Treatment strategies for Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH)

Clinical significance and different strategies for re-elevation of plasma EBV-DNA during treatment in pediatric EBV-associated hemophagocytic lymphohistiocytosis

OBJECTIVE

Monitoring the disease status of Epstein-Barr virus (EBV)-related hemophagocytic lymphohistiocytosis (HLH) patients is crucial. This study aimed to investigate the different strategies and outcomes of patients with EBV-HLH and re-elevated EBV-DNA.

METHOD

A retrospective analysis was conducted on 20 patients diagnosed with EBV-HLH. Clinical features, laboratory tests, treatments, plasma EBV-DNA levels, and outcomes were assessed. Three cases were highlighted for detailed analysis.

RESULTS

Nine of the 20 patients had a re-elevation of EBV-DNA during treatment, and 55.5 % (5/9) experienced relapses. Patients with persistently positive plasma EBV-DNA (n = 4) and those with re-elevated EBV-DNA after conversion (n = 9) showed a significantly higher relapse rate compared to those with persistently negative EBV-HLH (n = 7) (p < 0.05). Among the highlighted cases, Case 1 exhibited plasma EBV-DNA re-elevation after four weeks of treatment without relapse, maintaining stability with the original treatment regimen, and eventually, his plasma EBV-DNA turned negative. In Case 2, plasma EBV-DNA was elevated again with a recurrence of HLH after L-DEP. Consequently, she underwent allogeneic hematopoietic stem cell transplantation and eventually achieved complete remission (CR) with negative plasma EBV-DNA. Case 3 experienced plasma EBV-DNA re-elevation after L-DEP but remained in CR, discontinuing chemotherapy without relapse.

CONCLUSION

The re-elevation of plasma EBV-DNA during EBV-HLH treatment poses challenges in determining disease status and treatment strategies. Optimal management decisions require a combination of the level of elevated EBV-DNA, the intensity of hyperinflammation, and the patient's immune function.

Secondary hemophagocytic lymphohistiocytosis in children (Review)

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening condition characterized by hyperinflammation in an uncontrolled and ineffective immune response. Despite great improvement in diagnosis and treatment, it still represents a challenge in clinical management, with poor prognosis in the absence of an aggressive therapeutic approach. The present literature review focuses on secondary HLH at pediatric age, which represents a heterogeneous group in terms of etiology and therapeutic approach. It summarizes the most recent evidence on epidemiology, pathophysiology, diagnosis, treatment and prognosis, and provides a detailed description and comparison of the major subtypes of secondary HLH. Finally, it addresses the open questions with a focus on diagnosis and new treatment insights.

The Outcome of Induction Therapy for EBV-Related Hemophagocytic Lymphohistiocytosis: A Model for Risk Stratification

Background

Epstein–Barr virus (EBV)–related hemophagocytic lymphohistiocytosis (HLH) is an abnormal inflammation caused by EBV infection, which has high mortality during induction therapy.

Objectives

This study is aimed to build a model to predict the risk of death during induction therapy.

Methods

The patients with EBV-HLH admitted from January 2015 to December 2018 were retrospectively reviewed. The primary outcome was death during induction therapy. The interval from receiving therapy to death or the end of induction therapy was the observing time. The patients admitted from January 2015 to December 2017 were assigned to the primary group, and the patients admitted from January to December 2018 were assigned to the validation group.

Results

We included 234 patients with EBV-HLH, of whom 65 (27.4%) died during induction therapy. The middle observing time was 25 days. On the basis of the primary group, the multivariate Cox analysis demonstrated age &gt;18 years, blood urea nitrogen, procalcitonin &gt;2 µg/L, serum CD25, and EBV-DNA in peripheral blood mononuclear cell as the risk factors of death during induction therapy. We developed a nomogram integrating the above factors with high predictive accuracy (c-statistic, 0.86) and stratified all patients into the high-risk and the low-risk groups. On the basis of the validation group, the high-risk patients had a higher risk of death (hazard ratio, 4.93; P = 0.012). In the subgroup analysis based on patients receiving etoposide-based strategy, the mortality in high-risk and low-risk patients was 43.9 and 3.1 per 100 person-weeks, respectively.

Conclusion

We developed a nomogram for risk stratification of patients with EBV-HLH receiving induction therapy.

Secondary Hemophagocytic Lymphohistiocytosis With Epstein-Barr Virus-Associated Transformed Follicular Lymphoma: A Case Report and Literature Review

A 58-year-old male was admitted to our hospital due to lasting fever, progressive lymphadenopathy and bicytopenia, with a previously histological diagnosis of follicular lymphoma grade 3a with Epstein-Barr virus-encoded RNA positive one month ago. A second biopsy of axillary lymph node revealed concurrent diffuse large B-cell lymphoma with Epstein-Barr virus-encoded RNA positive. Another diagnosis of hemophagocytic lymphohistiocytosis secondary to Epstein-Barr virus positive diffuse large B-cell lymphoma was further concluded by clinical manifestation, laboratory test and atypical lymphocytes in peripheral-blood smear. After a pulse of steroid pre-phase treatment, the patient's clinical condition deteriorated and died in two weeks. The presence of Epstein-Barr virus infection in patients with follicular lymphoma is associated with more aggressive clinical course and increased risk of high-grade transformation. Hemophagocytic lymphohistiocytosis in response to Epstein-Barr virus infection or lymphoma remains fatal. Early diagnosis and initiation of treatment may improve the outcome.

