Primary Epstein-Barr virus infection with clonal T-cell lymphoproliferation

A clinicopathologic study of the spectrum of systemic forms of EBV-associated T-cell lymphoproliferative disorders of childhood: A single tertiary care pediatric institution experience in North America

BACKGROUND

Systemic forms of EBV-associated T-cell lymphoproliferative disorders of childhood (S-EBV-T-LPD) comprise three major forms: EBV-positive hemophagocytic lymphohistiocytosis (EBV-HLH), systemic EBV-positive T-cell lymphoma (S-EBV-TCL), and systemic chronic active EBV infection (S-CAEBV). These disorders occur rarely in children in Western countries. Here, we described eight children of such entities.

DESIGN

Eight cases (six clinical and two autopsy) with S-EBV-T-LPD of childhood were retrospectively identified from 1990 to 2015. Clinicopathologic parameters including histomorphology, immunophenotype, EBV studies, and T-cell receptor gene rearrangement studies were recorded.

RESULTS

Patients include five females and three males of Hispanic, Asian, and Caucasian origins with an age range of 14 months to 9 years. Fever, hepatosplenomegaly, cytopenias, abnormal EBV serologies, and very high EBV viral loads were common findings. Histologic findings showed EBV⁺ T-cell infiltrates with variable degrees of architectural distortion and cytologic atypia ranging from no to mild cytologic atypia to overt lymphoma and tissue hemophagocytosis. All showed aberrant CD4⁺ or CD8⁺ T cells with dim to absent CD5, CD7, and CD3, and bright CD2 and CD45 by flow cytometry or loss of CD5 by immunohistochemistry. TCR gene rearrangement studies showed monoclonal rearrangements in all clinical cases (6/6). Outcomes were poor with treatment consisting of chemotherapy per the HLH-94 or HLH-2004 protocols with or without bone marrow transplant.

CONCLUSION

In this large pediatric clinicopathologic study of S-EBV-T-LPD of childhood in the United States, EBV-HLH, S-EBV-TCL, and S-CAEBV show many overlapping features. Diagnosis is challenging, and overall outcome is poor using current HLH-directed therapies.

Clinicopathologic features of adult EBV-associated B-cell lymphoproliferative disease

In the present study, 21 cases of adult/late-onset EBV-associated lymphoproliferative disease (AELPD) with an uncertain malignant potential were investigated with regard to their histomorphology, immunophenotype, clonal rearrangement of the heavy chain (IgH) and T-cell receptor (TCR) genes and clinical course. The cases were histomorphologically reevaluated and assigned to one of three morphological groups: mononucleosis-like, Hodgkin-like, or polymorphous. In addition, cases with or without detectable necrosis were investigated for differences in clinical outcome. Overall survival was highest in the group with Hodgkin-like morphology (4/4 patients), followed by patients with mononucleosis-like phenotype (4/5 patients surviving). Cases with polymorphous morphology showed the poorest survival rates with 7/12 patients dead of disease (58%). 4/6 patients with histologically detectable necrosis died (66%), but only 4/15 patients without necrosis (27%). 11/21 cases with AELPD showed clonal rearrangement for IgH (n = 4), TCR (n = 5) or IgH + TCR (n = 2). 5/11 patients with clonal rearrangement died (45%), and this percentage was similar in all of the three subgroups. In conclusion, the present study shows that polymorphous morphology and detection of necrosis in AELPD are frequently linked to a fatal clinical course, whereas Hodgkin-like morphology seems to be associated with a more favourable prognosis. Clonal rearrangement of IgH or TCR is frequent in AELPD, but prognosis is unpredictable from this feature.

Spontaneous Regression of Pulmonary Nodules Presenting as Epstein-Barr Virus-related Atypical Infectious Mononucleosis

BACKGROUND

Pulmonary nodules associated with Epstein-Barr virus (EBV)-related atypical infectious mononucleosis have rarely been described.

