Among children with hemophagocytic lymphohistiocytosis (HLH), pediatric patients with malignancy-associated HLH (MA-HLH) had low mortalities rates; however, these patients may subsequently die due to underlying malignant disease, according to study results published in the Journal of the Formosan Medical Association. Study results also suggested that an extended activated partial thromboplastin time (aPTT) was a predictor of mortality and that impaired liver and renal functions were also associated with mortality.
Hemophagocytic syndrome, if left untreated, can lead to mortality rates as high as 95% in pediatric patients; therefore, a team of investigators conducted a retrospective to determine and assess the risk factors of poor outcomes in children with HLH.
The 51 pediatric patients (median age, 7 years) included in the study had been diagnosed with HLH and treated using either the HLH treatment protocols from 1994 or 2004. Their electronic medical records were examined for features, tests, and outcomes associated with HLH.
Children in the study had HLH related to a variety of etiologies, such as infection-associated hemophagocytic syndrome, which occurred in 53% of patients. Others included macrophage activation syndrome in 24%, malignancy-associated HLH in 16%, and idiopathic hemophagocytic lymphohistiocytosis in 8%.
Mortality occurred in 11 of the patients during hospitalization. Fatalities did not occur in patients with malignancy-associated HLH. Overall, intensive care unit stays lasted for a mean duration of 6 + 20.8 days.
Laboratory features such as extended aPTT, low serum sodium, elevated creatinine, and elevated aspartate aminotransferase were all significantly associated with HLH-related mortality. In multivariate analysis, only an increased aPTT showed an independent association with mortality (hazard ratio, 1.03; P =.045). An aPTT time of 44.35 seconds at diagnosis appeared to be the best threshold for predicting mortality. At this threshold, the sensitivity was 72% and the specificity was 66.7%. In addition, the researchers suggested that aPTT in HLH is linked to coagulopathy.
Limitations of the study included its retrospective design, lack of genetic confirmation, and unavailability of hematopoietic stem cell transplantation in the hospital during the period the study was conducted.
“We recommend a prospective study with a larger sample size to confirm prognostic factors for HLH,” the authors noted.
Chen TY, Hsu MH, Kuo HC, Sheen JM, Cheng MC, Lin YJ. Outcome analysis of pediatric hemophagocytic lymphohistiocytosis [published online April 16, 2020]. J Formos Med Assoc. doi: 10.1016/j.jfma.2020.03.025