Hemophagocytic syndrome following an Epstein-Barr virus infection: a case report and literature review

Hemophagocytosis is an uncommon disorder characterized by proliferation of histiocytes that actively engulf other hematopoietic cells causing cytopenia. Reactive or secondary hemophagocytosis is very rare in healthy adults in the US. Various infectious, as well as neoplastic and immunologic etiologies of reactive hemophagocytosis have been reported. It is a non-malignant, reactive disorder characterized by hemophagocytosis in the bone marrow and reticuloendothelial system (RES) resulting in pancytopenia, fever, hepatic dysfunction, and disseminated intravascular coagulation (DIC). No consensus exists in the literature regarding optimal treatment of virus-associated hemophagocytic syndrome (VAHS). We report a case of VAHS in a previously healthy immunocompetent male and review the diagnosis and management of this rare disorder.

Epstein-Barr virus (EBV) load in bone marrow transplant recipients at risk to develop posttransplant lymphoproliferative disease: prophylactic infusion of EBV-specific cytotoxic T cells

A semiquantitative polymerase chain reaction assay was used to monitor the blood levels of Epstein-Barr virus (EBV)-DNA in 9 patients receiving allogeneic bone marrow transplants (BMT). Four of 5 recipients of HLA-mismatched T-cell-depleted grafts showed a 4- to 5-log increase of EBV-DNA within 1 to 3 months after BMT. Administration of 2 to 4 infusions of 10(7) EBV-specific cytotoxic T-lymphocytes (CTLs)/m(2) starting from the time of maximal virus load resulted in a 2- to 3-log decrease of virus titers in 3 patients. One patient, who received a T-cell culture lacking a major EBV-specific component, progressed to fatal EBV-positive lymphoma. Administration of EBV-CTLs before the onset of the EBV-DNA peak resulted in stabilization of the virus titers within 2 to 3 logs above the normal levels in the fifth patient. A moderate increase of virus titers was also detected in 3 of 4 patients receiving unmanipulated HLA-matched grafts, whereas 1 patient with Wiskott-Aldrich syndrome reached a 5-log increase of EBV-DNA load within 70 days after BMT. Our results suggest that a rapid increase of circulating EBV-DNA occurs in the absence of EBV-specific T-cell precursors or in the presence of congenital immune defects that prevent the reestablishment of virus-specific immunity. Prophylactic administration of EBV-CTLs early after BMT appears to provide the most effective protection against the development of EBV-associated lymphoproliferative disease.

Chronic, active Epstein-Barr virus infection

Chronic active Epstein-Barr virus (EBV) infection is an uncommon outcome of EBV infection and may present as a waxing and waning or fulminant syndrome. Unlike acute infectious mononucleosis, wherein EBV establishes lifelong infection and survives by maintaining a delicate balance with the host as a latent infection, in chronic active EBV infection the host-virus balance is disturbed. The mechanisms by which this balance becomes perturbed are likely to be heterogenous and may involve host immune factors, viral factors, or both. A number of subtle immunologic defects have been reported in patients with chronic active EBV infection. Enhanced expression of viral genes has also been noted in some cases. Treatment of chronic active EBV infection has proven difficult, but new modalities including etoposide-based regimens and adoptive transfer of EBV-specific cytotoxic T lymphocytes have shown promise.

Management and outcome of liver recipients with post-transplant lymphoproliferative disease

BACKGROUND/AIMS

The possibility of development of post-transplant lymphoproliferative disease by patients receiving immunosuppressive therapy is well known. However, elective treatment and outcome remain controversial. We reviewed the management and outcome of our patients with post-transplant lymphoproliferative disease.

METHODOLOGY

Records of 457 patients who underwent orthotopic liver transplantation from 1986 to 1997 were analyzed. Patients who developed post-transplant lymphoproliferative disease were reviewed retrospectively. Incidence, clinical presentation, risk factors and outcomes were examined with special emphasis on ductopenic rejection and hilum involvement.

