Endothelial Activation and Stress Index Serves as a Predictor for Survival in Lymphoma‐Associated Hemophagocytic Lymphohistiocytosis: A Retrospective Multicenter Cohort Study of Jiangsu Cooperative Lymphoma Group

Lymphoma-associated hemophagocytic lymphohistiocytosis (LA-HLH) is a life-threatening hyperinflammatory syndrome, and hierarchical management based on a prognostic model is important. The endothelial activation and stress index (EASIX) score has demonstrated prognostic utility in recipients of allogeneic stem cell transplantation and chimeric antigen receptor (CAR) T-cell therapy. However, its role in LA-HLH remains unestablished. We conducted a multicenter retrospective analysis of patients with LA-HLH from 28 medical centers to explore the prognostic impacts of EASIX in LA-HLH. EASIX was calculated using baseline lactate dehydrogenase, serum creatinine, and platelet counts. A total of 490 patients with LA-HLH were included and stratified by EASIX quartiles (Q1-Q4). Patients with a higher EASIX score had significantly inferior 2-month survival and overall survival, according to the Kaplan-Meier analysis (log-rank p < 0.001). In multivariable analyses, after adjustment for age, gender, lymphoma type, splenomegaly, bone marrow infiltration, lymphoma status (treatment-naïve versus relapsed/refractory), hemoglobin, absolute neutrophil count, serum ferritin levels, and aspartate aminotransferase, the highest EASIX quartile (Q4) exhibited a 7.01-fold risk of death compared to the lowest quartile (Q1) (Hazard ratio [HR] = 7.01, 95% confidence interval [CI]: 3.98-12.36; p < 0.001). Additionally, the restricted cubic splines (RCS) analysis illustrated an increase in the risk of mortality with an increasing EASIX score. Our findings support EASIX being a robust, universally accessible prognostic marker for LA-HLH, strongly associated with early mortality risk. This index can be used to stratify the risk levels of patients with LA-HLH and predict their survival outcomes.