Is valganciclovir really effective in primary effusion lymphoma: case report of an HIV(−) EBV(−) HHV8(+) patient

Discovery of a small-molecule inhibitor of KSHV lytic replication from the MMV pandemic response box

Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent for primary effusion lymphoma (PEL), multicentric Castleman's disease (MCD) and Kaposi's sarcoma (KS). KSHV is one of the oncoviruses that contribute to 1.5 million new infection-related cancer cases annually. Currently, there are no targeted therapies for KSHV-associated diseases. Through the development of a medium-throughput phenotype-based ELISA screening platform based on KSHV ORF57 protein detection, we screened the Medicines for Malaria Venture (MMV) Pandemic Response Box for non-cytotoxic inhibitors of KSHV lytic replication. MMV1645152 was identified as a promising inhibitor of KSHV lytic replication, suppressing KSHV immediate-early and late lytic gene expression and blocking the production of infectious KSHV virion particles at non-cytotoxic concentrations in cell line models of KSHV infection with or without EBV coinfection. MMV1645152 is a promising hit compound for the development of future therapeutic agents against KSHV-associated malignancies.

Recent Advances in Developing Treatments of Kaposi's Sarcoma Herpesvirus-Related Diseases

Kaposi-sarcoma-associated herpesvirus (KSHV) or human herpesvirus 8 (HHV-8) is the causative agent of several malignancies, including Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman's disease (MCD). Active KSHV replication has also been associated with a pathological condition called KSHV inflammatory cytokine syndrome (KICS), and KSHV may play a role in rare cases of post-transplant polyclonal lymphoproliferative disorders. Several commonly used herpesviral DNA polymerase inhibitors are active against KSHV in tissue culture. Unfortunately, they are not always efficacious against KSHV-induced diseases. To improve the outcome for the patients, new therapeutics need to be developed, including treatment strategies that target either viral proteins or cellular pathways involved in tumor growth and/or supporting the viral life cycle. In this review, we summarize the most commonly established treatments against KSHV-related diseases and review recent developments and promising new compounds that are currently under investigation or on the way to clinical use.

The Changing Landscape of Lymphoma Associated with HIV Infection

Purpose of Review

Cancer remains a major cause of morbidity and mortality in HIV-infected individuals, with aggressive non-Hodgkin’s lymphoma as the most frequent one. However, the introduction of modern antiretroviral therapy (ART) drastically improved treatment options and prognosis in HIV-associated lymphomas. This review summarized the current treatment landscape and future challenges in HIV-positive patients with non-Hodgkin’s and Hodgkin’s lymphoma.

Recent Findings

Selecting the appropriate therapy for the individual patient, diffuse-large B cell lymphoma, Burkitt’s lymphoma, and Hodgkin’s disease may be curable diseases. In contrast, the prognosis of plasmablastic lymphoma and primary effusion lymphoma remain poor. New treatment approaches, as targeted therapies or CAR T cell therapy, may broaden the therapeutic armamentarium.

Summary

The continuous application of ART is mandatory for successful treatment. The choice of lymphoma therapy may follow the recommendations for HIV-negative patients, but prospective trials in HIV-lymphoma are needed.

Remission of an HHV8-related extracavitary primary effusion lymphoma in an HIV-positive patient during antiretroviral treatment containing dolutegravir

Background

Human herpes virus 8 (HHV8) is the causative agent of Kaposi’s sarcoma and has been associated with an increasing number of hematologic diseases such as primary effusion lymphoma (PEL) (both classic and extracavitary form), multicentric Castleman disease and the germinotropic lymphoproliferative disorder. PEL is a rare B cell non-Hodgkin lymphoma that primarily affects immunocompromised patients; aggressive chemotherapy and antiretroviral therapy (ART) with protease inhibitors have been used, with poor results. We present a case of extracavitary PEL in an HIV-infected patient, regressed after ART initiation.

