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Immunoregulatory differences between adult onset type 1 diabetes and latent autoimmune diabetes in adults (LADA)

Hillman, Magnus LU (2007)
Abstract (Swedish)
Popular Abstract in Swedish

Autoimmun diabetes karakteriseras av cell medierad autoimmunitet mot insulinproducerande beta celler i Langerhanska öar. Typ 1 diabetes är den största typen av diabetes i barn och ungdomar och antas vara orsakad av Th1-cell drivet angrepp av beta celler. Den betydligt vanligare typ 2 diabetes antas inte vara en autoimmun sjukdom men diabetes specifika autoantikroppar (ICA eller GADA) hittas i 5-15% av fallen. Dessa patienter brukar benämnas latent autoimmun diabetes hos vuxna eller LADA. Det har aldrig varit helt klart om LADA är en helt egen sjukdom eller om den borde räknas till typ1 diabetes. Individer med LADA har bättre bevarad insulin sekretion och långsammare beta-cell död vid klinisk... (More)
Popular Abstract in Swedish

Autoimmun diabetes karakteriseras av cell medierad autoimmunitet mot insulinproducerande beta celler i Langerhanska öar. Typ 1 diabetes är den största typen av diabetes i barn och ungdomar och antas vara orsakad av Th1-cell drivet angrepp av beta celler. Den betydligt vanligare typ 2 diabetes antas inte vara en autoimmun sjukdom men diabetes specifika autoantikroppar (ICA eller GADA) hittas i 5-15% av fallen. Dessa patienter brukar benämnas latent autoimmun diabetes hos vuxna eller LADA. Det har aldrig varit helt klart om LADA är en helt egen sjukdom eller om den borde räknas till typ1 diabetes. Individer med LADA har bättre bevarad insulin sekretion och långsammare beta-cell död vid klinisk diagnos jämfört med typ 1 diabetes. Dessutom finns det vuxna patienter med typ 1 diabetes som delar det snabba sjukdomsförloppet som normalt ses vid typ 1 diabetes hos barn. Hypotesen var därför att den autoimmuna aktiviteten skiljer sig mellan typ 1 diabetes och LADA. Syftet var att identifiera några av de immunoregulatoriska egenskaper som kan förklara skillnaden i sjukdomsförlopp mellan dessa två grupper.



Heterozygoti för de diabetes associerade hög risk haplotyperna HLA DR3/DQ2-DR4/DQ8 ansågs vara en riskfaktor för både typ 1 diabetes hos vuxna och LADA. Dessutom visade homozygoti för mikrosatellitmarkören TNFa2 en ökad risk för både typ 1 diabetes och LADA, troligen beroende på kopplingsojämvikten mellan HLA haplotyperna. Närvaro av antingen HLA DR3/DQ2 eller DR4/DQ8 medförde också en signifikant ökad risk för typ 1 diabetes men inte för LADA.



Autoantikroppar riktade mot glutaminsyradekarboxylas 65 (GADA) var framförallt av IgG1 subklass vid både typ 1 diabetes och LADA. Däremot var IgG4 subklassen den näst vanligaste subklassen vid LADA men kunde inte detekteras hos patienter med typ 1 diabetes vid klinisk diagnos. Detta talar för ett större engagemang av Th2 celler i LADA jämför med typ 1 diabetes. Nivåerna av alla GADA IgG-subklasser minskade i typ 1 diabetes under tre år efter diagnos medan de förblev oförändrade i LADA. Detta indikerar på en kvarhållande skillnad i autoimmun respons mot beta cell antigenet GAD65 mellan grupperna. Den långsammare beta cell destruktionen i LADA kan bero på ett mer balanserat T-cell svar vilket reducerar den cytotoxiska Th1 cellmedierade responsen. Typ 1 diabetes och LADA kan därför anses vara olika varianter av beta cell autoimmunitet. (Less)
Abstract
Autoimmune diabetes is characterized by cell mediated autoimmunity against insulin producing beta cells in pancreatic islets. Type 1 diabetes is the major cause of diabetes in children and adolescents and is believed to be mediated by a Thl driven destruction of beta cells. The much more prevalent type 2 diabetes is not considered as an autoimmune disease but diabetes specific autoantibodies (ICA or GADA) are found in 5-15% of the cases. These subjects are referred to as latent autoimmune diabetes in adults (LADA). It has been questioned if LADA is a unique entity or should be considered as type 1 diabetes. Subjects with LADA have a better preserved insulin secretion and a slower progression to beta cell failure at clinical onset compared... (More)
Autoimmune diabetes is characterized by cell mediated autoimmunity against insulin producing beta cells in pancreatic islets. Type 1 diabetes is the major cause of diabetes in children and adolescents and is believed to be mediated by a Thl driven destruction of beta cells. The much more prevalent type 2 diabetes is not considered as an autoimmune disease but diabetes specific autoantibodies (ICA or GADA) are found in 5-15% of the cases. These subjects are referred to as latent autoimmune diabetes in adults (LADA). It has been questioned if LADA is a unique entity or should be considered as type 1 diabetes. Subjects with LADA have a better preserved insulin secretion and a slower progression to beta cell failure at clinical onset compared to subjects with type 1 diabetes. Furthermore, there are adult onset type 1 diabetic patients that share the rapid progression to beta cell failure with juvenile onset diabetes. The hypothesis was therefore that type 1 diabetes and LADA have different autoimmune activity. The aim was to identify some of the immunoregulatory events that could explain differences in disease progression between the groups.