OBSERVATIONS

A 12-year-old Japanese boy, upon admission, revealed multiple small round nodules (a total of 7 nodules in 4 to 8 mm size) in the lungs on computed tomography. The hemorrhagic pharyngeal tonsils with hot signals on 18F-fluorodeoxyglucose-positron emission tomography-computed tomography were biopsied revealing the presence of EBV-encoded small nuclear RNA (EBER)-positive cells; however, no lymphoma was noted. The patient was diagnosed as having atypical EBV-infectious mononucleosis associated with primary EBV infection. Pulmonary nodules markedly reduced in numbers and sizes spontaneously over a 2-year period.

CONCLUSIONS

Differential diagnosis of pulmonary nodules in childhood should include atypical EBV infection.

Systemic Epstein-Barr virus-positive T-cell lymphoproliferative disease of childhood: Report of a case with review of the literature

Systemic Epstein-Barr virus (EBV)-positive T-cell lymphoproliferative disease (LPD) of childhood is an extremely rare and distinct clinicopathological entity. The majority of these cases occur with an apparent primary EBV infection. In this study, we describe a case of systemic EBV-positive T-cell LPD of childhood in a 23-year-old female with primary EBV infection, and review the clinicopathological features of this disease. A 23-year-old previously healthy female without an immunocompromized status presented with an acute onset of high fever. Laboratory examinations revealed a markedly elevated white blood cell count and liver and renal function. Peripheral blood smears identified a number of atypical lymphocytes with small azurophilic granules in the cytoplasm. Bone marrow aspiration revealed marked proliferation of small-sized lymphocytes with convoluted nuclei, which expressed EBER1, CD3, CD8 and cytotoxic granules. Monoclonal rearrangements of T-cell receptors were also detected. The patient underwent chemotherapy, but succumbed to multiorgan failure 20 weeks after administration. Upon review of 17 cases of this disease, including the one in the present study, we identified that the major clinicopathological features of systemic EBV-positive T-cell LPD of childhood are as follows: i) clonal systemic proliferation of EBV-infected T-cells that appear morphologically innocuous with an activated cytotoxic phenotype; ii) a high prevalence in the Asian population, commonly affecting children and young adults; iii) a predilection for males; iv) most commonly involved sites are the liver, spleen, lymph node and bone marrow, and the main clinical presentations are hepatosplenomegaly, fever and pancytopenia; v) almost all cases have an aggressive clinical course, which results in mortality. Cytological atypia of the neoplastic cells in this disease, as observed in the present case, is minimal. This study revealed that the cytomorphological features of atypical lymphocytes in the peripheral blood are indistinguishable from those of infectious mononucleosis.

Deciphering the role of Epstein-Barr virus in the pathogenesis of T and NK cell lymphoproliferations

Epstein-Barr virus (EBV) is a highly successful herpesvirus, colonizing more than 90% of the adult human population worldwide, although it is also associated with various malignant diseases. Primary infection is usually clinically silent, and subsequent establishment of latency in the memory B lymphocyte compartment allows persistence of the virus in the infected host for life. EBV is so markedly B-lymphotropic when exposed to human lymphocytes in vitro that the association of EBV with rare but distinct types of T and NK cell lymphoproliferations was quite unexpected. Whilst relatively rare, these EBV-associated T and NK lymphoproliferations can be therapeutically challenging and prognosis for the majority of patients is dismal. In this review, we summarize the current knowledge on the role of EBV in the pathogenesis of these tumours, and the implications for treatment.

Systemic Epstein-Barr-virus-positive T cell lymphoproliferative childhood disease in a 22-year-old Caucasian man: A case report and review of the literature

INTRODUCTION

Systemic Epstein-Barr-virus-positive T cell lymphoproliferative disease of childhood is an extremely rare disorder, characterized by clonal proliferation of Epstein-Barr-virus-infected T cells with an activated cytotoxic phenotype. The disease is more frequent in Asia and South America, with only few cases reported in Western countries. A prompt diagnosis, though often difficult, is a necessity due to the very aggressive clinical course of the disease.

