Anti-CD20 monoclonal antibody (Rituximab) and Cidofovir as successful treatment of an EBV-associated lymphoma with CNS involvement

Treatment of Epstein-Barr Virus infection in immunocompromised patients

Epstein-Barr Virus (EBV), is a ubiquitous γ-Herpesvirus that infects over 95% of the human population and can establish a life-long infection without causing any clinical symptoms in healthy individuals by residing in memory B-cells. Primary infection occurs in childhood and is mostly asymptomatic, however in some young adults it can result in infectious mononucleosis (IM). In immunocompromised individuals however, EBV infection has been associated with many different malignancies. Since EBV can infect both epithelial and B-cells and very rarely NK cells and T-cells, it is associated with both epithelial cancers like nasopharyngeal carcinoma (NPC) and gastric carcinoma (GC), with lymphomas including Burkitt Lymphoma (BL) or Post-transplant Lymphoproliferative Disorder (PTLD) and rarely with NK/T-cell lymphomas. Currently there are no approved antivirals active in PTLD nor in any other malignancy. Moreover, lytic phase disease almost never requires antiviral treatment. Although many novel therapies against EBV have been described, the management and/or prevention of EBV primary infections or reactivations remains difficult. In this review, we discuss EBV infection, therapies targeting EBV in both lytic and latent state with novel therapeutics developed that show anti-EBV activity as well as EBV-associated malignancies both, epithelial and lymphoproliferative malignancies and emerging therapies targeting the EBV-infected cells.

Outcome of Rituximab-Based Treatment for Post-Transplant Lymphoproliferative Disorder After Allogeneic Hematopoietic Stem Cell Transplantation: A Single-Center Experience

Background

Post-transplant lymphoproliferative disorder (PTLD) is a rare complication following solid organ transplantation and allogeneic hematopoietic stem cell transplantation (Allo-HSCT), which gives rise to high mortality rates.

Material/Methods

This was a single-center retrospective analysis based on 27 patients who were diagnosed with PTLD following Allo-HSCT between January 1, 2007 and June 2018 at the Chinese PLA General Hospital. The purpose of this analysis was to investigate responses and prognostic factors of rituximab-based treatment.

Results

Twenty-seven patients were treated with rituximab. Among them, 20 of 27 patients (74.07%) had a complete response, 2 of 27 patients (7.41%) had a partial response, 5 of 27 patients (18.52%) had no response, and 22 of 27 patients (81.48%) cleared Epstein-Barr virus (EBV) copies. There were no obvious side effects. The 1-year overall survival (OS) estimate was 46.8% (95% CI, 23.1–65.5%). Univariate analysis revealed that lower OS was correlated with Eastern Cooperative Oncology Group (ECOG) score standard (3–4), Epstein-Barr virus (EBV) viral load (≥10⁶ copies/mL), bacteria or fungal infection, and EBV reactivation were positive after treatment with 1 or 2 doses of rituximab (P<0.05). Multivariate analysis showed that each of the following were independently associated with lower OS (P<0.05): female, ECOG score standard (3–4), and EBV reactivation were positive after treatment with 1 or 2 doses of rituximab.

Conclusions

Our results demonstrated that rituximab-based treatment was a safe and effective strategy for patients who were diagnosed with PTLD following Allo-HSCT. The identified prognostic factors may help to detect which PTLD patients are at a higher risk of mortality.

