Complement Activity Total, (CH50)
Also known as: CH50 TOTAL
Use
The Complement Activity Total (CH50) test is used as an initial screening tool for identifying potential deficiencies in the classical complement pathway. A deficiency in the classical pathway can indicate inherited or acquired defects in the complement system, which is crucial for immune response regulation. CH50 testing can also be used to monitor therapeutic responses to complement deficiencies and to evaluate the extent of the body's classical pathway activity in various disease states like systemic lupus erythematosus and immune complex diseases.
Special Instructions
It is critical for the serum sample to be separated from cells as soon as possible, within two hours of collection, and frozen immediately to ensure accuracy of results. Grossly hemolyzed or severely lipemic specimens, as well as those that have been thawed and refrozen multiple times, are unacceptable as they may compromise test accuracy.
Limitations
This test cannot distinguish between different types of complement deficiencies or dysfunctions within the classical pathway. Furthermore, it may not adequately reflect complement activity under conditions where complement components are excessively consumed or degraded. Repeated testing may be required to confirm deficiencies, especially when low results do not match the clinical picture of the patient. Complement Activity Total (CH50) does not assess the alternate or lectin pathways, and anomalies in these pathways will not be detected.
New York Approved
Methodology
Immunoassay (Multiplex Protein Panel)
Biomarkers
LOINC Codes
- 4532-8
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
ARUP Standard Transport Tube
Collection Instructions
Allow specimen to clot for one hour at room temperature. Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube.
Storage Instructions
CRITICAL FROZEN
Causes for Rejection
Separator tubes. Specimens left to clot at 2-8 degrees C. Specimens exposed to repeated freeze/thaw cycles. Non-frozen specimens. Grossly hemolyzed or severely lipemic specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Unacceptable |
| Refrigerated | Unacceptable |
| Frozen | 1 month |