CASE PRESENTATION

We report the clinicopathological features of fulminant T cell lymphoproliferative disease that arose in the setting of acute primary Epstein-Barr virus infection. Our patient, a 23-year-old man, presented to our facility with persisting fever, hepatosplenomegaly and severe pancytopenia. On bone marrow biopsy, an abundant lymphoid infiltrate was observed. Immunophenotypic and molecular studies revealed that the atypical lymphoid cells displayed a CD8+, Epstein-Barr-encoded-RNA-positive T cell phenotype with clonal rearrangement of the T cell receptor genes, the final diagnosis being systemic Epstein-Barr-virus-positive T cell lymphoproliferative disease. On reviewing the literature we found only 14 similar cases, all presenting with very aggressive clinical courses and requiring extensive phenotyping and molecular techniques for final diagnosis.

CONCLUSION

Though extremely rare, this disease can occur in Europe, and a comprehensive diagnostic approach is thus recommended in all case of Epstein-Barr-virus-positive lymphoproliferative disorders. Unfortunately, at present no specific treatment is available; however, prompt administration of anti- Epstein-Barr virus treatment and rapid attempts to control the hemophagocytic syndrome are indicated.

T-cell receptor gene rearrangement in Epstein-Barr virus infectious mononucleosis

This report describes the case of a previously healthy young man who presented with fever, pharyngitis, cervical lymphadenopathy, lymphocytosis, and severe thrombocytopenia. Serological tests for Epstein-Barr virus were diagnostic of a primary Epstein-Barr virus infectious mononucleosis but severe thrombocytopenia aroused the suspicion of a lymphoproliferative disease. T-cell receptor gene analysis performed on peripheral and bone marrow blood revealed a T-cell receptor γ-chain rearrangement without the evidence of malignancy using standard histologic and immunophenotype studies. Signs and symptoms of the infectious disease, blood count, and T-cell receptor gene rearrangement resolved with observation without the evidence of emergence of a lymphoproliferative disease. In the contest of a suspected lymphoproliferative disease, molecular results should be integrated with all available data for an appropriate diagnosis.

Spectrum of childhood Epstein-Barr virus-associated T-cell proliferations and bone marrow findings

Systemic Epstein-Barr virus-positive (EBV+) T-cell lymphoproliferative disorder of childhood is a recently described entity. The majority of such cases have been reported from Asia, which suggests an underlying genetic predisposition. We analyzed the clinicopathologic characteristics of 5 children with EBV+ T-cell lymphoid proliferations evaluated and treated at our institute over a 2-year period. There were 3 males and 2 females of Latino (n  =  4) or Caucasian (n  =  1) heritage with a median age of 5 years (age range 2-18 years). All patients presented with EBV infection (acute, n  =  4) with elevated serum EBV viral loads at the time of diagnosis and had systemic manifestations, including fever, hepatosplenomegaly, and pancytopenia. The bone marrow biopsies showed EBV+/CD8+ T-cell lymphocytosis in all patients, with variable degrees of histiocytosis, plasmacytosis, and hemophagocytosis. Interestingly, there was marked and consistent depletion of mature and precursor B cells in the marrow (<1% of total marrow cellularity) in all patients. Three of the patients died of disease-associated complications 2 to 12 weeks after initial diagnosis. Our study describes the detailed bone marrow findings, contributes to the growing number of cases of systemic EBV+ T-cell lymphoproliferative disorder of childhood occurring in the Western hemisphere, and documents this disorder in patients from the Caribbean countries.

