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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 (CH50) level

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type

Serum Red


Specimen Required


Collection Container/Tube: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

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

2. Spin down and separate serum from clot.

3. Immediately freeze specimen.

Additional Information: Fasting preferred.


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Red Frozen 14 days

Reference Values

22-45 U/mL

Day(s) and Time(s) Performed

Monday through Saturday; Continuous with a 3 p.m. cutoff

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

86161

LOINC Code Information

Test ID Test Order Name Order LOINC Value
C4FX C4 Complement, Functional, S 26931-6

 

Result ID Test Result Name Result LOINC Value
C4FX C4 Complement, Functional, S No LOINC Needed

Method Description

C4 complement 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target liposomes are a commercial reagent (WAKO total complement CH50), and the assay is performed on a Hitachi 911.(Unpublished Mayo information Yamamoto S, Kubotsu K, Masaaki K, et al: Automated homogeneous liposome-based assay system for total complement activity. Clin Chem 1995;41:586-590)

Reject Due To

Hemolysis

Mild OK; Gross OK

Lipemia

Mild OK; Gross reject

Icterus

Mild OK; Gross OK

Other

Serum gel tube

Method Name

Automated Liposome Lysis Assay