Radiotherapy and Cytokine Storm: Risk and Mechanism

Radiotherapy (RT) shows advantages as one of the most important precise therapy strategies for cancer treatment, especially high-dose hypofractionated RT which is widely used in clinical applications due to the protection of local anatomical structure and relatively mild impairment. With the increase of single dose, ranging from 2~20 Gy, and the decrease of fractionation, the question that if there is any uniform standard of dose limits for different therapeutic regimens attracts more and more attention, and the potential adverse effects of higher dose radiation have not been elucidated. In this study, the immunological adverse responses induced by radiation, especially the cytokine storm and the underlying mechanisms such as DAMPs release, pro-inflammatory cytokine secretion and cGAS-STING pathway activation, will be elucidated, which contributes to achieving optimal hypofractionated RT regimen, improving the killing of cancer cells and avoiding the severe side effects.

Fludarabine/Melphalan 100 mg/m2 Conditioning Therapy Followed by Allogeneic Hematopoietic Cell Transplantation for Adult Patients with Secondary Hemophagocytic Lymphohistiocytosis

Our previous research indicated that a reduced-intensity conditioning regimen (fludarabine and melphalan at 100 mg/m²) was useful in allogeneic hematopoietic cell transplantation (HCT) for patients with lymphoma. This retrospective study evaluated the reduced-intensity conditioning regimen in allogeneic HCT for adult patients with hemophagocytic lymphohistiocytosis (HLH). Sixteen patients with HLH were evaluated, including 6 patients who were enrolled in a prospective clinical trial (NCT00772811) and 10 patients who received the same conditioning regimen (fludarabine at 30 mg/m²/day on days -6 to -2 and melphalan at 100 mg/m² on day -2). The median age was 42 years (range, 18 to 64), and 12 patients had Epstein-Barr virus (EBV)-associated HLH. Donors were an HLA matched sibling for 10 patients, an unrelated matched volunteer for 4 patients, and a mismatched family member for 2 patients. After excluding 3 patients who died soon after HCT, 12 patients achieved an engraftment (neutrophil median, day 12; platelet median, day 16). Five patients experienced acute graft-versus-host disease (GVHD), including 1 case of grade II and 4 cases of grades III to IV. Chronic GVHD occurred in 3 patients (moderate, 1 case; severe, 2 cases). After a median follow-up of 33.8 months 1 patient progressed, 3 patients relapsed, and 9 patients died. Five deaths were unrelated to relapse or progression and were caused by infection (n = 3), bleeding (n = 1), and GVHD (n = 1). No deaths or relapses were observed at >124 days post-transplant. The overall survival rate was 48.6%, and significant differences were observed according to pretransplant ferritin level (P = .007) and cytopenia lineage (P = .021). Before allogeneic HCT 10 of 12 patients still tested positive for EBV DNA: 6 patients tested negative for EBV DNA after HCT, 2 patients had persistent EBV DNA, and 2 patients were unassessable because of early death. Conditioning therapy using a lower dose of melphalan combined with fludarabine appears to be promising in allogeneic HCT for adults with HLH. However, strategies are needed to reduce the risk of early death.

Treatment outcomes and prognostic factors in adult patients with secondary hemophagocytic lymphohistiocytosis not associated with malignancy

Hemophagocytic lymphohistiocytosis is an overwhelming systemic inflammatory process that is life-threatening if not treated appropriately. We analyzed prognostic factors in patients with secondary hemophagocytic lymphohistiocytosis excluding malignancy. In this retrospective study, we analyzed 126 adult cases between 2001 and 2017. Treatment was based on dexamethasone with or without etoposide and cyclosporine. Patients who achieved a complete response by 4 weeks were defined as early stable responders, those who failed to achieve a complete response but showed continuous improvement until 8 weeks were defined as late responders, and those whose conditions waxed and waned until 8 weeks were defined as unstable responders. Patients with hemophagocytic lymphohistiocytosis caused by Epstein-Barr virus had a worse 5-year overall survival compared to those whose disease was secondary to autoimmune disease, other infections, or unknown causes (25.1% versus 82.4%, 78.7% and 55.5%, respectively; P<0.001). We observed that the overall response rate at 4 weeks was similar, but decreased at 8 weeks in the Epstein-Barr virus subgroup from 75.5% to 51.0%, and finally decreased to 30.6%. Multivariate analysis revealed that 8-week treatment response was the most relevant factor for overall survival. Excluding 8-week response, the presence of Epstein-Barr virus, old age, hyperferritinemia, and thrombocytopenia were associated with poor survival. We established a prognostic model with the parameters: low-risk (score 0–1), intermediate-risk (score 2), and high-risk (score ≥3). These groups had 5-year overall survival rates of 92.1%, 36.8%, and 18.0%, respectively (P<0.001). We found that 8-week treatment response was a good predictor for overall survival, and that Epstein-Barr virus, old age, thrombocytopenia, and hyperferritinemia were associated with poor survival outcomes. Physicians should take care to identify high-risk patients for appropriate treatment strategies.

