pancreas transplants from cadaveric donors and who underwent generalized immunosuppression. Circulating islet cell antibodies (ICA) and complement-fixing ICAs (CF-ICAs) have been tested at 1, 2, 3, 6, and 12 mo and at least once a year posttransplantation in 23 recipients of 25 transplants (22 simultaneous with kidney, 2 retransplants, 1 isolated; 23 segmental neoprene injected, 2 whole with enteric drainage). Patients were aged 35.3 +/- 1.9 yr with a duration of diabetes of 20.6 +/- 1.1 yr. Immunosuppression consisted of double or triple association of azathioprine, cyclosporin, and prednisone with or without temporary antilymphocyte globulins. The number of HLA-A and HLA-B compatibilities was none in 8 patients, one in 12 patients, two in 4 patients, and three in 1 patient. The mean follow-up was 4.0 +/- 0.4 yr/patient (range 0.4-7.2). ICAs were positive pretransplantation in 2 of 25 patients and reappeared 1-42 mo posttransplantation in another 7. In 6 patients, CF-ICAs were also positive. In 7 of 9 ICA+ patients the pancreas transplant failed; in 1 patient this occurred 4 mo before ICA reappearance, and in 6 patients it occurred 2-35 mo after the first detection of ICAs. Pancreas-transplant failure was significantly associated with the positivity for ICAs (P less than .05) and particularly for CF-ICAs (P less than .005). ICA positivity was transitory in 4 patients (2-27 mo) and persistent in the remaining 5 (up to 61 mo).(ABSTRACT TRUNCATED AT 250 WORDS)

Evidence against an immunogenetic basis for diabetes in chronic pancreatitis.

A possible immunogenetic basis for diabetes in chronic pancreatitis was explored by studying 19 patients with both disorders, most of whom required treatment with insulin. In contrast to patients with insulin-dependent (Type 1) diabetes, patients with diabetes and chronic pancreatitis had residual beta cell function but blunted C-peptide responses to intravenous glucagon, absence of circulating islet cell antibodies, and HLA-DR types similar to control subjects and patients with chronic pancreatitis without diabetes. Diabetes complicating chronic pancreatitis is therefore not associated with the biochemical or immunogenetic markers characteristic of Type 1 diabetes.

Immunologic factors in pathogenesis and treatment of human and animal diabetes.

AbstractRecent evidence suggests that the pathogenesis of insulindependent (type I, juvenile onset) diabetes mellitus may have an important autoimmune component, possibly triggered by a viral infection. This evidence includes mononuclear infiltration of the endocrine pancreas, circulating islet cell antibodies, and a strong association with certain HLA alleles (DR3 and DR4). The biologic response (apart from allograft rejection) of diabetic hosts to transplanted islets has been examined in an animal model of spontaneous diabetes which closely resembles the human condition (the BB rat). In this syndrome, MHC‐compatible islet allografts suffered autoimmune destruction even when rejection was excluded by experimental design. Implications of this finding with respect to human islet and/or pancreas transplantation are discussed.

Insulin and glucagon secretion in diabetic and non-diabetic patients with circulating islet cell antibodies

Thirty-nine patients (14 non-diabetics, 8 chemical diabetics, and 17 overt diabetics) with circulating islet cell antibodies (ICA) were studied. Insulin and glucagon secretion after oral (100 g) and intravenous glucose loading (200 mg/kg bolus injection followed by an infusion of 20 mg/min over 60 min) and arginine infusion (25 g over 30 minutes) were evaluated in these patients and in non diabetic and diabetic ICA-negative controls. In the non-diabetic groups with or without ICA, insulin and glucagon responses to glucose were similar. Moreover, in ICA positive patients the response of these hormones to arginine infusion was reduced. Similar alterations in insulin and glucagon secretion were observed in the CIA positive and negative patients with chemical or overt diabetes. In particular, fasting hyperglucagonaemia and glucagon hyperresponse to arginine are associated with a lack of insulin secretion in the patients with overt diabetes. Hormonal differences between diabetics with and without ICA could not be detected.