The complement system is a complex system of proteins that play a role in host defense and inflammation response by acting as a cascade involving three pathways – classical, alternative, and lectin. Deficiency of any of the proteins in these pathways may lead to recurrent infections or inappropriate inflammatory responses. An initial complement deficiency workup includes testing total complement activity (CH50) and alternative complement activity (AH50).

Refer to ARUP Laboratories’ test offerings below.