The familial form of hemophagocytic lymphohistiocytosis (HLH) is a lethal disorder. Although the prognosis for Epstein-Barr virus–associated HLH (EBV-HLH) remains uncertain, numerous reports indicate that it can also be fatal in a substantial proportion of cases. We therefore assessed the potential of immunochemotherapy with a core combination of steroids and etoposide to control EBV-HLH in 17 infants and children who met stringent diagnostic criteria for this reactive disorder of the mononuclear phagocyte system. Treatment of life-threatening emergencies was left to the discretion of participating investigators and typically included either intravenous Ig or cyclosporin A (CSA). Five patients (29%) entered complete remission during the induction phase (1 to 2 months), whereas 10 others (57%) required additional treatment to achieve this status. In 2 cases, immunochemotherapy was ineffective, prompting allogeneic bone marrow transplantation. Severe but reversible myelosuppression was a common finding; adverse late sequelae were limited to epileptic activity in one child and chronic EBV infection in 2 others. Fourteen of the 17 patients treated with immunochemotherapy have maintained their complete responses for 4+ to 39+ months (median, 15+ months), suggesting a low probability of disease recurrence. These results provide a new perspective on EBV-HLH, showing effective control (and perhaps cure) of the majority of EBV-HLH cases without bone marrow transplantation, using steroids and etoposide, with or without immunomodulatory agents.

HEMOPHAGOCYTIC lymphohistiocytosis (HLH) is an important differential diagnosis in infants and children who present with prolonged fever, hepatosplenomegaly, marked hypertriglyceridemia, systemic hypercytokinemia, and cytopenia (without evidence of aplastic anemia or a malignant hematologic disorder).1-3 In this reactive disorder of the mononuclear phagocytic system, infiltrating lymphocytes and histiocytes destroy blood cells in the central nervous system (CNS), bone marrow, and other organs as well. HLH consists of both primary (familial) and secondary (infection, or lymphoma-associated) forms. Fatal cases are seen most often in patients with the familial form of HLH, although in recent years there has been growing concern over the lethality of virus-associated HLH, especially when it involves Epstein-Barr virus (EBV-HLH).4-9 

The pathogenesis of EBV-HLH remains poorly understood, although the findings of several recent studies support the concept that proliferation of EBV-infected T cells may be a primary feature of the disease.9-13 Indeed, Kawaguchi et al12 showed the monoclonal growth of CD45RO-positive T cells infected with EBV, but not of EBV-infected B cells or histiocytes, in three cases of HLH in Japanese children. Thus, in contrast to the more common explanation that EBV-infected B lymphocytes trigger polyclonal proliferation of cytotoxic T cells, which in turn stimulate the accumulation and phagocytosing behavior of histiocytes and macrophages, EBV may target T lymphocytes directly. Whatever the mechanism, unrestricted release of inflammatory cytokines, such as interferon and tumor necrosis factor, is a prominent feature of HLH, including the EBV-related form, accounting for many of its clinical features and exerting a strong influence on prognosis.14-16 

Identification of optimal therapy for EBV-HLH has proven to be elusive. In general, cytotoxic chemotherapy, with or without immunomodulatory agents, will induce remissions in a substantial percentage of untreated patients, but these tend to be incomplete or of short duration.9-13,17-22 In one series of 12 patients with clonal HLH, of which 8 cases were EBV-related, the estimated 4-year survival rate was only 37% (95% confidence interval, 10% to 64%).23 Thus, allogeneic bone marrow transplantation (BMT), which consistently induces disease resolution and seems to be curative in many cases, has been suggested as the treatment of choice for EBV-HLH,24,25 although it is associated with high morbidity.

The HLH Study Group (Chairman: Dr Jan-Inge Henter, Stockholm, Sweden) of the Histiocyte Society as well as other study groups have long sought to improve clinical outcome in familial and virus-associated HLH by combining established cytotoxic induction regimens (epipodophyllotoxins, intrathecal methotrexate, and corticosteroids) with newer forms of immunomodulatory therapy (to maintain remissions until an acceptable marrow donor is found). Here, we report the results of the use of immunochemotherapy in 17 patients with EBV-HLH treated at various Japanese pediatric centers from 1992 to 1997 (see Table 1).

Table 1.

Clinical and Biological Status of 17 Patients With EBV-HLH

Sex  4M, 13F  
Median age (range) at diagnosis  4 yr (0.8-12.3)  
Family history of HLH  None  
Initial clinical presentation (no. of cases)  
 Persistent fever (≥38.5°C)  17 
 Hepatosplenomegaly  15  
 Coagulopathy  13  
 CNS symptoms  3  
 Lymphadenopathy  10  
 Jaundice  
 Pleural effusion  6  
Initial biological presentation (no. of cases)* 
 Cytopenia  17  
 Hypertriglyceridemia  12 
 Hypofibrinogenemia  13  
 Serum ferritin >1,000 ng/mL 12  
 Serum LDH >1,000 IU/L  16  
 Specimen positive for EBV-DNA  17 
Sex  4M, 13F  
Median age (range) at diagnosis  4 yr (0.8-12.3)  
Family history of HLH  None  
Initial clinical presentation (no. of cases)  
 Persistent fever (≥38.5°C)  17 
 Hepatosplenomegaly  15  
 Coagulopathy  13  
 CNS symptoms  3  
 Lymphadenopathy  10  
 Jaundice  
 Pleural effusion  6  
Initial biological presentation (no. of cases)* 
 Cytopenia  17  
 Hypertriglyceridemia  12 
 Hypofibrinogenemia  13  
 Serum ferritin >1,000 ng/mL 12  
 Serum LDH >1,000 IU/L  16  
 Specimen positive for EBV-DNA  17 

Abbreviations: EBV-HLH, Epstein-Barr virus–associated hemophagocytic lymphohistiocytosis; LDH, lactate dehydrogenase.