Systemic EBV+ T-cell lymphoma in elderly patients: comparison with children and young adult patients

Fulminant Epstein–Barr virus (EBV+) T-cell lymphoma in immunocompetent elderly patients is rare and its character has not been well defined. This study analyzed the clinicopathological features of five elderly patients (group A: 50–84 years) and compared them with those of eight children and young adult patients with systemic T-cell lymphomas (group B: 10–34 years). Group A more commonly presented with generalized lymphadenopathy (n = 3) than did group B (n = 1). Chronic active EBV infection (n = 3) and hydroa vacciniforme-like eruptions (n = 1) were seen in group B, while group A showed no evidence of chronic EBV infection, but did show chronic hepatitis B or C virus infections (n = 3). The histological and immunophenotypical findings were similar. All patients died within 1 to 14 months of diagnosis. These findings suggest that EBV+ T-cell lymphoma in elderly patients is a unique disease with an underlying derangement of T-cell immunity and failure to eradicate infected virus. Additional factors related to senility may play a role in the disruption of homeostasis between the virus and the host’s immune system.

Pyothorax-associated lymphoma: a case showing transition from T-cell-rich polymorphic lesion to diffuse large B-cell lymphoma

Pyothorax-associated lymphoma was found in a man who had a history of collapse therapy for pulmonary tuberculosis about 50 years ago. An autopsy specimen revealed histology of diffuse large B-cell lymphoma with latency III Epstein-Barr virus (EBV) infection. However, an open biopsy 2 years and 7 months before death showed a polymorphic appearance with abundant T-lymphocytes. Most of the EBV-infected atypical lymphocytes did not express either B- or T-cell markers as far as examined in the paraffin-embedded biopsy specimen, and rearrangements of immunoglobulin and T-cell receptors were not found. It seemed difficult to diagnose a B-cell lymphoma at the time of biopsy. However, retrospectively considered, if a phenotype of EBV-infected atypical lymphocytes is uncertain in cases showing polymorphic appearance, it might be better to consider the future evolution to overt B-cell lymphoma. Since pyothorax-associated lymphoma shows latency III infection of EBV, at least the immunohistochemistry of EBNA-2 and LMP-1 seems helpful for the diagnosis to prove which cells are infected by EBV.

Hemophagocytic syndrome in kidney transplant recipients: report of four cases from a single center

BACKGROUND

The prognosis of hemophagocytic syndrome (HPS) in kidney transplant recipients is reported to be poor, however the optimal therapeutic approach is still unclear.

PATIENTS AND METHODS

The clinical and follow-up data of the 4 patients with HPS (3 male, 1 female; age 39.7 +/- 11.3 years) among 368 kidney transplant recipients during a 5-year period were retrospectively analyzed.

RESULTS

HPS developed 35-61 days in the post-transplant period. All 4 patients presented with fever. Hepatosplenomegaly and lymphadenopathy were observed only in the first patient. Laboratory tests revealed pancytopenia and hyperferritinemia in all patients, but elevated liver enzymes were observed in 3. Two patients had cytomegalovirus infection, and 1 had Epstein-Barr virus infection. Three patients died despite aggressive supportive therapy, however the fourth case survived after graft nephrectomy.

CONCLUSION

HPS pathogenesis in kidney transplants appears to be related with the graft itself. Graft nephrectomy may be the preferable therapeutic approach for kidney transplant recipients with HPS resistant to standard supportive therapy.

Expression of cytolytic lymphocyte-associated antigens in pulmonary lymphomatoid granulomatosis

