How to read your medical test report: Serologic tests

All you need to know about reading your serologic test report.

Antigens are substances that induce an immune response. They can be microorganisms (bacteria, viruses, and fungi), toxins, foreign blood cells pollen, or some chemicals. They are perceived as being dangerous or not own by the body s immune system. This perception provokes your immune system to respond by producing antibodies to kill them. In autoimmune diseases, your body erroneously makes antibodies against its own cells and tissues. An antibody binds only to the antigen that induced its synthesis. IgG, IgA, IgM, IgD and IgE are the different types of antibodies present in the blood. Here's how to read your medical reports: Complete Blood Count

Serologic tests what are they?

Serologic tests are blood tests that identify antibodies in your blood serum (the liquid part of the blood without cells and clotting factors). They are based on the antibody-antigen response. Various methods are used depending on the type of antibody being studied. The tests mix antibody and specially prepared antigens and study the reactions. Broadly, the reactions that are looked for are precipitation and agglutination (clumping). Some of the agglutination tests are Widal test, Brucellosis test, hemagglutination test, cold agglutination test, Coombs test, etc. Precipitation tests are VDRL test, complement fixation test, ELISA test, the fluorescent antibody test, etc.

When are the tests recommended?

Serologic tests can be used to diagnose various bacterial, viral and other infections like typhoid, brucellosis, syphilis, HIV, etc. These tests may be recommended when an infection is suspected. They help diagnose an active or previous infection and can also establish your immunity to certain infections. Here's how to read your medical test report: Lipid profile

Serologic tests are also used to determine your blood type as well as check whether you have any autoimmune condition like rheumatoid arthritis, etc. The tests also help detect immune deficiency problems associated with the lack of certain necessary antibodies.

Blood serum may also be analyzed for forensic purposes like help establish a person s identity, the cause of death, etc.

Reading your serologic test report

Antibodies are typically not found in the blood sample. A negative test report indicates no current or past infection. A positive test report means a current or past exposure to an antigen. The presence of antibodies to your body s proteins points out to an autoimmune disorder.

Serologic tests based on agglutination may have the following report:

Reactive - presence of agglutination (clumping)

Non-reactive - no agglutination (clumping)

Fluorescent antibody test report may read:

Fluorescence - presence of specific antibody

No fluorescence - absence of specific antibody

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