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Test Code AH50 Alternative Complement Pathway, Functional, Serum

Additional Codes

Epic Ordering Code LAB3053089
NBS code LBC11750
Service code 36792

Reporting Name

Alternative Complement Path Func, S

Specimen Type

Serum


Ordering Guidance


COM / Complement, Total, Serum and this test are the most appropriate primary assays to use as screening methods for complement deficiencies. Abnormal results in one or the other, neither or both assays will help direct further testing.

 

This test is rarely useful when ordered in isolation.



Specimen Required


Patient Preparation:

Fasting: 8 hours, preferred but not required

Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 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 a plastic vial.

3. Freeze specimen within 30 minutes of centrifugation. Specimen 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 specimen is kept on ice before centrifugation, and immediately afterward, the serum aliquoted and frozen.


National University Hospital-Singapore Note:

NUH Outreach Laboratories:
Specimen Requirements
Submit only one of the following:
Preferred: Gold Top
Acceptable: Red Top
Processing Requirements
Place tube on wet ice and allow specimen to clot. Centrifuge cold and aliquot into plastic vial. Freeze serum immediately.
Specimen type: Serum
Volume: 1 mL
Storage/transport requirements: Frozen

Forms

If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.

Specimen Minimum Volume

0.75 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Frozen 14 days

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Method Name

Enzyme-Linked Immunosorbent Assay (ELISA)

Day(s) Performed

Varies

Report Available

3 to 5 days
National University Hospital-Singapore Note:

Please note that this is a referral test requiring transport to the external testing facility and an additional 3-5 days is required.

Reference Values

≥46% normal

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Investigation of suspected alternative pathway complement deficiency, atypical hemolytic uremic syndrome, C3 glomerulonephritis, and dense-deposit disease

CPT Code Information

86161

LOINC Code Information

Test ID Test Order Name Order LOINC Value
AH50 Alternative Complement Path Func, S 74520-8

 

Result ID Test Result Name Result LOINC Value
88676 Alternative Complement Path Func, S 74520-8

Secondary ID

88676

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.
National University Hospital-Singapore Additional Information:

Last updated 11/06/2026