Paraffin-embedded lung wedge biopsy specimens from 14 patients with pulmonary lymphomatoid granulomatosis (LYG) were analyzed using immunoperoxidase stains specific for T cell- and natural killer cell-associated antigens. Nine cases had a minor population of CD20+ large B-cells (B-cell LYG) amidst a background of CD3- and betaF1-immunoreactive T cells. In 8 of the 9 B-cell LYG cases, the majority of the background T lymphocytes had a cytotoxic phenotype as defined by the expression of CD8 and the cytotoxic granule proteins TIA-1 (granule membrane protein 17) and granzyme B. Five cases lacked CD20+ large cells and, instead, showed predominantly CD3+ and betaF1 + T cells (T-cell LYG). Whereas the small, medium, and large atypical lymphocytes were all positive for CD3 and betaF1 in the T-cell LYG cases, immunoreactivity for CD8, TIA-1, and granzyme B was limited to the small lymphocytes, with a distribution indistinguishable from that seen in B-cell LYG. These findings indicate that LYG is composed of a heterogeneous group of lymphoproliferative disorders that share, as unifying features, a relative paucity of neoplastic cells and a prominent reactive infiltrate rich in cytolytic lymphocytes.

The molecular characterization of fatal infectious mononucleosis

We describe a retrospective study of 4 cases of sporadic fatal infectious mononucleosis (IM), 1 case of fatal IM, and 1 case of sporadic severe IM. Patients were 26 months to 17 years old; 3 were male. Five died of complications of IM. All 5 of these patients had the Epstein-Barr virus (EBV) present in examined tissue specimens; EBV was monoclonal in 3 patients and biclonal in 1. EBV clonality studies were not performed in the remaining patient. All 5 patients also had monoclonal gene rearrangements. The sixth patient survived despite a life-threatening clinical course; EBV was oligoclonal, and gene rearrangements were not detected. EBV clonality and gene rearrangement studies may be usefulfor predicting which patients with clinically aggressive IM are at highest risk for fatal outcome. Patients in whom IM has a fatal outcome are more likely to have monoclonal or biclonal EBV and immunoglobulin heavy chain or T-cell receptor gene rearrangements. In contrast, patients with nonfatal IM may lack monoclonal EBV and monoclonal rearrangements of the aforementioned genes. The reasons EBV induces a monoclonal proliferation only in some patients remain to be elucidated.

Lymphoid tissues from patients with infectious mononucleosis lack monoclonal B and T cells

In typical cases of infectious mononucleosis (IM), lymphoid tissue is rarely submitted for pathological examination. When lymphoid tissues from IM cases are examined, the histological appearance of IM may be difficult to distinguish from malignant lymphoma. The purpose of this study was to address the utility of clinical molecular assays for T and B cell clonality in distinguishing IM from lymphoid malignancy. DNA was recovered from paraffin-embedded archival lymphoid tissues of 18 cases of IM and 13 control cases representing other reactive lymphoid hyperplasias. T cell receptor gamma (TCR-gamma) and immunoglobulin heavy chain (IgH) gene rearrangements were assayed using our standard clinical polymerase chain reaction procedures targeting each of the four functional variable (V) families and the three joining (J) families of the TCR-gamma gene, and framework III of the IgH gene, respectively. In 17 of 18 cases of IM, no monoclonal T or B cell populations were detectable. One case, the only spleen specimen in the study, had an oligoclonal pattern of TCR-gamma rearrangements. The control cases representing other reactive hyperplasias also lacked monoclonality. The assays used were sensitive to clonal populations as small as 5% of cells. In this case series, no monoclonal lymphoid populations were identified in any case of IM. This finding suggests that molecular studies are useful in distinguishing IM from lymphoid neoplasms.

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.

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

In Epstein-Barr virus (EBV) infection, the virus immortalizes B lymphocytes and cytotoxic T lymphocytes (CTLs) are directed toward both latent and lytic viral antigens expressed on EBV-infected B-cells. Various EBV-associated diseases occur as a result of this disruption of immune surveillance. In the majority of EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH) cases, the major cell types containing EBV DNA are not B-cells, but clonally proliferating T-cells or NK-cells. Proliferation of these cells produces severe immune reactions in the host, and the clinical features related to massive cytokine production at the onset of disease are unique and distinct from other EBV-associated diseases. In the treatment of EBV-HLH, therapeutic infusion of EBV-specific CTLs appears to be ineffective, and eradication of EBV-containing cells is useful but not sufficient to save lives, because of high incidence of acute mortality due to cytokine-induced multiple organ failure and neutropenia-associated opportunistic infections. The optimal treatment strategy for this disease consists of three steps: (1) control of cytokine storm including coagulopathy and multiple organ failure, (2) control of opportunistic infections, and (3) eradication of clonally proliferating EBV-containing T- or NK- cells by immunochemotherapy and, if necessary, hemopoietic stem cell/bone marrow transplantation (SCT/BMT).

