Treatment of AIDS-related primary central nervous system lymphoma with zidovudine, ganciclovir, and interleukin 2

Posttransplant lymphoproliferative disorder in a kidney transplant recipient: a case of Epstein-Barr virus-positive primary central nervous system lymphoma

Posttransplant lymphoproliferative disorders (PTLDs) are potentially life-threatening complications of chronic immunosuppression in patients who receive solid organ transplants or allogeneic hematopoietic cell transplantation. Most PTLD cases are associated with Epstein-Barr virus (EBV) serology, and their incidence is typically higher in the first year of transplantation. Isolated EBV-positive diffuse large-cell B-cell lymphoma in the renal transplant setting has rarely been reported. Isolated EBV-positive primary central nervous system lymphoma (PCNSL) is rare, even in renal transplant patients with chronic immunosuppression. We report a case of frontal lobe EBV-positive PCNSL in a renal transplant patient who presented with left-sided weakness and was later treated with a consolidated chemotherapeutic regimen without concurrent radiotherapy.

Clinical and Therapeutic Implications of Epstein-Barr Virus in HIV-Related Lymphomas

The incidence of lymphomas is increased in people living with HIV (PLWH). Aggressive B-cell non-Hodgkin lymphomas (NHLs) are the most common and are considered an AIDS-defining cancer (ADC). Although Hodgkin lymphoma (HL) is not considered an ADC, its incidence is also increased in PLWH. Among all HIV-related lymphomas (HRL), the prevalence of Epstein-Barr virus (EBV) is high. It has been shown that EBV is involved in different lymphomagenic mechanisms mediated by some of its proteins, contributing to the development of different lymphoma subtypes. Additionally, cooperation between both HIV and EBV can lead to the proliferation of aberrant B-cells, thereby being an additional lymphomagenic mechanism in EBV-associated HRL. Despite the close relationship between EBV and HRL, the impact of EBV on clinical aspects has not been extensively studied. These lymphomas are treated with the same therapeutic regimens as the general population in combination with cART. Nevertheless, new therapeutic strategies targeting EBV are promising for these lymphomas. In this article, the different types of HRL are extensively reviewed, focusing on the influence of EBV on the epidemiology, pathogenesis, clinical presentation, and pathological characteristics of each lymphoma subtype. Moreover, novel therapies targeting EBV and future strategies to treat HRL harboring EBV are discussed.

Primary Vitreoretinal Lymphoma in HIV Infection

Purpose: To describe the epidemiology, clinical characteristics, diagnosis and treatment of human immunodeficiency virus (HIV)-related primary vitreoretinal lymphoma (PVRL).Methods: Narrative literature review.Results: HIV-related PVRL occurs in persons who are relatively young and generally have very low CD4+ T-cell counts. Vitritis with subretinal or sub-retinal pigment epithelial infiltrates is typical. Vitreous cytology remains the gold standard for diagnosis, supplemented by flow cytometry and genetic analyses of tumor cells, and measurement of aqueous or vitreous interleukin-10 levels. Concurrent brain involvement also may establish the diagnosis. Treatment includes antiretroviral therapy (ART), systemic chemotherapy (usually methotrexate-based) and local ocular treatment (intravitreal methotrexate, intravitreal rituximab, external beam radiotherapy). Systemic chemotherapy is of uncertain value for PVRL without other central nervous system involvement. Prognosis is poor, but has improved significantly compared to the pre-ART era.Conclusions: Ophthalmologists should consider the diagnosis of PVRL in HIV-positive individuals who present with intermediate or posterior uveitis.

Opportunities to Target the Life Cycle of Epstein-Barr Virus (EBV) in EBV-Associated Lymphoproliferative Disorders

Many lymphoproliferative disorders (LPDs) are considered “EBV associated” based on detection of the virus in tumor tissue. EBV drives proliferation of LPDs via expression of the viral latent genes and many pre-clinical and clinical studies have shown EBV-associated LPDs can be treated by exploiting the viral life cycle. After a brief review of EBV virology and the natural life cycle within a host we will discuss the importance of the viral gene programs expressed during specific viral phases, as well as within immunocompetent vs. immunocompromised hosts and corresponding EBV-associated LPDs. We will then review established and emerging treatment approaches for EBV-associated LPDs based on EBV gene expression programs. Patients with EBV-associated LPDs can have a poor performance status, multiple comorbidities, and/or are immunocompromised from organ transplantation, autoimmune disease, or other congenital or acquired immunodeficiency making them poor candidates to receive intensive cytotoxic chemotherapy. With the emergence of EBV-directed therapy there is hope that we can devise more effective therapies that confer milder toxicity.

