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Complement C3

CPT: 86160
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Synonyms

  • C3
  • C3 (β1C/β1A Globulin)
  • C3 Complement

Expected Turnaround Time

1 - 2 days


Related Documents


Specimen Requirements


Specimen

Serum (preferred) or plasma


Volume

1 mL (adult), 0.5 mL (pediatric)


Container

Red-top tube, gel-barrier tube, or green-top (heparin) tube.


Collection

Remove serum or plasma within 45 minutes and transfer to a plastic transport tube. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.


Storage Instructions

Refrigerate


Stability Requirements

Temperature

Period

Room temperature

2 days

Refrigerated

3 days

Frozen

7 days

Freeze/thaw cycles

Stable x3


Causes for Rejection

Excessive lipemia (>1500 mg/dL) significantly increases the apparent C3 concentration.


Test Details


Use

Quantitation of C3 is used to detect individuals with inborn deficiency of this factor or those with immunologic disease in whom complement is consumed at an increased rate. These include lupus erythematosus, chronic active hepatitis, certain chronic infections, poststreptococcal and membranoproliferative glomerulonephritis, and others.


Limitations

Detects both biologically active and inactive C3


Methodology

Immunologic


Reference Interval

See table.

Age (d)

Male (mg/dL)

Female (mg/dL)

0 to 14

50−121

50−121

15 to 30

51−160

51−160

>30

82−167

82−167


Additional Information

C3 comprises about 70% of the total protein in the complement system and is central to activation of both the classical and alternate pathways. Increased levels are found in numerous inflammatory states as an acute phase response. CH50 (total complement hemolytic activity), C3 and/or C4 may be decreased in cases of systemic lupus erythematosus, especially in cases with lupus nephritis, acute and chronic hypocomplementemic nephritis, subacute bacterial endocarditis, DIC, and partial lipodystrophy (with associated nephritis-like activity in serum.) In cases of disseminated intravascular coagulation, plasmin attacks C3 directly, and C3 levels have been found low in the hemolytic uremic syndrome form of disseminated intravascular coagulation (DIC). Cases of hereditary C3 deficiency, while rare, have been reported and are characterized clinically by recurrent infections (eg, pneumonia, meningitis, paronychia, impetigo). Pathogenic bacteria causing infections in these cases have included both gram-positive and gram-negative organisms. C3 levels have also been found deficient in cases of uremia, chronic liver diseases, anorexia nervosa, and celiac disease.


LOINC® Map

Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
006452 Complement C3, Serum 4485-9 006453 Complement C3, Serum mg/dL 4485-9

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