Fulminant EBV+ T-cell lymphoproliferative disorder following acute/chronic EBV infection: a distinct clinicopathologic syndrome

This study describes the clinicopathologic features of 5 patients who developed a fulminant Epstein-Barr virus (EBV)-positive clonal T-cell lymphoproliferative disorder (LPD) after acute EBV infection. One additional patient developed a similar disorder in the setting of long-standing chronic active EBV infection. Detailed immunophenotyping, in situ hybridization for EBV early RNA-1 (EBER1) and polymerase chain reaction (PCR) analyses for immunoglobulin (Ig) heavy chain and T-cell receptor (TCR)-gamma gene rearrangements were performed on paraffin-embedded tissue from all patients. In addition, EBV strain typing and detection of the characteristic 30-bp deletion of the latent membrane protein-1 (LMP-1) gene were performed by PCR. Controls included 8 cases of uncomplicated infectious mononucleosis (IM). Patients included 4 males and 2 females with a median age of 18 years (2-37 years). Three patients were Mexican, 2 were white, and 1 was of Asian descent. All presented with fever, hepatosplenomegaly, and pancytopenia; 5 were previously healthy, but had a clinical history of a recent viral-like upper respiratory illness (1 week to 2 months), and 1 patient had documented chronic active EBV infection for 7 years. Serologic data for EBV were incomplete but titers were either negative or only modestly elevated in 3 cases. In 1 case serology was consistent with severe chronic active EBV infection. In the remaining 2 cases serologic studies were not performed. All patients died within 7 days to 8 months of presentation with T-cell LPD. On histologic examination, the liver and spleen showed prominent sinusoidal and portal lymphoid infiltrates of CD3+, βF1+, EBER1+ T cells lacking significant cytologic atypia. Two cases were CD4+, 2 cases were CD8+, and 2 cases had admixed CD4+ and CD8+ cells without clear subset predominance. All were TIA-1+, CD56−. Only rare B cells were noted. Marked erythrophagocytosis was present. Molecular analysis revealed identical T-cell clones in 2 or more sites (liver, spleen, lymph node) in 5 cases. All patients carried type A EBV; 4 cases had wild-type EBV-LMP, and 2 showed the 30-bp deletion. This fulminant T-cell LPD after acute/chronic EBV infection is characterized by hepatosplenomegaly, often without significant lymphadenopathy, fever, liver failure, pancytopenia, and erythrophagocytosis indicative of a hemophagocytic syndrome. EBV serology may be misleading, with lack of elevated titers. The presence of an EBER1+ T-cell infiltrate with scant B cells should alert one to this diagnosis. Although cytologic atypia is minimal, studies for T-cell clonality confirm the diagnosis.

Fulminant EBV+ T-cell lymphoproliferative disorder following acute/chronic EBV infection: a distinct clinicopathologic syndrome

