Long-term renal survival of paediatric patients with lupus nephritis

Background Childhood-onset systemic lupus erythematosus (SLE) is more severe than adult-onset disease, including more frequent kidney involvement. This study aimed to investigate baseline clinical features, treatment modalities and short- and long-term renal outcomes of paediatric patients with lupus nephritis (LN). Materials and methods This study enrolled 53 LN patients out of 102 childhood-onset SLE patients followed at Hacettepe University between 2000 and 2020. The demographic and clinical data were reviewed retrospectively from the medical charts and electronic records. All SLE patients with renal involvement underwent renal biopsy either at the time of diagnosis or during follow-up. Results The median age at onset of SLE was 13.3 years [interquartile range (IQR) 10.4-15.8]. The median follow-up duration was 43.1 months (IQR 24.3-69.3). Of the 102 SLE patients, 53 (52%) had LN. The most frequent histopathological class was Class IV LN (54.7%), followed by Class III (22.6%). The proportion of patients who achieved either complete or partial remission was 77.3% and 73% at 6 and 12 months, respectively. In the overall LN cohort, 5- and 10-year renal survival rates were 92% and 85.7%, respectively. The remission rate at Month 6 was significantly higher in mycophenolate mofetil (MMF)- and cyclophosphamide (CYC)-treated groups than other combination therapies (P = 0.02). Although no difference was found between the CYC and MMF response rates (P = 0.57) in proliferative LN (Classes III and IV), the majority of Class IV patients (79%) received CYC as induction therapy. There was no difference between the response rates in any treatment regimens at Month 12 (P = 0.56). In the multivariate analysis, male gender, requiring dialysis at the time of LN diagnosis and failure to achieve remission at 6 and 12 months were found to be associated with poor renal outcome. Conclusions Our study demonstrated that male gender, failure to achieve remission at 6 and 12 months and requiring dialysis at the time of diagnosis were the best predictors of poor renal outcome. Therefore appropriate and aggressive management of paediatric LN is essential to achieve and maintain remission.