RESULTS

Eleven patients developed a post-transplant lymphoproliferative disease (2.4%). These were B-cell non-Hodgkins lymphoma, Epstein-Barr virus-associated in all cases. Five patients (45.5%) received monoclonal antibodies or antithymocyte globulin. Seven patients (63.6%) developed a lymphoproliferative disease before 9 months post-transplant and 4 recipients (36.4%) after 20 months. No late lymphomas regressed after withdrawal from immunosuppression. Six patients (54.5%) were treated with chemotherapy. Eight patients (72.7%) had a tumoral remission. Five patients (45.5%) developed chronic rejection after immunosuppressant discontinuation. Four of them died as a consequence of ductopenic rejection and retransplantation was required in another; 2 died due to graft hilum infiltration. Five patients (45.5%) are alive after a follow-up of 36.5 +/- 32 months (range: 4-77 months).

CONCLUSIONS

Patients with post-transplant lymphoproliferative disease require a close follow-up in order to promptly treat conditions that could lead to death. In our series, these were more closely associated with a failing transplanted organ than with the lymphoma itself.

Epstein-Barr virus-induced posttransplant lymphoproliferative disorders. ASTS/ASTP EBV-PTLD Task Force and The Mayo Clinic Organized International Consensus Development Meeting

Epstein-Barr virus-induced posttransplant lymphoproliferative disease (EBV-PTLD) continues to be a major complication after solid organ transplantation in high-risk patients. Despite the identification of risk factors that predispose patients to develop EBV-PTLD, limitations in our knowledge of its pathogenesis, variable criteria for establishing the diagnosis, and lack of randomized studies addressing the prevention and treatment of EBV-PTLD hamper the optimal management of this transplant complication. This review summarizes the current knowledge of EBV-PTLD and, as a result of two separate international meetings on this topic, and provides recommendations for future areas of study.

The management of Epstein-Barr virus associated post-transplant lymphoproliferative disorders in pediatric solid-organ transplant recipients

Despite a growing understanding of the pathogenesis and spectrum of Epstein-Barr virus (EBV) and EBV-associated post-transplant lymphoproliferative disease (PTLD) in organ transplant recipients, the optimal management of this complication remains controversial. The absence of comparative data evaluating potential therapeutic strategies explains the lack of uniformly accepted guidelines for the management of PTLD. The purpose of this review is to provide an overview of potential therapies and offer a set of guidelines for the management of EBV-associated PTLD in children.

Selective amino acid substitutions of a subdominant Epstein-Barr virus LMP2-derived epitope increase HLA/peptide complex stability and immunogenicity: implications for immunotherapy of Epstein-Barr virus-associated malignancies

The latent membrane protein 2 is an immunogenic antigen expressed in Epstein-Barr virus (EBV)-associated tumors and consequently it may represent a target for specific cytotoxic T lymphocyte (CTL)-based immunotherapies. However, the efficacy of such a therapy is limited by the poor immunogenicity of the protein that induces weak CTL responses directed to the CLGGLLTMV (CLG) epitope only in the minority of EBV-seropositive donors. We have now demonstrated that selective peptide stimulation of peripheral blood lymphocytes induced CLG-specific CTL in all donors, suggesting that this epitope can be a suitable target for specific immunotherapies. We found that the CLG peptide has a low affinity for HLA-A*0201 and does not produce stable complexes, both factors that are likely to determine the strength of CTL responses to this epitope. Therefore, we synthesized and tested CLG analogues carrying single or combined amino acid substitutions to increase HLA/peptide stability. Among the analogues tested we identified two peptides which, compared to the natural epitope, showed higher affinity for HLA-A*0201 molecules, and produced stable complexes. These peptides demonstrated a potent, specific stimulatory capacity and could be used for selective CTL-based therapies.

