Fulminant childhood hemophagocytic syndrome mimicking histiocytic medullary reticulosis. An atypical form of Epstein-Barr virus infection

[A case of Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis in an elderly woman]

An 84-year-old woman who had diabetes mellitus and atrial fibrillation presented to our hospital with appetite loss and difficulty in standing up. Her cervical, axillary, and mediastinal lymph nodes were swollen. At first, malignant lymphoma was suspected, but positron emission tomography-computed tomography and cervical lymph node biopsy did not support this diagnosis. She was admitted to our hospital 41 days after the first consultation because of appetite loss and fever. We suspected a disorder related to Epstein-Barr virus infection because Epstein-Barr virus-encoded small RNAs were found in the lymph node. She was diagnosed with Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) based on the diagnostic criteria of the Japanese Society for Pediatric Infectious Diseases. Her symptoms, including appetite loss and fever, were alleviated after the administration of prednisolone (20 mg per day). She was discharged 90 days after admission. At two weeks after discharge, she was readmitted for respiratory failure, and died five days after readmission.To the best of our knowledge there are no previous reports of EBV-HLH in patients over 80 years of age, and the optimal treatment strategy is unknown. This case suggested that prednisolone may alleviate the symptoms of EBV-HLH. When a patient presents with swollen lymph nodes, clinicians should keep the possibility of EBV-HLH in mind.

Epstein-Barr virus NK and T cell lymphoproliferative disease: report of a 2018 international meeting

Epstein-Barr virus (EBV) normally infects B cells, but in some persons the virus infects T or NK cells. Infection of B cells can result in infectious mononucleosis, and the virus is associated with several B cell malignancies including Hodgkin lymphoma, Burkitt lymphoma, and diffuse large B cell lymphoma. Infection of T or NK cells with EBV is associated with extranodal NK/T cell lymphoma, aggressive NK-cell leukemia, systemic EBV-associated T-cell lymphoma, and chronic active EBV disease, which in some cases can include hydroa vacciniforme-like lymphoproliferative disease and severe mosquito bite allergy. While NK and T cell lymphoproliferative disease is more common in Asia and Latin America, increasing numbers of cases are being reported from the United States and Europe. This review focuses on classification, clinical findings, pathogenesis, and recent genetic advances in NK and T cell lymphoproliferative diseases associated with EBV.

EBV-Positive Lymphoproliferations of B- T- and NK-Cell Derivation in Non-Immunocompromised Hosts

The contribution of Epstein-Barr virus (EBV) to the development of specific types of benign lymphoproliferations and malignant lymphomas has been extensively studied since the discovery of the virus over the last 50 years. The importance and better understanding of the EBV-associated lymphoproliferative disorders (LPD) of B, T or natural killer (NK) cell type has resulted in the recognition of new entities like EBV+ mucocutaneous ulcer or the addition of chronic active EBV (CAEBV) infection in the revised 2016 World Health Organization (WHO) lymphoma classification. In this article, we review the definitions, morphology, pathogenesis, and evolving concepts of the various EBV-associated disorders including EBV+ diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS), EBV+ mucocutaneous ulcer, DLBCL associated with chronic inflammation, fibrin-associated DLBCL, lymphomatoid granulomatosis, the EBV+ T and NK-cell LPD of childhood, aggressive NK leukaemia, extranodal NK/T-cell lymphoma, nasal type, and the new provisional entity of primary EBV+ nodal T- or NK-cell lymphoma. The current knowledge regarding the pathogenesis of B-cell lymphomas that can be EBV-associated including Burkitt lymphoma, plasmablastic lymphoma and classic Hodgkin lymphoma will be also explored.

Epstein-Barr virus-associated T/natural killer-cell lymphoproliferative disorders

Primary infection with Epstein-Barr virus (EBV) is usually asymptomatic and, in a normal host, EBV remains latent in B cells after primary infection for the remainder of life. Uncommonly, EBV can infect T or natural killer (NK) cells in a person with a defect in innate immunity, and EBV infection can cause unique systemic lymphoproliferative diseases (LPD) of childhood. Primary infection in young children can be complicated by hemophagocytic lymphohistiocytosis or fulminant systemic T-cell LPD of childhood. Uncommonly, patients can develop chronic active EBV (CAEBV) disease-type T/NK LPD, which includes CAEBV infection of the systemic form, hydroa vacciniforme-like T-cell LPD, and mosquito-bite hypersensitivity. The clinical course of CAEBV disease-type T/NK LPD can be smoldering, persistent or progressive, depending on the balance between viral factors and host immunity. Aggressive NK-cell leukemia, hydroa vacciniforme-like T-cell lymphoma, or uncommonly extranodal NK/T-cell lymphoma can develop in children and young adults with CAEBV disease-type T/NK-cell LPD. Extranodal T/NK-cell lymphoma is a disease of adults, and its incidence begins to increase in the third decade and comprises the major subtype of T/NK LPD throughout life. Aggressive NK-cell leukemia and nodal T/NK-cell lymphoma of the elderly are fulminant diseases, and immune senescence may be an important pathogenetic factor. This review describes the current progress in identifying different types of EBV-associated T/NK-cell LPD and includes a brief presentation of data from Korea.

Epstein-Barr virus-positive T/NK-cell lymphoproliferative disorders

Epstein–Barr virus, a ubiquitous human herpesvirus, can induce both lytic and latent infections that result in a variety of human diseases, including lymphoproliferative disorders. The oncogenic potential of Epstein–Barr virus is related to its ability to infect and transform B lymphocytes into continuously proliferating lymphoblastoid cells. However, Epstein–Barr virus has also been implicated in the development of T/natural killer cell lymphoproliferative diseases. Epstein–Barr virus encodes a series of products that mimic several growth, transcription and anti-apoptotic factors, thus usurping control of pathways that regulate diverse homeostatic cellular functions and the microenvironment. However, the exact mechanism by which Epstein–Barr virus promotes oncogenesis and inflammatory lesion development remains unclear. Epstein–Barr virus-associated T/natural killer cell lymphoproliferative diseases often have overlapping clinical symptoms as well as histologic and immunophenotypic features because both lymphoid cell types derive from a common precursor. Accurate classification of Epstein–Barr virus-associated T/natural killer cell lymphoproliferative diseases is a prerequisite for appropriate clinical management. Currently, the treatment of most T/natural killer cell lymphoproliferative diseases is less than satisfactory. Novel and targeted therapies are strongly required to satisfy clinical demands. This review describes our current knowledge of the genetics, oncogenesis, biology, diagnosis and treatment of Epstein–Barr virus-associated T/natural killer cell lymphoproliferative diseases.

Co-infections, inflammation and oncogenesis: future directions for EBV research

Epstein-Barr virus (EBV) is aetiologically linked to a wide range of human tumours. Some arise as accidents of the virus' lifestyle in its natural niche, the B lymphoid system; these include B-lymphoproliferative disease of the immunocompromised, Hodgkin Lymphoma, Burkitt Lymphoma and particular forms of diffuse large B cell lymphoma. Interestingly, HIV infection increases the incidence of each of these B cell malignancies, though by different degrees and for different reasons. Other EBV-associated tumours arise through rare viral entry into unnatural target tissues; these include all cases of nasal T/NK cell lymphoma and of undifferentiated nasopharyngeal carcinoma plus a small but significant subset of gastric carcinomas, a tumour type more generally associated with chronic Helicobacter pylori infection. Understanding EBV's involvement in the pathogenesis of these different malignancies is an important long-term goal. This article focuses on two overlapping, but relatively neglected, areas of research that could contribute to that goal. The first addresses the mechanisms whereby coincident infections with other pathogens increase the risk of EBV-positive malignancies, and takes as its paradigm the actions of holoendemic malaria and HIV infections as co-factors in Burkitt lymphomagenesis. The second widens the argument to include both infectious and non-infectious sources of chronic inflammation in the pathogenesis of EBV-positive tumours such as T/NK cell lymphoma, nasopharyngeal carcinoma and gastric carcinoma.

