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Test Code C1QFX C1q Complement, Functional, Serum

Additional Codes

CNE Order Code: C1q Imm Complex

Reporting Name

C1Q Complement, Functional, S

Useful For

Diagnosis of C1 deficiency

 

Investigation of a patient with an absent total complement level

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Serum Red


Ordering Guidance


The total complement (CH50) 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 CH50.



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

34-63 U/mL

Day(s) Performed

Monday through Friday

CPT Code Information

86161

LOINC Code Information

Test ID Test Order Name Order LOINC Value
C1QFX C1Q Complement, Functional, S 87722-5

 

Result ID Test Result Name Result LOINC Value
C1QFX C1Q Complement, Functional, S 87722-5

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).

 

The measurement of C1q activity is an indicator of the amount of C1 present. Absent C1q levels in the presence of normal C3 and C4 values are consistent with a C1 deficiency. Low C1q levels in the presence of low C4 but normal C3 may indicate the presence of an acquired inhibitor (autoantibody) to C1 esterase inhibitor.

Report Available

1 to 3 days

Reject Due To

Gross hemolysis OK
Gross lipemia Reject
Gross icterus OK

Method Name

Automated Liposome Lysis Assay