Dosage optimization
The preliminary results supported CysC and MPO-tiered dosage regimen for individual medication, which can help prevent renal flares or the progress of glomerulonephritis. Dosage simulation indicated that a MMF dose of 750 mg (650 mg/m2) twice daily was required to achieve the target AUC0-12h of 30 mg/L·h in ANCA children with normal renal function and no inflammation. An initial MMF dose of 600 mg/m2 twice daily was suggested to reach target AUC0-12 in pediatric liver transplant recipients (44). Similarly, a median MMF dose of 659.5 mg/m2twice daily could reach target AUC0-12h in children after intestinal transplant (45). However, a higher dose of 900 mg/m2 twice daily in conjunction with cyclosporine after renal transplantation has been suggested (46). Furthermore, patients with idiopathic nephrotic syndrome administered a standard initial dose of MMF 1200 mg/m2/d, of which 40% decreased to a median dose of 940 mg/m2/d and 60% increased to a median dose of 1400 mg/m2/d (47).
There were some limitations in this study. First, this was a retrospective study so that we did not investigate all possible covariates, but we still found the valuable factors. Besides, this was a small study conducted in only 25 subjects over a period of 5 years because ANCA is a rare disease.