Case presentation

A 42-year-old male was admitted to the emergency room because of several months of malaise, fever and progressive deterioration of the general conditions. On physical examination soft non-painful subcutaneous masses were palpable at retronuchal, retroauricolar and thoracic regions. HIV serology resulted positive: HIV plasma viremia was 782,270 copies/mL, CD4 103 cells/mL. The excision of one of the masses, metabolically active at a positron emission tomography (PET-CT) scan, revealed an HHV8-related extracavitary PEL. HHV8 plasma viremia was 44,826 copies/mL. ART with tenofovir alafenamide/emtricitabine/dolutegravir was started together with ganciclovir for cytomegalovirus chorioretinitis. The progressive disappearance of the masses was seen after 6 weeks of ART, and a PET-CT scan resulted completely negative at 3 months. After 19 months of ART the patient was in remission of PEL, HIV viremia was undetectable (< 20 copies/mL), CD4 count was 766 cells/mL and HHV8 viremia was undetectable.

Conclusions

In this clinical case, the complete regression of PEL has been achieved after the immune recovery, as a consequence of ART introduction, without chemotherapy. It cannot be excluded that ganciclovir, used for the treatment of CMV chorioretinitis, may have contributed to the control of HHV8 replication. Whether to try or not a conservative approach in HIV-infected PEL patients must be carefully evaluated, considering the patient’s characteristics and the prognostic factors.

Primary effusion lymphoma of the pleural space: Report of a rare complication of cardiac transplant with review of the literature

Primary effusion lymphoma (PEL) is a rare mature B-cell non-Hodgkin's lymphoma arising in body cavities and presenting with effusions. It has been described predominantly in patients with impaired immunity from the acquired immunodeficiency syndrome and is associated with the Human Herpesvirus-8 (HHV-8). Seldom has PEL been diagnosed in persons negative for the human immunodeficiency virus (HIV), and in such cases it has occurred primarily in the setting of posttransplant immunosuppression. We report an instructive case of a Caribbean-American HIV-negative orthotopic heart transplant recipient with a history of HHV-8-associated Kaposi's sarcoma who developed HHV-8 viremia and PEL of the pleural space early in the posttransplant course. This case highlights the importance of considering PEL in the differential diagnosis of a new pleural effusion in a transplant recipient at risk for HHV-8-associated disease.

Malignant lymphoma in the HIV-positive patient

The introduction of combination antiretroviral therapy (cART) drastically improved performance status, immune function, and life expectancy of HIV-infected individuals. In addition, incidence of opportunistic infections and of AIDS-defining malignancies declined. Nevertheless, aggressive non-Hodgkin's lymphoma still remains the leading cause of AIDS-related deaths. The availability of cART, however, significantly improved the therapeutic options for HIV-positive patients with lymphomas. Diffuse large B-cell lymphoma, Burkitt's lymphoma, or Hodgkin lymphoma has increasingly become curable diseases. In light of these favorable developments in the treatment of HIV and HIV-associated lymphomas, reduction in treatment-associated toxicities and further improvement of outcome of patients with advanced immune suppression are major requirements for future clinical trials. This review summarizes the current treatment landscape and gives an overview on future needs in HIV-positive patients with lymphoma.

Human γ-Herpesvirus Infection, Tumorigenesis, and Immune Control in Mice with Reconstituted Human Immune System Components

The human γ-herpesviruses Epstein–Barr virus (EBV or HHV4) and Kaposi sarcoma-associated herpesvirus (KSHV or HHV8) are each associated with around 2% of all tumors in humans worldwide. However, investigations into their infection, oncogenesis, and immune responses that protect from the associated tumors have been hampered by the exclusive tropism of these pathogens for humans. Mice with reconstituted human immune system components (HIS mice) provide the unique opportunity to study persistent infection, virus associated lymphoma formation, and cell-mediated immune control of EBV and KSHV. Moreover, since these pathogens are unique stimuli for cytotoxic human lymphocyte responses, they also allow us to characterize long-lasting cell-mediated immune control and the requirements for its initiation, which would also be desirable to achieve during antitumor vaccination in general. Thus, human γ-herpesvirus infection of HIS mice provides unique insights into the biology of these important human pathogens and human cell-mediated immune responses that are considered to be the main protective entity against tumors.

