Autoimmunity: Some Examples Autoimmune Disorders

Systemic Lupus Erythematosus-Systemic

In this disease, autoantibodies are formed which include anti-DNA, anti-RNA, and anti-cardiolipin. The antibodies form complexes (immune complexes) with the antigens to which they are directed. These immune complexes can form anywhere in the body, including the kidneys, where deposition within the glomerulus can result in glomerulonephritis, and kidney failure. Also, formation of anti-cardiolipin antibody may result in a FALSE POSITIVE RPR, when doing reagin-screening tests for syphilis.

Clinical Features:

1. anemia
   
2. leukopenia--anti-Abs usually present
   
3. thrombocytopenia
4. Prolonged clotting time
5. May have anti-clotting factor Antibodies
6. Vasculitis
7. Glomerulonephritis
8. Joint Damage Due to Ag/Ab complex deposits in synovial fluid
9. Most tissue damage is due to these immune complex deposits

Hashimoto's Thyroiditis-Organ Specific

Hypothyroidism characterized by:

• infiltration of lymphocytes into thyroid gland
  
• thyroid hormone insufficiency
• anti-thyroglobulin antibody
• T cell mediated
• organ specific autoimmune disease

Grave's Disease-Organ Specific

B cell mediated hyperthyroidism caused by an IgG antibody that mimics the activity of TSH. This autoantibody is call LATS (long acting thyroid stimulator).

Guillain-Barré Syndrome-Organ Specific

Seen in come cases where living viral organisms are utilized for vaccination purposes. Very low incidence, but is an example of a post-vaccinial or post-infectious encephalomyelitis. Viral pathogens attack various tissue cells, including cells of the CNS. Affected cells of the CNS may be attacked by activated T cells, resulting in demyelinization of nervous tissue. Symptoms include backache, headache, muscle weakness (even paralysis), and loss of reflex responses. The disease is USUALLY self-limited, however some deaths have been reported. It may be that the self-limitation of the disease is due to the autoantibodies formed acting as blocking antibodies to the viral antigens, and preventing further recognition and response.
Paroxysmal Cold Hemoglobinuria- AHA Organ Specific

Antibody formed is usually anti-I against I antigens on cell surface of red cells. It is a complement dependent, cold reacting antibody causing hemolysis if cells are cooled, then rewarmed to body temperature. Cooling can occur, for example, when extremities are exposed to cold, or during certain types of surgery where body temperature is lowered.
Rheumatoid Arthritis-Systemic

• Etiology unknown
• RF is an IgM anti-IgG antibody that will react in vivo
• Stimulus for production is unknown
• RF is also seen in several other connective tissue disorders

Pernicious Anemia-Organ Specific

1. Inflammation and subsequent atrophy of gastric mucosa
2. Results in inability to secrete HCL, Intrinsic Factor, and pepsin
3. Macrocytic anemia
4. 95% of patients have demonstrable anti-parietal cell antibodies & or anti-Intrinsic Factor antibody
   

Goodpasteur's Syndrome-Organ Specific

1. Glomerulonephritis with pulmonary hemorrhages
2. Anti-glomerular basement membrane antibody
3. Lung damage---->formation of Ab----> Ab cross reacts with glomerular basement membrane producing glomerulonephritis

Category: Pathology Notes