Abdominal ultrasound findings in children with hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis, a variant of histiocytosis, is characterized by an uncontrolled activation of the cellular immune system, including hepatic mononuclear phagocytic cells. Abdominal ultrasound findings in children are evaluated in this disease. We present six pediatric cases, two with familial and four with sporadic hemophagocytic lymphohistiocytosis, examined by abdominal sonography. Three signs were frequently observed: thickening of the gallbladder wall (all cases), increased periportal echogenicity (four cases), and enlarged lymph nodes in the porta hepatis (four cases). Hepatomegaly, splenomegaly, and ascitic fluid may also be found. These imaging findings are not specific and may be seen in viral hepatitis. However, once hepatitis is excluded, they may suggest the diagnosis of hemophagocytic lymphohistiocytosis in a critically ill child. A bone smear must be done to establish the diagnosis. Received: 20 April 1998; Revision received: 18 August 1998; Accepted: 28 September 1998     

Hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a rare condition in children associated with immunodeficiency, life threatening infections and malignancy. Infection associated hemophagocytosis responds well to appropriate antimicrobioal therapy and rarely to steroids when the infective agent is suspected to be of viral origin.     

儿童EBV阳性噬血细胞综合征的遗传分析及其与Th1/Th2细胞因子的关系

目的 探讨遗传变异对EBV阳性噬血细胞综合征（HLH）患儿预后的影响及其与细胞因子的关系。方法 选取81例EBV阳性且已进行相关基因测序的HLH患儿，根据有无基因突变分为无突变组（n=35）和突变组（n=46），再根据基因突变方式分为单杂合突变（SHM）亚组、双杂合突变（DHM）亚组和纯合或复合杂合突变（H-CHM）亚组。测定各组患儿血清细胞因子水平，分析其与HLH基因突变的关系。结果 UNC13D基因突变出现频率最高（13/46，28%）。STXBP2 c.575G > A （p.R192H）和UNC13D c.604C > A （p.L202M）基因突变首次被报道，均判定为“可能致病的”。突变组TNF-α水平高于无突变组，IFN-γ水平低于无突变组（P < 0.05）。DHM亚组IL-4水平高于无突变组，H-CHM亚组IL-4水平低于DHM组（P < 0.0083）。H-CHM亚组的1年总生存率（39%±15%）低于无突变组、SHM亚组和DHM亚组（分别为85%±6%、86%±7%和91%±9%，P=0.001）。结论 具有基因突变的HLH患儿IFN-γ水平显著降低；H-CHM患儿的预后较差，而其他突变对其预后影响不显著，这可能有助于医生进行临床决策。     

The breakpoints of a constitutional inversion of chromosome 9 associated with haemophagocytic lymphohistiocytosis are not linked to the disease gene

Haemophagocytic lymphohistiocytosis (HLH) is a severe disorder of early infancy consistent with an autosomal recessive inheritance. Neither the genetic locus nor the biochemical defect is known for the disease. A constitutional pericentric inversion of chromosome 9, with breakpoints in bands 9p23 and 9q31, has been reported in a case of HLH, suggesting a possible relationship between this chromosome abnormality and the disease. We investigated such an association, performing a genetic linkage analysis in a set of five consanguineous HLH families. 27 polymorphic markers on chromosome 9 were studied, excluding most of chromosome 9 as a putative site for the HLH gene.     

High frequency of QPY allele and linkage disequilibrium of granzyme-B in Epstein-Barr-virus-associated hemophagocytic lymphohistiocytosis

Mediation of Epstein-Barr virus (EBV)-specific cytotoxicity in T lymphocyte via the perforin/granzyme pathway has been demonstrated; therefore, a study involving cytolytic molecules was essential for the clarification of hemophagocytic lymphohistiocytosis (HLH) pathogenesis. This investigation, which analysed the frequency of three allelic mutations of granzyme-B (55Q/R, 95P/A and 247Y/H) in patients with EBV-HLH and infectious mononucleosis, identified the high prevalence of the QPY haplotype in EBV-HLH patients in comparison with healthy controls. A > G polymorphism was also detected in intron 5; furthermore, nearly complete linkage disequilibrium was observed among these polymorphisms. The recessive role of the QPY haplotype of granzyme-B might be responsible for the pathogenesis of EBV-HLH. Cytotoxicity and DNA fragmentation of cytotoxic T lymphocytes did not differ among patients characterized by the QPY/QPY, RAH/RAH and QPY/RAH genotypes. This finding suggested that DNA fragmentation in target cells is mediated not only by granzyme-B but also by other molecules, including other granzymes or Fas.     