Hemophagocytic lymphohistiocytosis: an update on diagnosis and pathogenesis

Hemophagocytic lymphohistiocytosis (HLH) is a frequently fatal and likely underdiagnosed disease involving a final common pathway of hypercytokinemia, which can result in end-organ damage and death. Although an early diagnosis is crucial to decrease mortality, the definitive diagnosis is often challenging because of the lack of specificity of currently accepted diagnostic criteria and the absence of confirmatory gold standards. Because of the wide range of laboratory assays involved in the diagnosis of HLH, practicing pathologists from a broad spectrum of clinical specialties need to be aware of the disease so that they may appropriately flag results and convey them to their clinical counterparts. Our article summarizes these new advances in the diagnosis of HLH and includes a review of clinical findings, updated understanding of the pathogenesis, and promising new testing methods.

EBV-Positive T/NK-Cell Lymphoproliferative Disease of Childhood

Background

Epstein-Barr virus (EBV)-associated hemophagocytic lymphohistiocytosis (HLH), EBV-positive systemic T-cell lymphoproliferative disease (STLPD) of childhood, and chronic active EBV (CAEBV) infection may develop after primary EBV infection. This study reviewed the clinicopathological spectrum of EBV-associated T- and natural killer (NK)-cell LPD, including STLPD and CAEBV infection, with an analysis of T-cell clonality.

Methods

Clinicopathological features of seven patients with EBV-associated HLH or STLPD and 12 patients with CAEBV infection were reviewed. Immunohistochemical staining and a T-cell receptor (TCR) gene rearrangement study were performed.

Results

STLPD and EBV-positive HLH showed significantly overlapping clinicopathological findings. One patient with STLPD and one patient with EBV-positive HLH demonstrated moderate to severe atypia of the infiltrating lymphocytes, whereas the remaining patients lacked significant atypia. Twelve patients had CAEBV infection, four of whom suffered mosquito-bite hypersensitivity, five showed NK lymphocytosis, and one suffered hydroa vacciniforme. Infiltrating lymphocytes were predominantly small and devoid of atypia. Hemophagocytic histiocytosis was found in seven of 11 patients. Monoclonality was detected in three (50%) of the six patients with successful TCR gene analysis.

Conclusions

EBV-positive HLH and STLPD share similar clinicopathological findings and may constitute a continuous spectrum of acute EBV-associated T- or NK-cell proliferative disorders. The distinction of EBV-positive T-cell LPD from EBV-positive HLH may be difficult during routine diagnoses because of the technical limitations of clonality assessment.

Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis in Los Angeles County

Data on Epstein-Barr virus-related hemophagocytic lymphohistiocytosis (EBV-HLH) in adults in the United States remain very limited. A cluster of four cases of EBV-HLH was observed in a 4-month period at a tertiary center in Los Angeles County (LA County) and the clinical and molecular characteristics identified in these cases are being described. EBV typing, immunophenotypic and molecular genetic studies were performed. Diagnostic criteria that may be used to identify EBV as a cause of HLH in adults are also being suggested. Finally, the crude incidence rate for HLH in LA County was determined and was compared to the worldwide crude incidence rate for HLH. The cases each occurred in young male adult residents of California and were associated with evidence of EBV reactivation and ferritin levels of >20,000 µg/L. A higher rate of cases of EBV-HLH in 2010 was found at UCLA Medical Center than for 2007-2009 (4.9/10,000 hospital discharges vs. 0.14/10,000 hospital discharges, respectively; P = 0.0017). The cases were associated with EBV type 1, and the insertion of the codon CTC (leucine) was found in numerous of the EBNA-2 gene sequences. The annual incidence of secondary, non-familial HLH was estimated to be 0.9 cases per million persons >15 years of age in LA County. Although EBV-HLH is a rare disease, the incidence in adults in Western countries may be underestimated.

Clinical aspects, immunologic assessment, and genetic analysis in Taiwanese children with hemophagocytic lymphohistiocytosis

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening syndrome characterized by immune disturbance associated with certain genetic defects. This study aimed to define the clinical spectrum, immunology, and candidate genes in HLH in Taiwanese patients.

PATIENTS AND METHODS

The medical records of children who met the updated diagnostic criteria and had confirmed hemophagocytosis by bone marrow aspiration between 1992 and 2007 were retrospectively evaluated. The clinical course and prognosis were analyzed. Quantitative immunoglobulin, lymphocyte subsets, cytotoxicity to K562 cells, intracellular natural killer perforin expression, and candidate genes including SH2D1A, PFR1, Mun13-4, and STX11 genes were also investigated.

RESULTS

Thirty-two patients (16 male) were evaluated during the 15-year period. The underlying diseases were acute lymphoblastic leukemia, systemic lupus erythematosus, natural killer malignancy, juvenile idiopathic arthritis, and Chediak-Higashi syndrome. Epstein-Barr virus (EBV)-associated HLH was present in 12 patients, 6 of whom died, while 12 of 20 non-EBV-associated patients died despite aggressive polychemotherapy. Extreme immunoglobulin values occurred in 3 fatal cases. There was decreasing percentage of CD4, CD1656, and B-memory cells and increasing CD8, activated lymphocyte, and T-memory cells among the patients. Cytotoxicity in 14 patients and intracellular perforin expression in 13 were diminished but restored to borderline normal range during the convalescent stage. None of the mutations of SH2D1A, PFR1, Mun13-4, and STX11 genes were found.

CONCLUSIONS

In the treatment of Taiwanese HLH patients, aggressive chemotherapy in EBV-associated patients and stem cell transplantation in non-EBV-associated patients are recommended to improve survival. Individualized immune dysregulation instead of the well-known candidate genetic mutations can explain the genetic variation in our cohort.

Proposed categorization of pathological states of EBV-associated T/natural killer-cell lymphoproliferative disorder (LPD) in children and young adults: overlap with chronic active EBV infection and infantile fulminant EBV T-LPD

EBV-associated T/natural killer (NK)-cell lymphoproliferative disorder (EBV-T/NK LPD) of children and young adults is generally referred to with the blanket nosological term of severe chronic active EBV infection (CAEBV). This disease is rare, associated with high morbidity and mortality, and appears to be more prevalent in East Asian countries. But because there is no grading or categorization system for CAEBV, pathologists and clinicians often disagree regarding diagnosis and therapy. EBV-T/NK LPD includes polyclonal, oligoclonal, and monoclonal proliferation of cytotoxic T and/or NK cells. Moreover, a unique disease previously described as infantile fulminant EBV-associated T-LPD has been identified and overlaps with EBV-T/NK LPD. In the present review a clinicopathological categorization of EBV-T/NK LPD is proposed, based on pathological evaluation and molecular data, as follows: (i) category A1, polymorphic LPD without clonal proliferation of EBV-infected cells; (ii) category A2, polymorphic LPD with clonality; (iii) category A3, monomorphic LPD (T-cell or NK cell lymphoma/leukemia) with clonality; and (iv) category B, monomorphic LPD (T-cell lymphoma) with clonality and fulminant course. Categories A1, A2, and A3 possibly constitute a continuous spectrum and together are equivalent to CAEBV. Category B is the exact equivalent of infantile fulminant EBV-associated T-LPD. It is expected that this categorization system will provide a guide for the better understanding of this disorder. This proposal was approved at the third meeting of the Asian Hematopathology Association (Nagoya, 2006).

Enterovirus-associated hemophagocytic syndrome in children with malignancy: report of three cases and review of the literature

Enteroviruses can cause severe manifestations in children with malignancy. Infection-associated hemophagocytic syndrome (IAHS) due to enterovirus is a rare entity in children. Patients with malignancy and IAHS due to enterovirus were retrospectively evaluated at the University of Athens' Hematology-Oncology pediatric unit within a 6-year period (2000-2006). IAHS occurred in three cases among 56 patients with documented enteroviral infection. The diagnosis of IAHS was confirmed by bone marrow aspiration and biopsy. Nested reverse transcriptase-polymerase chain reaction (RT-PCR), sequencing of the amplified alleles, and immunohistochemistry were performed to document the presence of enterovirus. The type of enterovirus was specified by indirect immunofluorescence assay. At the early phase of the disease, patients presented mild, non-specific viral symptoms, persistent unexplained fever, and pancytopenia. At the late phase, patients had more severe manifestations, such as persistent high fever, diarrhea, weight loss, hepatosplenomegaly, and hepatic dysfunction. The therapeutic approach consisted of supportive care, administration of immunoglobulin (400 mg/kg or 2 g/kg), and pleconaril. All patients had fatal outcome; two patients succumbed to multiorgan failure (MOF), while one patient succumbed to ventricular fibrillation. IAHS usually has fulminant course and leads to severe and life-threatening complications, such as liver failure and MOF. IAHS should always be included in the differential diagnosis of viral syndrome or unexplained fever. The therapeutic approach for IAHS should be administered as early as possible, before the progression to irreversible tissue damage. Early therapeutic intervention involving high doses of immunoglobulin might be beneficial for the patient's outcome.