[Donor leukocyte infusion after allogeneic stem cell transplantation]

Adoptive cellular immunotherapy with donor leukocytes of patients submitted to allogenic stem cell transplantation has had significant success in the past few years, especially in the treatment of primary disease relapse and in the prevention and treatment of some post-transplant infectious complications. Most patients treated with donor leukocytes had a relapse of chronic myelogenous leukemia, which was successfully re-induced into remission. The most significant toxicities of this treatment are the development of graft versus host disease and marrow aplasia. Three strategies were developed to limit the former: the infusion of graded doses of donor leukocytes, the depletion of CD8+ cells and the transfer of donor leukocytes transvected with a timidine kinase gene, which renders these cells sensitive to gancyclovir. The post-transplant infectious complications treated successfully with donor leukocytes were Epstein-Barr virus-induced lymphoproliferative disorders and cytomegalovirus infection. The former, arising most frequently in recipients of unrelated and/or mismatched T-cell depleted grafts, were treated with donor unseparated leukocytes or Epstein-Barr virus-specific T-cells. Cytomegalovirus infection in the early post-transplant period was largely prevented by the infusion of virus-specific T-cell clones, which restored donor-specific immunity to cytomegalovirus in the recipient.

Interferon gamma (IFN-gamma) deficiency in generalized Epstein-Barr virus infection with interstitial lymphoid and granulomatous pneumonia, focal cerebral lesions, and genital ulcers: remission following IFN-gamma substitution therapy

A 26-year-old previously healthy woman developed granulomatous pneumonitis, encephalitis, and genital ulceration during primary Epstein-Barr virus (EBV) infection. EBV DNA was demonstrated by polymerase chain reaction analysis of serum, lung tissue, and genital ulcer specimens. Serology verified primary EBV infection. The patient lacked lymphocytes cytotoxic to autologous EBV-transformed B lymphocytes. No spontaneous or in vitro EBV-induced interferon gamma (IFN-gamma) production was evident in peripheral blood. The cells had normal IFN-gamma production when stimulated with Staphylococcus aureus exotoxin A. In the bone marrow and peripheral blood, the number of large granular CD56+ lymphocytes (natural killer cells) increased 39%-55%, but no CD4 or CD8 cell lymphocytosis was initially found. A partial clinical response was achieved with treatment with acyclovir, corticosteroids, and intravenous gamma-globulin. Because of persistent granulomatous central nervous system and lung involvement, subcutaneous IFN-gamma therapy was started but was discontinued after 3 months because of development of fever, pancytopenia, and hepatitis. This therapy initiated a complete clinical recovery, which occurred parallel to development of EBV-specific cytotoxic CD8+ T lymphocytes and normalization of natural killer cell lymphocytosis. These findings provide evidence for an EBV-induced lymphoproliferative disorder due to a T lymphocyte dysfunction associated with a selective lack of IFN-gamma synthesis.

Interferon-alpha and its effects on post-transplant lymphoproliferative disorders

EBV-transformation induces B lymphocytes to secrete high levels of human IL-10. Additionally, EBV contains a gene, BCRF1, that encodes for a protein that shares activity with human IL-10 in vitro. Thus, infection by EBV seems to promote a Th2 environment in the infected host. One may even hypothesize that EBV-derived IL-10 initiates a cascade of events that promotes a Th2 response and suppresses Th1 activity. This is further confirmed by data that suggest elevated concentrations of IL-4, IL-10, and IgE in patients with PTLD. This implies an association between PTLD and an imbalance in the immunoregulatory system with either an excess suppression of Th1 cells and/or an up-regulation of Th2 cells. One could speculate that if the imbalance in the immunoregulatory system is corrected, the patient's own immune system could potentially defend itself against the virus. Clearly, this is the case in those immunocompromised patients with PTLD who respond to just a reduction in their immunosuppression. Unfortunately, this is only beneficial in approximately half of patients with PTLD. Perhaps this is because patients often do not become entirely immunocompetent, either because all of their immunosuppression cannot be discontinued for fear of rejection or because once the above cascade is established the immune system is not capable of easily switching to the Th1 response necessary for combating the virus. Theoretically, IFN-alpha, because of its anti-viral effect, its anti-neoplastic effect and/or possibly by its ability to promote a Th1 response, should be useful in the treatment of PTLD. IFN-alpha modulates the immune system by several mechanisms including: preventing B cells from producing immunoglobulins, reducing IL-6 receptor density, and augmenting the inhibition of IL-4 by IL-12. In vitro studies document its effectiveness against EBV. Unfortunately, the available evidence as to its efficacy in vivo in patients with PTLD is very limited. At present, there are only 16 reported cases in the literature. There are also three cases of BLPD in immunocompromised patients that were all successfully treated with IFN-alpha and the two cases alluded to earlier from Children's Hospital of Pittsburgh (personal communication). Although the numbers are small, the results are promising. Of the 21 patients with BLPD who received IFN-alpha, 15 achieved complete remission. Four others improved and 2 died from BLPD. One of the 4 that improved died 3 months later from a relapse. Thus, there was an overall mortality of 14% (3 of 21) in those who received therapy with IFN-alpha. This is a very heterogeneous group of patients, several of whom had also received additional therapies. Thus, it is impossible to draw definitive conclusions. However, the mortality rate in this group of patients, who had already failed therapy with a reduction in their immunosuppression, compares very favorably to the reported mortality rate of approximately 23-81% in patients with PTLD. This data suggest that a large multi-centered prospective trial comparing IFN-alpha with and without IVIg to other treatment options (i.e., LAK cells) is warranted in those patients with EBV-positive PTLD who fail to respond to a reduction in their immunosuppression.

