Complement components C5, C6, C7, C8, C9

Keywords: C5, C6, C7, C8, C9


5 mL blood in plain tube.

The specimen should be placed on ice and transported immediately to the laboratory.


Immunoassay; functional assay.

Reference Interval:

Consult pathologist.


Complement CH50 or CH100 should be measured before these tests are requested.

Recurrent infection with Neisseria spp when CH50 or CH100 are known to be reduced.

Available only in specialised laboratories.


Deficiency of C5, C6, C7 or C8 is associated with predispositon to recurrent, serious infection with Neisseria spp.


Giglas P. In: Rose NR et al eds. Manual of Clinical Laboratory Immunology. 5th ed. ASM Press 1997.

Wen L et al. Journal of Allergy and Clinical Immunology. 2004; 113: 585-93.