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C3 + C4 (Complement)

Blood Sciences Test





Reference Range

  • C4    0.1 – 0.4 g/L
  • C3    0.9 – 1.8 g/L

Test Usage

The complement system is a cascading series of plasma proteins whose end-products cause bacterial lysis and remove the immune complexes found in post-streptococcal glomerulonephritis, SLE and other autoimmune disease.

There is reduction of C3 in PSGN and of both C3 and C4 in SLE.

They are increased in most other inflammatory states.


Local test

Turnaround Time

7 days

Can be added on to an existing request up to 4 days following sample receipt

Specimen Labelling Procedure
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