Investigation on pharmacokinetics of mycophenolic acid in Chinese adult renal transplant patients

We read with interest the recent paper by Zicheng et al. [1] on pharmacokinetics of mycophenolic acid (MPA) in Chinese renal transplant patients. Patients from north-east India, who belong to the Mongoloid race similar to the Chinese population, constituting a significant proportion of renal transplant patients receiving therapeutic drug monitoring services for MPA from our department, add to our interest in this paper. We congratulate the authors for highlighting the inter-racial differences in MPA pharmacokinetics, although earlier studies have indicated a comparable MPA pharmacokinetics among Whites and African-Americans [2]. Here we would like to draw the authors' attention to some of the issues not clearly mentioned in their paper, which will enhance the significance of their study.

Although the higher incidence of adverse drug events (ADEs) in Chinese patients receiving a fixed-dose regimen of MPA was a basis for conducting this study, details on ADEs observed among the study patients are lacking. The authors mentioned that five patients had a history of acute graft rejection and a few patients experienced minor ADEs [1]. Data on MPA concentrations measured in these patients will emphasize the role of plasma MPA concentrations on efficacy and safety of MPA.

The authors mentioned that 30% of the patients had supratherapeutic MPA concentrations [1]. It will be interesting to compare the demographic profiles of patients having MPA concentrations in the therapeutic range with those of patients having MPA concentrations in the supratherapeutic range. We believe that such a comparison will give a clearer picture of correlation between MPA area under the curve and patient characteristics.