Pathogenesis and mechanism of disease progression from hemophagocytic lymphohistiocytosis to Epstein-Barr virus-associated T-cell lymphoma: nuclear factor-kappa B pathway as a potential therapeutic target

Epstein-Barr virus (EBV) can infect T lymphocytes and manifests as hemophagocytic lymphohistiocytosis (HLH), a distinct entity of hemophagocytic syndrome (HPS) characterized by fever, hepatosplenomegaly, cytopenia, hypercytokinemia, and systemic macrophage activation with hemophagocytosis. In a substantial percentage of HLH patients, the disease may relapse or progress to T-cell lymphoma in months to years. In the present review, the authors summarize the previous studies on the pathogenesis of HLH and the potential mechanism for the progression of disease from HLH to T-cell lymphoma. The infection of T cells by EBV could activate T cells to secrete proinflammatory cytokines, particularly tumor necrosis factor-alpha (TNF-alpha), which subsequently activate macrophages. EBV latent membrane protein-1 (LMP-1) is the viral product responsible for the activation of the TNF receptor (TNFR) associated factors/nuclear factor-kappaB (NF-kappaB)/ERK pathway to enhance cytokine secretion mediated through the suppression of the SAP/SH2D1A gene. The activation of NF-kappaB will confer resistance to TNF-alpha-induced apoptosis on EBV-infected T cells through the down-regulation of TNFR-1. Consistent with in vitro observations, EBV-associated T or natural killer/T-cell lymphoma showed constitutive activation of NF-kappaB, explaining its drug resistance, hypercytokinemia, and poor prognosis. Therefore, similar to other inflammation-associated cancers, HLH provides a unique model to study the mechanism of disease progression from a benign virus-infected disorder (HLH) to T-cell lymphoma. Inhibition of the NF-kappaB signal pathway should provide a potential target for the treatment of HLH and EBV-associated T-cell lymphoma.

Emergence of anti-red blood cell antibodies triggers red cell phagocytosis by activated macrophages in a rabbit model of Epstein-Barr virus-associated hemophagocytic syndrome

Hemophagocytic syndrome (HPS) is a fatal complication frequently associated with viral infections. In childhood HPS, Epstein-Barr virus (EBV) is the major causative agent, and red blood cells (RBCs) are predominantly phagocytosed by macrophages. To investigate the mechanism of RBC phagocytosis triggered by EBV infection, we adopted a rabbit model of EBV-associated HPS previously established by using Herpesvirus papio (HVP). The kinetics of virus-host interaction was studied. Using flow cytometry, we detected the emergence of antibody-coated RBCs, as well as anti-platelet antibodies, at peak virus load period at weeks 3 to 4 after HVP injection, and the titers increased thereafter. The presence of anti-RBCs preceded RBC phagocytosis in tissues and predicted the full-blown development of HPS. The anti-RBC antibodies showed cross-reactivity with Paul-Bunnell heterophile antibodies. Preabsorption of the HVP-infected serum with control RBCs removed the majority of anti-RBC activities and remarkably reduced RBC phagocytosis. The RBC phagocytosis was specifically mediated via an Fc fragment of antibodies in the presence of macrophage activation. Therefore, the emergence of anti-RBC antibodies and the presence of macrophage activation are both essential in the development of HPS. Our observations in this animal model provide a potential mechanism for hemophagocytosis in EBV infection.

Macrophage activation syndrome: an autopsy case of sudden death

In a context of viral gastroenteritis, we report an unusual case of sudden death in an 8-year-old child. The only macroscopic abnormality observed in the autopsy was a diffuse mesenteric adenitis. Organ samples were taken for histopathological examination and a diffuse lymphocytic infiltration was observed. A sinusoidal histiocytic hyperplasia was found in the lymph nodes. Microscopic examination of the lungs and the lymph nodes revealed haemophagocytic lesions (lymphocytes within the cytoplasm of histiocytic macrophages). Immunohistochemical studies demonstrated that the histiocytes were CD68+ PS100- CD1A-. Following this microscopic examination macrophage activation or haemophagocytic syndrome was diagnosed. The syndrome is a distinct clinical entity characterised by fever, pancytopaenia, splenomegaly, and haemophagocytosis in the bone marrow, liver and lymph nodes. It is a clinical entity that is very difficult to diagnose due to the lack of specific clinical signs. It is generally a complication of an infectious process, an aggravation of an auto-immune disease or a complication of a neoplastic process. The physiopathology involves a disregulation of T lymphocytes and particularly T helper lymphocytes. To make this diagnosis the anatomopathological examination must be performed by an experienced practitioner. The presence of a lymphocyte infiltrate of macrophagic histiocytes in myeloid organs and especially positive CD68+ immune markers are the anatomopathological proofs of diagnosis. The autopsy examination must be carefully performed and include systematic sample harvesting for anatomopathological examination. The results of all these examinations taken together allow the diagnosis of haemophagocytic syndrome to be finally made.

Fetal and neonatal histiocytoses

PURPOSE

The histiocytoses are a group of disorders of the monophagocytic system having a variety of clinical and pathological findings. They occur less often during the perinatal period than later in life. Their biologic behavior, response to therapy, and histologic types are not the same.

METHODS

The study consisted of 221 fetuses and neonates collected from the literature and from personal files.

RESULTS

Langerhans' cell histiocytosis (LCH), the hemophagocytic lymphohistiocytoses (HLH), and juvenile xanthogranuloma (JXG), in order of rank, were the main histiocytoses occurring in the perinatal period. HLH accounted for the highest mortality (74%) followed by disseminated LCH (52%) and JXG (11%). All neonates with LCH and JXG limited to the skin and/or subcutaneous tissue survived with or without treatment.

CONCLUSIONS

This study suggests that there is an increased incidence of spontaneous regression of certain histiocytic lesions in neonates as compared to older individuals. Cutaneous forms JXG and LCH had the highest incidence of regression followed by infection associated HLH.

Epstein-Barr virus LMP1 inhibits the expression of SAP gene and upregulates Th1 cytokines in the pathogenesis of hemophagocytic syndrome

The primary infection of Epstein-Barr virus (EBV) may result in fatal infectious mononucleosis or hemophagocytic syndrome (HPS) in 2 diseases; that is, X-linked lymphoproliferative disorder (XLP) and hemophagocytic lymphohistiocytosis (HLH). XLP is linked to mutations of the SAP/SH2D1A gene with dysregulated T-cell activation in response to EBV infection. Patients with sporadic HLH, however, usually have no mutation of the SAP/SH2D1A gene, and EBV latent membrane protein-1 (LMP1) can up-regulate Th1 cytokines in EBV-infected T cells. Since both diseases share common manifestations of HPS, it is important to clarify whether a cross-talk exists between signaling lymphocyte activation molecule (SLAM)-associated protein (SAP) and LMP1-mediated pathways to explain the common pathogenesis of HPS. In this study, no mutation of the SAP/SH2D1A gene at exon 2/3 was detected in 7 HLH cases. Interestingly, EBV LMP1 could transcriptionally inhibit the expression of SAP/SH2D1A and activate downstream molecules ERK and interferon-gamma (IFN-gamma). LMP1-mediated SAP/ERK/IFN-gamma signals appear to act via the TNF receptor-associated factor (TRAF)2,5/nuclear factor kappaB (NF-kappaB) pathway, since dominant-negative TRAF2/5 and NF-kappaB inhibitor could rescue SAP expression and downregulate IFN-gamma. Although HLH is genetically distinct from XLP, our data suggest that both diseases share a common signal pathway, through either the mutation or LMP1-mediated suppression of the SAP gene, leading to overt T-cell activation and enhanced Th1 cytokine secretion in response to EBV infection.