*

Normal laboratory values are reported in the text.

PATIENTS AND METHODS

Eligibility and Diagnostic Criteria

Infants and children younger than 16 years of age who met the diagnostic guidelines for HLH1,2 with a positive EBV genome in various biological specimens and had not received treatment for this disease were eligible for registration. Briefly, fever persisting beyond 7 days with peaks ≥38.5°C, hepatosplenomegaly, cytopenia (affecting at least two lineages in the peripheral blood and not caused by a hypocellular or dysplastic bone marrow), and hypertriglyceridemia (fasting triglycerides >2.0 mmol/L) or hypofibrinogenemia (fibrinogen <1.5 g/L) raised strong suspicion of a hemophagocytic syndrome. Cytomorphologically, the bone marrow smears of all patients showed increased hemophagocytosis (median, 9.5%; range, 1.5 to 33.5% of nucleated cell counts; normal, <1.0%).

Serological tests for EBV infection26 were based on viral capsid antigen (VCA)-IgG, VCA-IgM, early antigen-DR-IgG, and Epstein-Barr virus nuclear antigen (EBNA) antibody titers. Peripheral blood mononuclear (PBM) cells, bone marrow cells, or other biological specimens, lymph nodes primarily, were routinely examined for EBV-DNA by the polymerase chain reaction (PCR).27 Approval was obtained from the Institutional Review Board for these studies. Informed consent was provided according to the Declaration of Helsinki.

Clonality Testing

Clonality was assessed by Southern blot analysis of DNA samples probed for EBV and/or T-cell receptor (TCR) gene sequences using standard methods.28-31 Briefly, each DNA sample was digested with EcoRI, BamHI, andHindIII (TCRβ); EcoRI, BamHI, and KpnI (TCRγ); and EcoRI and Pst I (EBV). The samples were then electrophoresed and transferred to nylon membranes. The EBV probe was a 32P-labeled 1.9-kb Xho I fragment containing the tandem repeat sequence of EBV.31 The32P-labeled TCR probes were the 0.4-kb BglII-EcoRV fragment of the cDNA that contained the constant region of the TCRβ gene, and a 0.8-kb HindIII-EcoRI Jγ1.3 fragment that cross-hybridized with both Jγ1 and Jγ2 sequences (TCRγ).

Cytokine Assays

Serum concentrations of soluble interleukin-2 receptor (IL-2R) and interferon-gamma (IFN-γ) were determined with commercial immunoassay (T Cell Science, Cambridge, MA) and immunoradiometric kits, as previously described.32 

Treatment Regimens

Induction chemotherapy.

The core elements of treatment were steroids and etoposide. In 9 of our 17 cases (53%), remission induction therapy followed the HLH-94 protocol,2 either closely or entirely. These 9 cases were among the more than 50 from Japan that have been registered in an international study to evaluate the HLH-94 protocol. Dexamethasone (starting dose: 10 mg/m2 per day, orally [PO] or intravenously [IV]) and etoposide (150 mg/m2per dose, IV, initially twice weekly for 2 weeks, then weekly) were administered over 8 weeks. The remaining 8 patients were treated on independent protocols that uniformly included prednisolone (2 mg/kg per day, PO, for 2 to 4 weeks) and with one exception, etoposide (150 mg/m2 per dose, IV, twice or three times a week). Intrathecal methotrexate was planned only for patients with clinical evidence of CNS progression or unimproved pleocytosis in cerebrospinal fluid. Short-term infusions of cyclosporin A (CSA; 6 mg/kg per day) were given to 3 patients, at the physician’s discretion, to control the unrestricted release of cytokines and their receptors during periods of neutropenia.

Plasma exchange or exchange transfusion was used in 7 cases to stabilize patients in medical crises caused by advanced disease. Intravenous Ig was administered with therapeutic intent33-36 to 4 patients. Additional features of the regimens are given in Table 2.

Table 2.