Incidence and outcome of primary Epstein-Barr virus infection and lymphoproliferative disease in pediatric heart transplant recipients

BACKGROUND

The objective of this study was to assess the relationship between Epstein-Barr virus (EBV) infection and posttransplantation lymphoproliferative disease (PTLD) in pediatric heart transplant recipients. EBV is implicated in the development of PTLD. However, the relationship between primary EBV infection and PTLD is not well understood.

METHODS

Serial EBV titers were determined prospectively in 50 children before and after heart transplantation. Results were correlated with the development of PTLD. The clinical presentation, management, and outcome of PTLD were characterized.

RESULTS

Before transplantation, EBV titers were positive in 19 and negative in 31 patients. After transplantation, all EBV-positive patients remained positive; 1 developed PTLD. Among EBV-negative patients, 12 of 31 remained negative; none developed PTLD. Nineteen patients demonstrated serologic evidence of primary EBV infection after heart transplantation; 12 developed PTLD. Mean follow-up after heart transplantation was 3.3 years (range 0.4 to 8.4 years). Mean time from heart transplantation to histologic confirmation of PTLD was 29 months (range 3 to 72 months). Survival with PTLD was 92%.

CONCLUSIONS

Twelve of 13 pediatric heart transplant recipients who developed PTLD had evidence of primary EBV infection. Serial monitoring of EBV titers may lead to earlier identification and improved treatment of PTLD.

Effective treatment of high-grade lymphoproliferative disorder after renal transplantation using autologous lymphocyte activated killer cell therapy

Posttransplantation lymphoproliferative disorders (PTLD) is not uncommon and can occur in 2% to 5% of solid organ recipients on immunosuppression. Epstein-Barr virus (EBV) infection or reactivation and intensive anti-T lymphocyte treatment are important pathogenetic factors for a large proportion of these disorders. Nonclonal lesions with polymorphous histology have a potential for regressing when the immunosuppressants are reduced or stopped. Clonal tumors with a monomorphous histology carry a poor prognosis, and the mortality rate for monoclonal lymphoma has been reported as high as 80%. We report a renal transplant recipient who developed high-grade monoclonal lymphoma only 4 months after a live-donor transplantation. The tumor was EBV positive. Reduction of immunosuppressants resulted in minimal regression of the tumor. The patient was treated with adoptive immunotherapy using ex vivo generation of autologous lymphocyte activated killer (LAK) cells. She had leukapheresis, and autologous peripheral blood mononuclear cells were obtained and cultured in interleukin-2 (IL-2)-rich medium for 9 to 10 days. The IL-2-activated LAK cells were reinfused into the patient without any systemic administration of IL-2. The patient experienced no side effects during the infusion. There was no rejection episode, and the renal function of the patient remained stable after treatment. Computed tomography scan performed 2 months after the infusion showed marked regression of the lesions in the liver and spleen. Five months later, magnetic resonance imaging showed complete resolution of the tumor lesions. Ultrasonography 13 months after the LAK cell infusion showed no lesion. The allograft function was not affected after treatment. Adoptive immunotherapy using IL-2-activated autologous LAK cells was effective in treating this renal transplant patient with EBV-positive high-grade lymphoma. The patient's kidney allograft functioned well without any rejection.

