Immunofixation with Free Light Chains, Quantitative, Urine
Use
Quantitative measurement of urine free kappa and lambda light chains, along with immunofixation, is useful in monitoring disease progression or response to therapy when urine electrophoresis cannot reliably quantify Bence Jones protein. However, results may be misleading in specimens with high levels of urinary polyclonal free light chains and absent Bence Jones protein; correlation with urine immunofixation is required. Total urinary protein is measured turbidimetrically, which may differ from chemical determination and underestimate light chains. Antigen excess cannot be excluded.
Special Instructions
Order questions include Hours Collected and Total Volume. Specimen must be collected over 24 hours with refrigeration during collection, then mixed and aliquoted into two plastic aliquot tubes.
Limitations
Quantitative results may be misleading with high polyclonal light chains and absent immunofixation findings. Turbidimetric total protein may differ from chemical methods. Undetected antigen excess, though rare, cannot be excluded; results must be interpreted with other clinical and lab findings.
New York Approved
Methodology
Immunoassay (Immunofixation Electrophoresis/Quantitative Immunoturbidimetry)
Biomarkers
LOINC Codes
- 30211-7
- 19153-6
- 2889-4
- 38176-4
- 38177-2
- 38178-0
- 38169-9
- 49277-7
Result Turnaround Time
1-9 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
8 mL (4 mL x 2 aliquots)
Minimum Volume
4 mL total (2 mL x 2 vials)
Container
Two plastic aliquot tubes
Collection Instructions
Collect urine for 24 hours (no preservative). Refrigerate during collection; mix then aliquot 4 mL per tube.
Storage Instructions
Send refrigerated.
Causes for Rejection
All specimens will be evaluated for test suitability.
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 21 days |
| Frozen | 180 days |