Fatal infectious mononucleosis with evidence suggestive of the development of B cell lymphoma

A 4-year-old girl presented to a local hospital in August 1999 with fever and cervical lymphadenopathy. A diagnosis of Epstein-Barr virus (EBV) infection was made and the patient was treated with corticosteroids. One month later she developed dyspnea secondary to tonsilar swelling, and underwent tonsillectomy and adenoidectomy. Her dyspnea increased, however, and by mid September she required mechanical ventilation. Six weeks later, she was transferred to Chiba Children's Hospital (Chiba, Japan). Despite vigorous treatment, she died within four weeks of admission. At autopsy, microscopic examination revealed numerous histiocytes with frequent hemophagocytosis in her lungs, liver, spleen, thymus, and lymph nodes. The tentative diagnosis was EBV-associated hemophagocytic syndrome (EBVAHS). A proliferation of atypical lymphocytes was observed in the lymph nodes, the majority of which stained positive with CD79a antibody. A whitish nodule, 8 mm in diameter, was noted in her right ovary. It consisted of a proliferation of pleomorphic lymphoid cells expressing CD79a antigen. In situ hybridization detected EBV RNA within CD79a antigen-positive cells in the lungs, spleen, thymus, bone marrow, lymph nodes, and the right ovary. Polymerase chain reaction analysis of DNA from the ovarian nodule demonstrated a monoclonal rearrangement of the immunoglobulin heavy chain gene indicating that it consisted of a clone of B lymphocytes. We suggest that EBVAHS develops into polyclonal and monoclonal lymphoproliferative disorder in a short period, and that EBVAHS is a preneoplastic condition that may result in B cell lymphoma.

Human herpesvirus 8-related childhood mononucleosis: a series of three cases

Human herpesvirus 8 has been implicated in the pathogenesis of a limited subset of lymphoproliferative disorders in adults, but its role in children is unclear. A prospective evaluation of children with atypical lymphocytosis residing in the Hualien area, where the incidence of adult Kaposi sarcoma is high, revealed 3 cases caused by human herpesvirus 8.

Histiocytic lesions involving the bone marrow

Histiocytic lesions involving the bone marrow include a number of reactive and neoplastic disorders. This article discusses the morphologic, immunophenotypic, and genotypic features of a variety of diseases associated with histiocytes and/or monocytes. Lysosomal storage disorders and hemophagocytic syndromes are often first diagnosed by bone marrow examination. Granulomas involving the bone marrow may also be the first indication of a systemic disorder. Apart from acute and chronic monocytic leukemias, the bone marrow is rarely involved by malignant histiocytic disorders, of which Langerhans cell histiocytosis is the most common.

Epstein-Barr virus-associated acute renal failure: diagnosis, treatment, and follow-up

We retrospectively reviewed our experience of Epstein-Barr virus (EBV)-associated acute renal failure. Of 165 previously healthy children hospitalized with serologically proven primary EBV infection, 8 had acute renal failure, of whom 5 (group A) did not have virus-associated hemophagocytic syndrome (VAHS), while 3 (group B) did have VAHS. All had complications in four or more organ systems. Two patients in group A had renal biopsies showing acute tubulointerstitial nephritis, and the clinical and laboratory findings in the other 3 group A patients were consistent with acute tubulointerstitial nephritis. Acyclovir was used in 1 patient, but she died of hepatic failure and pulmonary hemorrhage. The other 4 spontaneously recovered renal function after supportive care, including hemodialysis in 1 patient. Our experience does not support the routine use of corticosteroids or antiviral agents in these patients. Children in group B had a relatively normal urinalysis. Renal biopsies were not performed, but their presentations were compatible with acute tubular necrosis. We conclude that EBV should be considered as a possible etiological agent in all children presenting with acute renal failure of unknown cause. The diagnosis depends on a high index of suspicion and careful serological evaluation in atypical cases.

Hepatic manifestations of hemophagocytic syndrome: a study of 30 cases

OBJECTIVE

Hemophagocytic syndrome has been defined as the combination of a proliferation of cytologically benign, actively phagocytic macrophages in bone marrow, spleen, or lymph nodes in association with fever, cytopenia, splenomegaly, and hypertriglyceridemia. Hepatic dysfunction is often present but the nature of the hepatic lesions and related manifestations have not been fully characterized. The aim of this study was to ascertain the features of hepatic involvement in hemophagocytic syndrome.

METHODS

Thirty patients with hemophagocytic syndrome were retrospectively studied. Inclusion criteria included: 1) bone marrow with hemophagocytic histiocytosis, 2) clinical or biological signs of hepatic involvement, and 3) available liver specimen.

RESULTS

The association of fever, jaundice, and hepatomegaly or splenomegaly was present in 50% of the patients. Median value for serum alanine transaminase activity was five times the upper limit of normal values (range, 0.3-125), for serum alkaline phosphatase activity 2.7 upper limit of normal values (range, 0.2-47.7), for total bilirubin 136 micromol/L (range, 4-681 micromol/L), and for factor V 70% (range, 19-145%). Sinusoidal dilatation with hemophagocytic histiocytosis were found in the biopsy specimen in all patients. An underlying condition potentially responsible for altered immune function (lymphoma, leukemia, liver transplantation) was identified in 29 patients. Liver biopsy was diagnostic for the underlying condition in 15 patients (including eight cases with nonspecific bone marrow biopsy findings). High serum bilirubin, elevated serum alkaline phosphatase activity, low factor V level, and lack of treatment for the underlying disease were associated with a poor prognosis.

CONCLUSIONS

Hemophagocytic syndrome should be suspected in immunodeficient patients with fever, jaundice, and hepatosplenomegaly. Hepatic lesions are characterized by nonspecific sinusoidal dilatation with hemophagocytic histiocytosis and in 50% of the patients by alterations specific to the underlying condition. Liver biopsy is a useful diagnostic procedure in patients with this clinical presentation.

Reactive hemophagocytic syndrome presenting as a component of multiple organ dysfunction syndrome

OBJECTIVE

To report two cases of severe reactive hemophagocytic syndrome (RHS), to discuss their impact, and to present evidence that RHS may be a constitutive part of multiple organ dysfunction syndrome (MODS).

DESIGN

Case-report.

SETTING

Pediatric intensive care unit (PICU).

PATIENTS

Two patients with RHS and MODS.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Case #1: A 3 yr-old boy with Mucha-Haberman syndrome (pityriasis lichenoides) was admitted to the PICU for septic shock, acute respiratory distress syndrome, capillary leak, acute renal failure, liver dysfunction, and RHS (pancytopenia and hemophagocytosis on bone marrow aspirate). The pancytopenia was severe (white blood cell count, 0.9 x 10(9)/L; hemoglobin, 59 g/L; platelets, 36 x 10(9)/L), required many transfusions, and resolved 2 months later. The patient needed mechanical ventilation for 6 wks. Length of stay in PICU was 2 months. Case #2: A previously healthy 4 yr-old girl was admitted to the PICU for respiratory failure. She developed acute respiratory distress syndrome, cardiomyopathy with complete atrioventricular block, shock, capillary leak, liver dysfunction, and RHS (pancytopenia and hemophagocytosis on bone marrow aspirate). The pancytopenia was severe (white blood cell count, 1.92 x 10(9)/L; hemoglobin, 65 g/L; platelets, 58 x 10(9)/L) and necessitated transfusional support. Serology for respiratory syncytial virus was positive. RHS duration was 20 days; the patient recovered completely. Length of mechanical ventilation was 16 days and length of stay in PICU was 3 wks.

CONCLUSIONS

These cases show that RHS may be a significant cause of pancytopenia in the PICU. It needs to be recognized as a clinical entity because it can be reversible and nonneoplastic. RHS and MODS share some pathophysiologic elements and could be related to each other.

