Complement System Inhibitors in Nephrology: An Update-Narrative Review

Complement system inhibitors are emerging as promising therapies in nephrology, particularly for diseases where complement dysregulation is central to pathogenesis. This review summarizes the role of complement activation in kidney diseases and current evidence supporting complement-targeted treatments. As the complement system can be involved in the pathogenesis of different diseases to varying degrees, several research works have been conducted. These research efforts aim, firstly, to understand the mechanisms and role of complement cascade components in the most prevalent nephrological diseases and, secondly, to explore the potential of complement system inhibitors in these conditions and their possible clinical applications. Clinical trials demonstrate that complement inhibitors are most effective in conditions with significant complement involvement, such as C3 glomerulopathy (C3G), atypical hemolytic uremic syndrome (aHUS), and immune complex membranoproliferative glomerulonephritis (IC-MPGN). These agents show variable benefits in diseases with partial complement activation, including lupus nephritis and ANCA-associated vasculitis, while their role in disorders like diabetic nephropathy and focal-segmental glomerulosclerosis remains limited. Complement inhibition offers a targeted strategy to prevent disease progression and improve outcomes in selected nephrological disorders.