Complete and Durable Responses in Primary Central Nervous System Posttransplant Lymphoproliferative Disorder with Zidovudine, Ganciclovir, Rituximab, and Dexamethasone

Purpose: Primary central nervous system posttransplant lymphoproliferative disorder (PCNS-PTLD) is a complication of solid organ transplantation with a poor prognosis and typically associated with Epstein-Barr virus (EBV). We hypothesized EBV lytic-phase protein expression would allow successful treatment with antiviral therapy.Patients and Methods: Thirteen patients were treated with zidovudine (AZT), ganciclovir (GCV), dexamethasone, and rituximab in EBV⁺ PCNS-PTLD. Twice-daily, intravenous AZT 1,500 mg, GCV 5 mg/kg, and dexamethasone 10 mg were given for 14 days. Weekly rituximab 375 mg/m² was delivered for the first 4 weeks. Twice-daily valganciclovir 450 mg and AZT 300 mg started day 15. Lytic and latent protein expression was assessed using in situ hybridization and immunohistochemistry. Immunoblot assay assessed lytic gene activation. Cells transfected with lytic kinase vectors were assessed for sensitivity to our therapy using MTS tetrazolium and flow cytometry.Results: The median time to response was 2 months. Median therapy duration was 26.5 months. Median follow-up was 52 months. The estimated 2-year overall survival (OS) was 76.9% (95% CI, 44.2%-91.9%). Overall response rate (ORR) was 92% (95% CI, 64%-100%). BXLF1/vTK and BGLF4 expression was found in the seven tumor biopsies evaluated. Lytic gene expression was induced in vitro using the four-drug regimen. Transfection with viral kinase cDNA increased cellular sensitivity to antiviral therapy.Conclusions: EBV⁺ PCNS-PTLD expressed lytic kinases and therapy with AZT, GCV, rituximab and dexamethasone provided durable responses. Induction of the lytic protein expression and increased cellular sensitivity to antiviral therapy after transfection with viral kinase cDNA provides a mechanistic rationale for our approach. Clin Cancer Res; 24(14); 3273-81. ©2018 AACR.

Primary CNS lymphoma in HIV infection

Primary CNS lymphoma (PCNSL) has been designated an acquired immune deficiency syndrome (AIDS)-defining disease since 1983 and accounts for up to 15% of non-Hodgkin lymphomas in human immunodeficiency virus (HIV) patients. The majority of HIV patients are Epstein-Barr virus (EBV)-related. The most likely etiology is ineffective immunoregulation of EBV, inducing oncogenic protein expression, and subsequent loss of apoptosis and increased proliferation of lymphocytes. PCNSL generally presents with supratentorial, single or multiple, contrast-enhancing lesions. Neurologic symptoms can be headache, cognitive function disorders, focal neurologic, deficit and epilepsy. Differential diagnosis includes other oncologic or infectious causes, with cerebral toxoplasmosis being the most important. Magnetic resonance imaging characteristics, activity on ²⁰¹thallium single-photon emission computed tomography, presence of EBV DNA in the cerebrospinal fluid, and toxoplasmosis serology can make either PCNSL or cerebral toxoplasmosis more or less likely. However, definitive diagnosis of PCNSL relies on histopathologic confirmation. First-choice treatment is combination antiretroviral therapy in combination with high-dose methotrexate(-based) chemotherapy in patients in whom this is feasible. Combination antiretroviral therapy combined with whole-brain radiotherapy may be an alternative. Treatment of EBV with antiviral agents such as ganciclovir or zidovudine may be beneficial, but this needs further study. Prognosis of HIV-related PCNSL is poor, with median survival varying from 2 to 4 months, but patients treated with chemotherapy do better (median survival 1.5 years).

