Effects of alternative remission criteria on outcome of pediatric proliferative lupus nephritis: a multi-center retrospective study of pediatric proliferative lupus nephritis

Objectives: To observe the induction efficacy of mycophenolate mofetil and cyclophosphamide under different complete remission (CR) criteria in children with proliferative lupus nephritis, and to further explore the factors influencing the judgment of remission. Methods: From 2003 to 2019, children who diagnosed proliferative lupus nephritis underwent induction therapy of MMF or CYC in three hospitals were consecutively collected. Based on this population, we compared CR rates between two groups under six CR criteria selected from related recommendations and clinical trials. Then degrees and impact factors of disagreement among CR rates evaluated by selected criteria would be analyzed by Kappa test and multivariable logistic-regression models. Results: A total of 161 children were included in this study, 27 patients received induction therapy of mycophenolate mofetil (MMF) and 134 patients recieved cyclophosphamide (CYC). Under different CR criteria, CR rates in MMF group fluctuated between 18.5%-74.1% and that in CYC group ranged from 16.4%-73.9%. Moreover, comparison between the two drugs in induction treatment under different criteria showed an opposite trend in efficacy. The results of six criteria were inconsistent, with pair-to-pair Kappa values ranging from 0.118 to 0.858. The most important factors leading to disagreement in judgment were urinary protein and urinary red blood cells. Conclusions: The definition of complete response, especially the factors of the urinary protein and urinary red blood cells, significantly impacts the clinical judgment of children with lupus nephritis.