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The following is a summary of “Prognostic role of activation of the complement pathways in the progression of advanced IgA nephropathy to end-stage renal disease,” published in the October 2024 issue of Nephrology by Wang et al. 

Researchers conducted a retrospective study to analyze the role of the complement system in worsening kidney function in advanced (stage 4 CKD) IgA nephropathy (IgAN), which remains unclear. 

Researchers examined renal specimens from 69 patients with stage 4 IgAN (2010–2021) using immunofluorescence (IF) and immunohistochemistry (IHC) staining for glomerular complement components. The primary outcome was progression to end-stage renal disease (ESRD). Associations with baseline characteristics and outcomes were analyzed using Cox regression and Spearman analyses. 

The results showed that during a median follow-up of 18.0 months, 26 (37.7%) patients progressed to ESRD, and none died. C1q and C3 deposition were found in 12 and 66 patients, respectively. Higher eGFR [hazards ratio (HR), 0.852, 95% CI, 0.756–0.959; P = 0.008], greater C3 intensity (HR, 2.955, 95% CI, 1.063–8.220; P = 0.038), and T1-2 score (HR, 2.576, 95% CI, 1.205–5.576; P = 0.015) predicted ESRD progression. IHC showed higher expression of C1q (P = 0.005), C4d (P < 0.001), factor B (P < 0.001), C3 (P = 0.042), and C5b-9 (P = 0.004) in the ESRD group. Factor B and C1q were linked to lower baseline eGFR (P < 0.001 and P = 0.04, respectively) and worsening kidney function over follow-up (P = 0.046 and P = 0.015, respectively). 

The study concluded that complement deposition in stage 4 CKD IgAN accelerated kidney decline. Activation of complement pathways played a key role. 

Source: bmcnephrol.biomedcentral.com/articles/10.1186/s12882-024-03832-3