Proteomic Breakthrough Identifies CFHR1 as Critical Diagnostic Marker and Therapeutic Target for IgA Nephropathy

Fujita Health University researchers identify CFHR1 as a key protein in IgA nephropathy, offering a new way to diagnose and track the autoimmune kidney disease.

By: AXL Media

Published: Mar 30, 2026, 4:04 PM EDT

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

Challenges in Managing Chronic Renal Deterioration

Immunoglobulin A (IgA) nephropathy is a complex autoimmune disorder characterized by the buildup of IgA-containing immune complexes (IgA-ICs) within the kidney's glomerular mesangium. This deposition triggers a cascade of cellular proliferation and inflammatory infiltration, posing a significant lifelong risk of progression toward end-stage kidney disease. Current clinical guidelines categorize treatment into immunosuppressive agents and comprehensive supportive care, but the systemic use of corticosteroids remains limited due to severe adverse effects. Consequently, the medical community has faced an urgent need to identify specific molecular drivers and reliable biomarkers to guide more targeted therapeutic interventions.

Proteomic Analysis of Glomerular Immune Complexes

To address these gaps, a research team led by Professor Kazuo Takahashi at Fujita Health University conducted an extensive proteome study. The researchers analyzed formaline-fixed paraffin-embedded (FFPE) kidney tissues and isolated IgA-ICs from both patients and control groups. Their investigation revealed that proteins associated with the classical, alternative, and terminal complement pathways were heavily overexpressed in the glomeruli of those suffering from the disease. This molecular mapping provided a clearer picture of the components involved in glomerular injury, pointing specifically toward the role of the complement system in driving inflammation.

The Role of CFHR1 in Disease Pathology

The study’s most significant finding was the identification of complement factor H-related protein 1 (CFHR1) as a key player in the development of the disorder. CFHR1 levels were found to be significantly higher within the circulating IgA-ICs of patients compared to healthy individuals. Double immunofluorescence staining confirmed that CFHR1 colocalizes with mesangial IgA deposits in the kidney, suggesting it acts as a catalyst for the formation of harmful immune complexes. Professor Takahashi speculates that elevated CFHR1 reflects an activation of the alternative complement pathway, often triggered by mucosal microbial antigens, which then facilitates the deposition of abnormal IgA molecules in the renal structure.