Increased renal damage in hypocomplementemic patients with ANCA-associated vasculitis: retrospective cohort study.

Introduction: The complement system has an important role in the pathogenesis of vasculitis associated with antineutrophilic cytoplasmic antibody (AAV) mainly at the level of the kidneys because patients with complement deposits on the glomerular basal membrane present more aggressive disease compared with those with pauci-immune vasculitis.

Aim: To analyze the association of hypocomplementemia with the clinical manifestations, laboratory data, renal histology, progress to renal insufficiency, and mortality of patients with AAV.

Methods: Retrospective cohort study (2000-2007) included 93 patients with AAV.