A prospective quality improvement initiative in adult hemophagocytic lymphohistiocytosis to improve testing and a framework to facilitate trigger identification and mitigate hemorrhage from retrospective analysis

Hemophagocytic lymphohistiocytosis (HLH) is a highly fatal, hyperinflammatory syndrome in adults triggered by an underlying illness in most cases. As such, suspicion of HLH dictates further investigation to identify the HLH trigger and determine treatment. HLH is clinically challenging due to diverse presentations and underlying triggers, provider unfamiliarity, and bleeding complications. Clinically, we observed diagnostic error from incorrect testing and cognitive biases (interleukin-2 confused with soluble interleukin-2 receptor and natural killer cell quantification confused with functional assays).This study reports our single institutional experience with adult HLH with the aim to reduce erroneous testing with a quality improvement (QI) project, and to facilitate trigger discovery and mitigate hemorrhage. Provider education on HLH testing was the prospective intervention, followed by mistaken test removal. HLH triggers and diagnostic utility were determined by retrospective chart review. Risk factors for hemorrhage were determined by multivariable analysis.Erroneous HLH testing was reduced from 74% to 24% of patients (P < .001) by the QI intervention. These changes were projected to save $11,700 yearly. The majority (64%) of patients evaluated for HLH were on non-hematology/oncology services, highlighting the need for vigilance in hematology consultation. Sixty-three patients met classic HLH-2004 criteria for HLH. Malignancy (38%), infection (27%), Epstein-Barr virus (EBV) (14%), or autoimmune disease (8%) triggered most HLH cases. HLH triggers were most commonly identified by serologic testing (27%) and bone marrow biopsy (19%). Biopsy of other affected organs based on PET-CT imaging after unsuccessful initial diagnostic measures was helpful, and focal fluorodeoxyglucose uptake was predictive of an underlying malignancy (likelihood ratio 8.3, P = .004). Major hemorrhage occurred in 41% of patients. On multivariable analysis the odds ratios (OR) for major hemorrhage were increased for patients with intensive care unit level care (OR 10.47, P = .005), and disseminated intravascular coagulation in the first week of admission (OR 10.53, P = .04).These data are incorporated into a framework to encourage early HLH recognition with the HScore, facilitate trigger identification, identify those at risk for hemorrhage, and minimize low-yield or erroneous testing.

Macrophage Activation Syndrome

Hemophagocytic lymphohistiocytosis (HLH), or termed macrophage activation syndrome (MAS) when associated with rheumatic disorders, is a frequently fatal complication of infections, rheumatic disorders, and hematopoietic malignancies. Clinically, HLH/MAS is a life-threatening condition that is usually diagnosed among febrile hospitalized patients (children and adults) who commonly present with unremitting fever and a shock-like multiorgan dysfunction scenario. Laboratory studies reveal pancytopenia, elevated liver enzymes, elevated markers of inflammation (ESR, CRP), hyperferritinemia, and features of coagulopathy. In about 60% of cases, excess hemophagocytosis (macrophages/histiocytes engulfing other hematopoietic cell types) is noted on biopsy specimens from the bone marrow, liver, lymph nodes, and other organs. HLH/MAS has been hypothesized to occur when a threshold level of inflammation has been achieved, and genetic and environmental risk factors are believed to contribute to the hyperinflammatory state. A broad variety of infections, from viruses to fungi to bacteria, have been identified as triggers of HLH/MAS, either in isolation or in addition to an underlying inflammatory disease state. Certain infections, particularly by members of the herpesvirus family, are the most notorious triggers of HLH/MAS. Treatment for infection-triggered MAS requires therapy for both the underlying infection and dampening of the hyperactive immune response.

Combining an antiviral with rituximab in EBV-related haemophagocytic lymphohistiocytosis led to rapid viral clearance; and a comprehensive review

Epstein-Barr virus (EBV)-related haemophagocytic lymphohistiocytosis (EBVr-HLH) has a better prognosis when the virus is rapidly cleared, but the best antiviral approach is controversial. We present a patient to whom the therapeutic standard rituximab was co-administered with valacyclovir and an HLH-specific treatment with favourable viral and clinical responses. We conducted an extensive literature review and contacted several world reference centres and experts to inquire about their approaches and experience. We conclude that antivirals are infrequently used for EBVr-HLH, despite their laboratory-proven and likely clinical beneficial effect on some EBV-related diseases. However, the role of antivirals remains obscure. Concerns about their lack of efficacy are based on observational data and reports of the cellular tropism of EBV. Therefore, the adjunct use of antivirals may be considered when myelotoxicity is not the primary concern, and related outcomes should be systematically recorded to produce higher quality evidence.

Hematopoietic cell transplantation for hemophagocytic lymphohistiocytosis: recent advances and controversies

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory clinical syndrome of uncontrolled immune response which results in hypercytokinemia due to underlying primary or secondary immune defect. A number of genetic defects in transport, processing and function of cytotoxic granules which result in defective granule exocytosis and cytotoxicity of cytotoxic T lymphocytes (CTL) and natural killer (NK) cells have been well identified at the cellular and molecular level. Important advances have been made during the last 20 years in the diagnosis and treatment of HLH. The Histiocyte Society has proposed diagnostic guideline using both clinical and laboratory findings in HLH-2004 protocol, and this has been modified partly in 2009. HLH used to be a fatal disease, but the survival of HLH patients has improved to more than 60% with the use of chemoimmunotherapy combined with hematopoietic cell transplantation (HCT) over the past 2 decades. However, HCT is still the only curative option of treatment for primary HLH and refractory/relapsed HLH after proper chemoimmunotherapy. The outcome of HCT for HLH patients was also improved steadily during last decades, but HCT for HLH still carries significant mortality and morbidity. Moreover, there remain ongoing controversies in various aspects of HCT including indication of HCT, donor selection, timing of HCT, conditioning regimen, and mixed chimerism after HCT. This review summarized the important practical issues which were proven by previous studies on HCT for HLH, and tried to delineate the controversies among them.

Debate around infection-dependent hemophagocytic syndrome in paediatrics

Background

Hemophagocytic syndrome (HPS) is clinically defined as a combination of fever, liver dysfunction, coagulation abnormalities, pancytopenia, progressive macrophage proliferation throughout the reticuloendothelial system, and cytokine over-production, and may be primary or secondary to infectious, auto-immune, and tumoral diseases. The most consistent association is with viral infections but, as it is still debated whether any micro-organisms are involved in its pathogenesis, we critically appraised the literature concerning HPS and its relationship with infections.

