Clinical Features and Prognostic Factors of Early Outcome in Pediatric Hemophagocytic Lymphohistiocytosis: A Retrospective Analysis of 227 Cases

Hemophagocytic lymphohistiocytosis (HLH) is a rare but life-threatening clinical syndrome in children, and the knowledge of it is still limited. Two hundred twenty-seven children with HLH in our hospital were retrospectively analyzed from January 2001 to December 2018. The age of the patients on admission ranged from 1 day to 14 years old. The 3 most common clinical manifestations include fever (98.7%), hepatomegaly (95.6%), and splenomegaly (92.1%). The decrease of high-density lipoprotein cholesterol (99.1%) is very common in children with HLH. Albumin<25 g/L, activated partial thromboplastin time >65 s, and lactose dehydrogenase >1000 U/L were independent risk factors for poor early prognosis in children with HLH, and their odds ratio values were 2.515, 3.094, and 2.378, respectively, while age >28 months was identified as a protective factor (odds ratio=0.295). Of the 227 children, 67 (29.52%) died within 30 days of onset. The mortality rate in 2013 to 2018 was significantly lower than that in 2001 to 2012 (16.35% vs. 40.65%, P=0.000). The shortening of the time from onset to admission and the reduction of time from admission to definite diagnosis could be some of the reasons for the decrease of HLH mortality in 2013 to 2018 (P<0.05, respectively). Our study suggests that early identification of risk factors for HLH, timely diagnosis and treatment are important measures to improve the short-term prognosis of HLH in children.