Authors of a review examined the role of the lectin complement pathway in IgA nephropathy (IgAN), a progressive glomerular disease in which abnormal IgA-containing immune complexes can trigger inflammation and kidney injury. Although the alternative complement pathway appears to be activated more broadly, lectin pathway activity has been identified in a subset of patients and may contribute to disease progression by amplifying complement-mediated damage. Markers such as glomerular C4d and mannose-binding lectin (MBL) deposition have been associated with more severe proteinuria, lower eGFR, greater histologic damage, and poorer renal outcomes, suggesting that complement activation patterns may help distinguish higher-risk disease.
The authors also highlight growing interest in noninvasive biomarkers that could help assess disease activity and prognosis without relying solely on kidney biopsy. Urinary C4d, MBL, and other complement-related proteins have shown potential associations with renal pathology and disease progression, although larger prospective studies are needed before they can be incorporated into routine practice. Because lectin pathway activation appears to occur in only a subset of patients, the authors emphasize that future IgAN management may depend on better patient stratification and a more personalized understanding of how multiple complement pathways interact.
Reference: Yu X, Gao H, Sun X. Research progress on the lectin pathway of complement in IgA nephropathy. Front Immunol. 2026 Feb 27;17:1757595. doi: 10.3389/fimmu.2026.1757595.
Link: https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2026.1757595/full
