Epidemiology and Outcomes of Neonatal Hemophagocytic Lymphohistiocytosis

Front Pediatr. 2022 Apr 26:10:848004. doi: 10.3389/fped.2022.848004. eCollection 2022.

Abstract

Objectives: Neonatal hemophagocytic lymphohistiocytosis (HLH) is a rare entity. The objective of the study was to describe the prevalence, clinical characteristics, interventions and outcomes of neonates diagnosed with HLH in the United States.

Methods: A retrospective analysis of 2009, 2012, and 2016 Kids' Inpatient Database was performed. Neonates discharged/died with a diagnosis of HLH were identified and analyzed.

Results: Among 11,130,055 discharges, 76 neonates had a diagnosis of HLH. Fifty-two percent (95% CI: 38.6-63.6) were males and 54% (95% CI: 39.7-68.5) were white. Herpes simplex infection was present in 16% (95% CI: 9.2-28.1). 24.4% (95% CI: 14.5-37.9) received chemotherapy, 11.5% (95% CI: 5.2-23.6) IVIG and 3.6% (95% CI: 0.8-14.4) allogenic hemopoietic stem cell transplantation. Organ dysfunction was commonly seen and severe sepsis was documented in 26.6% (95% CI: 16.4-39.9). Median LOS was 16 (IQR 7-54) days. The mortality was 42% (95% CI: 30.8-55).

Conclusions: HLH is a rare diagnosis and carries a high mortality in neonates. Herpes simplex virus is the most common infection associated with neonatal HLH. HLH should be considered in the differential diagnosis in neonates presenting with multi-organ dysfunction or sepsis.

Keywords: HLH; hemophagocytic lymphohistiocytosis; multi organ dysfunction; neonatal; sepsis.