Vittayawacharin P.Lee B.J.E'leimat G.Cao Y.Reid J.Gamayo A.Rezk S.Brem E.A.Lee L.X.Kongtim P.Ciurea S.O.Mahidol University2025-04-012025-04-012025-01-01European Journal of Haematology (2025)09024441https://repository.li.mahidol.ac.th/handle/20.500.14594/108497Background: Data on bone marrow (BM) findings in secondary hemophagocytic lymphohistiocytosis (sHLH) and their association with overall survival (OS) are limited. Objectives: This study aimed to develop a prognostic model incorporating BM findings and clinico-laboratory factors affecting OS. Methods: We retrospectively evaluated 50 adults with sHLH and developed a clinicopathological prognostic model based on survival-associated factors. Results: Most patients demonstrated normocellular BM (46.3%) and mild hemophagocytic activity (44.2%). Factors associated with survival in multivariable analyses (MVA) were age above 70 years (hazard ratio [HR] 3.89, p = 0.016), infection-related (HR 4.62, p = 0.006), hemoglobin < 7 g/dL (HR 5.21, p < 0.001), and hypocellular marrow (HR 3.07, p = 0.04). A clinicopathological HLH risk model assigned 1 point to each MVA-identified survival factor, categorizing patients into low- (score 0–1), intermediate- (score 2–3), and high-risk (score 4) groups. The 6-month OS from bootstrapping internal validation among the low-, intermediate-, and high-risk groups were 84.2%, 55.6% (p < 0.001) and 7.7% (p < 0.001), respectively. The area under the receiver operating characteristic curve (AuROC) was 0.87. Conclusions: This model stratified sHLH patients into three risk groups with distinct survival outcomes, potentially guiding future therapy.MedicineArticleSCOPUS10.1111/ejh.144122-s2.0-10500044280316000609