Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011854 (type 1 diabetes)
 20,749 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The elimination of maternally acquired, diabetes-associated antibodies from the peripheral circulation of infants was studied in a population of 47 mothers and their newborn infants from families in which at least 1 first degree relative had type 1 diabetes. Blood samples were taken from the placental cord; from the infant at follow-up visits at the ages of 3, 6, 9, 12, 18, and 24 months; and from the mother at the time of delivery. The samples were analyzed for cytoplasmic islet cell antibodies (ICA), insulin antibodies (IA), autoantibodies to the 65-kDa isoform of glutamic acid decarboxylase (GADA), and autoantibodies to the protein tyrosine phosphatase-related IA-2 antigen (IA-2A). The mean elimination times for ICA, IA, GADA, and IA-2A were 3.1, 3.1, 4.5, and 4.3 months (P = NS), respectively. The initial levels of IA, GADA, and IA-2A in the cord blood correlated closely with the elimination time (r(s) = 0:84-0.91; P < 0.001). The mean proportions of ICA, IA, GADA, and IA-2A still detectable were 18%, 21%, 30%, and 20%, respectively, at 3 months; 2.2%, 14%, 10%, and 6% at 6 months; and 0.3%, 15%, 2.3%, and 5.1% at 9 months. One infant still tested positive for GADA at the age of 12 months, whereas all of the other antibodies had been eliminated by that age. When observing the natural history of beta-cell autoimmunity or when screening for secondary prevention in young children, cross-sectional autoantibody analyses do not provide sufficient information. Repeated testing is to be recommended in young children. In infancy, increasing antibody levels most likely reflect de novo synthesis of diabetes-associated autoantibodies.
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PMID:Postnatal elimination of transplacentally acquired disease-associated antibodies in infants born to families with type 1 diabetes. The Finnish TRIGR Study Group. Trial to Reduce IDDM in the Genetically at Risk. 1109 62

Assays to detect autoantibodies to glutamic acid decarboxylase (GAD65) and the protein tyrosine phosphatase-like molecule IA-2, which are both present in pancreatic islets, have been used in the diagnosis and prediction of type 1 diabetes. In this study a novel fusion protein combining the entire GAD65 molecule with the 40 kDa intracellular domain of IA-2 (GAD-IA-2) was constructed to detect autoantibodies to both antigens by one single assay. For the same purpose a truncated version of this fusion protein which contained the entire GAD65 linked to the 203 carboxy-terminal amino acids of IA-2 (GAD-dIA-2) was made. A panel of 34 diabetic sera which represented unequivocally positive or negative antibody responses to GAD65 and/or IA-2 as well as 20 serum samples from healthy controls were tested in a radioligand binding assay with the constructed fusion proteins as antigens. Nine of the samples from patients with type 1 diabetes reacted with GAD65 while being negative for IA-2. Six sera were positive for IA-2 only, 11 were double positive, and 8 negative for both antibodies using the standard in vitro transcription translation assay with single antigens. The full-length, as well as the truncated fusion protein detected all samples positive for antibodies either to GAD65 or IA-2 or both, except for one GAD65 antibody positive sample. All samples from healthy controls tested negative in all assays. We conclude that the principle of a combinatorial molecule where a fusion protein expresses both GAD65 and IA-2 epitopes is feasible, and such a fusion protein can be used instead of the single antigens to reduce time and costs of large-scale screening for clinical purposes.
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PMID:Novel fusion proteins in the analysis of diabetes-associated autoantibodies to GAD65 and IA-2. 1112 50

