Test Details
Methodology
Immunologic quantitation by radial immunodiffusion (RID)
Result Turnaround Time
6 - 11 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
Quantitation of antigenic (immunologic) C2
Use
Assess patients with hereditary deficiency of this component or acquired decrease in its level which may be seen due to hypercatabolism in hereditary angioneurotic edema, or consumption or loss as in vasculitides, glomerulonephritides, immune complex diseases. C2 deficiency is the most common complement deficiency (1 in 10,000) and is associated with SLE.
Limitations
Results of this test are labeled for research purposes only by the assay's manufacturer. The performance characteristics of this assay have not been established by the manufacturer. The result should not be used for treatment or for diagnostic purposes without confirmation of the diagnosis by another medically established diagnostic product or procedure. The performance characteristics were determined by LabCorp.
Custom Additional Information
Deficiencies of C1 components, C2 and C4 are associated with rheumatic diseases, including lupus, vasculitis, and dermatomyositis. Some individuals with deficiency may have no evidence of disease. The most common complement deficiency is C2, which is a homozygous abnormality in 1 in 10,000 to 40,000 individuals, and is heterozygous in 1% to 2% of the general population. Patients with C2 deficiency and lupus often have negative or low titer ANA.
Specimen Requirements
Specimen
Serum
Volume
2 mL
Minimum Volume
0.1 mL
Container
Red-top tube or gel-barrier tube
Collection Instructions
Separate serum from cells.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 12 days |
Refrigerated | 12 days |
Frozen | 12 days |
Freeze/thaw cycles | Stable x3 |
Reference Range
1.4−3.3 mg/dL
*Reference interval has been verified for all age groups including pediatrics (birth to 18 years) and geriatrics.
Storage Instructions
Room temperature
Causes for Rejection
Excessive hemolysis; plasma specimen
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 161414 | Complement C2 | 4484-2 | 161415 | Complement C2 | mg/dL | 4484-2 |
| Order Code | 161414 | |||||
| Order Code Name | Complement C2 | |||||
| Order Loinc | 4484-2 | |||||
| Result Code | 161415 | |||||
| Result Code Name | Complement C2 | |||||
| UofM | mg/dL | |||||
| Result LOINC | 4484-2 |