The immune system protects the body from infections, diseases and foreign substances. It involves a number of organs, tissues and cells that work together to keep invaders (antigens) from entering the body and the bloodstream. When antigens penetrate the blood, the immune system is capable of identifying and attacking the threat.

The components of the immune system include:

• White blood cells
• Antibodies
• Hormones
• Complement system (protective proteins in the blood)
• Bone marrow
• Thymus gland
• Spleen
• Lymph system

In some cases, these natural defenses mistakenly identify the body’s own tissues as foreign. This condition is known as an autoimmune disease. Examples include type 1 diabetes, latent autoimmune diabetes of adulthood, Hashimoto’s thyroiditis and Graves’ disease.

The immune system is affected when levels of glucose (blood sugar) rise above normal. As  a result, people with type 1 diabetes, type 2 diabetes, gestational diabetes or other forms of diabetes are at an increased risk for developing an infection. Once a person with diabetes has developed an infection, the body is less capable of fighting it off because high glucose levels interfere with the normal action of white blood cells.

Scientists are studying drugs that impede the immune system (immunosuppressives) as possible treatments for diabetes.