Haemophagocytic syndrome associated with infections

Haemophagocytic syndromes (HS) are the clinical manifestation of an increased macrophagic activity with haemophagocytosis. Pathophysiology is related to a deregulation of T-lymphocytes and excessive production of cytokines. The main clinicobiological features are fever, hepatosplenomegaly, adenopathies, skin rash, neurological features, cytopenias, hypertriglyceridaemia, hyperferritinaemia and coagulopathy. Diagnosis is based on examination of the bone marrow which shows benign histiocytes actively phagocytosing haemopoietic cells. Acquired HS are mostly associated with an underlying disease such as immunodeficiency, haematological neoplasias and autoimmune diseases. Infection-associated HS was originally described by Risdall in 1979, in viral disease. Since the initial description HS has also been documented in patients with bacterial, parasitic or fungal infections. Epstein-Barr virus (EBV) is the causative agent in most cases. In EBV-associated HS, which sometimes has a fatal course, unregulated T-cell reaction or uncontrolled B-cell proliferation may release cytokines. Management of HS consists of early diagnosis, careful screening for, and prompt treatment of, infections and detection and therapy of any underlying disease. Prognosis of infection-associated haemophagocytic syndrome (IAHS) is better than that in other types of secondary HS. Management of cytokine imbalance should be useful to improve the outcome and reduce the mortality rate in these cases.

Hemophagocytic syndromes and infection

Hemophagocytic lymphohistiocytosis (HLH) is an unusual syndrome characterized by fever, splenomegaly, jaundice, and the pathologic finding of hemophagocytosis (phagocytosis by macrophages of erythrocytes, leukocytes, platelets, and their precursors) in bone marrow and other tissues. HLH may be diagnosed in association with malignant, genetic, or autoimmune diseases but is also prominently linked with Epstein-Barr (EBV) virus infection. Hyperproduction of cytokines, including interferon-gamma and tumor necrosis factor-alpha, by EBV- infected T lymphocytes may play a role in the pathogenesis of HLH. EBV-associated HLH may mimic T-cell lymphoma and is treated with cytotoxic chemotherapy, while hemophagocytic syndromes associated with nonviral pathogens often respond to treatment of the underlying infection.

Nasal angiocentric lymphoma with hemophagocytic syndrome

OBJECTIVES

Hemophagocytic syndrome (HS) is a fatal complication of nasal angiocentric lymphoma (AL) and difficult to distinguish from malignant histiocyosis. Epstein-Barr virus (EBV)-associated HS is frequently observed in lymphoma of T-cell lineage and EBV is highly associated with nasal AL. Clinicopathologic features of 10 nasal ALs with HS were reviewed to determine the clinical significance and the pathogenetic association with EBV.

METHODS

Ten patients of HS were identified from a retrospective analysis of 42 nasal ALs diagnosed from 1987 to 1996. Immunohistochemical study and in situ hybridization were performed on the paraffin-embedded tumor specimens obtained from 10 patients. Serologic study of EBV-Ab was performed in 3 available patients.

RESULTS

Five patients had HS as initial manifestation, 3 at the time of relapse and 2 during the clinical remission of AL. Four patients were treated by combination chemotherapy (CHOP) and others had only supportive care. The median survival of all patients with HS was 4.1 months (range 2 days-36.5 months) and all had fatal outcome regardless of the treatment-modality. All cases were positive for UCHL1 (CD45RO) and EBV by EBER in situ hybridization. The data of serologic tests indicated the active EBV infection.

CONCLUSIONS

HS is a fatal complication of nasal AL and has a high association with EBV. Reactivation of EBV may contribute to HS and further investigation of predictive factors and effective treatment of HS should be pursued in the future.

Clinicopathological findings of virus-associated hemophagocytic syndrome in bone marrow: association with Epstein-Barr virus and apoptosis

Non-neoplastic hemophagocytic syndrome (HPS), also called virus-associated hemophagocytic syndrome (VAHS), has been thought to be a distinct clinical entity. A spontaneous recovery is common, but the prognosis of Epstein-Barr virus (EBV)-associated VAHS is poor. However, the role of EBV has yet to be clearly elucidated. A retrospective study of the bone marrow of 30 cases, in which the diagnosis of non-neoplastic VAHS was clinicopathologically confirmed, was performed. We were unable to histologically confirm the presence of neoplastic lesions, especially lymphoma cell infiltration. Ten of the patients were children (aged less than 15 years) and young adults (aged under 20 years; median age, 10 years). Twenty patients were adults (aged over 21 years; median age, 48 years). Twelve of these patients died, while 18 showed a spontaneous recovery. We performed immunological staining and in situ hybridization (ISH) for EBV. To clarify the presence of apoptosis, an in situ apoptosis detection (tunnel) method was used. In situ hydridization showed an EBV-presence in 16 of the 30 patients. In addition, the EBV-presence was confined in the lymphocytes, especially T lymphocytes in double stainings. The number of EBV-infected cells varied; however, the EBV presence was associated with ages. Nine of the 10 children and young adults showed an EBV-presence, while EBV was detected in seven of the 20 adults. Especially in 10 patients aged over 49 years, no EBV was detected. According to the in situ apoptosis detection, apoptotic cells were increased in number and considered to be lymphoid cells, but not myeloid or histiocytic cells. Some apoptotic cells were phagocyted with histiocytes. Histologically, apoptosis may be one of the factors that induced phagocytosis.

Longitudinal observation and outcome of nonfamilial childhood haemophagocytic syndrome receiving etoposide-containing regimens

The long-term outcome of 22 children treated with etoposide-containing regimens for haemophagocytic syndrome (HS) were longitudinally studied; none of them had a family history of the disease. All patients received etoposide-containing (150 mg/m2/d) regimens, combined, in 16 cases, with intravenous immunoglobulin (IVIG) and prednisolone. Complete remission (CR) was achieved in 12 patients, partial remission in seven, and early mortality occurred in three. Of the 12 CR patients, only four remain alive and disease-free, with a median follow-up of 47.4 months; one CR patient died due to infection and the remaining seven had relapsed diseases. Three patients with a partial response or with relapsed disease progressed to T-cell lymphoma, characterized, in the two cases tested, by clonal chromosomal abnormalities. Epstein-Barr virus (EBV) infection was implicated in disease pathogenesis in 15/22 patients. The overall survival was 45.5%, 40.9% and 40.9% at 1, 3 and 5 years, respectively, and disease-free survival for CR patients at these same times was 45.5%, 36.4% and 36.4%. The etoposide-containing regimen would appear to be an effective initial therapeutic option for childhood HS. However, in view of the frequency of partial remissions and relapsed disease, a more intensive chemotherapy or bone marrow transplantation should be applied. The progression to EBV-containing T-cell lymphoma in three patients is consistent with the previous observation that EBV-associated HS is a potentially malignant disease.

Antibody against the Epstein-Barr virus BHRF1 protein, a homologue of Bcl-2, in patients with nasopharyngeal carcinoma

The Epstein-Barr virus (EBV) open reading frame BHRF1, a homologue of the oncogene bcl-2, was cloned from a patient with nasopharyngeal carcinoma (NPC) and overexpressed in Escherichia coli. The resulting recombinant BHRF1 fusion protein, with an apparent molecular weight of 35 KD, was used as antigen in an immunoblotting assay for IgG antibody in human sera. Anti-BHRF1 antibody was detected in 57 (61.3%) of 93 patients with NPC, 5 (5.7%) of 87 patients with nonmalignant diseases of the nasopharynx, and in 1 (1.3%) of 78 healthy blood donors. The positivity rate in these nonmalignant patients was 4.4 times that of the normal controls. Negative results were observed in four patients with infectious mononucleosis and patients with other cancers, including 4 with esophageal cancer, 11 with lung cancer, 10 with lymphoma, 13 with gastric carcinoma, 10 with cervical carcinoma, and 10 with other head and neck cancers. Antibody neutralizing EBV DNase and IgA antibody to viral capsid antigen (VCA) were assayed in parallel. The results showed that 7.5% of the NPC patients were negative for anti-DNase and anti-VCA antibodies and EBV infection could be detected by the anti-BHRF1 antibody alone. The demonstration of anti-BHRF1 antibody in most NPC sera strongly supports the hypothesis that the EBV BHRF1 protein is expressed in most NPC patients and its specific antibody can be a useful marker for the diagnosis of NPC.