Secondary hemophagocytic syndrome after autologous hematopoietic cell transplant and immune therapy for neuroblastoma

Secondary hemophagocytic syndrome (HPS) has been described after autologous hematopoietic cell transplant (AutoHCT). We report two cases of secondary HPS after novel consolidation therapy for high‐risk neuroblastoma as part of an institutional phase 2 trial incorporating immunotherapy into a “standard” AutoHCT regimen. Both patients developed liver dysfunction beyond expected course of hepatic veno‐occlusive disease, coagulopathy, hyperferritinemia, and when evaluated, elevated soluble interleukin‐2 receptor and hemophagocytosis. These cases highlight the need for clinicians to have a high index of suspicion for immune‐related complications in patients receiving immune therapies.     

32例成人继发性噬血细胞综合征临床特点和预后分析

目的 探讨成人继发性噬血细胞综合征(HLH)临床特征和预后因素。 方法 收集32例成人继发性HLH患者临床资料,其中男17例(53%),女15 例(47%),19~88岁,中位年龄57岁。回顾性分析HLH患者的临床特点、病因及复发,采用单因素和Cox多因素分析预后因素。 结果 32例发热和血清铁蛋白升高,26例肝脾肿大,25例血细胞减少。病因分析中恶性肿瘤相关14例(43.75%),感染相关10例(31.25%),其他8例(25%)。32例最终死亡24例(75%),中位生存期27 d,复发率11.10%。单因素方差分析示,年龄、皮疹、血红蛋白、甘油三酯、凝血时间、活化部分凝血酶原时间与死亡相关(P<0.05),Cox多因素分析显示,年龄、甘油三酯水平是预后的独立危险因素。 结论 成人继发性HLH病因和临床特点多样,高龄和高甘油三酯是其死亡相关的独立预后因子。     

Plasmodium vivax malaria complicated by hemophagocytic syndrome in an immunocompetent serviceman

We describe a 23-year-old retired military officer who was immunocompetent but diagnosed with hemophagocytic syndrome (HPS) by Plasmodium vivax infection. Initially, the patient was suspected to have toxic hepatitis related to heavy drinking. But abnormal hematologic findings required a further bone marrow examination and the diagnosis of HPS was made. Antimalarial chemotherapy then brought complete remission. Plasmodium falciparum, a species causing more severe malarial infection, was listed as one of the major causes of HPS. However, P. vivax was not mentioned, and only one case was reported in the literature. In this study, we suggest that P. vivax malaria should be included in the differential diagnosis of HPS, even in an immunocompetent person.     

噬血细胞综合征12例临床分析

目的探讨噬血细胞综合征的临床表现、诊断及治疗方法。方法对12例患者进行回顾性分析。结果12例患者中感染相关性8例，肿瘤相关性3例，原因不明1例。治愈6例，好转1例，死亡5例。结论根据临床症状，体征和实验室检查，骨髓细胞学检查，多可获得诊断，对于治疗应主要针对病因，应用肾上腺糖皮质激素，由恶性疾病引起及病因未明者预后较差。     

Involvement of interferon-γ and macrophage colony-stimulating factor in pathogenesis of haemophagocytic lymphohistiocytosis in adults

Summary We investigated the role of monocyte/macrophage-activating cytokines in pathogenesis of haemophagocytic lymphohistiocytosis (HLH) in 21 adult patients. Sera from patients with active HLH contained extremely high levels of macrophage colony-stimulating factor (M-CSF) and of interferon-γ (IFN-γ). These levels returned to almost normal during remission. Neither interleukin-4 nor granulocyte/macrophage colony-stimulating factor could be detected. Active HLH sera also contained high concentrations of inflammatory monokines, such as interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α). Serum concentrations of soluble CD8 and soluble interleukin-2 receptor were extremely high during active HLH, and returned to virtually normal levels during remission. Circulating CD2⁺ T-cells obtained from patients with active HLH spontaneously secreted M-CSF and IFN-γ in vitro , whereas circulating monocytes did not produce detectable levels of both M-CSF and IFN-γ, but produced high levels of IL-6 and TNF-α. These findings suggest that IFN-γ and M-CSF at least partly from T-cells, such as CD8⁺ T-cells, might contribute to activation of monocytes or histiocytes, resulting in the up-regulated monokine production and haemophago-cytosis in HLH.