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.

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, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or slight bruising. This soon goes away.

Why the Test is Performed

Your health care provider may order this test if you have signs of an aspergillosis infection.

Normal Results

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 provider about the meaning of your specific test results.

What Abnormal Results Mean

A positive result means antibodies to the fungus have been detected. This result 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.

Risks

There is little risk involved with having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Taking blood 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 lightheaded
• Multiple punctures to locate veins
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

References

Iwen PC. Mycotic diseases. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 23rd ed. St Louis, MO: Elsevier; 2017:chap 62.

Thompson GR, Patterson TF. Aspergillus species. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 257.