Hemophagocytic syndrome associated with hematological neoplasias

Hemophagocytic syndrome (HPS) is a reactive process that complicates several diseases including hematological neoplasias (HN). It has been suggested that HPS may be a negative prognosis factor for neoplastic diseases. In this retrospective analysis, 13 cases with HPS associated to HN were compared with two age, sex, diagnosis, disease stage and treatment matched controls in order to determine the impact of this syndrome on the survival. Cases with HPS were adult patients with a male:female ratio of 1:1 and their clinical picture was characterized by fever, lymphadenopathy, hepatosplenomegaly, and pancytopenia. Median survival since HN diagnosis was 7 and 48 months for the HPS and control groups, respectively (P = 0.0001). In ten patients who died, median survival after HPS presentation was 1 month. These results suggest that the presence of HPS is a negative prognosis factor in patients with HN. Due to its high mortality rate, an individualized, early, and intensive chemotherapeutic regimen may be required for HN complicated with this syndrome.

Biomarker and morphological characteristics of Epstein-Barr virus-related hemophagocytic lymphohistiocytosis

BACKGROUND

Viruses may induce primary as well as secondary hemophagocytic lymphohistiocytosis (HLH), but it may not be possible to discriminate between these two in patients with a negative family history. Among these HLH cases, fulminant and fatal virus-associated hemophagocytic syndrome (VAHS) occurs mostly in relation to Epstein-Barr virus (EBV) infection. Although the immunological characteristics of EB-VAHS were previously reported, data on non-EB-VAHS were sporadic and fragmentary. This study has compared the clearly distinguishable groups of EBV-positive vs. EBV-negative HLH cases.

PROCEDURE

Among 26 patients with EBV-related HLH and 12 patients with non-EBV HLH, peripheral blood mononuclear cell (PBMC) subsets and serum concentrations of cytokines at the active phase of the disease were compared. Blood and bone marrow smears were also compared.

RESULTS AND CONCLUSIONS

The frequency of the CD3+HLADR+ subset in PBMC (median 34.3% vs. 4.8%), of serum concentrations of interferon (IFN)-gamma (median 105 U/ml vs. 2.4 U/ml), and of soluble interleukin-2-receptor (sIL-2R) (median 14,700 U/ml vs. 3,412 U/ml) were significantly different between these two groups. Morphological characteristics were noted for EBV-related HLH cases. Mortality also differed between these two groups, 9/26 vs. 0/12 (P = 0.05). Data indicate pronounced immunological imbalance and poor prognosis in EBV-related HLH cases. These parameters could be useful for determining an EBV involvement as well as risk factors in the early care and treatment of HLH patients.

Infection- and malignancy-associated hemophagocytic syndromes. Secondary hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis represents a spectrum of pathogenetically different diseases in which a T-cell induced, uncontrolled activation of phagocytosing macrophages may lead to fever, organomegaly, and pancytopenia. The underlying immunologic disturbance can either be genetically transmitted, like in FHL, or acquired, as in IAHS or MAHS. Triggering infections can be found in all these diseases and do not allow a reliable differentiation. An international treatment protocol has been developed for FHL. IAHS and MAHS also have a high fatality rate, justifying immunomodulatory treatment if the disease is progressive.

Malignant histiocytosis. Histologic, cytochemical, chromosomal, and molecular data with a nosologic discussion

Although myelomonoblastic leukemia is thought to originate from a malignant transformation of the stem cell of the mononuclear phagocyte system, malignant histiocytosis (MH) is classically assumed to represent a malignant change of the terminal and fixed elements of this system. Indeed, MH is characterized by the proliferation of large, clear, pleomorphic, "histiocytic-like" HLADR and CD30+ cells resulting in a nodal and extranodal disseminated neoplasm affecting preferentially and severely children and young adults. Although there is broad agreement on the clinicopathologic presentation of this condition, there is currently quite a controversy over the T-lymphoid or histiocytic origin of the proliferative cells that results in a nosologic discussion between the anaplastic large cell lymphoma (ALCL) advocates and the MH supporters. This article has dealt mainly with this nosologic discussion and with the contributions provided by the investigations performed on MH permanent cell lines. These in vitro studies have demonstrated that the proliferation is characterized by a unique chromosomal abnormality, the 5q35bp usually associated with a t(2;5) translocation generating a fusion gene NPM/ALK and the subsequent translation of p80 protein. Although it is known that no single chromosomal abnormality is strictly restricted to a cell lineage, this 5q35bp and associated translocations seem today to represent the hallmark for this condition. In view of these chromosomal aberrations, the CD30+ ALCLs represent a heterogeneous group because 15% to 50% express the NPM/ALK fusion gene. In addition, these in vitro investigations have shown that 5q35bp proliferative cells are glass-adherent, can develop an immunodependent phagocytosis, and are able to reduce NBT and produce TNF-alpha. More significantly, they express constitutively the c-fms (the receptor of the macrophage growth factor) and, under TPA stimulation, are able to modulate the expression of this receptor and its ligand, as well as TNF-alpha and IL-1. None of these cell lines express CD3, but several express CD68 and CD71. In contrast, genomic investigations have shown the underlying existence of monoallelic and even biallelic gene rearrangements for TCR beta and IgJH. In view of these discrepancies between the genomic and phenotypic features of these cells, the histogenetic debate should remain open but must take into account these new chromosomal and molecular data.

[Etiological aspects of reactive hemophagocytoses: retrospective study in 99 patients]

We describe the causes of reactive hemophagocytic process in a retrospective study including 99 patients. The main diagnosis were: lymphomas (18 cases), pyogenic bacteria infections (15 cases), herpes virus infections (12 cases), other infections (multiple, parasitic, fungal, mycobacterial, unidentified) (11 cases), acute hepatitis (five cases), systemic lupus erythematosus (three cases). We also found numerous other diseases involving the reticuloendothelial system. The cause remained undetermined in 16 cases. Lymphoma accounted for 64% of the cases in previously healthy patients who had been febrile for more than 10 days at the time of the diagnosis of reactive hemophagocytic process, and for 31% in HIV-positive patients. Lymphomas were rare (5%) in non HIV-positive, immunosuppressed patients. In this setting and in previously healthy patients who had been febrile for less than 10 days, infectious diseases were widely dominant (respectively 60% and 86% of the cases). Those were mainly due to pyogenic bacteria and to herpes virus. A rapidly fatal evolution occurred in some cases of lymphomas-related hemophagocytic process. These data support the choice of aggressive investigations in order to diagnose lymphoma in previously healthy patients presenting with reactive hemophagocytic process who have been febrile for more than 10 days, and in selected HIV-patients. Such a procedure is not recommended in the other cases.

Hemophagocytic syndrome complicating cardiac transplantation

Infection-associated hemophagocytic syndrome is one of the hemophagocytic disorders, and is most often seen in the pediatric population, typically in the setting of immunosuppression. We present the case of a 33-year-old man who had been well for more than 3 years following cardiac transplantation until he developed the infection-associated hemophagocytic syndrome. The patient had a fulminant downhill course, dying in shock 10 weeks after his first presentation. Serologic studies for Epstein-Barr virus suggested a remote infection; other viral and microbiologic studies were negative. The only previous report of infection-associated hemophagocytic syndrome complicating cardiac transplant appears to be that of a pediatric patient. The case presented illustrates the difficulties in antemortem diagnosis of this disorder, and in its treatment.

The use of cyclosporin-A in the treatment of virus-associated hemophagocytic syndrome in adults

Virus-associated hemophagocytic syndrome (VAHS) is one of the categories of hemophagocytic syndrome (HPS) which is a clinicopathologic entity characterized by systemic proliferation of benign hemophagocytic cells of the monocyte-macrophage-histiocyte lineage, associated with fever, cytopenia, hepatosplenomegaly, lymphadenopathy, and coagulopathy. The disease affects children and adults after infection with various viruses. However, clinical manifestations are quite different between children and adults. Although the etiology of VAHS is not fully understood, accumulating evidence has revealed dysregulation of the immune system. Standard treatment of VAHS has not been established, yet, but successful trials aiming at immunomodulation have been reported. In this report, current concepts and clinical features of VAHS are reviewed, focusing on the recently introduced cyclosporin A therapy in VAHS in adults.

