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Cryptococcus Antigen

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Test Description
  • Contact: Serology (319) 335-4291
  • Test Request Form: Serology/Immunology
  • SHL OpenELIS Code: 1140
Quantitative detection of antigens of Cryptococcus neoformans in patient serum or Cerebrospinal Fluid (CSF)
Performed Avg. Turnaround Time Method
Coralville, 8 a.m. - 5 p.m., M-F
1 - 3 business days Latex Agglutination
Fee CPT Code(s)
$23.93 87327
Specimen Requirements
Specimen Type: Minimum 1 mL Serum or 0.5 mL Cerebrospinal Fluid (CSF)
Collection Instructions: Allow blood samples to clot at room temperature prior to centrifugation. Aseptically transfer serum to a tightly closing sterile container for storage.

Red Top Tube: centrifuge and transfer serum to a secondary tube.
    Serum Separator Tube: collect 4 - 6 mL and centrifuge.
      CSF: Cerebrospinal Fluid (CSF) may be submitted for this test. Aseptically collect CSF from patient into a sterile, clear plastic tube with screw-top lid. Centrifuge at 1000 x g for 15 minutes to ensure the removal of all white cells and particulate matter. Carefully aspirate the CSF into a sterile container and seal.
        Shipping:
        Specimens should be stored and shipped under the same conditions. Wrap specimen container in absorbent material and place inside a biohazard bag. Transport specimen with cold pack. Ship to the Coralville location.
        Temperature and Stability: Refrigerate (2-8 degrees C); stable for up to 7 days. Freeze (-20 degrees C); stable for more than 7 days.
        Rejection Criteria: Specimens will be rejected if received under these conditions:

        Plasma. Grossly hemolyzed or lipemic samples as well as samples containing particulate matter or exhibiting obvious microbial contamination should not be tested. Specimens not received in the correct temperature ranges stated under "Temperature and Stability" will be rejected.
        Expected Results:
        Negative, Positive, Titer of Cryptococcus antigen present
        Comments
        A negative result does not exclude cryptococcal infection. False negative reactions may be caused by low titers, early infection, presence of immune complexes, and poorly encapsulated strains with low production of polysaccharide. If clinical symptoms are suggestive of Cryptococcosis, subsequent specimens and culture are strongly recommended. A positive reaction in serum or CSF of an untreated patient at titers of 1:4 or less is highly suggestive of Cryptococcal infection. Titers of 1:8 or higher usually indicate active Cryptococcosis. The antigen titer is usually proportional to the extent of infection, with increasing titers reflecting progressive infection and declining titers indicating response to therapy. Low titers may persist for an indefinite period in the presence of nonviable fungus and clinical improvement.
        Alternate Names
        Cryptococal antigen, Cryptococcus screen
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        State Hygienic Laboratory

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        319-335-4500 or 1-800-421-IOWA (4692)
        ask-shl@uiowa.edu

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