Potential of acyclic nucleoside phosphonates in the treatment of DNA virus and retrovirus infections

The acyclic nucleoside phosphonates [HPMPC: cidofovir, Vistide; PMEA: adefovir dipivoxil, Hepsera; and PMPA: tenofovir, Viread] have proven to be effective in vitro (cell culture systems) and in vivo (animal models and clinical studies) against a wide variety of DNA virus and retrovirus infections, for example, cidofovir against herpesvirus [herpes simplex virus type 1 and 2, varicella-zoster virus, cytomegalovirus, Epstein-Barr virus, human herpesvirus type 6, 7 and 8), polyoma-, papilloma-, adeno- and poxvirus (variola virus, cowpox virus, vaccinia virus, molluscum contagiosum virus and orf) infections; adefovir against herpesvirus, hepadnavirus [human hepatitis B virus] and retrovirus [HIV type-1 and 2, simian immunodeficiency virus and feline immunodeficiency virus] infections; and tenofovir against both hepadna- and retrovirus infections. Cidofovir has been officially approved for the treatment of cytomegalovirus retinitis in AIDS patients, tenofovir disoproxil fumarate (Viread) for the treatment of HIV infections (i.e., AIDS) and adefovir dipivoxil for the treatment of chronic hepatitis B.

Role of infectious agents in the carcinogenesis of brain and head and neck cancers

This review concentrates on tumours that are anatomically localised in head and neck regions. Brain cancers and head and neck cancers together account for more than 873,000 cases annually worldwide, with an increasing incidence each year. With poor survival rates at late stages, brain and head and neck cancers represent serious conditions. Carcinogenesis is a multi-step process and the role of infectious agents in this progression has not been fully identified. A major problem with such research is that the role of many infectious agents may be underestimated due to the lack of or inconsistency in experimental data obtained globally. In the case of brain cancer, no infection has been accepted as directly oncogenic, although a number of viruses and parasites are associated with the malignancy. Our analysis of the literature showed the presence of human cytomegalovirus (HCMV) in distinct types of brain tumour, namely glioblastoma multiforme (GBM) and medulloblastoma. In particular, there are reports of viral protein in up to 100% of GBM specimens. Several epidemiological studies reported associations of brain cancer and toxoplasmosis seropositivity. In head and neck cancers, there is a distinct correlation between Epstein-Barr virus (EBV) and nasopharyngeal carcinoma (NPC). Considering that almost every undifferentiated NPC is EBV-positive, virus titer levels can be measured to screen high-risk populations. In addition there is an apparent association between human papilloma virus (HPV) and head and neck squamous cell carcinoma (HNSCC); specifically, 26% of HNSCCs are positive for HPV. HPV type 16 was the most common type detected in HNSCCs (90%) and its dominance is even greater than that reported in cervical carcinoma. Although there are many studies showing an association of infectious agents with cancer, with various levels of involvement and either a direct or indirect causative effect, there is a scarcity of articles covering the role of infection in carcinogenesis of brain and head and neck cancers. We review recent studies on the infectious origin of these cancers and present our current understanding of carcinogenic mechanisms, thereby providing possible novel approaches to cancer treatment.

Using antimicrobial adjuvant therapy in cancer treatment: a review

Recent clinical and pre-clinical data demonstrate that adjuvant antimicrobial therapy is beneficial in cancer treatment. There could be several reasons for this effect, which include treating cancer associated bacteria and viruses, prophylaxis of post-chemotherapy infections due to immunosuppression, and antiproliferative effect of certain antimicrobials. Targeting cancer associated viruses and bacteria with antimicrobial agents is currently used for gastric, cervical, hematopoietic, liver and brain cancer. However this treatment is effective only in combination with conventional therapies. Antimicrobials can also have a direct antiproliferative and cytotoxic effect, and can cause apoptosis. Moreover, some antimicrobials are known to be helpful in overcoming side effects of drugs commonly used in cancer treatment. Chemotherapy related bacteremia and neutropenia can be overcome by the appropriately timed use of antimicrobials. This review summarizes the data on the effects of antivirals and antibiotics on cancer treatment and describes their mechanisms.

