Podocyte Stress Biomarker Shows Marginal Prognostic Value in Diabetic Kidney Disease

Understanding the progression of DKD is vital, and recent research suggests that urinary podocyte stress biomarkers could serve as surrogate markers for podocyte injury. This study delves into the prognostic value of these biomarkers, particularly the podocin:nephrin mRNA ratio, in patients with biopsy-proven DKD.

The study involved 118 patients with confirmed DKD through biopsy and 13 non-diabetic controls. Urinary mRNA levels of nephrin, podocin, and aquaporin-2 (AQP2) were quantified. Renal events, including death, dialysis, or a 40% reduction in glomerular filtration rate, were assessed at the 12-month mark.

Key Findings:

• The urinary podocin:nephrin mRNA ratio in DKD patients was significantly higher than in the control group (p = 0.0019).

• The ratio correlated with the severity of tubulointerstitial fibrosis in DKD patients (r = 0.254, p = 0.006).

• Higher urinary podocin:nephrin mRNA ratio was associated with reduced renal event-free survival at 12 months (unadjusted HR, 1.523; 95% CI 1.157–2.006; p = 0.003).

• After adjustments for clinical and pathological factors, the ratio exhibited a trend in predicting renal event-free survival (adjusted HR, 1.327; 95% CI 0.980–1.797; p = 0.067), though not reaching statistical significance.

The urinary podocin:nephrin mRNA ratio demonstrates marginal prognostic value in predicting renal events in biopsy-proven DKD. Further validation studies, especially in DKD patients without kidney biopsy, are crucial to establishing the biomarker's clinical significance.

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