Skip to main content

Please note that this is a beta version of our website. Should you encounter any bugs, glitches, lack of functionality or other problems on the website, please let us know immediately so we can rectify these accordingly. Your help in this regard is greatly appreciated! You can email us.

Login to North West London Pathology – consumables service

If you need a new account or you have a query about your order, please telephone the pathology call centre on 0203 313 5353.

If you have forgotten your password you can reset this yourself. Please click here if you have forgotten your password.

Results Line and Enquiries

0203 313 5353

Complement C3 and C4 components

Category Immunology
Test background

Lowered C3 or C4 levels may be due to excessive consumption of the complement cascade, as seen in immune complex-mediated disease, such as SLE with associated renal disease, or cryoglobulinaemic nephritis. May indicate disease flare or aid prognosis. Also, components can be low due to genetic/acquired defects. Commonest cause of low C3 and C4 is sample degradation. Raised levels may indicate an acute phase response.

Clinicial Indications

Diagnosis of glomerulonephritis Diagnosis of HAE or cryoglobulinaemia Diagnosis or exclusion: acute phase increases vs. underlying paraprotein pathology (serum electrophoresis reflex testing) Some utility in monitoring autoimmune conditions, such as SLE Single point determinations of C3 and C4 are of limited value and serial measurements are recommended.

Reference range

C3: 0.7-1.7 g/L C4: 0.16-0.54 g/L

Sample & container required SST (gold top)
Sample volume 5-10 mL (1 mL serum)
Turnaround time 4 days
Notes

The laboratory is currently unaccredited for this test due to a change in platform.