C3 Glomerulopathy: A Current Perspective in an Evolving Landscape.

Background: Complement 3 (C3) glomerulopathy (C3G) is a heterogenous disease characterized by dysregulation of the complement alternative pathway. Within 10 years of a diagnosis, roughly 50% of patients with C3G will progress to end-stage kidney disease. Historically, treatment options have been limited to nonspecific immune suppression with suboptimal response rates to recommended therapies. Advances in immunology and the emergence of novel complement-targeted therapies have shifted the focus toward identifying the distinct underlying etiologies of C3G.

Summary: In this review, we provide a description of the current landscape and challenges faced in the classification, evaluation, and treatment of patients with C3G.

Key message: C3G can be broadly separated into four distinct groups: (1) genetic mutations/variants, (2) autoimmune/acquired autoantibodies, (3) monoclonal immunoglobulin-associated C3G, and (4) C3G without an identified cause. Therapy directed toward the underlying pathogenetic cause of C3G may improve outcomes in a disease in which current treatment options are largely ineffective.