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Test Code C4 Func C4 Complement, Functional, Serum

Reporting Name

C4 Complement, Functional, S
Seattle Children's Hospital Note:

Clinical System Name: C4 Complement, Functional

Useful For

Diagnosis of C4 deficiency

 

Investigation of a patient with an undetectable total complement level

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Serum Red


Ordering Guidance


The total complement assay (COM / Complement, Total, Serum) should be used as a screen for suspected complement deficiencies before ordering individual complement component assays. A deficiency of an individual component of the complement cascade will result in an undetectable total complement level.

Specimen Required


Patient Preparation: Fasting preferred

Supplies: Sarstedt 5 mL Aliquot Tube (T914)

Collection Container/Tube: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

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

2. Centrifuge and aliquot serum into plastic vial.

3. Immediately freeze specimen.


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Red Frozen 14 days

Reference Values

22-45 U/mL

Day(s) Performed

Monday through Friday
Seattle Children's Hospital Note:

TAT: 3 - 5 days

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.

CPT Code Information

86161

LOINC Code Information

Test ID Test Order Name Order LOINC Value
C4FX C4 Complement, Functional, S 93978-5

 

Result ID Test Result Name Result LOINC Value
C4FX C4 Complement, Functional, S 93978-5

Method Description

C4 activity is measured by mixing patient serum with a C4-deficient serum. The lytic activity of the serum mixture is tested against sensitized, labeled liposomes. If lysis occurs, the patient serum must be the source of the C4. The target liposomes are a commercial reagent (WAKO total complement CH50), and the assay is performed on an Advia XPT.(Unpublished Mayo method)

Report Available

1 to 3 days

Reject Due To

Gross hemolysis OK
Gross lipemia Reject
Gross icterus OK

Method Name

Automated Liposome Lysis Assay