Aspergillosis precipitin

Definition

Aspergillosis precipitin is a laboratory test to detect antibodies in the blood resulting from exposure to the fungus Aspergillus.

Alternative Names

Aspergillus immunodiffusion test; Test for precipitating antibodies

How the test is performed

A blood sample is needed. For information on how this is done, see: Venipuncture

The sample is sent to a laboratory where it is examined for precipitin bands that form when Aspergillus antibodies are present.

How to prepare for the test

There is no special preparation.

How the test will feel

When the needle is inserted to draw blood, you may feel moderate pain, or only a prick or stinging sensation. Afterward, there may be some throbbing.

Why the test is performed

Your doctor may order this test if you have signs of an Aspergillosis infection.

Normal Values

A normal test result means you do not have Aspergillus antibodies.

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.

What abnormal results mean

A positive result means antibodies to the fungus have been detected. This means you have been exposed to the fungus at some point, but it does not necessarily mean you have an active infection.

False-negative results are possible. For example, invasive aspergillosis often does not produce a positive result, even though Aspergillus is present.

What the risks are

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include:

• Excessive bleeding
• Fainting or feeling light-headed
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

Special considerations

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References

Stevens DA. Aspergillosis. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 360.

Patterson TF. Aspergillus species. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap 258.