title: The Value of Monitoring the Serum Concentration of Mycophenolate Mofetil in Children with Steroid-Dependent/Frequent Relapsing Nephrotic Syndrome.
abstract: BACKGROUND
  Mycophenolate mofetil (MMF) is an alternative treatment strategy in children with steroid sensitivity who have frequent relapses or steroid-dependent nephrotic syndrome (FRNS/SDNS).
  
  
  METHODS
  From January 2009 to January 2015, 31 cases of children with FRNS/SDNS were prospectively recruited and administered MMF and prednisone; then, serum samples were collected, and the area under the curve (AUC) of mycophenolic acid (MPA-AUC) was calculated.
  
  
  RESULTS
  A MPA-AUC of 27.99 μg·h/ml had a diagnostic sensitivity of 65.2% and a specificity of 87.5% in discriminating relapsing from non-relapsing patients (receiver operating characteristic-AUC 0.848). The 31 patients were then grouped according to the results of the MPA-AUC as follows: low-AUC group, <30 μg·h/ml and high-AUC group, ≥30 μg·h/ml. The results indicated that there was a significant difference in the remission rate between the groups (x03C7;2 = 6.645, p = 0.01) during the 6 months of follow-up. Compared with the results before MMF therapy, the steroid dosage in both groups was significantly reduced at the 6- and 12-month follow-ups. Furthermore, the steroid dose was reduced more significantly in the high-AUC group than in the low-AUC group (0.447 ± 0.254 vs. 0.219 ± 0.161 mg/kg/day, p = 0.006) at the 6-month follow-up. Compared with the low-AUC group at the 6-month follow-up, the number of patients with relapse and relapse episodes in the high-AUC group were also significantly reduced (7/16 vs. 1/15, p = 0.037, and 15/27 vs. 1/29, p = 0.014, respectively).
  
  
  CONCLUSIONS
  MMF is a reasonable treatment choice to reduce the number of relapse episodes and steroid administration in children with FRNS/SDNS. Moreover, children in the high-AUC group (MPA-AUC ≥30 μg·h/ml) tended to require lower steroid doses and had greater remission rates than the patients in the low-AUC group (<30 μg·h/ml) at the 6-month follow-up.
authors.affiliation: Department of Nephrology, The Children's Hospital of Zhejiang University School of Medicine, Hangzhou, China.
authors.forename: Kezhen
authors.initials: K
authors.lastname: Tong
authors.forename: Jianhua
authors.initials: J
authors.lastname: Mao
authors.forename: Haidong
authors.initials: H
authors.lastname: Fu
authors.forename: Huijun
authors.initials: H
authors.lastname: Shen
authors.forename: Aimin
authors.initials: A
authors.lastname: Liu
authors.forename: Qiang
authors.initials: Q
authors.lastname: Shu
authors.forename: Lizhong
authors.initials: L
authors.lastname: Du
mesh_terms: D019540:Area Under Curve; D002648:Child; D002675:Child, Preschool; D016903:Drug Monitoring; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000097:blood* / Q000627:therapeutic use; D008297:Male; D009173:Mycophenolic Acid / Q000097:blood* / Q000627:therapeutic use; D009404:Nephrotic Syndrome / Q000188:drug therapy*; D011241:Prednisone / Q000008:administration & dosage*; D012372:ROC Curve; D012008:Recurrence
chemical_list: D007166:Immunosuppressive Agents; D009173:Mycophenolic Acid; D011241:Prednisone