Serum Endocan Correlated With Stage of Chronic Kidney Disease and Deterioration in Renal Transplant Recipients

Earlier detection and intervention for chronic renal allograft injury (CRAI) remain major challenges for transplantation physicians. Endocan plays a key role in the regulation of cell adhesion, inflammatory disorders, and tumor progression. We conducted this cross-sectional study of 97 renal transplant (RT) recipients with mean RT duration of 7.0 ± 5.7 years to determine whether Endocan could be a diagnostic and prognostic marker. The patients' mean age was 43.6 ± 13.2 years, and 55.7% (54/97) were male. Higher Endocan levels were found in more advanced chronic kidney disease (CKD) stages in a dose-dependent manner. Interestingly, the Endocan ≥643.19 pg/mL group had higher creatinine (Cr; 1.2 ± 0.4 vs 1.6 ± 1.1 mg/dL; P = .029) and lower estimated glomerular filtration rate (eGFR; 67.8 ± 23.8 mL/min vs 54.4 ± 22.0; P = .006) than the Endocan <643.19 pg/mL group after 3 months of follow-up, respectively. Linear regression analysis found tumor necrosis factor (TNF)-α correlated well with Endocan. To elucidate the response of endothelium activation, we stimulated human umbilical vein endothelial cells (HUVECs) with TNF-α in vitro, and found the levels of Endocan (P = .022) and transforming growth factor (TGF)-β1 (P = .034) increased with time, but interleukin (IL)-10 decreased (P = .013). In summary, Endocan may reflect the degree of endothelial cell injury in renal allografts, and showed a trend of elevation in late-stage CKD. An in vitro study demonstrated TNF-α–activated HUVECs secreted high levels of Endocan and TGF-β1, which could lead to a better understanding of the role of endothelium in immune balance. In conclusion, Endocan may have potential as a useful long-term indicator of CRAI in RT recipients, but further study is needed to verify our findings.