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Lab Dept:
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Microbiology/Virology
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Test Name:
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CRYPTOCOCCUS ANTIGEN
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General Information
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Lab Order Codes:
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CRAG (serum)
INK (CSF)
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Synonyms:
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Cryptococcal Antigen
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CPT Codes:
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86403 – Particle agglutination; screen, each antibody
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Test Includes:
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Screen for cryptococcal antigen and titer, if positive.
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Logistics
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Lab Testing Sections:
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Microbiology - Sendouts
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Referred to:
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Fairview University Diagnostic Laboratories- Microbiology (Fairview Code: CRYPTA)
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Phone Numbers:
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MIN Lab: 612-813-6280
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STP Lab: 651-220-6550
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Test Availability:
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Daily, 24 hours
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Turnaround Time:
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Performed Monday - Friday 07:30 – 15:00; results are reported within two days.
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Special Instructions:
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● Specimen site and date/time of collection are required for specimen processing.
● Consult Microbiology medical director if repeat titers (i.e.: >1 per week) are desired.
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Specimen
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Specimen Type:
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Blood or CSF
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Container:
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Blood: red top (plain, no gel) tube
CSF: sterile container
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Volume:
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Blood: 4 mL (Minimum: 1.5 mL)
CSF: 1 mL (Minimum: 0.5 mL)
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Collection:
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CSF
1. Disinfect skin site with 2% tincture of iodine.
2. Insert needle with stylet at L3 – L4, L4 – L5, or L5 – S1 interspace.
3. Upon reaching the subarachnoid space, remove the stylet and collect 1 – 2 mL of fluid into each of 2 sterile CSF tubes.
4. Transport to Microbiology immediately.
Blood
1. Cleanse venipuncture site with 70% alcohol.
2. Draw 4 mL (Minimum: 1.5 mL) blood in a red top tube.
3. Transport to laboratory.
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Special Processing:
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CSF: Processing dependant on testing requested
● If specimen is for cryptococcal antigen only, store frozen
● If specimen is to be cultured, store in refrigerator, but must arrive within 24 hours.
Blood: Centrifuge and aliquot 1.3 mL (Minimum: 0.5 mL) serum into a screw-capped round bottom vial. Store at frozen temperatures.
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Transport/Storage:
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Transport specimens to Children’s laboratory at room temperature.
Lab Staff: Ship and store antigen only specimens at frozen temperatures.
If a culture is ordered on CSF, store refrigerated and ship at room temperature. Fairview University must receive the specimen within 24 hours of collection.
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Sample Rejection:
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Specimens with transit time to the lab exceeding 2 hours after collection; gross hemolysis; lipemia; turbidity; improperly labeled specimen; insufficient volume; external contamination. If an unacceptable specimen is received, the physician or nursing unit will be notified and another specimen will be requested before the specimen is discarded.
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Interpretive
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Reference Range:
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No Cryptococcus antigen detected.
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Critical Values:
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The physician or patient’s nurse will be notified of positive results.
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Limitations:
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Positive results should be confirmed with culture. Although rare, false-positive results have been reported. False-negative results may occur if a low number of organisms are present in the spinal fluid but the culture may be positive as might be seen early in the course of the disease. Positive Rheumatoid Factor may interfere with this test.
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Methodology:
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Latex agglutination
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Contraindications:
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Positive rheumatoid factor may interfere with this test.
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References:
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Fairview Diagnostic Laboratories Web Page September 2010
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Cook, JH, and M Pezzlo (1992). Specimen receipt and accessioning. Section 1. Aerobic bacteriology, 1.2.1-4. In HD Isenberg (ed) Clinical Microbiology Procedures Handbook. American Society for Microbiology, Washington DC
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Miller, J Michael (1999) A Guide To Specimen Management in Clinical Microbiology, American Society for Microbiology, Washington DC
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Miller, J Michael, and HT Holmes (1999) Specimen Collection, Transport, and Storage In PR Murray et al, (ed), Manual of Clinical Microbiology, 7th edition, American Society for Microbiology, Washington DC, pp 33-104
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Updates:
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9/27/2010: Specimen volume changes.
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