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UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: Cryoglobulin, Qualitative

Test Code(s): CRYG / CRYO

CPT Code(s): 82595

Methodology: Manual

Clinical Significance: Cryoglobulins (serum) are proteins or protein complexes that undergo reversible precipitation at temperatures less than 37C.

Days Performed: Daily, dayshift.

Turnaround Time: Stat: Not available stat.
Routine: Specimens are processed on day 1 and evaluated for the next seven days.

Specimen Requirements

Specimen: Blood

Patient Preparation: Patient must fast for at least 6 hours prior to speciman collection. The patient may only have water or black coffee during the fasting period.

Collection Instructions: Keep specimen at 37C by wrapping a hot pack (infant heel warmer) around the tube immediately after collection. BEFORE COLLECTING SPECIMEN, pre-warm a red top tube (e.g. in an infant heel warmer). Have another infant heel warmer on hand to deliver the blood to the laboratory after collection. Transport specimen to Core Laboratory (B4/220) within 10 minutes of collection. Contact laboratory if unable to assure delivery within 10 minutes.  
Please indicate patient history and if patient is receiving anticoagulant (Coumadin/ Heparin/ Vitamin K antagonist), direct thrombin inhibitor or fibrinolytic agent therapy and duration.

Collection Container: Preferred: Red top

Collection Volume: Preferred: 9 mL
Pediatrics: 5 mL

Sample Analyzed: Serum

Volume Required: Preferred: 5 mL
Pediatrics: 2 mL

Specimen Processing: IMPORTANT: Keep whole blood specimen at 37C during entire processing procedure. While still in hot pack (infant heel warmer), rim clot. Place red top tube in 37C incubator for two hours. Remove serum to a pre-warmed glass tube. Spin tube at 2500 rpm for 10 minutes at 37C. Remove spun serum and divide into two labeled tubes. Place both tubes at 2-8C.

Specimen Transport: Transport whole blood specimen to UWHC Core Laboratory (B4/220) within ten minutes of collection - keep specimen at 37C by wrapping tube in a hot pack (infant heel warmer). Specimen MUST be processed prior to transport if coming from outreach location. Transport specimens with coolant pack after processing is complete.

Unacceptable Criteria: Lipemic specimens are not acceptable. Specimens collected in red cap with yellow ring (SST) tube are not acceptable.

Stability: Frozen: Not acceptable


Expected Results:

18 years and up: Negative

Test Limitations:

The cryoglobulin can be lost if the specimen is allowed to cool even a few degrees Celcius before final processing is complete.

Additional Information:

For all positive cryoglobulin samples: The ordering physician will be contacted by the Immunology laboratory regarding addition of an immunofixation test. If requested, the immunofixation testing will be performed by the Immunology laboratory on the cryoprecipitate at an additional charge (a professional fee is associated with immunofixation testing). A separate interpretive report will be issued. PLEASE NOTE: If a patient has a positive cryoglobulin, testing for other proteins (such as immunoglobulin levels, rheumatoid factor and other antibody testing) should be performed on specimens that have been processed at 37°C. Samples should be kept at 37°C until testing is complete (or reheated to 37°C before analysis). Please write "KEEP WARM" in red on request forms so samples are processed correctly.

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