Medical Health Encyclopedia

Immune response

For example, an individual who has had chickenpox is immune to getting chickenpox again.

PASSIVE IMMUNITY

Passive immunity involves antibodies that are produced in someone's body other than your own. Infants have passive immunity because they are born with antibodies that are transferred through the placenta from the mother. These antibodies disappear between 6 and 12 months of age. Gamma globulin is another form of getting passive immunity that is given by a doctor. Its protection is also temporary.

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IMMUNE SYSTEM DISORDERS AND ALLERGIES

Immune system disorders occur when the immune response is inappropriate, excessive, or lacking. Allergies involve an immune response to a substance that, in the majority of people, the body perceives as harmless. Transplant rejection involves the destruction of transplanted tissues or organs and is a major complication of organ transplantation. Blood transfusion reaction is a problem caused by receiving blood. Autoimmune disorders (such as systemic lupus erythematosus and rheumatoid arthritis) occur when the immune system acts to destroy normal body tissues. Immunodeficiency disorders (such as inherited immunodeficiency and AIDS) occur when there is a failure in all or part of the immune system.

SIGNS OF INFLAMMATION:

• Redness in the area
• Pain in the area
• Swelling of the affected area
• Warmth of the affected area
• Pus (sometimes)

In many cases, however, there are no noticeable symptoms.

Additional symptoms may include:

• Fever
• General discomfort, uneasiness, or ill feeling (malaise)
• Muscle aches
• Agitation or confusion

TESTS

During an infection, a complete blood count (CBC) usually shows increased numbers of white blood cells. A blood differential count may reveal an high percentage of phagocytes (white blood cells that eat other cells), meaning that the body is responding to a need to fight infection.