Outcome of Immunochemotherapy in 17 Patients With EBV-HLH

Case No. Induction Regimen Initial Response at 8 Weeks Continuation Regimen Total Duration of Therapy (mo) Final Response CR Duration (mo) Survival (mo)
1  PE, VCR/VP16/PSL/CSA* PR  HLH-94  4+ CR  4+  8+  
2  IVIG/HLH-94  PR  BMT  2  CR 7+  9+  
3  HLH-94  CR  None  2  CR  8+ 10+  
4  ET, HLH-94/CSA* PR  HLH-94  11+ CR/REL   6 11+  
5  HLH-94  CR/REL HLH-94  7  CR  11+  14+  
6  PE, VP16/PSL/MTX PR  VP16/PSL/MTX  5  CR  15+  19+  
IVIG/VP16/PSL  PR  VP16/PSL  12  CR  14+  18+ 
8  HLH-94  CR  None  2  CR  15+  17+  
IVIG/PSL/VP16  PR  HLH-94  12  CR  17+  21+ 
10  HLH-94 PR  HLH-94  12  CR  15+  23+ 
11  HLH-94  PR  HLH-94  9  CR  19+  25+  
12 VP16/VCR/PSL  CR  None  1  CR  22+  24+  
13 ET, HLH-94  PR/REL  NHL-chemo/CSA/BMT  7  CR  19+ 25+  
14  PE, VP16/HLH-94  PR  HLH-94  9  CR 30+  36+  
15  PSL/IVIG, VP16/PSL  PR  NHL-chemo 36  CR  39+  45+  
16  PE, VP16/PSL  PR/REL NHL/HD-chemo/CSA  27  CR  37+  62+  
17  PE, mPSL/Lipo-Dexa/CSA* CR  None  2  CR  5+  7+ 
Case No. Induction Regimen Initial Response at 8 Weeks Continuation Regimen Total Duration of Therapy (mo) Final Response CR Duration (mo) Survival (mo)
1  PE, VCR/VP16/PSL/CSA* PR  HLH-94  4+ CR  4+  8+  
2  IVIG/HLH-94  PR  BMT  2  CR 7+  9+  
3  HLH-94  CR  None  2  CR  8+ 10+  
4  ET, HLH-94/CSA* PR  HLH-94  11+ CR/REL   6 11+  
5  HLH-94  CR/REL HLH-94  7  CR  11+  14+  
6  PE, VP16/PSL/MTX PR  VP16/PSL/MTX  5  CR  15+  19+  
IVIG/VP16/PSL  PR  VP16/PSL  12  CR  14+  18+ 
8  HLH-94  CR  None  2  CR  15+  17+  
IVIG/PSL/VP16  PR  HLH-94  12  CR  17+  21+ 
10  HLH-94 PR  HLH-94  12  CR  15+  23+ 
11  HLH-94  PR  HLH-94  9  CR  19+  25+  
12 VP16/VCR/PSL  CR  None  1  CR  22+  24+  
13 ET, HLH-94  PR/REL  NHL-chemo/CSA/BMT  7  CR  19+ 25+  
14  PE, VP16/HLH-94  PR  HLH-94  9  CR 30+  36+  
15  PSL/IVIG, VP16/PSL  PR  NHL-chemo 36  CR  39+  45+  
16  PE, VP16/PSL  PR/REL NHL/HD-chemo/CSA  27  CR  37+  62+  
17  PE, mPSL/Lipo-Dexa/CSA* CR  None  2  CR  5+  7+ 

Abbreviations: EBV-HLH, Epstein-Barr virus-related hemophagocytic lymphohistiocytosis; PE, plasma exchange; ET, exchange transfusion; VCR, vincristine; VP16, etoposide; PSL, prednisolone; CSA, cyclosporin A; IVIG, intravenous immunoglobulin; HLH-94, HLH treatment protocol developed by investigators of the Histiocyte Society; MTX, methotrexate; mPSL, methyl-prednisolone; Lipo-Dexa, dexamethasone in lipid microspheres; PR, partial response; CR, complete response; REL, relapse; NHL-chemo, chemotherapy as given to NHL patients37; HD-chemo, chemotherapy as given to HD patients38; BMT, bone marrow transplantation.

*

Short-term continuous infusion.

With four intrathecal MTX injections.

Await for BMT after relapse.

Continuation treatment.

Responses to induction therapy were considered complete if after 8 weeks there was unequivocal resolution of clinical signs and symptoms, as well as the normalization of laboratory findings, particularly serum levels of ferritin. Patients with persistent fever and other symptoms of HLH, or with abnormally high levels of serum ferritin in the absence of definitive symptoms, were judged to have partial responses and were placed on intensification or maintenance regimens until a complete response was induced. In 7 cases, these treatments followed the HLH-94 protocol: dexamethasone pulses every other week, daily CSA, and biweekly etoposide. Other continuation regimens for refractory cases were modeled on chemotherapy for Hodgkin’s disease (HD) or non-Hodgkin’s lymphoma (NHL).37,38 Specific agents and their sequences of administration are reported in Table 2.

RESULTS

Table 1 summarizes the initial clinical and biological findings in our 17 patients. Persistent fever, hepatosplenomegaly, and cytopenia were defining features, with coagulopathy, jaundice, and lymphadenopathy also noted in more than half the patients. Additionally, the serum ferritin concentration (normal range, 8 to 78 ng/mL) exceeded 1,000 ng/mL in 12 cases, whereas the serum lactate dehydrogenase value (normal range, 234 to 471 IU/L) was higher than 1,000 IU/L in 16 cases. Soluble IL-2R levels (normal, <1,090 U/mL) were higher than 10,000 U/mL in all 17 cases, with 11 of 16 cases also showing substantially increased concentrations of IFN-γ (normal, <1.0 U/mL). None of the patients had a family history of HLH.

EBV-DNA was detected in biological specimens from each of the 17 patients (peripheral blood, 11; bone marrow, 9; lymph node, 3; Table3). Serological testing showed an elevated anti-VCA-IgG in all cases, with increased anti-VCA-IgM and anti-EADR-IgG titers indicating primary and reactivated EBV infections in 3 cases each. Of the 11 patients for whom EBV clonality results were available, 10 had evidence of monoclonal expansion of EBV-infected PBM cells (Table 3). In one child (case 11), the expansion seemed to be biclonal. TCR results also showed that 6 (cases 4, 5, 7, 8, 11, and 13) of the 11 cases studied had rearranged bands.

