Complement (C3, C4 Levels)

Department of Immunology

Notes

• Investigation into complement activation including immune complex disease.
• Low C3 and C4 levels can be seen in active SLE.
• Very low C3 in isolation can be seen in post streptococcal glomerulonephritis and C3 nephritic factor related disease.
• Very low C4 in isolation can be associated with C1 inhibitor deficiency. If C4 is normal, C1 inhibitor deficiency is very unlikely.

Sample Requirements

Adult

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

Paediatric

1ml Serum Sample

Turnaround Times

24 - 48 hours

Reference Ranges