We measured the concentrations of the soluble forms of the intercellular adhesion molecule-1 (sICAM-1) and L-selectin in 95 autoantibody-positive siblings of children with type 1 diabetes and 95 sex- and age-matched siblings testing negative for diabetes-associated autoantibodies to assess the possible role of soluble adhesion molecules as markers of progressive ss-cell destruction in preclinical diabetes and their ability to discriminate between those siblings who progress to clinical disease and those who remain nondiabetic. We observed an inverse correlation between age and the levels of both sICAM-1 (r = -0.31, p < 0.001) and sL-selectin (r = -0.27, p < 0.001) in the control siblings but no association with HLA-DR phenotypes. There was no difference in the circulating levels of soluble adhesion molecules between the antibody-positive and negative siblings. Among the antibody-positive siblings, those with at least three autoantibodies had higher sICAM-1 levels (p < 0.01) than those testing positive for only one, and siblings with three autoantibodies or more had higher concentrations of sL-selectin (p < 0.01) than those with two autoantibodies. Siblings with an islet cell antibody level of 20 Juvenile Diabetes Foundation units or more had higher sICAM-1 concentrations than those with a level below 20 (p < 0.001), and those testing positive for antibodies to the protein tyrosine phosphatase-related IA-2 antigen had increased levels of both sICAM-1 (p = 0.03) and sL-selectin (p = 0.02) compared with siblings who tested negative. The antibody-positive siblings who progressed to clinical type 1 diabetes were significantly younger than the nonprogressors (p < 0.001) and had higher levels of sICAM-1 initially (p < 0.001). The difference in sICAM-1 concentrations remained significant (p = 0.03) after age adjustment. Our results indicate that concentrations of soluble adhesion molecules are increased in the autoantibody-positive siblings who have the highest risk of developing clinical diabetes, suggesting that ss-cell destruction is reflected in increased circulating levels of these molecules. This is supported by the observation of elevated sICAM-1 concentrations in the 29 siblings who actually progressed to clinical type 1 diabetes. Peripheral levels of soluble adhesion molecules are not able to discriminate between progressors and nonprogressors, however, due to substantial overlapping between these two groups.
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PMID:Soluble adhesion molecules in preclinical type 1 diabetes. The Childhood Diabetes in Finland Study Group. 1113 83

Few studies have shown a significant increase of CD3+ T-cell receptor (TCR) gamma delta in the early phases of type 1 diabetes. We wished to determine if CD3+ TCR gamma delta is involved in the pathogenesis of gestational diabetes mellitus (GDM). We studied 29 GDM patients and 21 normal pregnant women. Lymphocyte subpopulations (CD3+ TCR alpha beta, CD3+ TCR gamma delta), islet cell antibodies (ICA), glutamic acid decarboxylase antibodies (GAD) and protein tyrosine phosphatase antibodies (IA2-Ab) were evaluated in all patients. The percentage of CD3+ TCR gamma delta was significantly higher in GDM women than in the control group (5.1 +/- 2.9% vs 3.7 +/- 1.7%; p < 0.05). No abnormalities of the other lymphocyte subpopulations were found. All subjects were negative for ICA; 2 GDM patients were positive for GAD, but no relationship was found between GAD positivity and CD3+ gamma delta levels in these 2 patients. Further follow-up studies of these patients are required to verify if the CD3+ TCR gamma delta receptor is a useful marker for diabetes development.
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PMID:Evaluation of T-cell receptor CD3+ gamma delta in gestational diabetes mellitus. 1145 May 5

The protein tyrosine phosphatases (PTPs) IA-2 and phogrin (IA-2beta) are major autoantigens in type 1 diabetes that possess common serological epitopes in their COOH termini. The epitopes recognized by the T-cells that cause the disease, however, remain to be defined. Eight phogrin-specific T-cell clones were generated from NOD mice, and their epitopes were mapped. The mapping was performed initially with recombinant gluthathione S-transferase-phogrin COOH deletion constructs and ultimately with overlapping synthetic peptides. Two dominant epitopes were identified: one (aa 629-649) immediately adjacent to the transmembrane domain (aa 604-628) and the second (aa 755-777) lying in the NH(2)-terminal region of the conserved PTP domain. T-cells that are specific to either of these peptides and that could destroy islet tissue in vivo though spontaneous T-cell proliferative responses were observed in prediabetic female NOD splenocytes only to the aa 755-777 epitope. In NOD female mice immunized with the epitope peptide, intramolecular determinant spreading occurred from the aa 629-649 epitope to the aa 755-777 epitope but not in the opposite direction. We concluded that the initial T-cell response to phogrin is restricted to a small number of dominant peptides and that it subsequently spreads to other regions of the molecule, including those containing the major humoral epitopes that are highly conserved between IA-2 and phogrin.
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PMID:T-cell epitope analysis on the autoantigen phogrin (IA-2beta) in the nonobese diabetic mouse. 1147 31