Table 3.

Results of EBV Clonality Analysis and Serological Tests

Case No. Source of EBV-DNAClonality Serology
VCA-IgG VCA-IgMEADR-IgG EBNA
1  BM  mono  80  <10 na  10  
2  PB  mono  640  <10  <10 10  
3  PB  na  80  <10  <10  <10  
BM, PB, mass  mono3-150 160  <10  <10  <10  
BM, PB  mono3-150 160  <10  10  <10  
6  BM mono  20  <10  na  <10  
7  PB mono3-150 160  <10  <10  <10  
8  PB  na3-150 40  <10  <10  <10  
9  BM  mono  160 <10  na  10  
10  PB  na  320  20 na  <10  
11  PB  bi3-150 160  <10 na  <10  
12  BM  na  160  <10 <10  10  
13  BM, PB  mono3-150 640  <10  40 <10  
14  BM, LN  na  320  <10  10  <10 
15  LN  mono  80  10  <10  <10  
16  PB, LN  mono  320  160  na  10  
17  BM, PB na  320  <10  na  <10 
Case No. Source of EBV-DNAClonality Serology
VCA-IgG VCA-IgMEADR-IgG EBNA
1  BM  mono  80  <10 na  10  
2  PB  mono  640  <10  <10 10  
3  PB  na  80  <10  <10  <10  
BM, PB, mass  mono3-150 160  <10  <10  <10  
BM, PB  mono3-150 160  <10  10  <10  
6  BM mono  20  <10  na  <10  
7  PB mono3-150 160  <10  <10  <10  
8  PB  na3-150 40  <10  <10  <10  
9  BM  mono  160 <10  na  10  
10  PB  na  320  20 na  <10  
11  PB  bi3-150 160  <10 na  <10  
12  BM  na  160  <10 <10  10  
13  BM, PB  mono3-150 640  <10  40 <10  
14  BM, LN  na  320  <10  10  <10 
15  LN  mono  80  10  <10  <10  
16  PB, LN  mono  320  160  na  10  
17  BM, PB na  320  <10  na  <10 

Abbreviations: BM, bone marrow; PB, peripheral blood; LN, lymph node; mass, mass in the CNS; na, not assessable; mono, monoclonal; bi, biclonal.

F3-150

TCR study showed rearranged bands.

Complete remissions were induced in 5 patients during the first 8 weeks of therapy, 3 on the HLH-94 protocol and 2 on independent treatment plans (Table 2). One of these responders (case 5) immediately relapsed and was placed on HLH-94 maintenance treatment; the remaining patients did not receive additional therapy for HLH. All other responses were considered partial, prompting a switch to continuation therapy that included dexamethasone pulses every other week, daily CSA, and biweekly etoposide (HLH-94 protocol) or diverse agents that have shown promising activity against HLH (etoposide, prednisolone, CSA, and HD- or NHL-type regimens). Patients were provided therapy for a median of 7 months (range, 1 to 36 months). Two cases (cases 2 and 13) were considered refractory to chemotherapy, requiring allogeneic BMT at 2 months and 7 months postdiagnosis respectively. In addition, another case (case 4) awaits BMT after relapse. At the time of the most recent follow-up evaluation (December 1997), all patients except one (case 4) were in complete remission for 4+ to 39+ months (median, 15+ months), with 2 still receiving treatment.

There were no bacterial infections during the study. Adverse late sequelae were limited to epileptic activity associated with CNS lesions in one child (case 10) and EBV antibody titers indicative of chronic EBV infection in 2 other cases (cases 9 and 16). In several cases, severe neutropenia during remission induction led to temporary withdrawal of all cytoreductive therapy, raising concern over disease progression and relapse. Continuous short-term infusions of CSA (2 mg/kg per day), as in cases 1, 4, and 17, seemed to control HLH while permitting hematopoietic recovery. Patients treated in this manner were able to receive their scheduled chemotherapy within 10 to 14 days after intervention with CSA (Table 2).

DISCUSSION

EBV-related hemophagocytic lymphohistiocytosis poses unusual challenges to pediatric hematologists. First of all, the reactive disorder may be difficult to distinguish from infectious mononucleosis, septicemia, certain hematologic malignancies, and systemic autoimmune disorders. All patients in our series met the HLH diagnostic criteria proposed by Henter et al,1 had EBV-DNA in one or more biological specimens by PCR or by Southern blot analysis, and lacked a family history of HLH. Thus, although the distinction between familial and virus-associated HLH is not always clear,39 we would contend that the constellation of presenting clinical and laboratory findings in our series, together with monoclonal or biclonal proliferation of EBV-infected cells (Table 3), adequately supports the diagnosis of EBV-HLH.

