Epidemiology and Outcomes of Neonatal Hemophagocytic Lymphohistiocytosis

ObjectivesNeonatal 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.MethodsA retrospective analysis of 2009, 2012, and 2016 Kids' Inpatient Database was performed. Neonates discharged/died with a diagnosis of HLH were identified and analyzed.ResultsAmong 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).ConclusionsHLH 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.