C3 glomerulopathy (C3G) is an ultra-rare kidney disease caused by dysregulation of the alternative pathway of the complement system. Excessive complement activation leads to C3 deposition within the glomeruli, resulting in glomerular injury and progressive loss of kidney function. Worldwide, approximately 1–2 new cases are diagnosed per million population each year.

C3G can affect both children and adults. Its clinical manifestations are often nonspecific and may include hematuria, proteinuria, edema, arterial hypertension, and declining kidney function.

Diagnosis requires a kidney biopsy with immunofluorescence examination. Ongoing research into the mechanisms of complement-mediated kidney injury is creating new opportunities for targeted therapeutic approaches.

The Department of Nephrology and Renal Replacement Therapy is actively contributing to efforts to raise awareness of C3 glomerulopathy. This topic was one of the key areas addressed during the latest educational event in the NephroHub series, “Glomerular Diseases. Part I - Current and Emerging Treatment Strategies,” held on September 18, 2026.

A dedicated session, “C3 Glomerulopathy (C3G) in Native and Transplanted Kidneys,” focused on the distinctive features of this rare disease, contemporary approaches to diagnosis and patient management, including the care of patients after kidney transplantation.

Modern nephrology is increasingly moving beyond purely morphologic diagnosis toward a deeper understanding of the molecular mechanisms underlying kidney disease. This shift is particularly important in C3G, where advances in complement biology have already led to the development of novel targeted therapies. In 2025, the first complement-targeted treatments for selected groups of patients with C3G were approved in the United States.

The mission of our Department is not only to improve awareness of rare kidney diseases, promote timely diagnosis, and facilitate access to specialized care, but also to systematically integrate the latest advances in this field into postgraduate medical education and everyday clinical practice.