Test Details
Methodology
Turbidimetry
Result Turnaround Time
5 - 7 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Test Includes
This test is a component of ANA Profile 11, ANA Profile 12, ANA 12 Plus Profile, Vasculitis Profile.
Use
Measurement of C4 in serum is used to detect individuals with inborn deficiency of this factor or those with immunologic disease in whom complement is consumed at an increased rate. These include lupus erythematosus, chronic active hepatitis, certain chronic infections, post-streptococcal and membranoproliferative glomerulonephritis, and others.
Specimen Requirements
Specimen
Serum
Volume
1 mL
Minimum Volume
0.3 mL (Note: This volume does not allow for repeat testing.)
Container
Gel tube or red-top tube
Collection Instructions
Separate serum from cells within one hour. Transfer to a plastic transport tube before freezing.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 2 days |
Refrigerated | 8 days |
Frozen | 3 months |
Freeze/thaw cycles | Stable x1 |
Storage Instructions
Store frozen or refrigerated.
Causes for Rejection
Grossly hemolyzed; bacterial contamination; lipemic, icteric, non-serum specimen types
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 520166 | C4 Complement (RDL) | 4498-2 | 520167 | C4 Complement (RDL) | mg/dL | 4498-2 |
| Order Code | 520166 | |||||
| Order Code Name | C4 Complement (RDL) | |||||
| Order Loinc | 4498-2 | |||||
| Result Code | 520167 | |||||
| Result Code Name | C4 Complement (RDL) | |||||
| UofM | mg/dL | |||||
| Result LOINC | 4498-2 |