Test Code AHUSD Atypical Hemolytic Uremic Syndrome Complement Panel, Serum and Plasma
Useful For
Detecting deficiencies in the alternative pathway that can cause atypical-hemolytic uremic syndrome, dense deposit disease, and C3 glomerulonephritis
A second-tier test that aids in the differential diagnosis of thrombotic microangiopathies
Profile Information
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
INTGA | AHUS Interpretation | No | Yes |
COM3 | Complement, Total, S | Yes, (order COM) | Yes |
AH503 | Alternative Complement Path Func, S | Yes, (order AH50) | Yes |
C3HUS | Complement C3, S | Yes, (order C3) | Yes |
C4HUS | Complement C4, S | Yes, (order C4) | Yes |
FBCA | Factor B Complement Antigen, S | No | Yes |
FHCA | Factor H Complement Antigen, S | No | Yes |
CBB | CBb Complement, P | No | Yes |
SC5B9 | SC5b-9 Complement, P | Yes, (C5B9) | Yes |
Reflex Tests
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
C1Q | Complement C1q, S | Yes | No |
C1QFX | C1Q Complement, Functional, S | Yes | No |
C2FXN | C2 Complement, Functional, S, NR | Yes | No |
C3FX | C3 Complement, Functional, S | Yes | No |
C4FX | C4 Complement, Functional, S | Yes | No |
C5FX | C5 Complement, Functional, S | Yes | No |
C6FX | C6 Complement, Functional, S | Yes | No |
C7FX | C7 Complement, Functional, S | Yes | No |
C8FX | C8 Complement, Functional, S | Yes | No |
C9FX | C9 Complement, Functional, S | Yes | No |
C5AG2 | C5 Complement, Antigen, S | Yes, (order C5AG) | No |
Method Name
C3HUS, C4HUS, FBCA, FHCA; C5AG2: Nephelometry
COM3: Automated Liposome Lysis Assay
AH503, CBB, SC5B9: Enzyme-Linked Immunosorbent Assay (ELISA)
INTGA: Medical Interpretation
Reporting Name
aHUS Complement Panel, S and PSpecimen Type
Plasma EDTASerum
Ordering Guidance
This test should be performed prior to treatment initiation and in the absence of therapy with complement inhibitors, such as eculizumab or ravulizumab. Complement inhibitors will affect performance of these assays.
For evaluating patients with possible thrombotic microangiopathies (TMA), the recommended first-tier test is ADM13 / ADAMTS13 Activity and Inhibitor Profile, Plasma. This test should be a second-tier test for TMA.
For patients who have received eculizumab or need to monitor response to eculizumab therapy, the recommended test is ECMP / Eculizumab Monitoring Panel, Serum. Soluble membrane attack complex should not be used as a standalone assay to monitor eculizumab efficiency.
For patients who have received ravulizumab or need to monitor response to ravulizumab therapy, the recommended test is RAVMP / Ravulizumab Monitoring Panel, Serum. Soluble membrane attack complex (sMAC) should not be used as a standalone assay to monitor ravulizumab efficiency.
Specimen Required
Both serum and plasma are required for this test.
Patient Preparation:
1. Fasting preferred but not required.
2. Do not collect specimens for at least 48 hours following plasma exchange.
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Specimen Type: Serum
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1.5 mL total in 3 separate plastic vials, each containing 0.5 mL
Collection Instructions:
1. Immediately after specimen collection, place the tube on wet ice and allow specimen to clot.
2. Centrifuge at 4° C and aliquot serum into 3 separate plastic vials, each containing 0.5 mL.
3. Within 30 minutes of centrifugation, freeze specimen. Sample must be placed on dry ice if not frozen immediately.
NOTE: If a refrigerated centrifuge is not available, it is acceptable to use a room temperature centrifuge, provided the sample is kept on ice before centrifugation, and immediately afterward, the serum is aliquoted and frozen.
Specimen Type: Plasma
Collection Container/Tube:
Preferred: Lavender top (K2 EDTA)
Acceptable: Lavender top (K3 EDTA), light-blue top (sodium citrate)
Submission Container/Tube: Plastic vial
Specimen Volume: 1.5 mL total in 2 separate plastic vials, each containing 0.75 mL
Collection Instructions:
1. Immediately after specimen collection, place the tube on wet ice.
2. Centrifuge between 1000 and 2000 x g for 10 minutes at 4° C and aliquot plasma into 2 separate plastic vials, each containing 0.75 mL.
3. Within 30 minutes of centrifugation, freeze specimen. Sample must be placed on dry ice if not frozen immediately.
NOTE: If a refrigerated centrifuge is not available, it is acceptable to use a room temperature centrifuge, provided the sample is kept on ice before centrifugation, and immediately afterward, the plasma is aliquoted and frozen.
Specimen Minimum Volume
Serum: 1.5 mL; plasma: 1.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Plasma EDTA | Frozen | 14 days | |
Serum | Frozen | 14 days |
Reference Values
FACTOR B COMPLEMENT ANTIGEN
15.2-42.3 mg/dL
SC5b-9 COMPLEMENT
≤250 ng/mL
FACTOR H COMPLEMENT ANTIGEN
18.5 to 40.8 mg/dL
CBb COMPLEMENT ACTIVATION FRAGMENT
≤1.6 mcg/mL
COMPLEMENT C4
14-40 mg/dL
COMPLEMENT C3
75-175 mg/dL
ALTERNATIVE COMPLEMENT, PATHWAY (AH50) FUNCTIONAL
≥46% Normal
COMPLEMENT, TOTAL
30-75 U/mL
Day(s) Performed
Varies
Report Available
12 to 21 daysPerforming Laboratory

CPT Code Information
86160 x 6
86161
86162
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
AHUSD | aHUS Complement Panel, S and P | In Process |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
62585 | CBb Complement, P | 4517-9 |
FBCA | Factor B Complement Antigen, S | 2269-9 |
FHCA | Factor H Complement Antigen, S | 4519-5 |
62586 | SC5b-9 Complement, P | 93244-2 |
38316 | Alternative Complement Path Func, S | 74520-8 |
COM3 | Complement, Total, S | 4532-8 |
C3HUS | Complement C3, S | 4485-9 |
C4HUS | Complement C4, S | 4498-2 |
39844 | AHUS Interpretation | 69048-7 |
ECPRO | Is Eculizumab or Ravulizumab taken? | 86955-2 |
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.Forms
If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
-Renal Diagnostics Test Request (T830)
-Coagulation Test Request (T753)