Original Hemophagocytic lymphohistiocytosis: presentation and outcome of twenty-one patients at a single institution

Introduction: Hemophagocytic lymphohistiocytosis comprises a systemic hyperactivation of macrophages that requires prompt recognition of symptoms and early treatment.Objective and Method: In this context, we described clinical and laboratory characteristics, therapeutic modality and outcome of 21 patients with HLH treated at a pediatric oncology hospital between January 2000 and February 2019.Results: HLH mainly affected females, fever was the most frequent clinical sign and hyper-ferritinemia was the most prevalent laboratory abnormality. All patients were admitted to the intensive care unit (ICU) at some point. Fifteen (71.4%) patients presented resolution cri-teria and eight (53.3%) of them presented reactivation. The mortality rate was 57.1% and the mean time between diagnosis and death was 9.98 months. The 5-year overall survival (OS) was 36.7%. We observed a significant difference in prognosis associated with reactivation of HLH. These patients demonstrated an estimated 5-year OS of 25%, while all patients that did not reactivate were alive until the end of the follow-up.Conclusion: In conclusion, HLH is a rare disease with a high mortality rate, especially in patients with disease reactivation and those with familial-or immunodeficiency -associ-ated forms, which makes early recognition and genetic testing crucial for appropriate man-agement and prompt SCT indication.(c) 2021 Published by Elsevier Espana, S.L.U. on behalf of Associacao Brasileira de Hematolo-gia, Hemoterapia e Terapia Celular. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).