Discussion

Infection-dependent HPS has been widely observed, but there are no data concerning its incidence in children. A better understanding of the pathophysiology of HPS may clarify the interactions between the immune system and the variously implicated potential infectious agents. Epstein-Barr virus (EBV) infection has been prominently associated with HPS, with clonal proliferation and the hyperactivation of EBV-infected T cells. However, a number of other viral, bacterial, fungal, and parasitic infections have been reported in association with HPS. In the case of low-risk HPS, corticosteroids and/or intravenous immunoglobulin or cyclosporine A may be sufficient to control the biological process, but etoposide is recommended as a means of reversing infection-dependent lymphohistiocytic dysregulation in high-risk cases.

Summary

HPS is a potential complication of various infections. A polymerase chain reaction search for infectious agents including EBV, cytomegalovirus and Leishmania is recommended in clinical settings characterised by non-remitting fever, organomegaly, cytopenia and hyperferritinemia.

Unrelated bone marrow transplantation induced long-term remission in a patient with life-threatening Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis

We present a case of life-threatening Epstein-Barr virus (EBV)-associated hemophagocytic lymphohistiocytosis (HLH) with severe hepatitis that was successfully treated by allogeneic stem cell transplantation from an unrelated donor. A 26-year-old woman was admitted to hospital with a high fever and liver dysfunction. Laboratory tests, including bone marrow aspiration, revealed severe HLH that occurred after EBV infection. High-dose methylprednisolone and etoposide therapy did not control the disease. We could control the HLH, but the EBV viremia continued following the CHOPE (cyclophosphamide, doxorubicin, vincristine, prednisone, and etoposide) chemotherapy regimen. Therefore, the patient underwent allogeneic bone marrow transplantation from an HLA-matched, unrelated donor. The patient has remained in good condition without disease recurrence for 2 years after bone marrow transplantation. Although there is no consensus regarding allogeneic stem cell transplantation for EBV-HLH, it is the treatment of choice for aggressive EBV-HLH when the patient is refractory to intensive chemotherapy.

Detection of T-cell receptor gene rearrangement in children with Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis using the BIOMED-2 multiplex polymerase chain reaction combined with GeneScan analysis

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a serious immune disorder. Epstein-Barr virus (EBV) is the most common trigger of secondary HLH. T-cell receptor (TCR) gene rearrangement is detectable in half of patients with EBV-associated HLH using Southern blotting and conventional polymerase chain reaction (PCR) analyses. However, its clinical significance is unclear. The impact of TCR gene clonality on the outcome of patients with EBV-HLH should be evaluated using more sensitive methods. In this study, we used BIOMED-2 multiplex PCR and GeneScan analysis to evaluate TCR gene rearrangement in childhood EBV-HLH.

METHODS

Six children with EBV-HLH were enrolled in this study. EBV load in blood was quantified by real-time PCR. TCR gene rearrangement was analyzed by BIOMED-2 multiplex PCR.

RESULTS

All 6 patients showed monoclonal peaks in TCRβ and/or TCRγ at diagnosis. Serial monitoring of one patient disclosed a change in the rearrangement pattern of the TCR genes in response to immunochemotherapy.

CONCLUSION

These findings suggest that BIOMED-2 multiplex PCR, a highly sensitive method for detecting T-cell clonality, is useful for predicting the therapeutic response in childhood EBV-HLH.

Viral infections associated with haemophagocytic syndrome

Haemophagocytic syndrome (HPS) or haemophagocytic lymphohistiocytosis (HLH) is a rare disease caused by a dysfunction of cytotoxic T cells and NK cells. This T cell/NK cell dysregulation causes an aberrant cytokine release, resulting in proliferation/activation of histiocytes with subsequent haemophagocytosis. Histiocytic infiltration of the reticuloendothelial system results in hepatomegaly, splenomegaly, lymphadenopathy and pancytopenia ultimately leading to multiple organ dysfunctions. Common clinical features include high fevers despite broad spectrum antimicrobials, maculopapular rash, neurological symptoms, coagulopathy and abnormal liver function tests. Haemophagocytic syndrome can be either primary, i.e. due to an underlying genetic defect or secondary, associated with malignancies, autoimmune diseases (also called macrophage activation syndrome) or infections. Infectious triggers are most commonly due to viral infections mainly of the herpes group, with EBV being the most common cause. HPS can be fatal if untreated. Early recognition of the clinical presentation and laboratory abnormalities associated with HPS and prompt initiation of treatment can be life saving. HPS triggered by viral infections generally does not respond to specific antiviral therapy but may be treated with immunosuppressive/immunomodulatory agents and, in refractory cases, with bone marrow transplantation.

