Serum albumin level is associated with mycophenolic acid concentration in children with idiopathic nephrotic syndrome

• Published in: European journal of pediatrics Vol. 181; no. 3; pp. 1159 - 1165
• Main Authors: Nishimura, Tatsuya, Uemura, Osamu, Hibino, Satoshi, Tanaka, Kazuki, Kitagata, Ryoichi, Yuzawa, Sotaro, Kasagi, Toshiki, Fujita, Naoya
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.03.2022; Springer Nature B.V
• Subjects: Acids; Age; Albumin; Area Under Curve; Attention; Child; Children; Cyclosporine - therapeutic use; Cyclosporins; Dosage; Epidermal growth factor receptors; Glomerular filtration rate; Humans; Immunosuppressive Agents - therapeutic use; Kidney diseases; Kidney Transplantation; Kidneys; Medicine; Medicine & Public Health; Mycophenolate mofetil; Mycophenolic acid; Mycophenolic Acid - therapeutic use; Nephrotic syndrome; Nephrotic Syndrome - drug therapy; Original Article; Pediatrics; Retrospective Studies; Serum Albumin; Hypoalbuminemia; Albumin; Nephrotic syndrome; Mycophenolic acid; Mycophenolate mofetil; Children
• ISSN: 0340-6199; 1432-1076
• DOI: 10.1007/s00431-021-04294-7

Mycophenolate mofetil is effective for the treatment of pediatric idiopathic nephrotic syndrome (INS). The dosage of mycophenolate mofetil is adjusted according to the serum concentration of mycophenolic acid (MPA). Kidney function or cyclosporine (CsA) concentrations affect serum MPA levels. However, few studies have focused on the association between serum concentrations of MPA and albumin. This retrospective observational study aimed to evaluate the relationship between the serum concentrations of MPA and albumin in INS children. Subjects were children with INS who underwent the therapeutic drug monitoring of CsA and MPA. We obtained the serum albumin (sAlb) concentration, estimated glomerular filtration rate (eGFR), age, and MPA and CsA areas under concentration–time curves from 0 to 12 h (AUC 0–12 ). Multiple linear regression analysis and generalized estimating equations were performed to predict values for MPA AUC 0–12 . We obtained information for 51 INS children with 261 MPA AUC 0–12 measurements. The standardized regression coefficients of sAlb, eGFR, CsA AUC 0–12 , and age were 0.54, − 0.21, − 0.07, and 0.04, respectively. Furthermore, MPA AUC 0–12 levels positively correlated with sAlb concentrations ( p  < 0.001) and were inversely correlated with eGFR values ( p  = 0.005) but not with CsA AUC 0–12 ( p  = 0.24) and age ( p  = 0.65). Conclusion : Serum albumin concentration was strongly associated with total MPA concentration compared with kidney function or CsA values. Although patients with INS may have a low serum concentration of total MPA in the presence of low sAlb concentration, close attention should be paid to the interpretation of the low MPA values. What is Known: • The dosage of mycophenolate mofetil is adjusted according to the serum concentration of total mycophenolic acid. • Kidney function, cyclosporin concentrations, or serum albumin concentrations influence serum mycophenolic acid levels. What is New: • Serum albumin concentration is more strongly associated with total mycophenolic acid concentration than kidney function or cyclosporin values. • In children with nephrotic syndrome, the total mycophenolic acid concentration may not increase in the presence of severe hypoalbuminemia.