Successful Treatment of Posttransplant EBV-Associated Lymphoma and Plasmacytoma Solely Localized to the CNS

Two patients with diabetic nephropathy were diagnosed with primary central nervous system posttransplant Epstein-Barr-virus-associated lymphoproliferative disorder (PTLD) 3 years after renal transplantation. The histological diagnoses of the isolated brain tumors were diffuse large B-cell lymphoma and plasmacytoma. Considerable co-morbidity precluded intensive chemotherapy. The first patient with lymphoid CD20+ PTLD had a partial resection of her tumor performed. She was treated with 4 weekly doses of rituximab, ganciclovir and prednisolone; the posttransplant immune suppression (tacrolimus) was reduced. After 4 weeks of treatment a magnetic resonance imaging (MRI) demonstrated complete regression of the CNS lesion. The patient continues to receive rituximab (every second month), valgangciclovir and low-dose prednisolone. Twenty-two months after initiation of therapy, she is still in complete remission. The second patient was only treated with craniospinal irradiation involving the medulla to the second cervical vertebra and valgangciclovir. Moreover, the posttransplant immune suppression was reduced. A new MRI two months after initiation of therapy showed a complete regression of the lesions in the CNS; this was again demonstrated by a MRI after 19 months. These 2 cases illustrate interesting alternative treatments of PTLD. To our knowledge, an EBV-associated PTLD of plasmacytic origin isolated to the CNS has never been described before.

Treatment of HIV-related primary central nervous system lymphoma with AZT high dose, HAART, interleukin-2 and foscarnet in three patients

PURPOSE

Combined immunomodulatory and antiviral treatment was administered to three patients with newly diagnosed HIV-associated primary central nervous system lymphoma (PCNSL) in an attempt to improve outcomes.

PATIENTS AND METHODS

Three patients from our institution who were recently diagnosed with HIV-associated PCNSL received intravenous azidothymidine (AZT) 1.6 gr. bid for two weeks, followed by oral AZT 250mg bid from day 15. In addition, complementary highly active antiretroviral therapy (HAART) with a second nucleoside reverse transcriptase inhibitor (NRTI) plus one protease inhibitor (PI) and interleukin 2 (IL-2) subcutaneously 2 million units twice daily (bid) plus foscarnet 90mg/kg bid were administered on days 1-14. One patient received anti-Epstein-Barr virus (EBV)-maintenance therapy with ganciclovir, followed by cidofovir.

RESULTS

All patients experienced progressive disease while on induction therapy, and switched early to whole-brain radiation therapy (WBRT) as second line-treatment. No grade 3 or 4 toxicities were observed. Two patients died on days 50 and 166 respectively due to progressive disease. The third patient with histo?logically proven lymphoproliferation and only suspected PCNSL remained alive at 53 months. He was on HAART and remained clinically and neurologically stable.

CONCLUSION

Although IL-2, HAART, high-dose AZT and foscarnet are used for other HIV-related conditions, they did not demonstrate benefit in lymphoma remission for 2 HIV- associated PCNSL patients. The third patient went into delayed remission after additional radiotherapy and was in good clinical and neurological health status over 53 months after diagnosis.

Epstein-Barr virus-associated B-cell lymphomas: pathogenesis and clinical outcomes

Epstein-Barr virus (EBV) is a ubiquitous human γ-herpesvirus that establishes a life-long asymptomatic infection in immunocompetent hosts. It is also found to be frequently associated with a broad spectrum of B-cell lymphomas predominantly seen in immunodeficient patients. Despite many resemblances, these EBV-linked lymphoproliferative disorders display heterogeneity at the clinical and the molecular level. Moreover, EBV-associated lymphoproliferative diseases differ in their differential expression patterns of the EBV-encoded latent antigens, which are directly related to their interactions with the host. EBV-driven primary B-cell immortalization is linked to the cooperative functions of these latent proteins, which are critical for perturbing many important cell-signaling pathways maintaining B-cell proliferation. Additionally, it is used as a surrogate model to explore the underlying mechanisms involved in the development of B-cell neoplasms. Recent discoveries have revealed that a number of sophisticated mechanisms are exploited by EBV during cancer progression. This finding will be instrumental in the design of novel approaches for therapeutic interventions against EBV-associated B-cell lymphomas. This review limits the discussion to the biology and pathogenesis of EBV-associated B-cell lymphomas and the related clinical implications.