Comprehensive analyses and characterization of haemophagocytic lymphohistiocytosis in Vietnamese children

Haemophagocytic lymphohistiocytosis (HLH) is a fatal haematological disorder with diverse aetiology. This prospective study was undertaken to characterize HLH cases in Vietnamese children. Clinical and laboratory data, genetic analyses and outcome of the HLH patients were analysed. A total of 33 patients were enrolled from March 2007 to December 2008, with a median age of 3 years. Mutations of the SH2D1A (SAP) and PRF1 genes were detected in one patient, respectively. The virus association was high, up to 63.6% (21/33), including Epstein-Barr virus (19/33), cytomegalovirus (2/33) and dengue virus (2/33). Five patients had malignant lymphoma and two had autoimmune diseases. Twenty-eight patients were treated according to the HLH-2004 protocol. The first response rate was 64.3% (18/28), with an early death rate of 35.7% (10/28). High levels of interferon-gamma, interleukin-10, MIG and interferon-inducible protein-10 (IP-10) were associated with early mortality (P < 0.05). Reactivation among the responders was high (9/18) and the uneventful resolution was low (3/18) after a median follow-up of 35 weeks. In conclusion, the majority of HLH cases are associated with virus infections in Vietnamese children. Familial HLH is rare. The frequent reactivation and high mortality demands a more appropriate therapeutic regimen in tropical areas like Vietnam.

Sequential transplants for respective relapse of Hodgkin disease and hemophagocytic lymphohistiocytosis: a treatment dilemma

The association of hemophagocytic lymphohistiocytosis (HLH) with Hodgkin disease (HD) seems to be uncommon. A 9-year-old boy, diagnosed with HD-HLH, received chemotherapy and remained in complete remission for 21 months. Then the patient received the first autologous transplant and unfortunately died due to multiorgan failure after the second allogeneic transplant because of sequentially respective relapse of HD and HLH. The recurrence of HLH with a high Epstein-Barr virus load but without relapse of HD in the patient suggests that Epstein-Barr virus may have a major pathogenetic role in the specific disorder HLH-HD. Detailed reports relating to HLH-HD were also reviewed.

Infection of T lymphocytes in Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis in children of non-Asian origin

BACKGROUND

Epstein-Barr virus (EBV) is one of the most frequent triggers of hemophagocytic lymphohistiocytosis (HLH). EBV-associated HLH (EBV-HLH) and ectopic infection of T cells has been particularly described in patients from Far East Asia.

PROCEDURE

In a cohort of 12 children with EBV-HLH treated in Germany, the EB viral load was detected by real-time polymerase chain reaction in plasma and peripheral blood mononuclear cells (PBMC). Virological and clinical data were analyzed retrospectively.

RESULTS

Among the 12 mainly German patients, children with underlying immunodeficiencies as well as otherwise healthy individuals were affected. The clinical course ranged from a steroid-responding to a fatal disease despite intensive treatment. Increased EBV copy numbers in plasma and/or PBMC were found in all patients. Serial measurements reflected the course of the disease. Cell-type specific viral load was determined in seven patients and revealed EBV-infection of T cells in all of them. In contrast to the reported Asian patients a significant viral load was also found in B cells.

CONCLUSIONS

T cell infection appears to be a typical feature of EBV-associated HLH irrespective of patients ethnic background and the clinical course. Evaluation of cell-type specific infection should be considered when targeted therapy is applied.

Epstein-Barr virus-induced infectious mononucleosis after two separate episodes of virus-associated hemophagocytic syndrome

A 24-year-old man, who had suffered previous two episodes of non- Epstein-Barr virus (EBV)-associated hemophagocytic syndrome (HPS) at the ages of 16 and 18, developed EBV-induced infectious mononucleosis. His antibody pattern to EBV highlighted the initial infection. The disease took a self-limited course without developing into HPS. No reactivation of EBV infection was noted over the following 6 years. The patient may have attained immune competency in adulthood, which was somehow impaired during his adolescence.

Allogeneic hematopoietic stem cell transplantation for Epstein-Barr virus-associated T/natural killer-cell lymphoproliferative disease in Japan

Epstein-Barr virus (EBV)-associated T/NK-cell lymphoproliferative disease (LPD) has been linked to several different disorders. Its prognosis is generally poor and a treatment strategy has yet to be established. There are reports, however, that hematopoietic stem cell transplantation (HSCT) can cure this disease. To clarify the current situation regarding allogeneic hematopoietic stem cell transplantation (allo-HSCT) for EBV-associated T/NK-LPD, a nationwide survey was performed in Japan. Data for 74 patients were collected. There were 42 cases of chronic active EBV infection (CAEBV), 10 cases of EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH), and 22 cases of EBV-associated lymphoma/leukemia (EBV-lymphoma/leukemia). Of those with CAEBV, 54% had the EBV-infected T-cell type and 59% with EBV-lymphoma/leukemia had the EBV-infected NK-cell type. Most patients with EBV-HLH and EBV-lymphoma/leukemia received allo-HSCT within 1 year after onset compared to only 14% of patients with CAEBV. The event-free survival (EFS) rate following allo-HSCT was 0.561 +/- 0.086 for CAEBV, 0.614 +/- 0.186 for EBV-HLH, and 0.309 +/- 0.107 for EBV-lymphoma/leukemia. The EFS of allo-HSCT with conventional conditioning was 0.488 +/- 0.074 and with reduced-intensity conditioning was 0.563 +/- 0.124. Thus, in a substantial number of cases, EBV-associated T/NK-LPD can be cured by either allogeneic conventional stem cell transplantation or reduced-intensity stem cell transplantation.

Familial hemophagocytic lymphohistiocytosis in two brothers with X-linked agammaglobulinemia

Hemophagocytic lymphohistiocytosis (HLH) is often familial and is associated with high mortality. Primary (familial) HLH is known to occur in children with mutations in perforin, Munc13-4, or syntaxin 11. We describe a case series of two brothers who developed HLH in the setting of X-linked agammaglobulinemia (XLA, Bruton's disease) and adenovirus infection. Further studies revealed absence of Bruton's tyrosine kinase (BTK) protein expression and a novel BTK mutation.

