Aspects of human disease: 48. Herpesvirus infections

This series outlines, briefly, the clinical presentation, diagnosis and management of a further 20 chronic medical problems which are most common and important in the developed countries, but space also precludes coverage of acute infections and most malignant disease.

Rapidly progressive Epstein-Barr virus-associated lymphoproliferative disorder unpredictable by weekly viral load monitoring

We report a case of Epstein-Barr virus (EBV)-associated lymphoproliferative disease (LPD) following unrelated bone marrow transplantation (UBMT) for severe aplastic anemia treated with a conditioning regimen that included anti-thymocyte globulin (ATG). The patient showed signs of EBV reactivation as early as 34 days after UBMT. Our weekly schedule for EBV monitoring failed to trace rapid changes in EBV viral load and the patient eventually developed EBV-LPD. However, early intervention with monoclonal antibody against CD20, rituximab, stopped the further progression of EBV-LPD. As several recent reports have suggested, the safety and efficacy of rituximab treatment for EBV-LPD is supported by our limited experience with post transplant EBV-LPD.

Adoptive Immunotherapy for EBV-associated Malignancies

Latent Epstein-Barr virus (EBV) infection is associated with a diverse group of malignancies including Burkitt's lymphoma, Hodgkin's disease, nasopharyngeal carcinoma (NPC), and lymphoproliferative disease (LPD). EBV proteins expressed in these malignancies provide targets for the adoptive immunotherapy with antigen-specific cytotoxic T cells (CTL) and EBV-specific CTL have been used successfully for the prophylaxis and treatment of EBV-LPD post hematopoietic stem cell transplantation (HSCT). The clinical experience with EBV-specific CTL for other EBV-associated malignancies such as Hodgkin's disease and NPC is limited and the results obtained so far indicate that EBV-specific CTL are less effective than for EBV-LPD post HSCT. Decreased CTL efficacy most likely reflect immune evasion strategies by tumor cells such as down regulation of immunodominant EBV proteins and secretion of inhibitory cytokines. To overcome these immune evasion strategies a number of approaches have been developed including targeting CTL to subdominant EBV antigens and genetically modifying CTL to increase their potency.

Epileptic spasms after stem cell transplantation for chronic Epstein-Barr virus infection

Stem cell transplantation has been performed for various diseases, contributing to a markedly improved prognosis in some cases. However, several complications, including posterior reversible encephalopathy syndrome, have been evident. Although posterior reversible encephalopathy syndrome was originally defined as a reversible disease, it has become clear that it is not reversible in all patients. Epstein-Barr virus causes a wide spectrum of neurologic disorders, including epilepsy. To our knowledge, Epstein-Barr virus was not previously reported to cause epileptic spasms. We describe a girl with epileptic spasms after posterior reversible encephalopathy syndrome associated with stem cell transplantation for chronic Epstein-Barr virus infection. Although direct correlation was not clarified, this is a rare case that may contribute to our understanding of the neurologic complications of stem cell transplantation for chronic Epstein-Barr virus infection.

Brain tumor as an unusual presentation of posttransplant lymphoproliferative disorder

OBJECTIVES

Posttransplant lymphoproliferative disorder following solid organ transplant is a lifethreatening form of posttransplant malignancy. Its occurrence is typically associated with Epstein-Barr virus and profound immunosuppressive therapy. We describe a case of posttransplant lymphoproliferative disorder in the brain parenchyma, 4 years after renal transplant.

CASE REPORT

A 23-year-old man was evaluated for generalized headache 4 years after receiving a deceased donor renal transplant. After initial immunosuppression with tacrolimus and prednisolone, mycophenolate mofetil was added for maintenance immunosuppression. A tumor in the right occipitoparietal lobe was detected by magnetic resonance imaging and excised. Immunohistochemical testing of the tumor revealed B-cell marker and Epstein-Barr virus. After surgery, the dosage of immunosuppressive drugs was reduced, and the patient was treated with chemotherapy and radiotherapy. Our patient is well after treatment.

CONCLUSIONS

Reduction in immunosuppressive therapy is an important component of treatment for Epstein-Barr virus-positive posttransplant lymphoproliferative disorder and may lead to remission in early disease. If reduced immunosuppression fails to control early disease, cytotoxic chemotherapy, surgery and radiotherapy, antiviral therapies, and cell-based therapies are other options for treatment.

