POS1308 PREDICTORS OF DISEASE PROGRESSION IN A MONOCENTRIC COHORT OF 100 PATIENTS WITH CHILDHOOD-ONSET SYSTEMIC LUPUS ERYTHEMATOSUS
Authors: Chighizola C. , Pontikaki I. , Costi S. , Armentaro G. , Gattinara M. , Giani T. , Cimaz R. 
Published: May 2021

Background:Childhood-onset systemic lupus erythematosus (cSLE) accounts for 10-20% of overall cases, usually presenting in early adolescence. SLE in children is characterized by a severe clinical course.Objectives:This study describes the evolution of clinical manifestations of cSLE, with the aims of i) identifying biomarkers predictive of disease progression and ii) assessing the effects of treatment on disease course.Methods:Laboratory and clinical data of cSLE patients followed in our Paediatric Rheumatology Unit were retrospectively collected at diagnosis and during follow-up. Continuous data were expressed as median (interquartile range [IQR]) and categorical data as percentages. The association between categorical variables was assessed by chi-squared test, the correlation between variables was tested by Pearson’s test. Univariate linear regression analyses were performed to investigate the relationship between the rate of new disease manifestations at follow-up and candidate predictors. Statistical analysis was performed using GraphPadPrism v6. P values <0.05 were regarded statistically significant.Results:One-hundred patients (89% of female gender) with cSLE were included in this study, with a median age at disease onset of 13 years (10.5-15). Clinical details are presented in Table 1. Complement levels were reduced in 71 patients (C3 in 62 and C4 in 65). At a median follow-up of 118 months (57-239), the disease progressed in 93 patients, with a median of two new manifestations per patient (1-3). No correlation emerged between the number of new disease manifestations and both age at diagnosis and disease duration. Among serological biomarkers, a reduction in complement fractions at diagnosis emerged as the only predictor of new clinical manifestations due to cSLE (p=0.013 for low C3 and p=0.0004 for low C4). Among the several different pharmacological tools, hydroxychloroquine (HCQ, p=0.021, 95% confidence interval (CI) 0.0084-0.1007), azathioprine (AZA, p=0.0217, 95%CI 0.013-0.1703) and cyclophosphamide (CTX, p=0.0305, 95%CI 0.013-0.170) were identified as protective.At follow-up, patients most commonly developed new haematological and cutaneous involvements, which were diagnosed in 43 and 11 patients, respectively. A trend towards statistical significance emerged for low C4 levels to predict new haematological involvement at follow-up (p=0.064, chi-squared: 3.42). Differently, positivity for antibodies against dsDNA emerged as the only predictor of the onset of cutaneous manifestations during follow-up (p=0.022, chi-squared: 7.62). Low C3 levels approached statistical significance in the prediction of skin involvement (p=0.058, chi-squared 5.68).Conclusion:According to the data from our monocentric cohort of 100 patients, complement and anti-dsDNA antibodies are the most accurate tools to predict disease progression in cSLE. HCQ, AZA and CTX reduce the rate of disease progression.Table 1.Clinical manifestations, laboratory features and treatment details of recruited patients at diagnosis.Number of patientsSkin manifestations44Haematological involvement51Lupus nephritis16Musculoskeletal involvement72Serositis14Neuropsychiatric involvement6Anti-nuclear antibodies90Anti-Ro antibodies11Anti-Sm antibodies13Anti-dsDNA antibodies67Anti-phospholipid antibodies29Hydroxychloroquine89Azathioprine40Cyclophosphosphamide29Micophenolate mofetil13Cyclosporine15Rituximab1Belimumab2Steroids91Disclosure of Interests:None declared