There are several markers of the autoimmune destruction, detectable in the body fluids of IDDM patients and they include:
1) Islet cell auto-antibodies (ICA)
2) Auto-antibodies to insulin (IAA)
3) Auto-antibodies to glutamic acid decarboxylase (GAD65)
4) Auto-antibodies to the tyrosine phosphatases IA-2 and IA-2 beta

    Along with the autoimmune reaction associated with IDDM there is also a strong genetic link. Type 1 diabetes mellitus is strongly genetically linked with HLA on chromosome 6.Recent studies have indicated that HLA-DR3-DQ2, HLA-DR4, and DQ8 are the more the most important. Although there are no doubts that genetic factors are closely related to the incidence of IDDM a twin study revealed only a 50% concordance, supporting the very important role of environmental factors. These environmental factors include such things as viral infections, chemicals, and even cow’s milk.

Pathophysiology of IDDM:
    The autoimmune destruction of pancreatic-beta cells leads to a deficiency of insulin secretion. It is this loss of insulin secretion that leads to signs, symptoms and complications associated with IDDM. Along with loss of insulin production the function of the alpha-cells also becomes abnormal. There is excessive secretion of glucagons in IDDM patients. The inappropriately high level of glucagons exacerbates the metabolic defects due to insulin deficiency. The most pronounced example of this is the development of diabetes keto-acidosis in the absence of insulin administration.

To learn about the rise of childhood type 1 diabetes in the 20th century click on the following: http://www.medscape.com/viewarticle/445672