Upregulation of tumor necrosis factor-alpha gene by Epstein-Barr virus and activation of macrophages in Epstein-Barr virus-infected T cells in the pathogenesis of hemophagocytic syndrome

A potentially fatal hemophagocytic syndrome has been noted in patients with malignant lymphomas, particularly in EBV-infected T cell lymphoma. Cytokines, such as interferon-gamma (IFN-gamma), TNF-alpha, and IL-1alpha, are elevated in patients' sera. To verify whether infection of T cells by EBV will upregulate specific cytokine genes and subsequently activate macrophages leading to hemophagocytic syndrome, we studied the transcripts of TNF-alpha, IFN-gamma, and IL-1alpha in EBV-infected and EBV-negative lymphoma tissues. By reverse transcription PCR analysis, transcripts of TNF-alpha were detected in 8 (57%) of 14 EBV-infected T cell lymphomas, higher than that detected in EBV-negative T cell lymphoma (one of six, 17%), EBV-positive B cell lymphoma (two of five, 40%) and EBV-negative B cell lymphomas (one of seven, 14%). Transcripts of IFN-gamma were consistently detected in T cell lymphoma and occasionally in B cell lymphoma, but were independent of EBV status. IL-1alpha expression was not detectable in any category. Consistent with these in vivo observations, in vitro EBV infection of T cell lymphoma lines caused upregulation of TNF-alpha gene, and increased secretion of TNF-alpha, but not IFN-gamma or IL-1alpha. Expression of TNF-alpha, IFN-gamma, and IL-1alpha was not changed by EBV infection of B cell lymphoma lines. To identify the specific cytokine(s) responsible for macrophage activation, culture supernatants from EBV-infected T cells were cocultured with a monocytic cell line U937 for 24 h. Enhanced phagocytosis and secretion of TNF-alpha, IFN-gamma, and IL-1alpha by U937 cells were observed, and could be inhibited to a large extent by anti-TNF-alpha (70%), less effectively by anti-IFN-gamma (31%), but almost completely by the combination of anti-TNF-alpha and anti-IFN-gamma (85%). Taken together, the in vivo and in vitro observations suggest that infection of T cells by EBV selectively upregulates the TNF-alpha expression which, in combination with IFN-gamma and probably other cytokines, can activate macrophages. This study not only highlights a probable pathogenesis for virus-associated hemophagocytic syndrome, but also suggests that anti-TNF-alpha will have therapeutic potential in the context of their fatal syndrome.

Clinicopathologic study of nasal T/NK-cell lymphoma among the Japanese

A high prevalence of nasal lymphoma expressing a T- or natural killer (NK)-cell phenotype (NTCL) with frequent association of Epstein-Barr virus (EBV) has been indicated in Asians. To characterize NTCL among the Japanese, the clinicopathologic features of 32 cases were evaluated and the cases were also analyzed for EBV-RNA using an ISH method. Morphologically, 31 cases were identified by atypical pleomorphic lymphoid infiltrates with polymorphous, angicentric, and necrotic features. Their lymphoma cells ranged in size from small to large and were mixed in varying proportion from case to case. The other one case showed a monomorphic 'blastic' appearance. EBV-encoded small RNA (EBER) was detected in the neoplastic cells of 27 of the 32 cases examined. In the five EBV-negative cases, one was the 'blastic' type. Clonal T-cell receptor gene rearrangement was detected in none of seven cases examined. The patients had a median follow-up of 9 months (range, 1 month to 14 years and 11 months). The Kaplan-Meier estimate of overall survival was 49% at 5 years, correlating with clinical stage. These data support the concept that most cases of NTCL are identified as tumors with T/NK-cell characteristics and EBV association, distinctly different from other peripheral T-cell lymphomas. Furthermore, the one case of an EBV-negative 'blastic' variant appears not to fit well into the pleomorphic category but more closely resembles the pathologic features of extranasal angiocentric lymphoma with lymphoblastoid appearance. This study also showed no clear difference in clinical aspects other than the original site or in prognosis, between NTCL and extranasal angiocentric lymphomas despite the higher incidence of EBV association and the tendency for that peculiar anatomical site to be restricted to the former group.

A study of the possible etiologic association of Epstein-Barr virus with reactive hemophagocytic syndrome in Hong Kong Chinese

The herpes group of viruses, particularly Epstein-Barr virus (EBV), has frequently been implicated in the causation of reactive hemophagocytic syndrome (RHS) in the Western populations. EBV has also been implicated in the rare fulminant form of RHS occurring in Oriental children. However, our previous adult-predominant study indicated little clinical and serological evidence of EBV infection in patients with RHS in Hong Kong. In the present study, we further examined this issue using a more sensitive and specific technique for the demonstration of EBV, ie, in situ hybridization for EBV encoded RNA (EBER). The 43 Chinese patients studied were mostly adults with a mean age of 44 years, and a male to female ratio of 1.5:1. About two-thirds (28) of patients had associated malignant lymphoma at the time of diagnosis. Five patients had documented infection (typhoid fever 2; systemic candidiasis 1; adenovirus pneumonia 1; viral encephalitis 1), and two had systemic lupus erythematosus. EBER signals were detected in only 11 cases (25.6%). All positive cases were associated with malignant lymphoma, and the positive signals were exclusively localized to the lymphoma cells but not in the histiocytes. On comparing the results (11 of 28 cases positive; 39.3%) with our previous data on EBER-expression in malignant lymphomas in Hong Kong, no significant difference is observed in the frequency of EBV-positivity between the two groups of lymphomas. Thus, a definite pathogenetic link between EBV and lymphoma-associated RHS cannot be established. However, the overrepresentation of T and T/NK lineage lymphoma in this sample of lymphoma-associated with RHS (61%) versus nonselected cases of lymphomas (31%) suggests that it is the T and T/NK cell origin of the lymphoma rather than the EBV positivity that predisposes to RHS. Notwithstanding the previous findings, EBER in situ hybridization may still serve as a useful adjunct in the investigation of patients with RHS, because the presence of EBER-positive cells should raise a strong suspicion of an underlying malignant lymphoma.

Hemophagocytic syndrome in Epstein-Barr virus-associated T-lymphoproliferative disorders: disease spectrum, pathogenesis, and management

The Epstein-Barr virus (EBV) has been shown to infect T lymphocytes and is associated with two recently recognized human T-lymphoproliferative disorders: childhood EBV-associated hemophagocytic syndrome (VAHS) representing a primary or active EBV infection of T cells in young children, and the EBV-containing T cell lymphoma in adults predominantly affecting the nose, skin and gastrointestinal tract. In both diseases, hemophagocytic syndrome (HS) accounts for the major cause of mortality. The patients developing HS share common clinicopathologic features such as fever, skin lesions, lung infiltrates, hepatosplenomegaly with jaundice, cytopenias, and coagulopathy. The liver, spleen, lymph nodes, and bone marrow usually show florid histiocytic proliferation with hemophagocytosis in addition to the proliferation of atypical T lymphocytes or immunoblasts. The HS in T cell lymphoma may develop simultaneously with initial lymphoma presentation, at tumor relapse, or even during remission. The cytokines, in particular tumor necrosis factor-alpha, released from the EBV-infected T lymphocytes are presumed to cause the histiocytic activation and the subsequent hemophagocytic process. Chemotherapy or antiviral agents fail to arrest the hemophagocytic process in both diseases. Immunomodulatory treatment incorporating etoposide and intravenous immunoglobulin, however, has been effective in the control of the progression of the hemophagocytic process in a substantial number of VAHS patients. Preliminary data suggest that bone marrow transplantation may be a promising way for eliminating both the virus and the proliferating T cells. Further investigations are mandatory for combating this aggressive hemophagocytic process in EBV-associated T lymphoproliferative disorders.

