Text Box: THE STUDY OF EXPRESSION OF CYCLOPHILIN mRNA IN CHILDREN REFRACTORY NEPHROPATHY Xia ZK, Liu GL, Gao YF, Fu J,F YF, Fan ZM, Zhang LF Department of Pediatric, Nanjing JinLing Hospital, Nanjing, China Objective: Cyclophilin (CyP) is the receptor of cyclosporin A (CsA), in order to discussing the clinic role and expression of CyP gene in children refractory nephropathy, he authors studied the expression of CyP gene from white blood cells in children nephropathy. Methods: We have measured the expression of CyP gene in 28 cases, children refractory nephropathy by reverse transcription polymerase chain reaction. Results: It was showed that base of CyP is 408bp differentiating from β-Actin (234bp). Meanwhile, it was also found that the expression of CyP gene in MsPGN and FSGS was higher than that in MCN; the expression of CyP gene in different types refractory nephropathy was no difference;It was also found that the expression of CyP gene from white blood cells in children refractory nephropathy in acute stage was significantly higher than one in restorable stage and control.Meanwhile,it was found that was negative relation between the concentration of CsA and the expression of Cyp gene, positive relation between the expression of CyP gene and 24 hour urine protein,and no relation between the expression of CyP gene and BUN,creatinine. Conclusions: We survey that the expression of CyP mRNA in children refractory nephropathy may response seizure and give CsA treatment that is very effective for remission of nephropathy. 1001