Significance of serum total bilirubin as a prognostic factor for hemophagocytic lymphohistiocytosis in childhood

소아에서 발생한 혈구탐식증후군의 예후인자로서 혈청 빌리루빈의 의의

Background: Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease. Despite of proper treatment and improving treatment regimens, HLH patients still show a fatal prognosis. Therefore the evaluation of prognostic factor is important and there are many studies about hyperbilirubinemia as a prognostic factor in HLH. So we studied the prognostic value of hyperbilirubinemia in HLH children. Methods: A retrospective analysis was performed about 33 patients who were diagnosed with HLH at Pusan National University Hospital and Yangsan Pusan University Hospital between January 2000 to December 2012. We reviewed the clinical characteristics, laboratory findings, and results of treatment to identify hyper-bilirubinemia as a prognostic factor in HLH patients. Results: The median age of patients at diagnosis was 32 months. Most of patients presented with fever, pale appearance, abdominal pain and jaundice. Forty-eight point five percentage of patients showed normal serum bilirubiln level (<2.0 mg/dL) and 51.5% showed hyperbilirubinemia (${\geq}2.0mg/dL$). In normal serum bilirubin group, 1 patient (6.3%) was relapsed and 1 patient (5.9%) was relapsed in hyperbilirubinemia group. In the hyperbilirubinemia group, the mortality was higher than the normal bilirubin group but, there was no statistical significance. Conclusion: As a prognostic factor serum bilirubin at diagnosis in HLH patients, there was no significant correlation between hyperbilirubinemia and poor outcome. But, our study has a limitation that the number of patients is too small and almost showed good prognosis.