Heterozygosity of the diabetes associated high risk HLA haplotypes DR3/DQ2-DR4/DQ8 was considered as a risk factor for both adult onset type 1 diabetes and LADA. Also homozygosity for the microsatellite marker TNFa2 conferred an increased risk for both type 1 diabetes and LADA even though this was probably due to linkage disequilibrium with the HLA haplotypes. However, presence of either one of HLA DR3/DQ2 or DR4/DQ8 conferred an increased risk of type 1 diabetes but not LADA.



Autoantibodies directed against glutamic acid decarboxylase 65 (GADA) were predominantly of the IgGl subclass in both adult onset type 1 diabetes and LADA. Moreover, the IgG4 subclass was the second most common subclass in LADA but below detection limit in type 1 diabetes at clinical onset. This suggests a larger involvement of Th2 cells in LADA compared to in type 1 diabetes. The levels of all the GADA IgG subclasses decreased in type 1 diabetes three years after clinical onset while LADA remained their subclass profiles indicating a sustained difference in autoimmune response against the beta cell antigen GAD65 between the groups. The slower progression of beta cell failure in LADA might be due to a more balanced T cell response that reduces the cytotoxic Thl cell mediated response. Type 1 diabetes and LADA could thus be considered as different variations of autoimmunity. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Professor Nerup, Jörn, Steno Diabetes Centra, Gentofte, Denmark
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Endokrinologi, sekretion, diabetologi, diabetology, secreting systems, Isotype class switch, Endocrinology, LADA, Autoantibodies, Autoimmunity, Type 1 diabetes
pages
68 pages
publisher
Department of Clinical Sciences, Lund University
defense location
BMC Segerfalk lecture hall
defense date
2007-05-16 13:15
ISSN
1652-8220
ISBN
978-91-85559-61-9
language
English
LU publication?
yes
id
486b0197-2368-461e-aa01-738f47a7bce0 (old id 548589)
date added to LUP
2007-09-12 08:00:47
date last changed
2017-06-18 14:09:26
@phdthesis{486b0197-2368-461e-aa01-738f47a7bce0,
  abstract     = {Autoimmune diabetes is characterized by cell mediated autoimmunity against insulin producing beta cells in pancreatic islets. Type 1 diabetes is the major cause of diabetes in children and adolescents and is believed to be mediated by a Thl driven destruction of beta cells. The much more prevalent type 2 diabetes is not considered as an autoimmune disease but diabetes specific autoantibodies (ICA or GADA) are found in 5-15% of the cases. These subjects are referred to as latent autoimmune diabetes in adults (LADA). It has been questioned if LADA is a unique entity or should be considered as type 1 diabetes. Subjects with LADA have a better preserved insulin secretion and a slower progression to beta cell failure at clinical onset compared to subjects with type 1 diabetes. Furthermore, there are adult onset type 1 diabetic patients that share the rapid progression to beta cell failure with juvenile onset diabetes. The hypothesis was therefore that type 1 diabetes and LADA have different autoimmune activity. The aim was to identify some of the immunoregulatory events that could explain differences in disease progression between the groups.<br/><br>
<br/><br>
Heterozygosity of the diabetes associated high risk HLA haplotypes DR3/DQ2-DR4/DQ8 was considered as a risk factor for both adult onset type 1 diabetes and LADA. Also homozygosity for the microsatellite marker TNFa2 conferred an increased risk for both type 1 diabetes and LADA even though this was probably due to linkage disequilibrium with the HLA haplotypes. However, presence of either one of HLA DR3/DQ2 or DR4/DQ8 conferred an increased risk of type 1 diabetes but not LADA.<br/><br>
<br/><br>
Autoantibodies directed against glutamic acid decarboxylase 65 (GADA) were predominantly of the IgGl subclass in both adult onset type 1 diabetes and LADA. Moreover, the IgG4 subclass was the second most common subclass in LADA but below detection limit in type 1 diabetes at clinical onset. This suggests a larger involvement of Th2 cells in LADA compared to in type 1 diabetes. The levels of all the GADA IgG subclasses decreased in type 1 diabetes three years after clinical onset while LADA remained their subclass profiles indicating a sustained difference in autoimmune response against the beta cell antigen GAD65 between the groups. The slower progression of beta cell failure in LADA might be due to a more balanced T cell response that reduces the cytotoxic Thl cell mediated response. Type 1 diabetes and LADA could thus be considered as different variations of autoimmunity.},
  author       = {Hillman, Magnus},
  isbn         = {978-91-85559-61-9},
  issn         = {1652-8220},
  keyword      = {Endokrinologi,sekretion,diabetologi,diabetology,secreting systems,Isotype class switch,Endocrinology,LADA,Autoantibodies,Autoimmunity,Type 1 diabetes},
  language     = {eng},
  pages        = {68},
  publisher    = {Department of Clinical Sciences, Lund University},
  school       = {Lund University},
  title        = {Immunoregulatory differences between adult onset type 1 diabetes and latent autoimmune diabetes in adults (LADA)},
  year         = {2007},
}