By Dr Ananya Mandal, MD
In type 1 diabetes, the cells of the immune system mistake the insulin-producing beta cells in the pancreas for foreign bodies and launches an immune attack against them. This damage or destruction of the beta cells leads to an inadequate production of insulin and the cells of the body are not stimulated to uptake glucose from the blood to provide energy for cellular functions. The level of blood glucose is therefore raised to an above normal level.
Exactly why the immune system turns on the body's own cells in this way (a phenomenon called autoimmunity) is not yet clearly understood. While some researchers have suggested viral infection is the trigger, others think the disease has a genetic basis.
Some of the approaches to preventing type 1 diabetes include:
Immunization - The basic premise of immunization is to alter the active state of the immune system from a Th1 state (the killer cell phase) to the Th2 state when new antibodies are developed. This shift results in the production of chemical messengers that inhibit inflammation rather than promote it. This is called acquired immune tolerance.
Use of DiaPep277 - This is a special protein or peptide fragment of a larger more common protein called the HSP60. This protein helps in bringing about the shift from Th1 to Th2 resulting in acquired immune tolerance. It has been shown to delay the progression of type 1 diabetes and is useful in those with latent autoimmune diabetes of adults.
Insulin nasal spray - This approach also attempts to achieve a shift from the Th1 to the Th2 state by administering insulin to the immune cells within the nose.
Use of BCG vaccine - The Bacillus Calmette-Guérin (BCG) vaccine is a vaccine used against tuberculosis. It helps produce tumor necrosis factor-alpha, or TNF-α, which is deficient in people with type 1 diabetes. This TNF-α helps to destroy the immune cells that are concerned with destroying the beta cells of the pancreas. However, the approach has not yet been attempted on humans.
Use of the Diamyd vaccine - This involves injections of an autoantigen called GAD65. This delays the onset of disease in individuals who are susceptible to type 1 diabetes by producing the anti-inflammatory regulatory cytokines that protect the beta cells.
Reviewed by Sally Robertson, BSc