Mucocutaneous manifestations of Epstein-Barr virus infection

This review focuses on Epstein-Barr virus (EBV) infection, diagnosis, and current treatment, with emphasis on EBV-associated mucocutaneous manifestations in primary infections, acute EBV-associated syndromes, chronic infections, lymphoproliferative disorders, and lymphomas. In primary infection, EBV infects B cells and can cause mucocutaneous manifestations in infectious mononucleosis or acute EBV-associated syndromes such as Gianotti-Crosti syndrome and hemophagocytic syndrome. EBV then persists in the majority of humans generally without causing disease. In some cases, however, latent EBV infection may result in diseases such as hydroa vacciniforme, hypersensitivity to mosquito bites, and lymphoproliferative disorders such as plasmablastic lymphoma, oral hairy leukoplakia, and post-transplant lymphoproliferative disorders, particularly in immunocompromised patients. Latent EBV infection has also been implicated in a variety of malignant conditions such as Burkitt lymphoma, Hodgkin lymphoma, nasopharyngeal carcinoma, and Kikuchi histocytic necrotizing lymphadenitis. Since the immune system is critical in preventing the progression of EBV disease, the immunologic status of the patient plays a crucial role in the subsequent development of pathologies.

Overview of gene therapy clinical progress including cancer treatment with gene-modified T cells

It is now twenty years since the first legal gene transfer studies were approved, and there has been considerable disappointment in the slow rate of progress that followed the initial studies. Gradually, however, as the limitations of available vectors are acknowledged and overcome, and with advances in our understanding of the molecular and cell biology of genetic diseases and of cancer, unequivocal successes are now being reported. In this paper we describe the remaining major roadblocks to successful gene therapy and outline approaches to overcome them. We also illustrate how genetically modified immune system cells are already being used for the effective treatment of hematological and other malignancies, and how these approaches are being modified so that they can be effective in treating a broader range of malignancies.

Epstein-Barr virus nuclear antigen 1-specific CD4+ T cells directly kill Epstein-Barr virus-carrying natural killer and T cells

Epstein-Barr virus (EBV) nuclear antigen (EBNA)1 is expressed in every EBV-infected cell, regardless of the state of EBV infection. Although EBNA1 is thought to be a promising antigen for immunotherapy of all EBV-associated malignancies, it is less clear whether EBNA1-specific CD4(+) T cells can act as direct effectors. Herein, we investigated the ability of CD4(+) T-cell clones induced with overlapping peptides covering the C-terminal region of EBNA1, and identified minimal epitopes and their restricted major histocompatibility complex class II molecules. Of these, a novel epitope, EYHQEGGPD, was found to be presented by DRB1*0401, 0403 and 0406. Five CD4(+) T-cell clones recognized endogenously processed and presented antigens on EBV-transformed lymphoblastoid cell lines (LCL) and one example proved capable of killing EBV-carrying natural killer (NK) and T-cell lines derived from patients with chronic active EBV infection (CAEBV). Identification of minimal epitopes facilitates design of peptide-based vaccines and our data suggest that EBNA1-specific CD4(+) T cells may play roles as direct effectors for immunotherapy targeting EBV-carrying NK and T-cell malignancies.

Adoptive transfer of antigen-specific T-cells of donor type for immunotherapy of viral infections following allogeneic hematopoietic cell transplants

Allogeneic marrow and cytokine-mobilized peripheral blood stem cells adequately depleted of T cells prevent acute and chronic forms of graft versus host disease in HLA-matched and non-identical hosts without any posttransplant immunosuppressive prophylaxis. Current cytoreductive regimens secure consistent durable engraftment, and full donor chimerism. The risk of relapse following such transplants in patients with AML and ALL has been low, and not different from that recorded following unmodified transplants. However, in HLA-disparate hosts the risk of infections caused by EBV, CMV, and certain fungi are increased. To address this limitation, others and we are exploring adoptive immunotherapies with in vitro generated, pathogen-specific T cells. Early clinical trials already indicate the potential of such T cells to treat and prevent life threatening diseases caused by these pathogens, particularly in recipients of T cell depleted grafts who do not require ongoing treatment with immunosuppressive agents, and therefore provide a permissive environment for the expansion and persistence of the T cells following adoptive transfer. New more predictable strategies are under development, which should allow such therapies to be broadly applicable.

