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HelpTest Code FCUIX CU Index
Specimen Required
Patient Preparation: Patients taking calcineurin inhibitors should stop medication 72 hours prior to draw. Patients taking prednisone should be off their medication for 2 weeks prior to draw.
Specimen Type: Serum
Collection Container/Tube: Red or SST
Submission Container/Tube: Plastic vial
Specimen Volume: 2 mL
Collection Instructions:
1. Draw 5 mL blood in a serum separator tube (SST) (plain, red-top tube is acceptable).
2. Separate from cells within 2 hours of draw. Send 2 mL of serum ambient in a plastic vial.
Secondary ID
57549Method Name
Ex Vivo Challenge, Cell Culture and Histamine Analysis
Reporting Name
CU IndexSpecimen Type
SerumSpecimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Ambient (preferred) | 14 days | |
| Frozen | 14 days | ||
| Refrigerated | 14 days |
Reject Due To
| Hemolysis: | NA |
| Thawing: | Warm OK; Cold OK |
| Lipemia: | NA |
| Icterus: | NA |
| Other: | NA |
Clinical Information
Patients with a chronic form of urticaria who are positive (>10) with the CU index have an autoimmune basis for their disease. A positive result does not indicate which autoantibody (anti-IgE, anti-FceRI or anti-FCERII) is present.
Reference Values
< 10.0
The CU Index test is the second generation Functional Anti-FceR test. Patient with a CU Index greater than or equal to 10 have basophil reactive factors in their serum which supports an autoimmune basis for disease.
Method Description
Ex-Vivo Challenge and cell culture: Donor blood cells are incubated with patient serum, a negative control and a positive control. Following the ex-vivo challenge, the cells are centrifuged and the supernatant is recovered for assay of histamine released. Histamine Analysis: Using a quantitative enzyme immunoassay, the histamine released into the supernatant is measured and compared to the total histamine in the basophils.
Day(s) Performed
Monday and Thursday
Performing Laboratory
Eurofins ViracorTest Classification
This test was developed and its performance characteristics determined by Viracor Eurofins. It has not been cleared or approved by the U.S. Food and Drug Administration.CPT Code Information
86343
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| FCUIX | CU Index | 63369-3 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| FCUIX | CU Index | 63369-3 |