Case report of a primary effusion lymphoma successfully treated with oral valganciclovir after failing chemotherapy

Primary effusion lymphoma is a rare non-Hodgkin lymphoma that presents with pleural effusions and lacking of tumour mass. It is universally associated with human herpesvirus 8 (HHV8) and is more frequent among immunosuppressed patients. There is no standard treatment, chemotherapy and anti-HIV therapy have been used with poor results, but there is still no strong evidence supporting the use of valganciclovir. We present the case of a HIV positive man that presented with pleural effusion compatible with primary effusion lymphoma and positivity for HHV8 DNA in blood. Bortezomib-containing treatment protocol was started, but the disease progressed within the chemotherapy. Therefore, treatment with oral valganciclovir was decided and the patient achieved a sustained radiological complete response. HHV8 DNA turned negative 6 months after starting the treatment with valganciclovir.

Clinical management of HIV-associated hematologic malignancies

HIV is associated with an excess risk for lymphoid malignancies. Although the risk of lymphoma has decreased in HIV-infected individuals in the era of effective combination antiretroviral therapy, it remains high. Treatment outcomes have improved due to improvements in HIV and cancer therapeutics for the common HIV-associated lymphomas. R-CHOP/R-EPOCH are the standard of care for HIV-associated diffuse large B-cell lymphoma. HIV-infected patients with Burkitt lymphoma and good performance status should receive dose-intensive regimens. HIV-infected patients with primary central nervous system lymphoma can respond favorably to high-dose methotrexate-based therapy. In many cases, treatment and expected outcomes for HIV-infected patients with either Hodgkin or non-Hodgkin's lymphomas are very similar to HIV-negative patients. There is currently no standard treatment for HIV-associated multicentric Castleman disease or primary effusion lymphoma. For those hematologic cancers in which transplantation is part of standard care, this modality should be considered an option in those with well-controlled HIV infection.

Diverse clinicopathologic features in human herpesvirus 8-associated lymphomas lead to diagnostic problems

OBJECTIVES

Human herpesvirus 8 (HHV8)-associated lymphomas are uncommon, mainly affect men infected with the human immunodeficiency virus (HIV), and usually have a poor prognosis. We sought to characterize the HHV8+ lymphomas seen at our institution since the mid-1990s.

METHODS

We identified 15 patients with HHV8-associated lymphomas and evaluated their clinical and pathologic features.

RESULTS

Diagnoses included primary effusion lymphoma (PEL) (n = 2), extracavitary PEL (n = 8), intravascular large B-cell lymphoma (n = 1), HHV8+ plasmablastic microlymphoma (n = 3), and germinotropic lymphoproliferative disorder (GLD) (n = 1). The case of GLD progressed to a high-grade HHV8+ Epstein-Barr virus-positive lymphoma, an evolution that has not been previously reported. Four patients were HIV-(three from an HHV8-endemic area). Potentially misleading pathologic features in our series of extracavitary PEL included classic Hodgkin lymphoma-like features, lymph node sinus involvement, and T-cell antigen expression.

CONCLUSIONS

HHV8-associated lymphomas can be clinically and pathologically heterogeneous, with features that may lead to misdiagnosis as other types of lymphoma.

Sustained complete remission of primary effusion lymphoma with adjunctive ganciclovir treatment in an HIV-positive patient

Primary effusion lymphoma (PEL) is one of the least common of the AIDS-related lymphomas, accounting for less than 1-4% of cases. Clinical manifestations depend on the extent and distribution of disease and, as in the majority of patients no detectable mass lesion is found, symptoms are related to fluid accumulation, dyspnoea (pleural or pericardial effusions), abdominal distension (ascites) or joint swelling. The median survival after diagnosis, even with aggressive chemotherapy, remains poor and remissions are often of short duration. We present the case of a 31-year-old man with AIDS and diagnosis of PEL, in whom sustained and complete remission of the tumour was achieved with adjunctive ganciclovir therapy. Since the disease is so uncommon, there is a paucity of data to guide the treatment of these patients; ganciclovir might be a potential antiviral therapeutic option, as demonstrated by the 2-year remission achieved in our patient.