What is an Autoimmune Disease?

Autoimmune diseases refer to diseases caused by the body's own tissue damage caused by the body's immune response to autoantigens. Many diseases have been listed as autoimmune diseases one after another. It is worth mentioning that the existence of autoantibodies and autoimmune diseases are not two equivalent concepts. Autoantibodies can exist in normal people without autoimmune diseases, especially the elderly. Such as anti-thyroglobulin antibodies, thyroid epithelial cell antibodies, gastric parietal cell antibodies, nuclear DNA antibodies and so on. Sometimes, damaged or changed antigenicity can stimulate the production of autoantibodies. For example, when myocardial ischemia occurs, necrotic myocardium can lead to the formation of anti-cardiac autoantibodies, but this antibody has no pathogenic effect and is a secondary immune response.

Basic Information

English name

AutoimmuneDisorders

Visiting department

Immunology

Common symptoms

Emergence of autoantigens, abnormal immune regulation, cross antigens, genetic factors

Contagious

no

Causes of autoimmune diseases

The emergence of autoantigens

(1) Release of covert antigen.

(2) Changes in autoantigens.

2. Abnormal immune regulation

(1) Alternative activation of polyclonal stimulants.

(2) Th1 and Th2 cell imbalance.

3. Cross antigen

(1) Coxsackie virus diabetes.

(2) Streptococcal infection acute glomerulonephritis, rheumatic heart disease.

4. Genetic factors.

Clinical manifestations of autoimmune diseases

Organ-specific autoimmune disease

The pathological damage and dysfunction of tissues and organs is limited to an organ targeted by antibodies or sensitized lymphocytes. Mainly chronic lymphocytic thyroiditis, hyperthyroidism, insulin-dependent diabetes mellitus, myasthenia gravis, ulcerative colitis, malignant anemia with chronic atrophic gastritis, pulmonary hemorrhagic nephritis syndrome, pemphigus vulgaris, pemphigoid , Primary biliary cirrhosis, multiple cerebrospinal sclerosis, acute idiopathic polyneuritis, etc., the common ones will be described separately in each system disease.

2. Systemic autoimmune disease

Systemic autoimmune diseases are called systemic autoimmune diseases due to the extensive deposition of antigen-antibody complexes on the walls of blood vessels and other causes. It is also commonly known as collagen disease or connective tissue disease, which is caused by the cell wall and interstitial cell-like necrotic inflammation caused by immune damage and subsequent proliferation of collagen fibers in multiple organs. In fact, from the perspective of ultrastructure and biochemical metabolism, most of the collagen fibers have no primary changes. Common autoimmune diseases include the following:

(1) Systemic lupus erythematosus This disease is more common in women of childbearing age. It can include all the clinical features of connective tissue disease. It is manifested as multi-organ system involvement, which can include fever, facial erythema, joint pain, hair loss, oral ulcers, etc., which can affect the kidney , Blood system, cardiovascular and nervous system.

(2) Rheumatoid arthritis occurs in middle-aged and elderly women. It is a systemic disease, and the disease mainly affects the joints. Joint symptoms usually recur. As the number of attacks increases, joint destruction becomes increasingly serious, eventually leading to varying degrees of dysfunction and deformity. In addition to joints, cutaneous rheumatoid nodules, arteritis, pericarditis, scleritis, lymphadenitis, hepatosplenomegaly, and neuropathy are not uncommon.

(3) Systemic vasculitis includes a series of lesions characterized by the vascular wall damage caused by chronic inflammation of the vascular wall. More common is nodular polyarteritis. Most of the patients are male. The lesions mainly invade the middle arteries and small arteries in the muscle, leading to stenosis of the lumen. The kidneys and heart are the organs most commonly affected. Lesions can also invade the digestive tract, peripheral nerves, skin, lungs, brain, liver, spleen, testes, and so on. Early symptoms are usually symptoms of fever, fatigue, weight loss, and affected organs.

(4) Scleroderma is characterized by excessive hyperplasia of skin fibrous tissue, which occurs in women. As the skin thickens and hardens, the appearance is tight and waxy, and the patient's face is dull and lacks expression. There are two types of scleroderma, one is limited and the skin lesions are limited to the skin; the other is systemic, with joint, gastrointestinal, renal, cardiovascular, and lung lesions. Dyskinesia and dysphagia are common symptoms. Antinuclear antibodies and rheumatoid factors can be found in the serum.

(5) Pemphigus is a type of skin disease characterized by bullous lesions on the surface of the skin. Autoantibodies against skin antigens can be found in patients' blood. There are different types of pemphigus, and some of the lesions are self-limiting and can alleviate on their own; some are combined with visceral lesions and can be fatal quickly.

(6) Dermatomyositis is an autoimmune disease characterized by skin involvement and muscle weakness. Due to muscle atrophy, the patient feels extremely weak. Another feature is often accompanied by malignant lesions, especially in elderly patients.

(7) The clinical manifestations of mixed connective tissue disease are cross symptoms of rheumatoid arthritis, systemic lupus erythematosus, scleroderma, and dermatomyositis. There are high titers of antinuclear antibodies and anti-U1RNP antibodies, and Sm antibodies are negative. Most patients respond well to corticosteroid treatment, and the disease has a tendency to develop systemic scleroderma.

(8) The serum of patients with autoimmune hemolytic anemia contains antibodies against auto-erythrocytes. Some of these antibodies can agglutinate red blood cells, and some can lyse red blood cells with complement. According to the suitable temperature of autoantibodies, these antibodies can be divided into two categories: hot antibodies and cold antibodies. The most suitable temperature for the so-called hot antibodies is 37 ° C. Patients have varying degrees of anemia and mild clinical symptoms. Obviously, severe can be accompanied by jaundice and acute blood loss symptoms.

(9) Thyroid autoimmune disease Thyroid autoimmune disease is a local autoimmune disease. Such as Hashimoto's thyroiditis, primary myxedema (antithyroid antibodies can also be measured, but the titer is low. Eventually leading to thyroid atrophy, which may be the final stage of development of Hashimoto's thyroiditis), hyperthyroidism Clinical manifestations are goiter, tremor, exophthalmos, and increased basal metabolic rate).

(10) Ulcerative colitis is more common in women. It mainly affects the rectum and sigmoid colon and presents as a superficial ulcer. Repeated illness, causing connective tissue hyperplasia in the intestinal wall.

Autoimmune disease test

Consider different diseases according to clinical manifestations and do corresponding examinations.

Diagnosis of autoimmune diseases

Diagnosis can be made based on typical clinical manifestations and findings.

Treatment of autoimmune diseases

Generally speaking, symptomatic treatment and control of the disease progress. The treatment plan and drug dosage should pay attention to the principle of individualization, and pay attention to observe the adverse reactions of the drug.