Hanyang Med Rev.  2009 May;29(2):168-175.

Pathogenesis of Type 1 Diabetes

• Kim KA
• Lee MS

Abstract

Type 1 diabetes mellitus (T1D) is a chronic autoimmune disease characterized by selective destruction of pancreatic islet betacells causing insulin deficiency. T1D has been shown to be a polygenic trait, associated with several loci, among which the human leukocyte antigen (HLA) region accounts for 40% of the genetic risk to develop T1D. The betacell autoimmune response is triggered by environmental or unknown events in the predisposing genetic background. The triggers of autoimmunity can lead to a localized imbalance between regulatory T cells and autoimmune effector T cells. The macrophages and autoreactive lymphocytes infiltrate the islets and the interaction of betacells and immune cells leads to inductionamplification of insulitis and loss of betacells. T cells destroy betacells in a direct cytotoxic manner or influence the induction of betacell apoptosis through the release of cytotoxic molecules, such as cytokines. The autoimmune process progresses subclinically for many years in the majority of patients, and clinical symptom do not appear until more than 80% of betacells have been destroyed. Although no current "cure" exists, there is a major effort to develop immunotherapies to prevent or halt the disorder that still requires much research to fully understand exact triggering events leading toautoimmune activation. Other strategies involve beta- cell replacement by islet transplantation, but researchs to enhance the islet mass transplanted and preserve beta-cell function are necessary.

Keyword

Pancreatic beta-cell; Type 1 diabetes mellitus; Autoimmunity; Apoptosis; Preventive trial

MeSH Terms

Apoptosis
Autoimmune Diseases
Autoimmunity
Cytokines
Diabetes Mellitus, Type 1
Humans
Immunotherapy
Insulin
Islets of Langerhans
Islets of Langerhans Transplantation
Leukocytes
Lymphocytes
Macrophages
Multifactorial Inheritance
T-Lymphocytes
T-Lymphocytes, Regulatory
Transplants
Cytokines
Insulin