Epstein-Barr virus-targeted immunotherapy for nasopharyngeal carcinoma

Epstein-Barr virus (EBV) is constantly present in undifferentiated and poorly-differentiated nasopharyngeal cancer. Thus, tumour-associated viral antigens are potential targets for immunotherapy. Recently, both preclinical and early clinical studies have shown that various strategies can enhance EBV-specific immunity. Moreover, significant anti-tumour effect has been observed, and was generally correlated with biological response. The present review discusses the rational for EBV-targeted immunotherapy and summarises the latest developments in this area.

T cell therapy of Epstein-Barr virus and adenovirus infections after hemopoietic stem cell transplant

Epstein-Barr virus (EBV)-associated post-transplant lymphoproliferative disease (PTLD) and adenovirus (AdV)-related pathologies are life-threatening complications of immunosuppression in recipients of hematopoietic stem cell transplantation (HSCT). In certain cohorts (unrelated and haploidentical donor HSCT, T-cell-depleted allograft), the risk of developing these complications is higher. Here we describe the impact of T cell therapy, within programs of specific routine surveillance and preemptive treatment, on the course of EBV infection, and development of related disease, in pediatric recipients of T-cell-depleted, HLA-haploidentical HSCT. Future prospectives include the transfer of this technology to treat AdV-related complications following HSCT.

Successful reduced-intensity stem cell transplantation with cord blood for a poor-prognosis adult with refractory chronic active epstein-barr virus infection

A 56-year-old woman with a poor-prognosis chronic active Epstein-Barr virus (CAEBV) infection underwent reduced-intensity stem cell transplantation (RIST) using cryopreserved cord blood (CB). Administration of EBV-seronegative CB cells following a reduced-intensity conditioning regimen was effective and well tolerated. Complete remission with no symptoms, low titers of EBV-related antibodies, and an undetectable level of EBV DNA in peripheral blood mononuclear cells continued for 16 months after RIST. This report is the first of successful RIST with CB for an adult with CAEBV infection. The results also show that a graft-versus-CAEBV effect can be achieved in an allogeneic hematopoietic stem cell transplantation setting.

Advanced therapeutic and prophylactic strategies for Epstein-Barr virus infection in immunocompromised patients

Epstein-Barr virus (EBV) is an ubiquitous human herpesvirus. Primary infection is generally subclinical but in certain circumstances, such as in patients with either hereditary or secondary immunodeficiency, EBV infection may cause overt disease that is often lethal. Strategies for the prophylaxis and treatment of these potentially life-threatening complications of EBV infection have advanced dramatically. They include immunological-based approaches targeted at EBV-infected cells, as well as improvement in the treatment of the underlying and predisposing disease. This review will discuss EBV biology and immune events that occur in both immunocompetent and immunocompromised individuals and introduce the novel prophylactic and therapeutic strategies for EBV-associated life-threatening diseases.

Improving T cell therapy for cancer

Adoptive transfer of antigen-specific T lymphocytes is a powerful therapy for the treatment of opportunistic disease and some virus-associated malignancies such as Epstein-Barr virus-positive post-transplant lymphoproliferative disease. However, this strategy has been less successful in patients with nonviral cancers owing to their many and varied immune evasion mechanisms. These mechanisms include downregulation of target antigens and antigen-presenting machinery, secretion of inhibitory cytokines, and recruitment of regulatory immune cells to the tumor site. With increased understanding of the tumor microenvironment and the behavior and persistence of ex vivo-manipulated, adoptively transferred T cells, two novel approaches for increasing the efficacy of T cell therapy have been proposed. The first involves genetic modification of tumor-specific T cells to improve their biological function, for example by augmenting their ability to recognize tumor cells or their resistance to tumor-mediated immunosuppression. The second requires modifications to the host environment to improve the homeostatic expansion of infused T cells or to eliminate inhibitory T cell subsets. In this review, we discuss current, promising strategies to improve adoptive T cell therapy for the treatment of cancer.

Lymphoepithelial carcinoma of the parotid gland: is an association with Epstein-Barr virus possible in non-endemic areas?

Lymphoepithelial carcinoma (LEC) is a rare histological type of cancer of the salivary glands. Here is reported a case of LEC of the parotid gland that developed in a Caucasian female, whose serology was positive for Epstein-Barr virus antibody. The patient underwent surgical treatment and postoperative radiotherapy. Because of the relatively limited clinical data concerning LEC of the salivary glands compared to other more common histological types, the clinical course, optimal treatment and prognosis have not been extensively studied. The aim of this report was to summarize all the key points, following a comprehensive literature review.

