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Test Code AH50 Alternative Complement Pathway, Functional, 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: Patient should be fasting.

Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube: Red top (serum gel/SST are not acceptable)

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. Immediately after specimen collection, place the tube on wet ice.

2. After sample has clotted on wet ice, centrifuge at 4° C and aliquot serum into a plastic vial.

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


Children's Mercy Hospital Note:

CMH COLLECTION: 2 mL in red vacutainer

Specimen Minimum Volume

0.2 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Red Frozen 14 days

Useful For

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

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Day(s) Performed

Monday, Thursday

Report Available

3 to 5 days

Reporting Name

Alternative Complement Path Func, S

Reference Values

≥46% normal

Method Name

Enzyme-Linked Immunosorbent Assay (ELISA)

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

86161