Two complex protein defense systems—complement and coagulation—are based on
amplifying enzyme cascades triggered by specific local stimuli. Excess systemic activation of
either system is pathologic and is normally prevented by a family of regulatory proteins. The
2 systems are ancient biological processes which share a common origin that predates
vertebrate evolution. Recent research has uncovered multiple opportunities for cross talk
between complement and coagulation including proteins traditionally viewed as coagulation …