Zidovudine-based lytic-inducing chemotherapy for Epstein-Barr virus-related lymphomas

Treatment of Epstein-Barr virus (EBV)-related lymphomas with lytic-inducing agents is an attractive targeted approach for eliminating virus-infected tumor cells. Zidovudine (AZT) is an excellent substrate for EBV-thymidine kinase: it can induce EBV lytic gene expression and apoptosis in primary EBV+ lymphoma cell lines. We hypothesized that the combination of AZT with lytic-inducing chemotherapy agents would be effective in treating EBV+ lymphomas. We report a retrospective analysis of 19 patients with aggressive EBV+ non-Hodgkin lymphoma, including nine cases of acquired immune deficiency syndrome-associated primary central nervous system lymphoma (AIDS-PCNSL) treated with AZT-based chemotherapy. Our results demonstrate that high-dose AZT-methotrexate is efficacious in treating highly aggressive systemic EBV+ lymphomas in the upfront setting. In primary EBV+ lymphoma cell lines, the combination of AZT with hydroxyurea resulted in synergistic EBV lytic induction and cell death. Further, AZT-hydroxyurea treatment resulted in dramatic responses in patients with AIDS-PCNSL. The combination of AZT with chemotherapy, especially lytic-inducing agents, should be explored further in clinical trials for the treatment of EBV-related lymphomas.

Primary CNS lymphoma: a clinician's guide

Primary CNS lymphoma is a high malignant disease of the brain which can lead rapidly to death if diagnosis and/or the start of treatment is delayed. The age at time of diagnosis is a strong factor influencing prognosis so that in younger patients <65 years of age long-term survival may be achieved in a substantial percentage of patients, while in elderly patients long-term survival is seen much more rarely. First-line therapy consists of high-dose methotrexate-based (poly)chemotherapy. This review provides an overview of clinical presentation, steps to diagnosis, detailed information about current treatment concepts and specific information for particular clinical situations.

Newly emerging therapies targeting viral-related lymphomas

Gamma-(γ)-herpes virus lymphomas comprise a heterogenous group of B-cell and T-cell neoplasms most commonly associated with Epstein-Barr virus and rarely human herpes virus-8 infection. Adult T-cell leukemia/lymphoma (ATLL) is a unique disease entity caused by the human T-cell lymphotrophic virus, type 1 (HTLV-I), the only retrovirus known to cause cancer in humans. Viral lymphomas behave aggressively and disproportionally affect immunocompromised individuals and those living in underdeveloped regions. These diseases are often difficult to treat with conventional approaches. Despite recent advancements using cytotoxic, lymphoma-specific, and adoptive therapies, the long-term outcome of patients with γ-herpesvirus lymphomas occurring in severely immunocompromised patients and ATLL continues to be poor. Lytic-inducing therapies targeting NF-κB, and viral and tumor cell epigenetic mechanisms afford the advantage of exploiting the intrinsic presence of oncogenic viruses to eradicate infected tumor cells. In this review, viral-related lymphomas and newly emerging clinical approaches targeting viral latency are discussed.

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.

Oral and extraoral plasmablastic lymphoma: similarities and differences in clinicopathologic characteristics

Plasmablastic lymphoma (PBL), initially characterized as an aggressive lymphoma arising in the jaw and oral mucosa in HIV-infected patients, was recently reported to occur with extraoral manifestations, heterogeneous histologic findings, and variable association with immunodeficiency states. We reviewed clinical, morphologic, and immunophenotypic features of 13 cases of PBL to determine whether these different subtypes represent distinct morphologic and clinical entities. Two distinct subtypes of PBL were identified and classified as oral and extraoral PBL. The oral PBLs were strongly associated with HIV infection and commonly demonstrated plasmablastic morphologic features without plasmacytic differentiation. Extraoral PBLs tended to occur in patients with underlying non-HIV-related immunosuppression and universally demonstrated plasmacytic differentiation. The patients with oral PBL demonstrated better overall survival compared with patients with extraoral PBL (P = .02). Our findings suggest that PBL with oral and extraoral manifestation represent 2 distinct clinicopathologic entities.

