C5 Inhibitors Drug Monitoring Panel
Ordering Recommendation
Use to monitor complement blockage in patients treated with C5 inhibitor drugs.
New York DOH Approval Status
Specimen Required
Plain red.
Separate serum from cells ASAP or within 2 hours of collection. Transfer 2.0 mL serum to an ARUP standard transport tube and freeze immediately. (Min: 2.0 mL)
CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered.
Specimens received refrigerated, ambient, lipemic specimens, or grossly hemolyzed specimens. Serum separator tubes. Specimens collected using calcium-binding anticoagulants (i.e., EDTA, ACD).
Refer to individual components.
Methodology
Quantitative Turbidimetric/Quantitative Radial Immunodiffusion
Performed
Tue, Fri
Reported
1-9 days
Reference Interval
Test Number |
Components |
Reference Interval |
---|---|---|
Complement Activity, Total Turbidimetric | 38.7-89.9 U/mL | |
Complement C5, Concentration | 7-20 mg/dL | |
Alternative Complement Pathway Activity | 31 percent normal or greater | |
Complement C5, Functional | 23.0 U/mL or greater |
Interpretive Data
Component |
Interpretation |
---|---|
Complement Activity, Total Turbidimetric | Low: 38.6 U/mL or less Normal: 38.7-89.9 U/mL High: 90.0 U/mL or greater |
Complement C5, Functional | Low: 22.9 U/mL or less Low-Normal: 23.0-28.3 U/mL Normal: 28.4 U/mL or greater |
Alternative Complement Pathway Activity | See Report |
C5 Inhibitors Drug Monitoring Pan Interp | Patients treated with C5 inhibitors may show decreased/absent activity in total complement functional assay (CH50), alternative pathway functional assay (AH50), and C5 functional assay with normal or elevated C5 protein concentrations. Normal CH50, AH50, or C5 functional activity with normal or elevated C5 protein concentrations indicate inadequate complement blockage. Serial measurements are recommended when monitoring treatment efficacy. Decreases in both C5 concentration and C5 functional activity suggests a secondary consumption process or C5 deficiency. Repeat testing using a new specimen is suggested if in vitro complement activation and consumption of components due to conditions of collection, transport, and/or handling is suspected. |
Laboratory Developed Test (LDT)
Note
Hotline History
Hotline History
CPT Codes
86160; 86161 x2; 86162
Components
Component Test Code* | Component Chart Name | LOINC |
---|---|---|
0050156 | Complement C5, Concentration | 4505-4 |
2005374 | Alternative Complement Pathway Activity | 74520-8 |
3002576 | Complement Activity, Total Turbidimetric | 4532-8 |
3005962 | Complement C5, Functional | 60472-8 |
3006097 | C5 Inhibitors Drug Monitoring Pan Interp | 48767-8 |
Aliases
- AH50
- anti-C5
- C5 inhibitor
- CH50 total
- Complement blocking
- Complement C5
- Complement C5 functional
- Complement monitoring
- concentration
- Eculizumab
- Ravulizumab