How do we recognize autoimmune disease?

The main scientific conference opened with the plenary address by Dr Noel Rose (Johns Hopkins, USA) with his discussion on how we recognize auto-immune disease. The main complaint in all autoimmune diseases is fatigue. Autoimmunity is an immune response to the normal antigens of the host.

Autoimmune disease is disease caused or significantly promoted by autoimmunity—with production of self-reactive T and B-cells. We are in fact developing lymphocytes and are “auto-immune” all the time, but we have mechanisms which recognize and control them. Disease occurs as a result of an uncontrolled response. Having antibodies is normal and not “disease”. A cause of disease by autoimmunity is hard to prove, but may be promoted by existing disease or make it worse.

There is prevalence of 80 diseases affecting every organ system. These diseases are among the 10 leading causes of death in women under 65. These diseases equate to up to 23 million people in the USA. They are diseases which share common features, are expensive and lifelong, and for which there are no cures. They are diseases which are on the rise. Systems affected most commonly include blood, connective tissue, endocrine, neuroloic, gastrointestinal, skin, kidneys and heart.

Evidence for autoimmune disease includes:

• Direct transmission—e.g., via serum or maternal/foetal (lupus).
• Indirect transmission when the antigen is defined and introduced to replicate the disease using animal models.
• Circumstantial—no evidence of causation, but much evidence of disease—e.g., auto-antibodies, clustering, sex bias (75% female), HLA association, response to immunosuppression.

Some diseases look autoimmune but there is no evidence of self-reactive T-cells. They are more likely “auto-inflammatory” (caused by an innate immune response).

Factors leading to autoimmune disease

A combination of genetic predisposition, environmental factors and endocrine effect lead to autoimmune disease.

Genetic predisposition includes:

• Evidence from family history. There may be evidence of multiple autoimmune diseases in a family. There is 30% identical twin concordance.
• Major histocompatibility complex
• Immunoregulatory genes. There are gene changes due to insertion of methyl groups etc. leading to changes in CD4, T-cell and B-cell changes.

Environmental factors include:

• Viruses (e.g., EBV and MS), bacteria (e.g., B haem strep and rheumatic fever)
• Food (e.g., iodine and its effect on the thyroid)
• Pollutants (e.g., mercury)

Other effects include:

• Hormones
• Stress
• Drugs

Pregnancy has a profound effect on autoimmune disease—some types become better, some worse.

We should use autoantibody presence in the blood with caution. This is NOT proof of autoimmune disease. Autoimmune diseases develop very slowly and a patient may have multiple antibodies over time.

The main conference papers were then presented, and the first session covered the latest research in immunology.