Epstein-Barr virus-induced hemophagocytic lymphohistiocytosis and X-linked lymphoproliferative disease: a mimicker of sepsis in the pediatric intensive care unit

A rare complication of infection with the Epstein-Barr virus is the development of hemophagocytic lymphohistiocytosis. Although most cases of Epstein-Barr virus-induced hemophagocytic lymphohistiocytosis develop in immunocompetent individuals, the rare immunodeficiency X-linked lymphoproliferative disease is often unmasked by Epstein-Barr virus infection and is clinically indistinguishable from Epstein-Barr virus-induced hemophagocytic lymphohistiocytosis. We describe the clinical course and management of a previously healthy 17-year-old boy who presented with hemodynamic collapse and severe systemic inflammatory response syndrome resulting from overwhelming hemophagocytosis in the setting of X-linked lymphoproliferative disease. A novel therapeutic approach using anti-tumor necrosis factor alpha therapy was instituted, aimed at attenuating the viral-induced hyperinflammatory state. Given the similarity to overwhelming sepsis, yet a substantially different therapeutic approach, this case illustrates the importance of early recognition and prompt treatment that are necessary to reduce the high morbidity and mortality associated with Epstein-Barr virus-induced hemophagocytic lymphohistiocytosis and X-linked lymphoproliferative disease.

Hemophagocytic lymphohistiocytosis: diagnosis, pathophysiology, treatment, and future perspectives

Hemophagocytic lymphohistiocytosis (HLH) is a rare life-threatening disease in which the immune system becomes overactive due to its inability to effectively respond to infections and/or shut down the immune response to such infections. The discovery of genetic defects in the secretory pathway of natural killer (NK) cells and cytotoxic T cells in some patients with this disease has raised important questions of the role of cytotoxic cells in the control of infections and in immune regulation. This review will give a brief overview of the clinical presentation and accepted treatment of HLH. Furthermore, it will give an in-depth review into the known genetic defects and current knowledge of the pathophysiology of this disorder, and will highlight recent evidence suggesting that cytotoxic defects in CD4+ T regulatory cells may contribute to the pathogenesis of HLH.

Successful treatment of Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis with HLH-94 protocol

Hemophagocytic lymphohistiocytosis (HLH) is a rare, fatal disorder of children, affecting predominantly the mononuclear phagocytic system. Previous reports indicate that Epstein-Barr virus (EBV)-associated hemophagocytic lymphohistiocytosis (EBV-HLH) can also be fatal in many cases, although the prognosis for EBV-HLH is better than for the familial form of hemophagocytic lymphohistiocytosis. We treated four patients with EBV-HLH using immunochemotherapy including steroid, etoposide (VP-16), and cyclosporin, according to the HLH-94 protocol. All patients experienced persistent fever, cytopenia, and hypertriglyceridemia. Serological testing for EBV showed reactivated EBV infections in all patients. EBV DNA detected by PCR and EBV-encoded small RNA measured by in situ hybridization were confirmed in the patients' bone marrow specimens. Hemophagocytosis was shown in bone marrow aspirates and liver biopsy specimen. Complete remission was achieved in all patients after induction and continuation therapy for 4-10 months (median, 7 months) and was maintained for 15-27 months (median, 19 months) without the need for bone marrow transplantation. These results suggest that EBV-HLH can be effectively controlled by immunochemotherapy using the HLH-94 protocol.

Effective anti-viral therapy for hemophagocytic syndrome associated with B-cell lymphoma

A rheumatoid arthritis (RA) patient treated with low-dose methotrexate (MTX) therapy suffered from hemophagocytic syndrome (HPS) associated with B-cell lymphoma (B-LAHS). Administration of acyclovir and intravenous immunoglobulin promptly resolved laboratory test abnormalities accompanied with HPS. Moreover, hemophagocytic histiocytes and lymphoma cells in the bone marrow disappeared without anti-cancer therapy. Two months after reintroduction of MTX for RA flare, lymphoma re-grew rapidly without bone marrow involvement and HPS. Two cycles of combination chemotherapy induced the lymphoma to a complete remission/unconfirmed (CRu), but then the chemotherapy was discontinued due to severe side effects. In this case, on the basis of RA and MTX induced immunosuppressive state, Epstein-Barr virus (EBV) infection was associated with the development of HPS and lymphoma. Anti-viral therapy alone was effective against HPS and lymphoma at initial presentation and improved her general condition. This case indicates that anti-cancer therapy should be preceded by anti-viral therapy and withdrawal of immunosuppressive therapy in patients under immunosuppressive therapy, as long as the clinical situation permits.

Coronavirus neurovirulence correlates with the ability of the virus to induce proinflammatory cytokine signals from astrocytes and microglia

The molecular and cellular basis of coronavirus neurovirulence is poorly understood. Since neurovirulence may be determined at the early stages of infection of the central nervous system (CNS), we hypothesize that it may depend on the ability of the virus to induce proinflammatory signals from brain cells for the recruitment of blood-derived inflammatory cells. To test this hypothesis, we studied the interaction between coronaviruses (mouse hepatitis virus) of different neurovirulences with primary cell cultures of brain immune cells (astrocytes and microglia) and mouse tissues. We found that the level of neurovirulence of the virus correlates with its differential ability to induce proinflammatory cytokines (interleukin 12 [IL-12] p40, tumor necrosis factor alpha, IL-6, IL-15, and IL-1beta) in astrocytes and microglia and in mouse brains and spinal cords. These findings suggest that coronavirus neurovirulence may depend on a novel discriminatory ability of astrocytes and microglia to induce a proinflammatory response in the CNS.

