Characteristics of hemophagocytic lymphohistiocytosis in neonates: a nationwide survey in Japan.
OBJECTIVE
To assess the etiology, prognosis, and appropriate treatment of hemophagocytic lymphohistiocytosis (HLH) in neonates.


STUDY DESIGN
We collected information on neonates in whom HLH was diagnosed between 1997 and 2007 from participating members of the Japanese Society of Pediatric Hematology.


RESULTS
HLH was diagnosed in 20 patients within 4 weeks after birth. Of the diagnostic criteria for HLH-2004, the incidence of fever was quite low in preterm infants, and hypertriglyceridemia and neutropenia were uncommon. Familial HLH (n = 6) or severe combined immunodeficiency-associated HLH (n = 1) was diagnosed in 7 patients, and 2 of them have survived. Herpes simplex virus-associated HLH was diagnosed in 6 patients, and 2 of them have survived. The overall survival rate for the 20 patients was 40%.


CONCLUSIONS
HLH is rare in neonates and has a poor prognosis. Early diagnosis and immediate treatment are required when considering the possibility of herpes simplex virus-associated or familial HLH.