This study describes the clinicopathologic features of 5 patients who developed a fulminant Epstein-Barr virus (EBV)-positive clonal T-cell lymphoproliferative disorder (LPD) after acute EBV infection. One additional patient developed a similar disorder in the setting of long-standing chronic active EBV infection. Detailed immunophenotyping, in situ hybridization for EBV early RNA-1 (EBER1) and polymerase chain reaction (PCR) analyses for immunoglobulin (Ig) heavy chain and T-cell receptor (TCR)-gamma gene rearrangements were performed on paraffin-embedded tissue from all patients. In addition, EBV strain typing and detection of the characteristic 30-bp deletion of the latent membrane protein-1 (LMP-1) gene were performed by PCR. Controls included 8 cases of uncomplicated infectious mononucleosis (IM). Patients included 4 males and 2 females with a median age of 18 years (2-37 years). Three patients were Mexican, 2 were white, and 1 was of Asian descent. All presented with fever, hepatosplenomegaly, and pancytopenia; 5 were previously healthy, but had a clinical history of a recent viral-like upper respiratory illness (1 week to 2 months), and 1 patient had documented chronic active EBV infection for 7 years. Serologic data for EBV were incomplete but titers were either negative or only modestly elevated in 3 cases. In 1 case serology was consistent with severe chronic active EBV infection. In the remaining 2 cases serologic studies were not performed. All patients died within 7 days to 8 months of presentation with T-cell LPD. On histologic examination, the liver and spleen showed prominent sinusoidal and portal lymphoid infiltrates of CD3+, βF1+, EBER1+ T cells lacking significant cytologic atypia. Two cases were CD4+, 2 cases were CD8+, and 2 cases had admixed CD4+ and CD8+ cells without clear subset predominance. All were TIA-1+, CD56−. Only rare B cells were noted. Marked erythrophagocytosis was present. Molecular analysis revealed identical T-cell clones in 2 or more sites (liver, spleen, lymph node) in 5 cases. All patients carried type A EBV; 4 cases had wild-type EBV-LMP, and 2 showed the 30-bp deletion. This fulminant T-cell LPD after acute/chronic EBV infection is characterized by hepatosplenomegaly, often without significant lymphadenopathy, fever, liver failure, pancytopenia, and erythrophagocytosis indicative of a hemophagocytic syndrome. EBV serology may be misleading, with lack of elevated titers. The presence of an EBER1+ T-cell infiltrate with scant B cells should alert one to this diagnosis. Although cytologic atypia is minimal, studies for T-cell clonality confirm the diagnosis.

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.

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.

[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.

t(3;17)(q21;q25) in Epstein-Barr virus associated peripheral T-cell lymphoma: a paediatric case

We describe an immunocompetent 8-year-old boy with a serological profile indicating chronic infection by Epstein-Barr virus (EBV) who developed subcutaneous and pulmonary lesions related to a peripheral T-cell proliferation. No clonal rearrangement of T-cell receptor or immunoglobulin genes was seen. However, the finding of a t(3;17)(q21;q25) in 44 metaphases from one skin lesion demonstrated a clonal origin. We also showed that the proliferative T cells contained EBV genome leading to the diagnosis of EBV-associated peripheral T-cell lymphoma. Further cytogenetic and molecular studies are needed to identify genes implicated in the pathogenesis of this haematological malignancy.

Atypical clonal T-cell proliferation in infectious mononucleosis

An atypical case of infectious mononucleosis characterized by fever, acute tonsillitis, and bilateral cervical adenopathy is reported in a previously healthy young man. Although serology was positive for the Epstein-Barr virus, the patient did not display peripheral blood lymphocytosis or atypical, reactive lymphocytes. The patient's tonsilar tissue revealed an expanded T-zone of diffuse, monomorphous lymphocytes suggestive of lymphoma. Immunophenotypic analysis of the tonsilar tissue demonstrated more than 90% expression of pan-T markers, while pan-B markers were positive in 5-10% of the interfollicular T-zone cells and in 90% of germinal centre cells. In situ hybridization with a probe specific for EBER1 demonstrated positive staining in approximately 1% of the interfollicular tonsilar lymphocytes. Finally, Southern blot analysis of tonsilar tissue demonstrated a clonal rearrangement of the T-cell receptor gene. The patient recovered from his infection and remains in good health years after presenting with his illness. This case illustrates that T-cell clonality must be evaluated with caution in the setting of a viral infection and can occur in association with benign, self-limited infectious mononucleosis.