Anti-B-cell monoclonal antibody treatment of severe posttransplant B-lymphoproliferative disorder: prognostic factors and long-term outcome

B-lymphoproliferative disorder (BLPD) is a rare but severe complication of organ and bone marrow transplantation (BMT). Profound cytotoxic T-cell deficiency is thought to allow the outgrowth of Epstein-Barr virus-transformed B cells. When possible, reduction of immunosuppressive treatment or surgery for localized disease may cure BLPD. Therapeutic approaches using chemotherapy or antiviral drugs have limited effects on survival. Adoptive immunotherapy with donor T-cell infusions has given promising results in BMT recipients. We previously reported that administration of two monoclonal anti-B-cell antibodies (anti-CD21 and anti-CD24) could contribute to the control of oligoclonal BLPD. Here we report the long-term results of treatment with these monoclonal anti-B-cell antibodies for cases of severe BLPD. In an open multicenter trial, 58 patients in whom aggressive B-cell lymphoproliferative disorder developed after BMT (n = 27) or organ (n = 31) transplantation received 0.2 mg/kg/d of specific anti-CD21 and anti-CD24 murine monoclonal antibodies (MoAbs) for 10 days. The treatment was well tolerated. Thirty-six of the 59 episodes of BLPD in the 58 patients presented complete remission (61%). The relapse rate was low (3 of 36, 8%). Multivariate analysis identified the following risk factors for partial or no response to anti-B-cell MoAb therapy: multivisceral disease (P </= .005), central nervous system involvement (P </= .05), and late onset of BLPD (P </= .005). The overall long-term survival was 46% (median follow-up, 61 months); it was lower among BMT patients (35%) than organ transplant patients (55%). None of the patients who had received BMT for hematological malignancy survived for 1 year. Eight of these 11 patients presented monoclonal BLPD. Tumor burden was the only other variable that contributed significantly to poor survival. Thus, as assessed from this long-term study, the use of anti-B-cell MoAbs therefore appears to be a safe and relatively effective therapy for severe posttransplant BLPD.

Gene and cell transfer for specific immunotherapy

The realisation that human tumor cells may express and process tumor specific and tumor associated antigens has increased interest in immunotherapeutic approaches to cancer treatment. This interest has been coupled with a burgeoning ability to genetically modify tumor cells and components of the immune system, in an effort to maximize the anti-neoplastic response. In a number of settings, gene modified tumor vaccines, cytotoxic T cells and dendritic cells are producing both immunomodulation and clinically evident benefits. Continued exploration of this approach seems well justified.

EBV specific CTL: a model for immune therapy

We have been generating Epstein-Barr virus specific cytotoxic T cells for patients at high risk of developing EBV driven lymphoma. To discover the fate of the cells in vivo, we first marked them genetically, using a retroviral vector. Our results in 51 patients show that the approach is safe, that the CTL persist for several years and that they are able to mediate anti-viral and anti-tumor effects. We are now studying other virally-linked malignancies to discover whether a similar approach will be of therapeutic value.

Epstein-Barr virus lymphoproliferative disorders after liver transplantation

Post-transplant lymphoproliferative disorders (PTLD) represent a spectrum of histological and immunological abnormalities, ranging from benign polyclonal B-cell hyperplasia to monoclonal malignant lymphoma. The important role of Epstein-Barr virus (EBV) in PTLD in liver transplant patients, particularly in pediatric recipients, is reviewed. Understanding the risks of EBV infection, the clinical presentations and diagnosis of PTLD, and its pathophysiology are crucial to the management of these disorders. Current treatment methods have resulted in better outcomes of these disorders, which in the past were uniformly fatal.