Second, because of the poor long-term results of chemotherapy only for familial HLH,40 it has been suggested that EBV-related disease might be similarly resistant, requiring allogeneic BMT; however, occasional reports indicate that some patients may resolve while they are receiving supportive care.17-22,24,25Neither the medical literature nor our previous experience clearly distinguishes between patients in whom EBV-HLH has a fatal outcome and those who recover at the beginning of treatment. The dilemma, then, is whether to begin aggressive therapy immediately or to control the disease course until there is justification for BMT. Lacking clear risk factors or reliable epidemiological data on which to base therapeutic decisions, we chose instead to treat the disease with immunochemotherapy, switching to BMT only when recurrent disease developed. A total of 11 patients (65%) were treated on the HLH-94 protocol, either entirely or in conjunction with other agents (Table2). Six others received treatment that was based on precedents in the medical literature,41,42 but that incorporated a core combination of a steroid and etoposide, as in the HLH-94 regimen. In one case (case 17), treatment was limited to steroids and CSA, with etoposide omitted altogether.

All but 2 of the patients achieved complete response on immunochemotherapy (2 cases attained complete response after BMT) and have maintained these responses for 4+ to 39+ months. Thus, it was possible to control EBV-HLH in a high proportion of cases without resorting to BMT. In earlier studies,23,40patients with familial or virus-associated HLH have generally relapsed within 5 months of attaining complete response on different regimens of immunochemotherapy. In our EBV-HLH cases, 13 of the 17 cases needed continuation treatment with etoposide and steroids with or without CSA, or with other forms of chemotherapy. BMT was successfully performed in 2 cases that showed resistance to all available immunochemotherapy, and is being planned for one other patient. The median response duration in our series, 15+ months, suggests a low probability of disease recurrence in EBV-HLH; however, with the current poor understanding of HLH pathogenesis, we cannot rule out the possibility of delayed relapses.

Steroids and etoposide were common features of treatment, both in the induction phase and in the continuation phase for patients who showed resistance to other agents. Thus, we attribute the excellent outcome largely to judicious use of prednisolone or dexamethasone and etoposide. That dexamethasone crosses the blood-brain barrier more readily than prednisolone2 suggests that it would confer greater protection against HLH in the CNS, a frequent site of involvement in patients with this disease.43,44 CSA, which has not been widely used in therapy for EBV-HLH, seems to have controlled the dysregulated release of cytokines and their receptors in patients with neutropenia and therefore, should be considered a useful component of combination treatment of this disorder, as currently suggested.45-55 Plasma exchange or exchange transfusion56,57 was used at the investigators’ discretion when patients presented with advanced disease complicated by coagulopathy. Without appropriate controls, we are unable to assess the efficacy of these procedures, but would suggest that they be considered as possible effective means to stabilize the patient’s condition in preparation for induction therapy. The value of intravenous immunoglobulin (IVIG) administered early in the induction phase to 4 patients is also difficult to establish. However, reports of deleterious effects produced by IVIG in patients with hemophagocytic syndrome, caused by the presence of cytokines in the Ig preparations,58,59 together with its unimpressive activity against EBV-HLH in the present study (Table 2), indicate that this agent could be omitted from first-line protocols without significant loss of efficacy.

Ideally, one could select therapy for EBV-HLH on the basis of the relapse hazard, reserving BMT for cases with a very high risk of failure. In practice, however, the disease is extremely heterogeneous with few clinical and biological markers that accurately predict responsiveness to immunologic or cytotoxic agents.39 High serum levels of ferritin, lactate dehydrogenase, soluble IL-2R, and IFN-γ have all been implicated as factors that increase the risk of relapse in patients with HLH,14,15,23,60,61 but these associations need to be established in larger trials. One particularly ominous finding indicates that some cases of EBV-HLH involve clonal proliferations of EBV-infected T lymphocytes,9-13,62-64 so that treatment strategies must include methods to control transformed T cells as well as hemophagocytic histiocytes.

With these concerns in mind, we recommend the following therapeutic approach to newly diagnosed cases of EBV-HLH: (1) induction therapy with steroids and etoposide that follows the HLH-94 protocol (8 weeks) with or without exchange transfusion/plasma exchange to alleviate life-threatening complications at presentation; (2) for patients without CR after 8 weeks, continuation of the HLH-94 protocol including the addition of CSA (6 to 12 months); and (3) NHL- or HD-type or other chemotherapy for refractory cases as possible salvage. Although not used in the patients presented here, anti-thymocytoglobulin may also be a reasonable therapeutic choice for refractory disease.45Allogeneic BMT should be held in reserve and used only for patients with highly continuous refractory disease, as EBV-HLH seems to be much more responsible to immunochemotherapy than the familial form of HLH.

As one of several types of hemophagocytic lymphohistiocytosis, it is important to conclude that EBV-HLH has a surprisingly good prognosis, using the immunochemotherapy included in the HLH-94 protocol. Because the ultimate utility and safety of the immunochemotherapy we describe will depend on the outcome of trials in larger numbers of patients, we urge greater cooperation among pediatric centers worldwide to ensure that all essential information on EBV-HLH is gathered and analyzed in a timely manner.

ACKNOWLEDGMENT

The authors thank members of the HLH Study Group of the Histiocyte Society for the critical reading of the manuscript and are grateful to Yasuko Hashimoto for her excellent secretarial assistance.

Supported in part by grants from the Histiocytosis Association of America, the Histiocytosis Association of Canada, and the Ministry of Health and Welfare in Japan.

The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. section 1734 solely to indicate this fact.