Intraocular lymphoma: update on diagnosis and management

BACKGROUND

Primary intraocular lymphoma (PIOL) is a subset of primary central nervous system lymphoma (PCNSL) in which lymphoma cells initially invade the retina, vitreous, or optic nerve head, with or without concomitant CNS involvement. The incidence of this previously rare condition has increased dramatically. Given its nonspecific presentation and aggressive course, PIOL provides a diagnostic and therapeutic challenge.

METHODS

We review the current strategies for diagnosis and treatment of PIOL and present our own experience with PIOL.

RESULTS

Recent developments in the diagnosis of PIOL include immunohistochemistry, flow cytometry, cytokine evaluation, and molecular analysis. However, definitive diagnosis still requires harvesting of tissue for histopathology. Optimal treatment for PIOL remains unclear. Initial therapeutic regimens should include methotrexate-based chemotherapy and radiotherapy to the brain and eye. In addition, promising results have been seen with intravitreal methotrexate and autologous stem cell transplantation for recurrent and refractory disease.

CONCLUSIONS

Efforts to further determine the immunophenotype and molecular characteristics of PIOL will continue to assist in the diagnosis of PIOL. Future studies are required to determine the role of radiotherapy and optimal local and systemic chemotherapeutic regimens.

Real-time quantitative PCR for assessment of antiviral drug effects against Epstein-Barr virus replication and EBV late mRNA expression

This study assesses the ability of quantitative real-time PCR to measure the effects of virus DNA polymerase inhibitors on EBV DNA and late mRNAs syntheses in EBV-producing cell lines. In-house real-time quantitative PCRs were used to measure EBV DNA (thymidine kinase) and mRNAs (BLLF1 gene/gp350/220, BVRF2 gene/protease) in P3HR-1 and B95-8 cells induced for EBV production by PMA and exposed to ganciclovir, cidofovir and foscarnet. The calculated 50% effective concentrations (EC(50)) for viral DNA replication inhibition in P3HR-1 cells after 7 days of drug exposure were 0.28+/-0.06, 0.29+/-0.01 and 13.6+/-0.17 microg/mL for ganciclovir, cidofovir and foscarnet, respectively. The EC(50) for B95-8 cells were 0.44+/-0.02, 0.70+/-0.06 and 46.8+/-0.5 microg/mL, respectively. The quantitation of the late viral mRNAs showed a decrease of 79-89% in the mRNA amount after 4 days of antiviral treatment. Nevertheless, a substantial amount of mRNA still remained detectable after drug exposure. The real-time PCR is an improvement in the attempt to simplify EBV DNA-quantitation for antiviral assays. The quantitation of late mRNA does not appear as more informative than DNA quantitation for the assessment of the DNA polymerase inhibitor activity, but it may be useful to assess the antiviral activity of drugs acting by another mechanism.

Epstein-Barr virus-associated post-transplant lymphoproliferative disease with central nervous system involvement after unrelated allogeneic hematopoietic stem cell transplantation

Post-transplant lymphoproliferative disorders (PTLD) represent an heterogeneous group of abnormal lymphoid proliferation related to Epstein-Barr virus (EBV) reactivation that arise early after allogeneic hematopoietic stem cell transplant (HSCT). PLTD with central nervous system (CNS) involvement has been reported in few cases. We describe the case of a 31-year-old-man who developed an EBV-related PTLD with CNS involvement 2 months after an allogeneic unrelated HSCT for acute myeloid leukemia in first complete remission who was successfully treated with rituximab, cidofovir and intrathecal infusion of methotrexate and methylprednisolone.

