2026/03/30 by Mads Okkels Birk Lorenzen, Martin Jensen, Rasmus Rask Kragh Jørgensen +6 · 1 citation
paper · doi:10.1111/ejh.70181
ABSTRACT Adult hemophagocytic lymphohistiocytosis (HLH) is a rare, life‐threatening syndrome triggered by various conditions. A nationwide study of the incidence and outcomes of HLH in Denmark over 23 years (2000–2023) was performed. Adults (≥ 18 years) with HLH and triggering diseases were identified in the Danish National Patient Registry and/or the Danish Pathology Registry. A total of 325 cases were identified. The incidence increased from 0.82 per 1 million person‐years (1 M‐PY) (95% CI 0.61–1.04) in 2000–2011 to 4.05 per 1 M‐PY (95% CI 3.56–4.53) in 2012–2023. Hematologic malignancies were the triggering diagnosis in 46% of cases, mostly lymphomas (32%). There was no clear improvement in overall survival over time. However, survival differed markedly between subgroups, with the lowest 1‐year overall survival of 31% for hematologic malignancy–associated HLH, compared with 75% for idiopathic HLH. In conclusion, HLH remains a rare syndrome with a dismal prognosis, especially when associated with hematologic malignancy.