C3 nephritic factor

Keywords: C3 NeF

Specimen:

10 mL blood in plain tube. The specimen should be placed on melting ice and transported immediately to the laboratory.

Method:

Immunoassay.

Reference Interval:

Qualitative test.

Application:

Levels of C3 and C4 should be determined before this test is requested; see Complement components C3 and C4.

C3 NeF should only be requested when C3 levels are significantly reduced and C4 is normal, indicating alternative pathway activation.

Limited application in distinguishing types of mesangiocapillary glomerulonephritis.

C3 NeF is also present in partial lipodystrophy.

Interpretation:

C3 NeF is detected in type II mesangiocapillary glomerulonephritis and in patients with partial lipodystrophy.

Reference:

Garg A. Am J Med 2000; 108: 143-152.

Sanjeev Sethi et al. N Engl J Med 2012; 366: 1119-1131.