Hepatosinusoidal leukaemia/lymphoma consisting of Epstein-Barr virus-containing natural killer cell leukaemia/lymphoma and T-cell lymphoma; mimicking malignant histiocytosis

Previously diagnosed cases of hepatosinusoidal T-cell lymphoma and malignant histiocytosis (MH) may include lymphoid neoplasms of natural killer (NK) cell lineage associated with Epstein-Barr virus (EBV). Such hepatosinusoidal neoplasms were found to demonstrate hepatomegaly but not lymphadenopathy, and all were diagnosed by a liver biopsy. Sixteen adult patients diagnosed with hepatosinusoidal leukaemia/lymphoma (six NK-cell leukaemia/lymphomas [NKLLs], five instances of MH, three T-cell malignant lymphomas [T-MLs], and two adult T-cell leukaemia/lymphomas [ATLLs] were examined for EBV by in situ hybridization, then were studied immunohistochemically and subjected to a DNA analysis. Among our five patients with MH, neoplastic cells showed T-cells, but no histiocytic markers, and they were considered to have either a T-cell or NK-cell lineage. All NKLLs, MHs and T-MLs, except for ATLLs accompanied by reactive hemophagocytic histiocytes, varied in number in each case. In situ hybridization revealed the presence of EBV in the nuclei of atypical cells in all of the six lymphoid neoplasms of NK-cell lineage. Each case of MH and each T-ML which represented EBV demonstrated no definite T-cell or histiocytic markers. Patients with ATLL did not reveal EBV. In all patients with hemophagocytosis, EBV was present in the nuclei of the neoplastic lymphocytes, but not in the hemophagocytic cells. Finally, the 16 cases were reclassified into eight cases with EBV-containing NKLLs, six T-MLs, and two ATLLs. In addition, no true histiocytic neoplasms were observed. The mechanism of hemophagocytosis may be therefore the production of lymphokines (macrophage-activating factors) by neoplastic lymphocytes. EBV-associated hepatosinusoidal leukaemia/lymphoma may thus contain a lymphoid neoplasm of NK-cell lineage, which made it difficult to be distinguished from the previously designated malignant histiocytosis.

Immunomodulation treatment for childhood virus-associated haemophagocytic lymphohistiocytosis

The Epstein-Barr virus (EBV), or human herpesvirus-6 (HHV-6) associated haemophagocytic lymphohistiocytosis, has been found prevalent in Taiwan; it affects previously healthy children and is always fatal when treated only supportively. Recognition of the underlying pathogenesis for this disease prompted adoption of an immunomodulatory regimen of intravenous immunoglobulin (IVIG) and/or etoposide on 17 such patients treated between 1990 and 1993. Remarkable improvement in patients' prognoses was demonstrated. Eight patients are still alive with a median follow-up of 1 year and 2 months post-treatment. Both IVIG and etoposide had positive immunomodulation effects such as alleviation of fever and normalization of haematological and hepatic parameters. Sustained complete response was obtained in two of nine cases of EBV-associated diseases treated with IVIG only. EBV transcripts became undetectable after etoposide and/or IVIG treatment without antiviral agents. Etoposide given by split-doses schedule appeared to be superior to conventional three-consecutive-days schedule for both remission induction and disease-free survival. Our preliminary trial apparently provides a promising improvement in the treatment of this previously fatal disease. IVIG or etoposide is effective in reversing the process of lymphohistiocytic dysregulation resulting from virus infection of immune cells in this syndrome and probably helps hosts to control active virus replication in certain cases, through immunomodulation.

EBV-associated Kaposi's sarcoma in a pediatric renal transplant recipient

A 7-year-old boy had undergone kidney transplantation for chronic renal failure secondary to bilateral renal hypoplasia. He developed acute and chronic rejection and received immunosuppressive therapy. A year later he died with EBV-associated hemophagocytic syndrome. The main pathologic findings disclosed visceral (lung and stomach) and abdominal lymph node involvement of Kaposi's sarcoma and EBV-positive immunoblasts in several organs. In the lungs and lymph nodes these had the features of polymorphous lymphoimmunoblastic lesions. Because of the peculiar distribution of Kaposi's sarcoma lesions a pathogenetic hypothesis is proposed based on the site of entry of the virus. This case contributes to expanding the relationship between Kaposi's sarcoma and kidney transplantation in the pediatric population.

Angiotropic B-cell lymphoma with hemophagocytic syndrome

A unique autopsy case of angiotropic lymphoma, which is a rare lymphoma characterized by the lymphoma cells confined in blood vessels and with a minimal involvement of lymph nodes, is presented. The clinical diagnosis was a malignant histiocytosis (histiocytic medullary reticulosis), since clinical manifestations were muscle weakness of the extremities, pancytopenia, fever and hepatosplenonephromegaly, and biopsy exhibited infiltration by histiocytic cells showing hemophagocytosis in the liver sinusoids and the bone marrow, the latter with myelofibrosis. Postmortem examination revealed lymphoma cell proliferation within small blood vessels of the kidneys, perineural tissue of extremities and lungs. Lymph nodes were not involved. In the liver, spleen and bone marrow, prominent infiltration of benign histiocytic cells with active hemophagocytosis was evident but there was no lymphoma cell infiltration. No viral infection, including Epstein-Barr (EBV), was demonstrable either serologically or immunohistochemically. Autopsy diagnosis was angiotropic lymphoma of B-cell origin (immunophenotypically CD 45+, CD 20-related+, CD 45R+, CD 45 RO-, CD 43-, CD 57-, CD 30-, CD 68-) accompanied by hemophagocytic syndrome clinicopathologically simulating malignant histiocytosis.

Clinicopathological spectrum of haemophagocytic syndrome in Epstein-Barr virus-associated peripheral T-cell lymphoma

Haemophagocytic syndrome (HS) is frequently observed in Epstein-Barr virus-associated peripheral T-cell lymphoma (EBV-PTCL) and represents a major cause of death. In this communication we have further analysed the spectrum of HS in 12 patients with EBV-PTCL. The patients could be divided into three groups according to the time of onset of HS during the clinical course of PTCL. Group I patients (four cases) had HS as the initial clinical manifestation. All four patients were initially suspected to have malignant histiocytosis (MH) but a MH-like PTCL was later diagnosed. Group II patients (six cases) developed HS at the time of lymphoma relapse. Four of them belonged to the angioinvasive type PTCL. Group III patients (two cases) developed HS at clinical remission; both were angioinvasive type PTCL. Nine patients had serological evidence suggesting active EBV infection. The clinical course after the onset of HS was generally fulminant in each group with a median survival of only 44d despite combination chemotherapy and/or empirical therapy with high-dose immunoglobulin and corticosteroids in six patients. In conclusion, HS represents a severe complication of EBV-PTCL. Although most patients develop HS at a time of active lymphoma, the syndrome may occur when the lymphoma is in remission. Because of the poor outcome, early diagnosis and a new modality of treatment for HS associated with EBV-PTCL should be pursued in future.

Epstein-Barr virus (EBV) infects T lymphocytes in childhood EBV-associated hemophagocytic syndrome in Taiwan

We have reported the prevalence of a fulminant hemophagocytic syndrome (HS) in previously healthy young children in Taiwan, most of which probably represent a lethal form of primary or active Epstein-Barr virus (EBV) infection. To further confirm their EBV association, in situ EBV hybridization (ISH) was performed on tissue biopsies from 15 pediatric HS patients (median age, 3 years and 4 months) using digoxigenin-labeled RNA probes EBER1. Double labeling immunostaining and ISH was then performed to define the immunophenotype of the lymphoid cells containing the EBV transcripts. Among the 13 patients who had serological evidence of acute or active EBV infection, 9 had demonstrable EBER1 transcripts in bone marrow, liver, and/or skin biopsies. EBER1-specific signal was not detectable in the two specimens from EBV-seronegative patients. The distribution of EBV-containing cells could be extensive or scattered. To our surprise, the EBER1 transcripts existed exclusively in T lymphoid cells in all nine cases examined rather than in B cells as previously believed in infectious mononucleosis. Considering the young affected age of the HS patients and the serological response to EBV, we suggest that EBV can infect T cells in primary EBV infection and the proliferation of these EBV-infected T cells may be responsible for the ominous outcome in childhood HS patients in Taiwan.

Reactive hemophagocytic syndrome in childhood--frequent occurrence of atypical mononuclear cells

Reactive hemophagocytic syndrome, which is characterized by systemic proliferation of benign hemophagocytic histiocytes, usually presents as an acute febrile illness with pancytopenia and hepatosplenomegaly. The commoner diseases associated with the syndrome are infection and malignant lymphoma. In this report, eight cases of reactive hemophagocytic syndrome occurring in infants and young children are described. Unlike the disease occurring in adults, there is frequent occurrence of atypical mononuclear cells both in the peripheral blood and bone marrow. The morphological spectrum of these atypical cells is however still within that seen in infectious mononucleosis, and their reactive nature is substantiated by their spontaneous disappearance and subsequent recovery of the patients. It is important to distinguish this reactive proliferation from the neoplastic cells of 'malignant histiocytosis' or malignant lymphoma, since cytotoxic drugs are not warranted for treatment of this non-neoplastic condition.