Complement CH50 or CH100

Keywords: Complement CH50, Complement CH100

Specimen:

10 mL blood in plain tube.

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

Method:

ELISA

Lysis of haemolysin-treated sheep red cells in solution or agarose.

CH50 is a tube method, measuring 50% cell lysis. CH100 is a screening plate method measuring 100% cell lysis.

Reference Interval:

Consult pathologist.

Application:

A screening test for patients with suspected inherited complement component deficiency. The tests are of no value in monitoring complement activation in acquired disorders eg, SLE.

Interpretation:

Incorrect specimen collection is the most common cause of reduced levels. Reduced levels may also indicate deficiency in one of the components of complement. Levels will be variably reduced in acquired disorders associated with complement activation.

Reference:

Ruddy S. In: Rose NR et al eds. Manual of Clinical Laboratory Immunology. 4th ed. ASM Press 1997.

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