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Test Code 0232728 C2 Complement, Functional, with Reflex, Serum

Additional Codes

Mayo Test ID
C2

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Investigation of a patient with a low (absent) hemolytic complement (CH50), with reflex testing to C3 and C4, if appropriate

Testing Algorithm

If the C2 result is less than 15 U/mL, then complement C3 and C4 will be performed at an additional charge.

Method Name

Automated Liposome Lysis Assay

Reporting Name

C2 Complement,Functional,w/Reflex,S

Specimen Type

Serum Red


Advisory Information


This test is for assessment of complement C2 and includes assessment of C3 and C4 as reflex testing. Unless a deficiency has already been identified, initial assessment should begin with the total complement assay (COM / Complement, Total, Serum), which is a screen for suspected complement deficiencies and should be performed 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 but not required

Supplies: Aliquot Tube, 5 mL (T465)

Collection Container/Tube: Red top

Submission Container/Tube: Plastic, 5-mL tube

Specimen Volume: 1 mL

Collection Instructions:

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

2. Centrifuge and separate serum from clot.

3. Immediately freeze specimen.


CentraCare Laboratory Services Note:

Freeze serum within 30 minutes of collection and submit frozen.

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Red Frozen 21 days

Reject Due To

Hemolysis

Mild OK; Gross OK

Lipemia

Mild OK; Gross reject

Icterus

Mild OK; Gross OK

Other

Serum gel tube

Reference Values

25-47 U/mL

Interpretation

Low levels of complement may be due to inherited deficiencies, acquired deficiencies, or due to complement consumption (eg, as a consequence of infectious or autoimmune processes).

 

Absent (or low) C2 levels in the presence of normal C3 and C4 values are consistent with a C2 deficiency.

 

Low C2 levels in the presence of low C3 and C4 values are consistent with a complement-consumptive process.

 

Low C2 and C4 values, in the presence of normal values for C3 is suggestive of C1 esterase inhibitor deficiency.

Day(s) and Time(s) Performed

Monday through Saturday; 3 p.m.

Analytic Time

Same day/1 day

Specimen Retention Time

14 days

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

86160 x 2 (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
C2 C2 Complement,Functional,w/Reflex,S In Process

 

Result ID Test Result Name Result LOINC Value
C2FX C2 Complement,Functional,S In Process
INT53 Interpretation 69048-7

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
C4 Complement C4, S Yes No
C3 Complement C3, S Yes No