Management of patients with post-transplant lymphoproliferative disorder: the role of rituximab

Post-transplant lymphoproliferative disorder (PTLD) is a serious complication of solid organ and bone marrow transplantations. Rituximab (Rituxan, Mabthera), a chimeric monoclonal antibody to the CD20 antigen on the surface of B-cell lymphocytes, has been used increasingly in the treatment of PTLD. Rituximab was initially approved for the treatment of low-grade non-Hodgkin lymphomas, but multiple case studies, retrospective analyses, and phase II trials demonstrate the benefit of rituximab in PTLD. This paper reviews the current data on rituximab and its promising role in the management of PTLD.

Epstein-Barr virus and cancer

EBV was the first human virus to be directly implicated in carcinogenesis. It infects >90% of the world's population. Although most humans coexist with the virus without serious sequelae, a small proportion will develop tumors. Normal host populations can have vastly different susceptibility to EBV-related tumors as demonstrated by geographical and immunological variations in the prevalence of these cancers. EBV has been implicated in the pathogenesis of Burkitt's lymphoma, Hodgkin's disease, non-Hodgkin's lymphoma, nasopharyngeal carcinoma, and lymphomas, as well as leiomyosarcomas arising in immunocompromised individuals. The presence of this virus has also been associated with epithelial malignancies arising in the gastric region and the breast, although some of this work remains in dispute. EBV uses its viral proteins, the actions of which mimic several growth factors, transcription factors, and antiapoptotic factors, to usurp control of the cellular pathways that regulate diverse homeostatic cellular functions. Recent advances in antiviral therapeutics, application of monoclonal antibodies, and generation of EBV-specific CTLs are beginning to show promise in the treatment of EBV-related disorders.

Clinical potential of the acyclic nucleoside phosphonates cidofovir, adefovir, and tenofovir in treatment of DNA virus and retrovirus infections

The acyclic nucleoside phosphonates HPMPC (cidofovir), PMEA (adefovir), and PMPA (tenofovir) have proved to be effective in vitro (cell culture systems) and in vivo (animal models and clinical studies) against a wide variety of DNA virus and retrovirus infections: cidofovir against herpesvirus (herpes simplex virus types 1 and 2 varicella-zoster virus, cytomegalovirus [CMV], Epstein-Barr virus, and human herpesviruses 6, 7, and 8), polyomavirus, papillomavirus, adenovirus, and poxvirus (variola virus, cowpox virus, vaccinia virus, molluscum contagiosum virus, and orf virus) infections; adefovir against herpesvirus, hepadnavirus (human hepatitis B virus), and retrovirus (human immunodeficiency virus types 1 [HIV-1] and 2 [HIV-2], simian immunodeficiency virus, and feline immunodeficiency virus) infections; and tenofovir against both hepadnavirus and retrovirus infections. Cidofovir (Vistide) has been officially approved for the treatment of CMV retinitis in AIDS patients, tenofovir disoproxil fumarate (Viread) has been approved for the treatment of HIV infections (i.e., AIDS), and adefovir dipivoxil (Hepsera) has been approved for the treatment of chronic hepatitis B. Nephrotoxicity is the dose-limiting side effect for cidofovir (Vistide) when used intravenously (5 mg/kg); no toxic side effects have been described for adefovir dipivoxil and tenofovir disoproxil fumarate, at the approved doses (Hepsera at 10 mg orally daily and Viread at 300 mg orally daily).

Primary central nervous system lymphoma in immunocompetent adults: poor results mainly associated with high treatment related toxicities

Treatment of primary central nervous system lymphoma (PCNSL) occurring in immunocompetent patients remains controversial but long-term survival has been reported in patients treated by chemotherapy regimens containing non-lipophilic drugs. We report 34 consecutive PCNSL patients treated at our institution by a chemotherapy regimen that combined drugs crossing and not crossing the blood-brain barrier. Early toxicity was high as 10 of 17 deaths that occurred within the first year of diagnosis were treatment related. Infections and thromboembolism were the main causes of toxicity. We concluded that the use of drugs of uncertain efficacy in these particularly fragile patients is questionable.