Blood Indoxyl Sulfate and TGF-β1 Protein and mRNA Levels in Chronic Kidney Disease: Updated Insights

Chronic kidney disease (CKD) is characterized by systemic inflammation and the accumulation of uremic toxins such as indoxyl sulfate (IS), which induces fibrogenic signaling via transforming growth factor-beta 1 (TGF-β1). Forty CKD patients and ten healthy controls were enrolled. IS was measured by HPLC, TGF-β1 protein by ELISA, and TGF-β1 mRNA by RT-qPCR in PBMCs. IS and TGF-β1 mRNA levels increased significantly with CKD stage, particularly in stages 3 and 4. TGF-β1 mRNA correlated with IS levels (R=0.4, P<0.01), while TGF-β1 protein levels were associated with platelet count (R=0.817, P<0.001). TGF-β1 mRNA in PBMCs may serve as an early biomarker of CKD-related fibrosis. IS is a key uremic toxin influencing fibrogenic gene expression.