MO1006COMPARISON OF DIFFERENT DEFINITION OF PARTIAL AND COMPLETE REMISSION IN A COHORT OF CHILDREN WITH LUPUS NEPHRITIS*

Abstract

Abstract Background and Aims Lupus Nephritis (LN) occurs in up to 80% of children with SLE and it affects the long term outcome and the overall survival. Achieving and maintaining renal remission is crucial. However definition of remission in children is not clearly defined. We compared the outcomes using different published definitions of complete and partial remission. Method 248 children with biopsy proven LN class III or higher (ISN/RPS) diagnosed and treated in 23 international centers in the last 10 years were included. Data regarding their renal outcome were collected for twenty-four months after the start of induction therapy. We applied seven definitions of remission to compare the number of children achieving partial and complete remission. Definitions applied have been adapted from the Bristol-Myers Squibb (BMS) trial, the American College of Rheumatology (ACR) recommendations, the Lupus Nephritis Assesment with Rituximab (LUNAR) trial, the Aspreva Lupus Management Study (ALMS) trial, the Abatacept and Cyclophosphamide Combination: Efficacy and Safety Study (ACCESS) trial, the Kidney Disease Improving Global outcomes (KDIGO) guidelines and the Two-Year, Randomized, Controlled Trial of Belimumab in Lupus Nephritis (BLISS-LN). We also focused on the BMS trial, the ACCESS trial and the KDIGO guidelines definitions to analyse the importance of gender, age, ethnicity and the economic income of the country (as defined by the World Bank) where patients had been treated. Results The mean age at diagnosis was 11 years and 4 month. 71.4% were females. They were mainly East-Asian (34.3%), South-Asian (24.6%) and Caucasian (18.6%). 42.7 % were from middle income countries and 57.3% high income countries. The kidney biopsies showed LN class III in 35.5%; class IV in 45.6% and class V in 18.9%. The different definitions varied significantly in terms of outcomes, with that of the ACCESS trial having the highest percentages of complete remission and the BMS trial the lowest (Figure 1). A relatively small percentage of children achieved partial remission during the follow-up for all the definitions (Figure 2). Focusing on the BMS, ACCESS and KDIGO definitions, we found no statistically significant differences of gender and age in the rate of children entering complete remission at 6, 12 and 24 months. East Asian children did however achieve remission more often than other ethnic groups (p < 0.05) (Figure 3). Children treated in high income countries showed a statistically significant higher percentage of complete remission at 12 and 24 months (p < 0.05) (Figure 4). Conclusion Rate of complete and partial remission varied considerably when using the different definitions. Ethnicity and income of the country where the patients were treated did influence outcome. The findings of our study can help in deciding how to define remission in urgently needed future treatment studies in children.