REFERENCES

REFERENCES
1
Henter
J-I
Elinder
G
Ost
A
the HLH Study Group of the Histiocyte Society
Diagnostic guidelines for hemophagocytic lymphohistiocytosis.
Semin Oncol
18
1991
29
2
Henter
J-I
Arico
M
Egeler
RM
Elinder
G
Favara
BE
Filipovich
AH
Gadner
H
Imashuku
S
Janka Schaub
G
Komp
D
Ladisch
S
Webb
D
for the HLH Study Group of the Histiocyte Society
HLH-94: A treatment protocol for hemophagocytic lymphohistiocytosis.
Med Pediatr Oncol
28
1997
342
3
Favara
BE
Hemophagocytic lymphohistiocytosis: A hemophagocytic syndrome.
Semin Diagn Pathol
9
1992
62
4
Janka
G
Imashuku
S
Elinder
G
Schneider
M
Henter
J-I
Infection- and malignancy-associated hemophagocytic syndromes. Secondary Hemophagocytic Lymphohistiocytosis.
Hematol Oncol Clin North Am
12
1998
435
5
Christensson
B
Braconier
JH
Winqvist
I
Relander
T
Dictor
M
Fulminant course of infectious mononucleosis with virus-associated hemophagocytic syndrome.
Scand J Infect Dis
19
1987
373
6
Mroczek
EC
Weisenburger
DD
Grierson
HL
Markin
R
Purtilo
DT
Fatal infectious mononucleosis and virus-associated hemophagocytic syndrome.
Arch Pathol Lab Med
111
1987
530
7
Wilson
ER
Malluh
A
Stagno
S
Crist
WM
Fatal Epstein-Barr virus-associated hemophagocytic syndrome.
J Pediatr
98
1981
260
8
Kikuta
H
Sakiyama
Y
Matsumoto
S
Oh-Ishi
T
Nakano
T
Nagashima
T
Oka
T
Hironaka
T
Hirai
K
Fatal Epstein-Barr virus-associated hemophagocytic syndrome.
Blood
82
1993
3259
9
Mori
M
Kurozumi
H
Akagi
K
Tanaka
Y
Imai
S
Osato
T
Monoclonal proliferation of T cells containing Epstein-Barr virus in fatal mononucleosis.
N Engl J Med
327
1992
58
10
Gaillard
F
Mechinaud-Lacroix
F
Papin
S
Moreau
A
Mollat
C
Fiche
M
Peltier
S
DeFaucal
PJ
Rousselet
MC
Praloran
V
Harousseau
J-L
Primary Epstein-Barr virus infection with clonal T-cell lymphoproliferation.
Am J Clin Pathol
98
1992
324
11
Dolezal
MV
Kamel
OW
van de Rijn
M
Cleary
ML
Sibley
RK
Warnke
RA
Virus-associated hemophagocytic syndrome characterized by clonal Epstein-Barr virus genome.
Am J Clin Pathol
103
1995
189
12
Kawaguchi
H
Miyashita
T
Herbst
H
Niedobitek
G
Asada
M
Tsuchida
M
Hanada
R
Kinoshita
A
Sakurai
M
Kobayashi
N
Mizutani
S
Epstein-Barr virus-infected T lymphocytes in Epstein-Barr virus-associated hemophagocytic syndrome.
J Clin Invest
92
1993
1444
13
Su
IJ
Hsu
YH
Lin
MT
Cheng
AL
Wang
CH
Weiss
LM
Epstein-Barr virus-containing T-cell lymphoma presents with hemophagocytic syndrome mimicking malignant histiocytosis.
Cancer
72
1993
2019
14
Ishii
E
Ohga
S
Aoki
T
Yamada
S
Sako
M
Tasaka
H
Kuwano
A
Sasaki
M
Tsunematsu
Y
Ueda
K
Prognosis of children with virus-associated hemophagocytic syndrome and malignant histiocytosis: Correlation with levels of serum interleukin-1 and tumor necrosis factor.
Acta Haematol
85
1991
93
15
Imashuku
S
Hibi
S
Fujiwara
F
Ikushima
S
Todo
S
Haemophagocytic lymphohistiocytosis, interferon-gamma-naemia and Epstein-Barr virus involvement.
Br J Haematol
88
1994
656
16
Fujiwara
F
Hibi
S
Imashuku
S
Hypercytokinemia in hemophagocytic syndrome.
Am J Pediatr Hematol Oncol
15
1993
92
17
Chen
R-L
Lin
K-H
Lin
D-T
Su
IJ
Huang
LM
Lee
PI
Hseih
KH
Lin
KS
Lee
CY
Immunomodulation treatment for childhood virus-associated haemophagocytic lymphohistiocytosis.
Br J Haematol
89
1995
282
18
Sullivan
JL
Woda
BA
Herrod
HG
Koh
G
Rivara
FP
Mulder
C
Epstein-Barr virus-associated hemophagocytic syndrome: Virological and immunopathological studies.
Blood
65
1985
1097
19
Yoshimura
N
Nishioka
S
Tanida
T
Shima
M
Ikemoto
E
Kamei
K
Agawa
Y
Nishino
N
An adult case of virus-associated hemophagocytic syndrome (VAHS) and a review of this syndrome in adults in Japan.
Kansenshogaku Zasshi
65
1991
472
20
Inoue
T
Furukawa
Y
Yamane
T
Hiyoshi
M
Sasaki
A
Kishida
T
Im
T
Tatsumi
N
Sannomiya
Y
Virus-associated hemophagocytic syndrome due to EB virus.
Rinsho Ketsueki
30
1989
1826
21
Nomura
S
Koshikawa
K
Hamamoto
K
Okubo
S
Yasunaga
K
Steroid and gamma globulin therapy against virus-associated hemophagocytic syndrome.