Type 1 diabetes mellitus is strongly associated with HLA-DQ8 in humans and I-A(g7) in the NOD mouse. The disease is characterized by loss of tolerance to auto-antigens such as GAD, insulin, and the protein tyrosine phosphatase-like molecule, IA-2. We identified T cell epitopes on the intracytoplasmic region of IA-2 by immunizing DQ8/NOD, DQ8/B10, and NOD mice with overlapping 18 mer peptides in CFA. We identified four peptides presented both by DQ8 and NOD, five DQ8 specific peptides, and six NOD specific peptides. Both mouse lines failed to respond to ten peptides. We demonstrated MHC class II and CD4 restriction of proliferative responses using appropriate blocking antibodies. To understand the role of non-MHC genes in the generation of immune response to the islet auto-antigen, we evaluated cytokine secretion following immunization of DQ8 transgenic mice with strongly immunogenic peptides. The NOD background resulted in increased secretion of cytokines. In conclusion, we have identified IA-2 peptides that induce lymphoproliferative responses in DQ8 transgenic and NOD mice and shown that these peptides stimulate production of Th1 and Th2 cytokines.
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PMID:HLA-DQ8 transgenic and NOD mice recognize different epitopes within the cytoplasmic region of the tyrosine phosphatase-like molecule, IA-2. 1160 Feb 16

Little is known about the timing of the etiological events and the preclinical process of type 1 diabetes during the first years of life in the general population. In this population-based prospective birth cohort study, the appearance of diabetes-associated autoantibodies as a sign of beta-cell autoimmunity and the development of type 1 diabetes were monitored from birth. Of 25,983 newborn infants, 2,448 genetically susceptible children were monitored for islet cell antibodies (ICA) at 3- to 6-month intervals. If an infant seroconverted to ICA positivity, all his/her samples were also analyzed for insulin autoantibodies (IAA), antibodies to the 65-kDa isoform of glutamic acid decarboxylase, and antibodies to the protein tyrosine phosphatase-related IA-2 molecule. Fifteen children of those who carried the high-risk genotype (2.7%) and 23 of those who carried the moderate-risk genotype (1.2%; P = 0.019) tested positive for ICA at least once. Among those who showed positivity for at least 2 antibodies during the observation period (25 of 38), IAA appeared as the first or among the first antibodies in 22 children (88%) and emerged earlier than the other antibodies (P < 0.019 or less). The first autoantibodies appeared in the majority of the children in the fall and winter (30 of 38 vs. 8 of 38 in the spring and summer, P < 0.001). These observations suggest that young children in the general population with a strong human-leukocyte-antigen-DQ-defined genetic risk of type 1 diabetes show signs of beta-cell autoimmunity proportionally more often than those with a moderate genetic risk. IAA emerge as the first detectable antibody more commonly than any other antibody specificity, implying that insulin may be the primary antigen in most cases of human type 1 diabetes associated with the DR4-DQB1*0302 haplotype. The seasonal variation in the emergence of the first signs of beta-cell autoimmunity suggests that infectious agents may play a role in the induction of such autoimmunity.
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PMID:The first signs of beta-cell autoimmunity appear in infancy in genetically susceptible children from the general population: the Finnish Type 1 Diabetes Prediction and Prevention Study. 1160 May 41

As part of a genetic study of type 1 diabetes in Mexican-Americans, 360 first-degree relatives of 108 type 1 diabetic probands were studied. Islet cell antibody (ICA), insulin autoantibody, glutamic acid decarboxylase (GAD(65)), and protein tyrosine phosphatase autoantibodies were measured and human leucocyte antigen (HLA) class II alleles DRB1 and DQB1 genotyping was performed. ICA was positive in 37% of the probands and 5.8% of the relatives. A subgroup of 26 probands (12 ICA+, 14 ICA-) was tested for GAD(65) and was found positive. 4/14 ICA+ first-degree relatives were GAD(65) positive. Four relatives, positive for two antibodies, subsequently developed type 1 diabetes. Life-Table analysis of first-degree relatives with autoantibodies indicated an 80% disease-free survival at 3.5 yr. HLA-DRB1 was found to be associated with the presence of ICA in both probands and relatives, whereas HLA-DPB1 was associated with autoantibody in relatives of type 1 diabetic probands. These results suggest that autoimmunity occurs in type 1 diabetes families of Mexican descent in similar frequencies to that of non-Hispanic, Caucasian families. The presence of autoantibodies appears to be regulated in part by HLA class II genes, even in the absence of overt diabetes.
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PMID:Autoantibodies and human leucocyte antigen class II in first-degree family members of Mexican-American type 1 diabetic patients. 1160 May 69