HIV-associated plasmablastic lymphoma: lessons learned from 112 published cases

Plasmablastic lymphoma (PBL) is a distinct subtype of non-Hodgkin B-cell lymphoma, originally described with a strong predilection to the oral cavity of human immunodeficiency virus (HIV)-infected individuals. Data regarding patient age and gender, HIV status, initiation of and response to highly active antiretroviral therapy (HAART), tumor extent, pathology, treatment, and outcome were extracted from 112 cases of PBL identified in the literature. The median age at presentation was 38 years with a male predominance of 7:1, and the median CD4+ count was 178 cells/mm(3). PBL presented on average 5 years after diagnosis of HIV. Common primary sites of presentation included the oral cavity, gastrointestinal tract, and lymph nodes. Most cases presented with either stage I or stage IV disease. There was a variable expression of B-cell markers in tumor cells, but plasma cell markers were expressed in all cases. EBV was detected in 74%. Chemotherapy was used to treat 55% patients and was combined with radiotherapy in 21% cases. Complete response was obtained in 66% of treated cases; the majority of these responses were seen after CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone). The refractory/relapsed disease rate was 54%. Death occurred in 53% of patients, with a median overall survival of 15 months. Sex, CD4+ count, viral load, clinical stage, EBV status, primary site of involvement, and use of CHOP failed to show an association with survival. PBL is an aggressive B-cell lymphoma that presents in both oral and extra-oral sites of chronically HIV-infected immunosuppressed young men.

The significance of Epstein-Barr virus detected in the cerebrospinal fluid of people with HIV infection

INTRODUCTION

Epstein-Barr virus (EBV) is detected in the cerebrospinal fluid (CSF) in people with HIV infection who develop primary cerebral lymphoma (PCL). However, EBV may also be detected in the CSF of patients without PCL, and here the significance is uncertain.

METHODS

Ninety-eight HIV-positive patients had lumbar punctures performed and polymerase chain reaction (PCR) for EBV was undertaken on the CSF. Thirty-eight patients had non-Hodgkin's lymphoma (NHL), including four with PCL. Sixty patients had a CSF examination for other indications. The clinicopathological details, symptoms, diagnosis, CSF and neuroimaging findings and therapy at time of CSF were recorded and correlated with CSF EBV PCR results.

RESULTS

EBV was detected in the CSF in three of four patients (75%) with PCL, one of three (33%) with systemic lymphoma and meningeal involvement, and four of 31 (13%) with systemic lymphoma and no meningeal disease. Seven of 60 patients (12%) without lymphoma were CSF EBV-positive. There were no differences in immunological, clinical, biochemical or radiological parameters between patients with and without EBV in the CSF. After a median follow-up time of 30 weeks (maximum 102 weeks), none of the seven CSF EBV-positive patients has developed PCL.

CONCLUSION

EBV was detected in up to 12% of patients with neurological symptoms but without lymphoma. A positive result did not correlate with more advanced immunosuppression or a particular neurological diagnosis. Patients with EBV in their CSF did not appear to be at increased risk of developing PCL in the short term.

AIDS malignancies

Among individuals with HIV-infection, coinfection with oncogenic viruses including EBV, HHV-8, and HPV cause significant cancer-related morbidity and mortality. It is clear that these viruses interact with HIV in unique ways that predispose HIV-infected individuals to malignant diseases. In general, treatment directed specifically against these viruses does not appear to change the natural history of the malignant disease, and once the malignancy develops, if their health permits, HIV-infected patients should be treated using similar treatment protocols to HIV-negative patients. However, for the less frequent HIV-related malignancies, such as PEL, or MCD, optimal treatments are still emerging. For certain AIDS-defining malignancies, it is clear that the widespread access to HAART has significantly decreased the incidence, and improved outcomes. However, for other cancers, such as the HPV-related tumors, the role of HAART is much less clear. Further research into prevention and treatment of these oncogenic virally mediated AIDS-related malignancies is necessary.

