Predictive factors for severity and poor treatment response in children with Evans syndrome: A retrospective cohort study

Evans syndrome (ES) is a rare disorder characterized by autoimmune cytopenias affecting multiple blood cell lineages. In children, management remains particularly challenging due to the absence of clear guidelines for acute treatment and escalation to second-line therapies. We conducted a retrospective, longitudinal study (2010-2024) including pediatric patients (<18 years) with ES to identify predictors of severe presentation, need for second-line therapy, and fatal outcome. Predictors were identified using Cox Regression. Fifty patients were included (sequential = 27, concomitant = 23), with a median age at diagnosis of 4.1 years (IQR:1.5-8.5). Secondary ES was observed in 41(82%) cases, among which 38 (76%) had IEI. Severe clinical presentation at diagnosis occurred in 50% of patients and was independently associated with age < 24months and hemoglobin level < 80g/L. Corticosteroid dependence was observed in 34 cases (68%), with second-line therapy required in 31 patients (62%, cumulative risk=88%). This was associated with the presence of hepatomegaly and abnormal IgM levels. At last follow-up, 38(76%) patients were in remission and 19(38%) had relapsed. Fatal outcome (8 patients) was associated with age < 24 months at diagnosis (p=0.04), family history of IEI (p=10^-3), splenomegaly (p=0.02), and hepatomegaly (p=0.05). Pediatric ES is therefore a severe condition particularly in infants. Outcomes are strongly influenced by underlying immune dysregulation, highlighting the need for early etiological evaluation to guide timely and appropriate therapeutic strategies including the early use of targeted or curative approaches.