Cryoglobulin Screen with Reflex to Cryoglobulin Panel

Message

*Draw 2 plain red top tubes. Keep tubes warm in a heal warmer and bring to processing ASAP.
*Collect specimen Monday through Friday only before 1600 EST. Do not collect the day before a holiday.

Test Code

37358

Alias/See Also

LAB713

CPT Codes
82595

Includes

If cryoglobulin is present (positive), it is identified. Positives are semi-quantitated (as % cryoglobulin) by cryocrit.
If Cryoglobulin Screen is positive, then Cryoglobulin Panel (Cryocrit Immunofixation, Cryocrit Immunodiffusion and Rheumatoid Factor) will be performed at an additional charge (CPT Code(s): 86334, 86329, 86431).

Preferred Specimen

3 mL serum collected in a red-top tube (no gel)

Patient Preparation
Overnight fasting is required

Minimum Volume

2 mL

Instructions

Allow blood to clot for one (1) hour in a 37° C water bath, incubator, heat block or heel warmer. After clotting, centrifuge the specimen as quickly as possible. It is not necessary to use a warm centrifuge but do not use a refrigerated one. Decant all of the serum into one screw-cap vial (do not aliquot any of the cryoglobulin serum into any other tube). Transport at room temperature.

Note: If the sample is NOT kept at 37° C during clotting, the cryoglobulin, if present, can precipitate during centrifugation and be lost in the clot resulting in a false negative result.

Transport Container

Transport tube(s)

Transport Temperature

Room temperature

Specimen Stability

Room temperature: 5 days
Refrigerated: 7 days
Frozen: 30 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Gross hemolysis • Grossly lipemic • Icteric • Serum separator tube (SST)

Methodology
Cryocrit • Electrophoresis • Immunodiffusion (ID) • Immunofixation (if needed) • Rate Nephelometry

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule

Sun-fri

Reference Range

Cryoglobulin, QL

Negative in normal individuals

Clinical Significance

Cryoglobulins are proteins that precipitate from serum at temperatures below 37° C. Most precipitate when serum is cooled at 4° C, but some gel even at room temperature. The gel or precipitate must redissolve at 37° C to be classified as a cryoglobulin.

Performing Laboratory

Quest Diagnostics Nichols Institute-San Juan Capistrano, CA

33608 Ortega Highway

San Juan Capistrano, CA 92675-2042

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.