Antiviral and Immunomodulatory Treatment for AIDS-Related Primary Central Nervous System Lymphoma: AIDS Malignancies Consortium Pilot Study 019

PURPOSE

A consistent association with Epstein-Barr Virus (EBV) distinguishes acquired immunodeficiency syndrome (AIDS)-related primary central nervous system lymphoma (PCNSL) from that which occurs in the general population. Recent descriptions of long-term remissions in patients with posttransplantation EBV-associated PCNSL who received EBV-specific therapy suggest some antitumor effect is anti-EBV mediated.

PATIENTS AND METHODS

We enrolled 4 patients with AIDS-related PCNSL into a novel antiviral and immunomodulatory protocol. An additional patient was treated in a similar fashion off protocol. Treatment consisted of intravenously administered zidovudine (1.5 g twice daily), ganciclovir (5 mg/kg twice daily), and interleukin-2 (2,000,000 U twice daily). After 2 weeks of therapy, patients were switched to oral ganciclovir (1 g 3 times daily), patient-specific, highly active, antiretroviral therapy, and subcutaneous interleukin-2 (2,000,000 U 3 times weekly). A final patient was treated with intravenous zidovudine and hydroxyurea. All 6 patients had advanced-stage AIDS as reflected by a CD4+ T-lymphocyte cell count of < 50/microL and a detectable human immunodeficiency virus (HIV)-1 viral RNA load (median copies, 135,000/mL; range, 2170-360,000/mL). One of 4 protocol-enrolled patients remains in complete remission with > 4 years' follow-up.

RESULTS

Three patients died from complications of progressive PCNSL. Two patients treated off protocol exhibited favorable responses and remain in complete remission at 28 months and 52 months, respectively. Grade 3/4 myelosuppression was uniformly noted, but there were no clinically significant hemorrhagic or infectious complications.

CONCLUSION

We conclude that for patients with AIDS and PCNSL, treatments with dual efficacy against HIV and EBV merit further investigation. Our experience provides a platform for future studies.

AIDS and associated malignancies

AIDS associated malignancies (ARL) is a major complication associated with AIDS patients upon immunosuppression. Chronically immunocompromised patients have a markedly increased risk of developing lymphoproliferative disease. In the era of potent antiretrovirals therapy (ARV), the malignant complications due to HIV-1 infection have decreased in developed nations where ARV is administered, but still poses a major problem in developing countries where HIV-1 incidence is high and ARV is still not yet widely available. Even in ARV treated individuals there is a concern that the prolonged survival of many HIV-1 carriers is likely to eventually result in an increased number of malignancies diagnosed. Malignancies that were found to have high incidence in HIV-infected individuals are Kaposi's sarcoma (KS), Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL). The incidence of NHL has increased nearly 200 fold in HIV-positive patients, and accounts for a greater percentage of AIDS defining illness in the US and Europe since the advent of HAART therapy. These AIDS related lymphomas are distinct from their counterparts seen in HIV-1 seronegative patients. For example nearly half of all cases of ARL are associated with the presence of a gamma herpesvirus, Epstein Barr virus (EBV) or human herpesvirus-8 (HHV-8)/ Kaposi's sarcoma associated herpesvirus (KSHV). The pathogenesis of ARLs is complex. B-cell proliferation driven by chronic antigenemia resulting in the induction of polyclonal and ultimately monoclonal lymphoproliferation may occur in the setting of severe immunosuppression.

Ganciclovir is associated with low or undetectable Epstein-Barr virus DNA load in cerebrospinal fluid of patients with HIV-related primary central nervous system lymphoma

BACKGROUND

Epstein-Barr virus (EBV) is pathogenically linked to human immunodeficiency virus (HIV)-related primary central nervous system lymphoma (PCNSL) and is found in virtually all HIV-related PCNSL cases. The objective of this study was to assess the effect of ganciclovir on EBV DNA replication in patients with HIV-related PCNSL.

PATIENTS AND METHODS

EBV DNA was measured by real-time polymerase chain reaction in cerebrospinal fluid and plasma samples from 25 patients with HIV-related PCNSL. Eight of these patients were receiving ganciclovir for concurrent cytomegalovirus infections.