The convenience of combining the measurement of antibodies to glutamic acid decarboxylase (GADA), protein tyrosine phosphatase (IA-2A), and autoantibodies to insulin (IAA) in diabetic patients was assessed. We analysed 71 type 1 and 115 adult-onset diabetic patients. The latter were grouped into three categories according to the time of evolution to insulin dependence. The main findings were as follows: (i) in type 1 diabetes, the combined analysis of GADA and IA-2A showed a sensitivity of 87.4% and was not appreciably improved by adding IAA; (ii) out of 31 adults who required insulin immediately or within the first two years of diagnosis, 41.9, 29.0, and 6.5% were positive for at least one, two or all three, and all three markers, respectively; GADA was the most prevalent (35.5%) and IA-2A the least represented (16.1%); (iii) 34 adult patients with slow evolution to insulin dependence showed a completely different profile: 5.9% were GADA positive and 23.5% were IAA positive and no double or triple positivity was observed as all patients were IA-2A negative; and (iv) 50 type 2 patients who had not required insulin treatment showed a low incidence of GADA (4%) as the only marker present. We conclude that a combined double-antigen test for GADA and IA-2A is a useful strategy for prospective screening of type 1 diabetes. However, in adults, the profile of individual markers discloses the course to insulin dependence. Therefore, it seems advisable to measure the markers separately, to allow a better classification of these patients, and help define their treatment.
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PMID:Combined measurement of diabetes mellitus immunological markers: an assessment of its benefits in adult-onset patients. 1168 97

The IA-2 is a major autoantigen of type 1 diabetes belonging to the protein tyrosine phosphatase family. We report on the humoral autoimmunity to an alternatively-spliced variant of IA-2 (IA-2 variant) and autoimmune-mediated diabetes age of onset association with IA-2 autoantibody epitope specificities, in 144 recent-onset patients with type 1 diabetes and 54 GAD autoantibody-positive patients with type 2 diabetes. The cytoplasmic domain of IA-2 (IA-2ic) detected a somewhat greater proportion of patients expressing autoantibodies than IA-2 variant (56%vs. 52% of patients with type 1 diabetes and 17%vs. 9% of GAD autoantibody-positive patients with type 2 diabetes). Conversely, only 1% of IA-2 variant autoantibody-positive patients failed to react to IA-2ic construct. Among 80 patients with type 1 diabetes who were positive for autoantibodies to IA-2ic, 8% recognized the juxtamembrane region (JM, representing amino acids 601-629) only, 64% bound the protein tyrosine phosphatase (PTP)-like domain of IA-2 only, and 29% bound both JM and PTP epitopes. Autoantibodies to the PTP-like domain were prevalent in children and adolescents with type 1 diabetes. The age of disease onset in patients with IA-2JM autoantibodies only, was significantly higher than those in patients reacted with the PTP-like domain of IA-2 (P< 0.02). Among GAD autoantibody-positive patients with type 2 diabetes reacted with IA-2ic, 44% bound the JM region only, and 33% bound epitopes in the PTP-like domain only; 22% had autoantibodies to both regions. The frequency of GAD autoantibody-positive patients with type 2 diabetes positive for autoantibodies to the JM region only, was significantly higher than that in patients with type 1 diabetes (P< 0.01). IA-2PTP autoantibodies were significantly associated with HLA-DR4, while the additional reactivity to IA-2JM was associated with HLA-DR9 allele. These results suggest that autoantibody recognition of IA-2 epitopes in autoimmune diabetes is associated with age of disease onset, which may reflect the intensity of the beta-cell destruction process.
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PMID:Association between IA-2 autoantibody epitope specificities and age of onset in Japanese patients with autoimmune diabetes. 1177 57


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