Rheumatoid arthritis and type 1 diabetes are classified as autoimmune diseases because in each of them
- A. the immune system attacks the body's own tissues
- B. the body cannot make any antibody at all
- C. a virus destroys the helper T cells
- D. an allergen provokes the release of histamine
Explanation
Self tolerance breaks down and lymphocytes treat a normal body component as foreign, the synovial membrane in rheumatoid arthritis and the insulin secreting beta cells in type 1 diabetes. The damage is therefore done by the patient's own immune system, which is why treatment suppresses immunity. An inability to make antibody is immunodeficiency, and an exaggerated response to a harmless substance is allergy.