Hodgkin's lymphoma, Epstein-Barr virus reactivation and fatal haemophagocytic syndrome

Haemophagocytic syndrome is a serious disorder, often related to Epstein-Barr virus (EBV) or other infectious agents. Frequently an underlying immune abnormality or a T-cell lymphoma is present. The combination of haemophagocytosis and Hodgkin's lymphoma seems to be rare. A 70-year-old female with rheumatoid arthritis was admitted with constitutional symptoms, persistent fever, pancytopenia, deranged liver enzymes, lymphadenopathy and splenomegaly. A fatal coagulopathy supervened. The clinical picture and the bone marrow findings indicated a haemophagocytic syndrome and a lymph node biopsy disclosed an EBV-positive Hodgkin's lymphoma. EBV serology pointed at viral reactivation and a high EBV DNA content was detected in serum by real-time quantitative PCR analysis (5.5 x 10(6) copies per mL). The case history is presented and the literature is reviewed.

Treatment of Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) in young adults: a report from the HLH study center

BACKGROUND

Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH), also known as EBV-associated hemophagocytic syndrome, develops mostly in children and young adults and may be fatal. Early etoposide treatment has been confirmed to be effective in children. However, it is unclear whether the same treatment is useful in adults.

PROCEDURE

To assess whether etoposide is effective in treating young adult cases, we retrospectively studied the therapeutic measures taken and outcomes in 20 young adult cases of EBV-HLH. Eleven cases were registered in our HLH study center in Kyoto and nine derived from the literature. The patients were between 17 and 33 years old and eight were males. The influence of gender, cell lineage (T- or natural killer-), EBV serology pattern, jaundice and treatment on the outcome was assessed.

RESULTS AND CONCLUSIONS

Patients receiving etoposide within four weeks after diagnosis had a good prognosis as five of the seven patients survived compared to one of 13 not treated with etoposide or treated late (chi-square test for survival, P = 0.0095). The Kaplan-Meier analysis showed the 2.5-year survival of 85.7 +/- 13.2% in the early etoposide-treated patients, compared to 10.3 +/- 9.4% in the remaining patients (log-rank test, P = 0.0141). Thus, early etoposide treatment is effective in treating EBV-HLH in young adults as well as in children.

Characteristic perforin gene mutations of haemophagocytic lymphohistiocytosis patients in Japan

Perforin gene (PRF1) mutations appear to occur in about 30% of patients with haemophagocytic lymphohistiocytosis (HLH). We tested perforin expression and gene mutations in 14 HLH patients and six patients with Epstein-Barr virus-associated HLH (EBV-HLH) in Japan. Five of the 14 HLH patients had perforin abnormalities. The presence of PRF1 genetic abnormality correlated well with the lack of perforin expression as determined by flow cytometry. Sequencing showed that four patients had a compound heterozygous mutation while the fifth patient had a homozygous mutation. Three of the mutations we detected were novel. In contrast, none of the six EBV-HLH patients showed perforin abnormalities. Our data, combined with the PRF1 mutations in three previously reported Japanese patients, suggest that the 1090-1091delCT and 207delC mutations of the perforin gene are frequently present in Japanese HLH patients (62.5% and 37.5% respectively). Examination of the geographical origins of the ancestors in the perforin-mutant HLH patients revealed that they mostly came from the Western part of Japan, suggesting that the present-day cases may largely derive from a common ancestor.

Clinical features and treatment strategies of Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis

Epstein-Barr virus (EBV) is the major triggering factor producing hemophagocytic syndrome or hemophagocytic lymphohistiocytosis (HLH). In this review, diagnostic problems, clinical and histopathological features, and treatment strategies of EBV-HLH have been described. In patients with EBV-HLH, the EBV-infected T cells or natural killer (NK) cells are mostly mono- or oligo-clonally proliferating, where hypercytokinemia plays a major role and causes hemophagocytosis, cellular damage and dysfunction of various organs. Although the majority of EBV-HLH cases develop in apparently immunocompetent children and adolescents, it also occurs in association with infectious mononucleosis, chronic active EBV infection, familial HLH, X-linked lymphoproliferative disease, lymphoproliferative disease like peripheral T-cell lymphoma and NK cell leukemia. In terms of treatment, special therapeutic measures are required to control the cytokine storm generated by EBV and to suppress proliferating EBV-genome-containing cells, because the clinical courses are often fulminant and result in a poor outcome.

Low natural killer activity and central nervous system disease as a high-risk prognostic indicator in young patients with hemophagocytic lymphohistiocytosis

BACKGROUND

Familial hemophagocytic lymphohistiocytosis HLH (FHL) is fatal, unless patients are rescued with hematopoietic stem cell transplantation (SCT). Although the molecular identification of FHL now is possible at least in part from perforin gene study, many cases escape detection or never are tested due to the lack of specific hallmarks, making diagnosis difficult. To the authors' knowledge, it remains to be determined whether persistently low natural killer cell (NK) activity and a high incidence of central nervous system (CNS) disease increase the probability of FHL.

METHODS

The authors analyzed 42 HLH patients age < 2 years, 13 of whom developed overt CNS disease and 5 of whom demonstrated persistently deficient NK activity (Group 1). The remaining 24 patients had no CNS disease and had NK activity of moderate decrease to within the normal range (Group 2).

RESULTS

In Group 1, CNS symptoms were detected in 6 cases within 1 month and between 4.5-9 months in 6 other patients. In these cases, spotty lesions demonstrating a high T2 signal in the white matter were noted on brain magnetic resonance imaging. The survival was significantly poor for patients in Group 1 unless they were rescued with SCT, which was performed in 5 of the 13 patients with CNS disease and in all 5 patients with persistent NK activity deficiency. SCT was successful in 9 patients, with no CNS sequelae reported after the transplantation. Conversely, the prognosis of the 24 patients in Group 2 was better and only 1 patient required SCT.

