engleski

Predicting organ damage in patients with childhood-onset systemic lupus erythematosus: a retrospective study over the last 25 years

Introduction: Childhood-onset systemic lupus erythematosus (cSLE) is a multisystemic, chronic autoimmune disease occurring in children and adolescents under 18, presenting heterogeneously, with the course of the disease often more severe than in adults, and the activity of the disease widely being evaluated by Systemic Lupus Erythematosus Disease Activity Index (SLEDAI 2K) and damage by the SLICC/ACR damage index (SDI). Objectives: To compare and explore the correlation between the SLEDAI-2K disease activity index at the time of diagnosis and the SLICC/ACR damage index (SDI) of patients at their last follow up, to examine the quantity of organ damage in regard to patients’ characteristics and disease duration and to predict the risk of organ damage occurrence in time. Methods: The retrospective study included children treated for cSLE in the period from January 1991 to September 2017 at Department of Pediatrics, University Hospital Center Zagreb. The follow up data of patients after the age of majority at 18 and who were under care of the Department of Internal Medicine, University Hospital Center Zagreb was also included. All children were diagnosed according to the ACR 1997 and SLICC 2012 criteria. Data analysis was done using R environment for statistical computing. Results: The disease development of 93 children (74 females and 19 males) with cSLE was examined in this study. The median (range) follow up time was 7 (0.5-24) years and the median (range) age at diagnosis was 13 (5-19) years. Two patients have died during the examined period. Mean (SD) SLEDAI- 2K was 18.3 (9.0) at the disease onset. 35 children (38 %) had organ damage at the last follow up with the median (range) SDI 0 (0-7). The first organ systems damaged in affected patients were renal (28%), musculoskeletal (22%), ocular (19%), neuropsychiatric (17%), cardiovascular (11%) and peripheral vascular (2.8%), but with no significant statistical difference regarding the type of organ damage. Kendall rank correlation coefficient was used to evaluate the relationship between SLEDAI-2K at the disease onset and SDI, determining a positive correlation which was statistically significant (τb = 0.252, p = 0.003). However, no significant correlation was determined between the duration of the disease and SDI (τb = 0.042, p = 0.628) or follow up period and SDI (τb = 0.111, p = 0.191) nor was there significant difference of SDI in regard to gender (Asymptotic Wilcoxon- Mann-Whitney Test, p= 0.574). Using Kaplan-Meier method we estimated the decrease in ratio of patients without organ damage since diagnosis or the occurrence of the first symptoms. Since the estimated ratio of patients with organ damage at the endpoint was less than 50%, we could not estimate the time required for damage development in 50% of patients. However, we are 95% sure that the damage is not happening in the first 9 or 10 years after diagnosis or the occurrence of the first symptoms, respectively. Conclusion: The high correlation detected between SLEDAI-2K and SDI indicated that the presentation of the cSLE at onset can be prognostic of the course and long-term prognosis of lupus. Our findings suggest that it is unlikely that organ damage will occur in 50% of patients in the first nine years of the disease course.

Childhood-onset systemic lupus erythematosus ; SLEDAI 2K ; SDI

Sažetak je objavljen kao suplement časopisu (indeksiran u CC-u): Pediatric Rheumatology ; 2018 ; 16 (Suppl 2): 52