Abstract：
BACKGROUND: Hemophagocytic syndrome, macrophage activation syndrome, reactive histiocytosis or hemophagocytic lymphohistiocytosis (HLH) represent a group of diseases whose common thread is reactive or neoplastic mononuclear phagocytic system cells and dendritic cell proliferation.
METHODS: We present a case of an HLH probably associated with Epstein-Barr virus (EBV) in a 4-year-old male patient treated with HLH-04 protocol. Viral etiology in HLH is well accepted. In this case, clinical picture of HLH was assumed secondary to EBV infection because IgM serology at the time of clinical presentation was the only positive factor in the viral panel.
CONCLUSIONS: Diagnosis of HLH is the critical first step to successful treatment. The earlier it is identified, the less the tissue damage and reduced risk of multiple organ failure, which favors treatment response.
METHODS: We present a case of an HLH probably associated with Epstein-Barr virus (EBV) in a 4-year-old male patient treated with HLH-04 protocol. Viral etiology in HLH is well accepted. In this case, clinical picture of HLH was assumed secondary to EBV infection because IgM serology at the time of clinical presentation was the only positive factor in the viral panel.
CONCLUSIONS: Diagnosis of HLH is the critical first step to successful treatment. The earlier it is identified, the less the tissue damage and reduced risk of multiple organ failure, which favors treatment response.
摘要：
背景：噬血细胞综合征，巨噬细胞活化综合征,反应性组织细胞增生症或噬血细胞性淋巴组织细胞增生症（HLH）代表一组疾病，其共同点是反应性或肿瘤性单核吞噬细胞系统细胞和树突状细胞增殖。
方法：我们在接受HLH-04方案治疗的4岁男性患者中介绍一例HLH可能与EB病毒（EBV）相关的病例。HLH中的病毒病因学是公认的。在这种情况下,假设HLH的临床表现继发于EBV感染,因为临床表现时的IgM血清学是病毒组中唯一的积极因素.
结论：诊断HLH是成功治疗的关键第一步。它越早被识别，组织损伤越小，多器官衰竭的风险降低，这有利于治疗反应。
方法：我们在接受HLH-04方案治疗的4岁男性患者中介绍一例HLH可能与EB病毒（EBV）相关的病例。HLH中的病毒病因学是公认的。在这种情况下,假设HLH的临床表现继发于EBV感染,因为临床表现时的IgM血清学是病毒组中唯一的积极因素.
结论：诊断HLH是成功治疗的关键第一步。它越早被识别，组织损伤越小，多器官衰竭的风险降低，这有利于治疗反应。