RESULTS

EBV DNA was detected in cerebrospinal fluid samples obtained from 15 (88%) of 17 ganciclovir-untreated patients and 4 (50%) of 8 ganciclovir-treated patients (P = .028). EBV DNA load was significantly lower for treated patients, compared with untreated patients (median value, 2.15 vs. 4.16 log copies/mL; P = .001). Analysis of sequential cerebrospinal fluid samples from 7 patients showed that EBV DNA decreased in samples obtained from 2 patients following the start of ganciclovir administration but did not decrease in samples obtained from the 5 untreated patients. In addition, patients who received ganciclovir survived longer than the untreated patients (median duration of survival, 181 vs. 72 days; P = .006).

CONCLUSION

The effect of ganciclovir on EBV DNA load in cerebrospinal fluid supports the hypothesis that EBV is replicating in patients with PCNSL. This observation, together with the effect of ganciclovir therapy on patient survival, suggests that this drug might be useful for the management of PCNSL.

Changing pattern of primary cerebral lymphoma in the highly active antiretroviral therapy era

Before the introduction of highly active antiretroviral therapy (HAART), human immunodeficiency virus (HIV)-related primary central nervous system lymphoma (PCNSL) represented one of the most prevalent causes of focal brain lesions in HIV-infected people. The prognosis of PCNSL was very poor, with median survival time not exceeding 2 months. Brain biopsy was the method of choice for the definitive diagnosis, but it was and remains an invasive procedure with morbidity and mortality as well as considerable costs in terms of patients' management and quality of life. The strict association between AIDS-PCNSL and Epstein-Barr virus led to the suggestion that EBV DNA in cerebrospinal spinal fluid (CSF) might serve as a diagnostic marker, reducing the time required for diagnosis and allowing a minimally invasive approach. The clinical usefulness of this methodology has been largely demonstrated through clinical practice. After the introduction of HAART in clinical practice, a survival benefit has been observed for most persons with acquired immunodeficiency syndrome (AIDS)-associated opportunistic infections and cancers. In particular, for patients with non-Hodgkin lymphoma, a higher likelihood of response to chemotherapy as well as a longer survival has been found as a consequence of the use of combined antiretroviral therapy. Although larger studies did not show significant changes in survival of HIV-infected patients with PCNSL in the era of HAART, small case series and anecdotal reports showed the benefit of HAART in the treatment of PCNSL. Nevertheless, these patients' survival still remains very poor and it could be hypothesized that, other than specific cancer prognostic determinants and severe immunodeficiency, viral pathogenesis as well as EBV-specific immunologic dysfunction may be responsible.

Therapy insight: AIDS-related malignancies--the influence of antiviral therapy on pathogenesis and management

Patients with HIV infection are at an increased risk of a number of malignancies, including Kaposi's sarcoma (KS) and certain B-cell lymphomas. Most of these tumors are caused by oncogenic DNA viruses, including KS-associated herpesvirus and Epstein-Barr virus. HIV contributes to the development of these tumors through several mechanisms, including immunodeficiency, immunodysregulation, and the effects of HIV proteins such as Tat. The development of highly active antiretroviral therapy (HAART) has reduced the incidence of many HIV-associated tumors and has generally improved their responsiveness to therapy. However, the number of people living with AIDS is increasing, and it is possible that the number of AIDS-associated malignancies will rise and the pattern of tumors will change as more people live longer with HIV infection. The goal of KS therapy is long-term tumor control with minimal toxicity. HAART is an important component of this therapy, and some patients do not require other KS-specific therapies. By contrast, the goal of AIDS-related lymphoma therapy in most cases is the attainment of a complete response with curative intent, and the benefits of administering HAART during therapy must be weighed against possible disadvantages. The past decade has seen substantial improvements in the treatment of AIDS-related lymphoma, which is attributed partially to a shift in tumor type and more effective regimens. There is currently an interest in developing new therapies for HIV-associated malignancies, based on viral, vascular or other pathogenesis-based targets.

AIDS-Related Primary Central Nervous System Lymphoma

Primary central nervous system lymphoma (PCNSL) can develop in the setting of profound immunosuppression, including late-stage infection with HIV. The management of such patients has yet to be defined optimally and differs substantially from that of immunocompetent patients who have PCNSL. The clinical features, diagnosis, and management of AIDS-related PCNSL are reviewed. The authors focus on commonly encountered diagnostic and therapeutic dilemmas and explore some promises and pitfalls of Epstein-Barr virus-directed therapies.

