Molecular Mapping of Urinary Complement Peptides in Kidney Diseases

Area of Science:

• Nephrology
• Immunology
• Proteomics

Background:

• Defective complement activation is linked to various kidney diseases.
• Complement fragments in urine may indicate disease etiology and progression.

Purpose of the Study:

• To investigate urinary complement fragments (C3, C4, CFB) in relation to kidney function and disease etiology.
• To explore the potential of these fragments as non-invasive biomarkers for kidney disease.

Main Methods:

• Analysis of mass spectrometry-based peptidomics data from 16,027 subjects.
• Identification and quantification of urinary peptides from complement proteins C3, C4, and factor B (CFB).
• Association analysis with estimated glomerular filtration rate (eGFR) and kidney disease etiologies.

Main Results:

• Twenty-three urinary peptides from C3, C4, and CFB were identified.
• C3 peptides inversely associated with eGFR; CFB peptides positively associated with eGFR.
• Several complement-derived peptides significantly associated with specific kidney disease etiologies.

Conclusions:

• Urinary complement fragments reflect kidney function and disease-specific complement activation.
• These peptides show potential as non-invasive biomarkers for patient stratification and monitoring therapeutic impact.
• Further research may enhance understanding of kidney disease pathophysiology and guide treatment strategies.