Initial properdin binding contributes to alternative pathway activation at the surface of viable and necrotic cells.

Properdin, the only known positive regulator of the complement system, stabilizes the C3 convertase, thereby increasing its half-life. In contrast to most other complement factors, properdin is mainly produced extrahepatically by myeloid cells. Recent data suggest a role for properdin as a pattern recognition molecule.

The association between presenting complaints and clinical outcomes in emergency department patients of different age categories.

Background And Importance: Although aging societies in Western Europe use presenting complaints (PCs) in emergency departments (EDs) triage systems to determine the urgency and severity of the care demand, it is unclear whether their prognostic value is age-dependent.

Objective: To assess the frequency and association of PCs with hospitalization and mortality across age categories.

Methods: An observational multicenter study using all consecutive visits of three EDs in the Netherlands Emergency department Evaluation Database.