[Hemophagocytic syndromes]

Hemophagocytic syndromes are the clinicobiological translation of an unconnected macrophagic activity with hemophagocytosis. Their physiopathology is related with a deregulation of the T lymphocytes and an excessive production of cytokines. Acquired hemophagocytic syndromes are mostly associated with underlying pathology which they can reveal: immunodeficiency, infections (mostly of viral origin), hemopathies and cancers, auto-immune diseases. The main clinicobiological features are fever, hepatosplenomegaly and peripheric bicytopeny. In the majority of cases, the diagnosis is confirmed by a myelogram which shows the presence of benign histiocytes, actively phagocyting the hematopoietic cells. The pejorative prognosis of hemophagocytic syndromes (actual mortality rate 30 to 45%) requires an early therapy which associates etiological treatment of the underlying affection with pathogenic treatment (pulse of corticosteroids, immunoglobulins, immunosuppressors, or plasmapheresis).

Epstein-Barr virus as an agent of haematological disease

Epstein-Barr virus (EBV) encodes genes that permit its persistence in human B lymphocytes and genes that ensure its replication in epithelial cells. Immune restraints on the virus are usually so effective that most EBV infections are limited to a minute fraction of B lymphocytes and of epithelial cells. As a result, most EBV infections are never symptomatic. Occasionally, the virus causes disease, often with the cooperation of the immune system or other less characterized cofactors. Infectious mononucleosis, a generally self-limited lymphoproliferative illness common in adolescents and young adults, is due to primary EBV infection and to the brisk cellular immune response it elicits. Lymphoproliferative disorders of EBV-infected B cells arise almost exclusively when cellular immunity is grossly compromised. EBV-positive Burkitt's lymphoma contain a translocated and deregulated c-myc oncogene and EBV-positive non-Hodgkin's lymphomas are characterized by the presence of Reed-Sternberg's and Hodgkin's cells, features that have not been directly linked to EBV. Many recent observations, however, including evidence that virus infection precedes malignant transformation and is often associated with a characteristic pattern of viral gene expression, provide continued interest in the relationship between the virus and these haematological malignancies.

Epstein-Barr virus (EBV)-related lymphoproliferative disorder with subsequent EBV-negative T-cell lymphoma

A 58-year-old Chinese man presented initially with generalized lymphadenopathy, and lymph-node biopsy showed disturbed architecture with preponderance of large B-blasts mixed with numerous CD8+ T lymphocytes, consistent with an acute Epstein-Barr virus (EBV) infection. Immunohistological and gene rearrangement studies confirmed the absence of clonal T or B cells. Polyclonal EBV with lytic infection was detected by Southern blot hybridization (SoBH). Expression of EBV proteins (EBNA2, LMP and ZEBRA) was detected in a proportion of cells by immunostaining. EBV-lytic proteins EA-D, VCA, MA were also detected in rare scattered cells. Double immunostaining showed that the LMP-positive cells were of B and of T phenotype: 73% CD19+, 26% CD2+, 23% CD3+, 8% CD4+, 17% CD8+. After biopsy, there was spontaneous regression of lymph-node enlargement, but lymphadenopathy recurred 8 months later, and the second lymph-node biopsy showed T-cell lymphoma, confirmed by detection of clonally rearranged T-cell-receptor beta-chain gene. However, EBV genome could not be detected in the second biopsy by SoBH, in situ hybridization for EBV-encoded EBER RNA, and immunostaining for EBNA2, LMP and ZEBRA was also negative. This case is of special interest because an EBV-negative T-cell lymphoma developed shortly after an acute episode of EBV-related lymphoproliferation, even though many EBV-positive T cells were detected during the acute episode. EBV was apparently not a direct cause of the lymphoma, but the close temporal association of the 2 lesions supports the hypothesis that EBV can act as a co-factor in lymphomagenesis.