摘要Background Cyclosporine is effective in treating nephrotic syndrome (NS) with idiopathic membranous nephropathy (IMN) in adults.But high relapse rate remains a major concern.The way to manipulate cyclosporine is inconclusive.The aim of this study was to introduce the way how to titrate the cyclosporine to maintain complete remission without relapse.Methods Patients with biopsy-proven IMN with NS treated with cyclosporine for at least 1 month from 1996 to 2011 at Peking Union Medical College Hospital were reviewed.Results Mean age of the 51 eligible patients was 52 years,with 39 men.Mean proteinuria was (7.47+3.14) g/d,serum albumin (24.50±6.29) g/L,and serum creatinine (82.62+21.18) μmol/L.Cyclosporine was commenced at a mean dose of (3.46±0.63) mg.kg1.d-1.Ora1 prednisone (0.40±0.29) mg·kg1·d-1 was given concomitantly in 38 patients.Cyclosporine was administered for a median of 16 months (range 1-93 months) and stopped in non-responders by month six.By month 3 (n=47),the number in complete remission (CR) and partial remission (PR) was 3 and 24,which shifted to 12 and 17 by month 6 (n=41).Male gender,heavy proteinuria,low serum albumin level,and high serum creatinine level were significant determinants in poor response by month six (P ＜0.05 in all variables compared with responders).There was a significant reversible serum creatinine increase within 25％ during month 3 to 12 (P ＜0.05 in all variables compared with baseline value).Eleven patients maintained cyclosporine for more than 24 months with a cyclosporine dose of (1.04±1.06)mg·kg1·d-1.Nine patients were in CR.Renal function,systolic and diastolic blood pressure remained stable.Renal impairment (＞30％ rise of serum creatinine),secondary infection,hypertension,gingival hyperplasia and liver impairment occurred in 6,4,10,4,and 1 patients,respectively.Conclusions The observation time for cyclosporine to effectively induce CR of NS in IMN adults should be at least six months.Long-term and low-dose of cyclosporine therapy is safe and effective to maintain CR in those responders.