Urinary Connective Tissue Growth Factor Is a Biomarker in a Rat Model of Chronic Nephropathy

Aim. This study sought to determine whether urinary connective tissue growth factor (CTGF) was a molecular marker for chronic allograft nephropathy (CAN). Methods. F344 rat renal grafts orthotopically transplanted into Lewis rats following the procedure of Kamada were harvested at 4,8,12, or 16 weeks. Morphological changes were studied using hematoxylin eosin (HE) and Masson trichrome stains. Serum creatinine (SCr) was measured. CAN grades were evaluated according to the Banff97 schema. Expressions of CTGF in the kidney and urine were determined using real-time polymerase chain reaction (PCR) Western blots, and competitive indirect enzyme-linked immunosorbent assay (ELISA). Spearman correlation analysis was used to compare urinary CTGF expression and CAN development. Results. SCr levels and Banff scores increased in a time-dependent manner. The expression of CTGF in the graft was markedly elevated compared with the control group. Urine CTGF increased by week 4, and maintained high levels up to week 16. The urinary levels correlated positively with the histological presence of CAN. Thus, urine CTGF concentrations reflected the course of CAN, especially at an early stage. Conclusion. CTGF plays a significant role in the pathological changes of CAN after kidney transplantation. Urinary CTGF has the potential to be a biomarker for CAN.