C3 Nephritic Factor (C3N)

Department of Immunology

Notes

• C3 nephritic factor is an autoantibody to the alternate complement pathway's C3 convertase, C3bBb. It stabilises this enzyme leading to an increased consumption of C3.
• Assay will only be performed on samples with an abnormally low C3.
• Associated with mesangiocapillary glomerulonephritis.
• Test performed by Immunology, North Bristol NHS Trust.

Sample Requirements

Clotted blood.

Adult

5ml Gold-top SST tube or 3.5ml Rust-top gel tube (Trust users only)

Paediatric

1ml serum Sample

Time limit for add-on

3 days

Turnaround Times

14 days

Reference Range

Negative = Normal