There is ample evidence suggesting that the onset of type 1 diabetes is associated with abnormal autoimmunity. This is mainly manifested in the following aspects:
Cellular immune abnormalities:
Approximately 60% of type 1 diabetes patients have a positive leukocyte migration inhibition test, and abnormal peripheral lymphocytes have been observed in some diabetic nude mice and human type 1 diabetes patients. In the lymphocyte subgroups, the levels of OKT4, OKT4/OKT8 ratios, and activated T lymphocytes increase. In some short-term deceased type 1 diabetes patients, autopsy findings reveal extensive lymphocyte infiltration in the islets, which is referred to as “insulitis.”
Humoral immunity disorder:
60% – 85% of newly diagnosed type 1 diabetic patients are positive for islet cell autoimmune antibodies, while the positive rate of type 2 diabetic patients and non-diabetic patients is <5%.
Foreign scholars reported that the positive rate of icab within 1 year of diagnosis of type 1 diabetes was 50%, which decreased to 20% after 2-5 years. Icab decreased with the course of the disease, which may be related to the progressive reduction of islet cells acting as antigens, suggesting that type 1 diabetes is an autoimmune syndrome, In recent years, further studies have found that islet cell surface antibodies and complement dependent cytotoxic icab are all associated with type 1 diabetes, deepening the understanding of islet β Understanding of the specificity of cellular immune response.
Type 1 diabetic patients are often complicated with other autoimmune diseases, such as anti hyperthyroidism, primary adrenal hypofunction, etc. there are also high autoantibodies against autologous organs in the serum, such as anti thyroid cell antibody and anti gastric parietal cell antibody, which are 2-4 times higher than those of normal people. Anti adrenal antibody is rare in normal people, while it is about 30 times higher in diabetic patients than normal people.
Viral infection and autoimmunity. Viral infection may be the direct or indirect cause of the above immune abnormalities. Viral infection can cause “insulitis” – like manifestations. We have mentioned the common factors of viral infection, which all suggest that autoimmunity plays an important role in the occurrence and development of type 1 diabetes.