Fujita Health University Researchers Identify CFHR1 as Critical New Biomarker and Therapeutic Target for IgA Nephropathy

Fujita Health University researchers find that CFHR1 protein levels can predict IgA nephropathy severity and guide new complement-targeting treatments.

By: AXL Media

Published: Mar 30, 2026, 7:00 AM EDT

Source: Information for this report was sourced from Fujita Health University via EurekAlert!

Unraveling the Pathogenesis of Glomerular Injury

Immunoglobulin A (IgA) nephropathy is a chronic autoimmune condition characterized by the buildup of IgA-containing immune complexes (IgA-ICs) in the kidneys. This deposition triggers inflammation, cell proliferation, and eventual kidney scarring, placing patients at lifelong risk of end-stage renal disease. While current international guidelines categorize treatments into immunosuppressive agents and supportive care, the lack of specific molecular targets has made personalized treatment difficult. Researchers at Fujita Health University have now identified the specific proteins within these complexes that drive renal deterioration.

The Role of the Complement Pathway

The research team performed extensive proteomic analyses on kidney tissues and isolated IgA-ICs from patients. They discovered that several proteins associated with the "complement pathway"—a part of the immune system that enhances the ability of antibodies to clear pathogens—were significantly overexpressed. Specifically, proteins such as CFHR1, CFHR2, and CFHR5 were found in high concentrations within the affected areas of the kidney. Among these, CFHR1 emerged as the most significant marker, showing a direct correlation with the severity of the immune complex deposition.

CFHR1 as a Diagnostic and Prognostic Tool

The study revealed that serum levels of CFHR1 and its concentration within circulating IgA-ICs were notably higher in patients with IgA nephropathy compared to healthy individuals. Furthermore, longitudinal data showed that after two years of immunosuppressive treatment, the levels of CFHR1 within the immune complexes were significantly reduced. This suggests that monitoring CFHR1 could not only help diagnose the disease earlier but also provide a measurable way to track how well a patient is responding to intensive therapy.