CONCLUSIONS

Very young HLH patients (age < 2 years) who are at high risk of fatal FHL with persistently deficient NK activity and/or overt CNS disease require appropriate SCT to reverse CNS disease and achieve a complete cure.

Risk of etoposide-related acute myeloid leukemia in the treatment of Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis

We studied the impact of etoposide on the prognosis of 81 patients (77 of whom were children <15 years old) with Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH). The study group received a median cumulative dose of 1,500 mg/m2 etoposide (range, 0-14,550 mg/m2), with a median follow-up period of 44 months (range, 20-88 months) from the diagnosis. Only 1 patient, who received 3150 mg/m2 etoposide, developed therapy-related acute myeloid leukemia (t-AML), at 31 months after diagnosis. Excluding 9 patients who underwent hemopoietic stem cell transplantation during the course of treatment, the prognosis was poorer for those patients who received less than a 1,000 mg/m2 cumulative dose of etoposide. Our results indicate that the risk of etoposide-related t-AML is low. An appropriate dosage of etoposide for the treatment of EBV-HLH would be in the range of 1,000 to 3,000 mg/m2. However, even at these doses, care must be taken to prevent the rare risk of t-AML.

Quantitative analysis of cell-free Epstein-Barr virus genome copy number in patients with EBV-associated hemophagocytic lymphohistiocytosis

To determine whether the EBV genome content in serum or plasma reflects clinical features and outcome in EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH), we quantified the cell-free EBV genome copy number by real-time PCR in 38 patients with EBV-HLH, and compared this to the values from 15 patients with infectious mononucleosis (IM). The median (range) cell-free EBV genome copy number at diagnosis was 3.0 x 10(3) (undetectable -5.5 x 10(7)) copies/ml in EBV-HLH, which was significantly higher than the 6.6 x 10(1) (undetectable -1.0 x 10(3)) copies/ml in IM (P = 0.0008). We serially analyzed cell-free EBV genome copy number in 10 cases of EBV-HLH up to 4 months from diagnosis. In four patients who achieved remission, the EBV genome became undetectable soon after starting therapy. In the remaining six patients who responded poorly to therapy, the EBV genome copy number in the serum or plasma remained at high levels except for one case. In addition, we confirmed that the EBV genome became undetectable after hematopoietic stem cell transplantation in 4 EBV-HLH cases. These results suggest that the quantitative analysis of cell-free EBV genome copy number is useful for evaluating disease activity and for predicting the response to therapy in EBV-HLH.

A clinical analysis of 52 adult patients with hemophagocytic syndrome: the prognostic significance of the underlying diseases

We retrospectively analyzed 52 adult patients with hemophagocytic syndrome (HPS). The underlying diseases were heterogeneous, including malignant lymphoma (lymphoma-associated hemophagocytic syndrome [LAHS]) in 26 patients, systemic lupus erythematosus in 3 patients, viral infections in 7 patients, and bacteria] or fungal infections in 6 patients. More than 83% of patients received prednisolone as an initial treatment. Multiple-agent chemotherapies (cyclophosphamide, doxorubicin, and vincristine) were administered to 96% of LAHS patients after a histopathological diagnosis of lymphoma. HPSs were controllable and remissions were achieved except for those patients with LAHS, fulminant Epstein-Barr virus-associated HPS, and an immunosuppressive state. Twenty-one (81%) of the LAHS patients had uncontrollable HPS and died of multiple organ failure and disseminated intravascular coagulation. The median survival time of LAHS patients was 83 days. In contrast, 3 (12%) of the other HPS patients died of multiple organ failure within 44 days.The clinical manifestations and the laboratory findings of LAHS and the other HPSs were too variable to establish the prognosis based only on the findings at the onset of HPS. The prognostic factors of adult HPS were found to be the underlying diseases, notably malignant lymphoma and infections, accompanied by the immunosuppressive state.

Requirement for etoposide in the treatment of Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis

PURPOSE

We sought to identify the clinical variables most critical to successful treatment of Epstein-Barr virus (EBV)-associated hemophagocytic lymphohistiocytosis (HLH).

PATIENTS AND METHODS

Among the factors tested were age at diagnosis (< 2 years or > or = 2 years), time from diagnosis to initiation of treatment with or without etoposide-containing regimens, timing of cyclosporin A (CSA) administration during induction therapy, and the presence or absence of etoposide.

RESULTS

By Kaplan-Meier analysis, the overall survival rate for the entire cohort of 47 patients, most of whom had moderately severe to severe disease, was 78.3% +/- 6.7% (SE) at 4 years. The probability of long-term survival was significantly higher when etoposide treatment was begun less than 4 weeks from diagnosis (90.2% +/- 6.9% v 56.5% +/- 12.6% for patients receiving this agent later or not at all; P <.01, log-rank test). Multivariate analysis with the Cox proportional hazards model demonstrated the independent prognostic significance of a short interval from EBV-HLH diagnosis to etoposide administration (relative risk of death for patients lacking this feature, 14.1; 95% confidence interval, 1.16 to 166.7; P =.04). None of the competing variables analyzed had significant predictive strength in the Cox model. However, concomitant use of CSA with etoposide in a subset of patients appears to have prevented serious complications from neutropenia during the first year of treatment.

CONCLUSION

We conclude that early administration of etoposide, preferably with CSA, is the treatment of choice for patients with EBV-HLH.