Rinsho Ketsueki
33
1992
1242
22
Imashuku
S
Case records of pediatric hemophagocytic syndrome.
Nihon Ijishinpo
3678
1994
43
23
Imashuku
S
Hibi
S
Todo
S
Hemophagocytic lymphohistiocytosis in infancy and childhood.
J Pediatr
130
1997
352
24
Teshima
T
Miyaji
R
Fukuda
M
Ohshima
K
Bone-marrow transplantation for Epstein-Barr-virus-associated natural killer cell-large granular lymphocyte leukaemia.
Lancet
347
1996
1124
25
Imashuku
S
Naya
M
Yamori
M
Nakabayashi
Y
Hojo
M
Kihara
A
Tabata
Y
Akioka
C
Hibi
S
Todo
S
Bone marrow transplantation for Epstein-Barr virus-related clonal T cell proliferation associated with hemophagocytosis.
Bone Marrow Transplant
19
1997
1059
26
Sumaya
CV
Ench
Y
Epstein-Barr virus infectious mononucleosis in children. II. Heterophil antibody and viral-specific responses.
Pediatrics
75
1985
1101
27
Telenti
A
Marshall
WF
Smith
TF
Detection of Epstein-Barr virus by polymerase chain reaction.
J Clin Microbiol
28
1990
2187
28
Sambrook
J
Fitsch
EF
Maniatis
T
Molecular Cloning: A Laboratory Manual
ed 2
1989
Cold Spring Harbor Laboratory Press
Cold Spring Harbor, NY
29
Toyonaga
B
Yanagi
Y
Sucu-Foca
N
Minden
M
Mak
TW
Rearrangement of T-cell antigen receptor gene YT35 in human DNA from thymic T-cell lines and functional T-cell clones.
Nature
311
1984
385
30
LeFranc
MP
Rabbitts
TH
Two tandemly organized human genes encoding the T-cell γ constant region sequences show multiple rearrangement in different T-cell types.
Nature
316
1985
464
31
Raab-Traub
N
Flynn
K
The structure of the termini of the Epstein-Barr virus as a marker of clonal cellular proliferation.
Cell
47
1986
883
32
Imashuku
S
Ikushima
S
Esumi
N
Todo
S
Saito
M
Serum levels of interferon-gamma, cytotoxic factor and soluble interleukin-2 receptor in childhood hemophagocytic syndromes.
Leuk Lymphoma
3
1991
287
33
Gill
DS
Spencer
A
Cobcroft
RG
High-dose gamma globulin therapy in the reactive hemophagocytic syndrome.
Br J Haematol
88
1994
204
34
Goulder
P
Seward
D
Hatton
C
Intravenous immunoglobulin in virus-associated hemophagocytic syndrome.
Arch Dis Child
65
1990
1275
35
Freeman
B
Rathore
MH
Salman
E
Joyce
MJ
Pitel
P
Intravenously administered immune globulin for the treatment of infection-associated hemophagocytic syndrome.
J Pediatr
123
1993
479
36
Fort
DW
Buchanan
GR
Treatment of infection-associated hemophagocytic syndrome with immune globulin.
J Pediatr
124
1994
332
(ltr)
37
Anderson
JR
Wilson
JF
Jenkin
DT
Meadows
AT
Kersey
J
Chilcote
RR
Coccia
P
Exelby
P
Kushner
J
Siegel
S
Hammond
D
Childhood non-Hodgkin’s lymphoma. The results of a randomized therapeutic trial comparing a 4-drug regimen (COMP) with a 10-drug regimen (LSA2L2).
N Engl J Med
308
1983
559
38
Canellos
G
Anderson
JR
Propert
KJ
Nissen
N
Cooper
MR
Henderson
ES
Green
MR
Gottlieb
A
Peterson
BA
Chemotherapy of advanced Hodgkin’s disease with MOPP, ABVD, or MOPP alternating with ABVD.
N Engl J Med
327
1992
1478
39
Imashuku
S
Differential diagnosis of hemophagocytic syndrome: Underlying disorders and selection of the most effective treatment.
Int J Hematol
66
1997
135
40
Arico
M
Janka
G
Fischer
A
Henter
J-I
Blanche
S
Elinder
G
Martinetti
M
Rusca
MP
for the FHL Study Group of the Histiocyte Society
Hemophagocytic lymphohistiocytosis: Diagnosis, treatment, and prognostic factors. Report of 122 children from the international registry.
Leukemia
10
1996
197
41
Esumi
N
Hashida
T
Matsumura
T
Takeuchi
Y
Arakawa
S
Imashuku
S
Malignant histiocytosis in childhood. Clinical features and therapeutic results by combination chemotherapy.
Am J Pediatr Hematol Oncol
8
1986
300
42
Brugieres
L
Caillaux
JM
Patte
C
Rodary
C
Bernard
A
Kalifa
C
Hartmann
O
Lemerle
J
Malignant histiocytosis; therapeutic results in 27 children treated with a single polychemotherapy regimen.
Med Pediatr Oncol
17
1989
193
43
Henter
J-I
Nennesmo
I
Neuropathologic findings and neurologic symptoms in twenty-three children with hemophagocytic lymphohistiocytosis.