Successful treatment of lymphoproliferative disease complicating primary immunodeficiency/immunodysregulatory disorders with reduced-intensity allogeneic stem-cell transplantation

Lymphoproliferative disease (LPD) is a recognized complication of primary immunodeficiency (PID) and immunodysregulatory syndromes. Historically, it has a very poor outcome. For patients surviving LPD, myeloablative hematopoietic stem cell transplantation (SCT) was the only cure for the underlying PID, with a high risk of developing posttransplantation complications, including recurrent lymphoproliferative disease. We describe 8 patients with a range of PID and immunodysregulatory syndromes complicated by LPD. After initial treatment of the LPD (including the use of anti-CD20 monoclonal antibody, rituximab, in 6 of the patients), all patients underwent reduced-intensity conditioning (RIC) SCT with prospective monitoring for Epstein-Barr virus (EBV) viremia. After transplantation, 3 patients received rituximab, and 3 patients received prophylactic EBV-specific cytotoxic T-lymphocytes. Only 1 patient developed recurrent LPD posttransplantation, which responded to rituximab. All patients who underwent transplantation survive free of LPD and are cured of their PID at a median follow-up of 4 years (range, 1-7 years). With careful monitoring and pre-emptive therapy, we advocate this RIC SCT approach to patients with PID who have pre-existing EBV-LPD.

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

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

Allogeneic cytotoxic T-cell therapy for EBV-positive posttransplantation lymphoproliferative disease: results of a phase 2 multicenter clinical trial

We present the results of a multicenter clinical trial using Epstein-Barr virus (EBV)-specific cytotoxic T lymphocytes (CTLs) generated from EBV-seropositive blood donors to treat patients with EBV-positive posttransplantation lymphoproliferative disease (PTLD) on the basis of the best HLA match and specific in vitro cytotoxicity. Thirty-three PTLD patients who had failed on conventional therapy were enrolled. No adverse effects of CTL infusions were observed and the response rate (complete or partial) in 33 patients was 64% at 5 weeks and 52% at 6 months. Fourteen patients achieved a complete remission, 3 showed a partial response, and 16 had no response at 6 months (5 died before completing treatment). At 5 weeks, there was a significant trend toward better responses with higher numbers of CD4(+) cells in infused CTL lines (P = .001) that were maintained at 6 months (P = .001). Patients receiving CTLs with closer HLA matching responded better at 6 months (P = .048). Female patients responded better than male patients, but the differences were not statistically significant. Our results show that allogeneic CTLs are a safe and rapid therapy for PTLD, bypassing the need to grow CTLs for individual patients. The response rate in this poor prognosis patient group is encouraging.

The ABC of Epstein-Barr Virus Infections

The EBV has evolved mechanisms that allow it to take advantages of different aspects of the human immune system, resulting in evasion of the defense mechanisms of the host. The virus is capable of resting calmly in a "sea of tranquility". The virus has the unique ability among herpesviruses to transform infected B lymphocytes, thereby creating the potential for uncontrolled lymphoproliferation. Such lymphoproliferation occurs when the immune system is deregulated as a result of inborn defects or acquired defects (e.g., XLP syndrome and organ transplantation, respectively). Otherwise, EBV is kept in check by the surveillance activity of cytotoxic T lymphocytes and NK cells.

Interferon-gamma expressing EBV LMP2A-specific T cells for cellular immunotherapy

To generate therapeutic T cells for adoptive immunotherapy, T cells specific to Epstein-Barr virus LMP2A were enriched on the basis of antigen-specific production of interferon-gamma (IFNgamma). The enriched T cells, contained over 60% LMP2A-specific effectors, were polyclonal and targeted multiple LMP2A epitopes. A high proportion of the enriched T cells produced the Th1 cytokines interleukin (IL)-2 and granulocyte monocyte colony stimulating factor, while few cells expressed the Th2 cytokines IL4 and IL10. The enriched T cells specifically lysed LMP2A-expressing target cells, with concomitant production of IFNgamma and surface expression of CD107, suggesting the involvement of the granule exocytosis-mediated cytolytic pathway. In addition, the enriched T cells expressed CD45RO, CD28 and CD27, but not CD45RA, consistent with a differentiation stage capable of self-renewal for long-term persistence. LMP2A-specific T cells enriched based on IFNgamma-production may provide improved efficacy for the treatment of Epstein-Barr virus related malignancy.