J Pediatr
130
1997
358
44
Haddad
E
Sulis
M-L
Jabado
N
Blanche
S
Fischer
A
Tardieu
M
Frequency and severity of central nervous system lesions in hemophagocytic lymphohistiocytosis.
Blood
89
1997
794
45
Stephan
JL
Donadieu
J
Ledeist
F
Blanche
S
Griscelli
C
Fischer
A
Treatment of familial hemophagocytic lymphohistiocytosis with antithymocyte globulins, steroids, and cyclosporine A.
Blood
82
1993
2319
46
Abella
EM
Artrip
J
Schultz
K
Ravindranath
Y
Treatment of familial erythrophagocytic lymphohistiocytosis with cyclosporine A.
J Pediatr
130
1997
467
47
Ostrov
BE
Athreva
BH
Eichenfield
AH
Goldsmith
DP
Successful treatment of severe cytophagic histiocytic panniculitis with cyclosporine A.
Semin Arthritis Rheum
25
1996
404
48
Gabor
EP
Mishalani
S
Lee
S
Rapid response to cyclosporine therapy and sustained remission in large granular lymphocyte leukemia.
Blood
87
1996
1199
49
Bible
KC
Tefferi
A
Cyclosporine A alleviates severe anaemia associated with refractory large granular lymphocytic leukaemia and chronic natural killer cell lymphocytosis.
Br J Haematol
93
1996
406
50
Grom
AA
Passo
M
Macrophage activation syndrome in systemic juvenile rheumatoid arthritis.
J Pediatr
129
1996
630
51
Mouy
R
Stephan
J-L
Pillet
P
Haddad
E
Hubert
P
Prieur
AM
Efficacy of cyclosporine A in the treatment of macrophage activation syndrome in juvenile arthritis: Report of five cases.
J Pediatr
129
1996
750
52
Fishman
D
Rooney
M
Woo
P
Successful management of reactive haemophagocytic syndrome in systemic-onset juvenile chronic arthritis.
Br J Rheumatol
34
1995
888
53
Laneuville
P
Cyclosporin A induced remission of CD4+ T-CLL associated with eosinophilia and fasciitis.
Br J Haematol
80
1992
252
54
Moreland
AA
Robertson
DB
Heffner
LT
Treatment of cutaneous T cell lymphoma with cyclosporin A.
J Am Acad Dermatol
12
1985
886
(ltr)
55
Street
ML
Muller
SA
Pittelkow
MR
Cyclosporine in the treatment of cutaneous T cell lymphoma.
J Am Acad Dermatol
23
1990
1084
56
Ladisch
S
Ho
W
Matheson
D
Pilkington
R
Hartman
G
Immunologic and clinical effects of repeated blood exchange in familial erythrophagocytic lymphohistiocytosis.
Blood
60
1982
814
57
Kizaki
Z
Fukumochi
H
Sawai
T
Ishimura
K
Esumi
N
Nagai
T
Todo
S
Imashuku
S
Exchange transfusion and combination chemotherapy in the treatment of 4 cases of childhood malignant histiocytosis.
Rinsho Ketsueki
28
1987
845
58
Nagasawa
M
Okawa
H
Yata
J
Deleterious effects of high dose γ-globulin therapy on patients with hemophagocytic syndrome.
Int J Hematol
60
1994
91
59
Aukrust
P
Froland
SS
Liabakk
N-B
Muller
F
Nordoy
I
Haug
C
Espevik
T
Release of cytokines, soluble cytokine receptors, and interleukin-1 receptor antagonist after intravenous immunoglobulin administration in vivo.
Blood
84
1994
2136
60
Esumi
N
Ikushima
S
Hibi
S
Todo
S
Imashuku
S
High serum ferritin level as a marker of malignant histiocytosis and virus-associated hemophagocytic syndrome.
Cancer
61
1988
2071
61
Imashuku
S
Hibi
S
Sako
M
Ishida
Y
Mugishima
H
Chen
J
Tsunematsu
Y
Soluble interleukin-2 receptor: A useful prognostic factor for patients with hemophagocytic lymphohistiocytosis.
Blood
86
1995
4706
62
Smith
KJ
Skelton
HG
III
Giblin
WL
James
WD
Cutaneous lesions of hemophagocytic syndrome in a patient with T-cell lymphoma and active Epstein-Barr infection.
J Am Acad Dermatol
25
1991
919
63
Kueck
BD
Hanson
CA
Weissman
DE
Bayliss
K
Primary lymph node presentation of angiocentric lymphoma associated with features of a hemophagocytic syndrome.
Am J Hematol
30
1989
104
64
Cheng
AL
Su
IJ
Chen
YC
Ven
WC
Wang
CH
Characteristic clinicopathologic features of Epstein-Barr virus-associated peripheral T-cell lymphoma.
Cancer
72
1993
909

Author notes

Address reprint requests to Shinsaku Imashuku, MD, Division of Pediatrics, Children’s Research Hospital, Kyoto Prefectural University of Medicine, Hirokoji, Kawaramachi, Kamigyo-ku, Kyoto, Japan 602-0841.