Update in HIV-associated lymphoma

PURPOSE OF REVIEW

Infection with human immunodeficiency virus (HIV) is associated with an increased risk of non-Hodgkin lymphoma and Hodgkin disease. This review summarizes developments within the past 18 months.

RECENT FINDINGS

Investigators continue to demonstrate that many standard therapies similar to those used in the non-HIV- infected population may be used in the HAART era for patients infected with HIV. Biologic differences do exist, however, and not all treatments and outcomes are directly translatable. Some treatments, such as rituximab in combination with CHOP, may have unforeseen toxicity. Nonetheless, high-dose therapy does appear feasible and may offer curative therapy for those with refractory and relapsed disease.

SUMMARY

HIV-infected persons appear to benefit from most, but not all standard treatments for lymphoma.

Survival is prolonged by highly active antiretroviral therapy in AIDS patients with primary central nervous system lymphoma

OBJECTIVE

To determine the effects of highly active antiretroviral therapy (HAART) on survival in AIDS-related primary central nervous system lymphoma (PCNSL).

METHODS

Survival in consecutive patients with PCNSL at a large county teaching hospital from 1995 to 2001 were analyzed by the log rank test and Cox proportional hazards ratios (HR) were calculated for factors potentially affecting survival.

RESULTS

During the study period, 25 patients were diagnosed with PCNSL: 19 definite and 6 probable. At diagnosis, median CD4 cell count was 12 x 10(6) cells/l (range 1-151) and median HIV viral load was 5.3 log(10) copies/ml (range 3.9-5.9). Sixteen patients died (median survival 87 days; range, 0 to > 2112). Longer survival was noted for patients who received HAART after diagnosis [HR for death, 0.06; 95% confidence interval (CI), 0.01-0.48]. Six of seven HAART-treated patients were alive versus 0/18 untreated patients at a median follow-up time of 667 days (P = 0.0007 by log rank test). A survival benefit was seen for patients who had >/= 0.5 log(10) copies/ml decrease in HIV viral load after diagnosis (n = 6; HR, 0.07; 95% CI, 0.01-0.55) and for patients with a significant CD4 cell rebound (increase >/= 50 x 106 cells/l) in response to HAART (n = 6): all survived versus 0/19 survived (P = 0.0003). Cranial radiation therapy (n = 13) prolonged survival (HR, 0.20; 95% CI, 0.07-0.58). Median survival was only 29 days for 11 patients who received neither radiation nor HAART.

CONCLUSIONS

Receipt of HAART after diagnosis is associated with a significantly longer survival in patients with AIDS-related CNS lymphoma.

Immunotherapy for Epstein-Barr virus-associated cancers in children

Latent Epstein-Barr virus (EBV) infection is associated with several malignancies, including Burkitt's lymphoma, Hodgkin's disease, nasopharyngeal carcinoma, and post-transplant lymphoproliferative disease (LPD). The presence of EBV antigens in these tumors provides a target for immunotherapy approaches, and immunotherapy with EBV-specific cytotoxic T cells (CTLs) has proved effective in post-transplant LPDs, which are highly immunogenic tumors expressing type III latency. The malignant cells in Hodgkin's disease and nasopharyngeal carcinoma express type II latency and hence a more restricted pattern of EBV antigens. Trials with autologous EBV-specific CTL responses are under way in both of these diseases, and while some activity has been seen, no patient has yet been cured. This reduced CTL efficacy may reflect either downregulation of immunodominant EBV proteins, which are major CTL targets, or the ability of these tumors to evade the immune response by secreting inhibitory cytokines. Further improvement of EBV-specific CTL therapy for these type II latency tumors will require improved methods to activate and expand CTLs specific for the subdominant EBV genes expressed and to genetically modify the expanded CTLs to render them resistant to inhibitory cytokines. If these strategies to improve the therapeutic potential of immunotherapy for EBV-associated tumors prove successful, this type of treatment may be adapted to other tumors expressing known (viral) antigens.

Primary nervous system lymphoma

Primary nervous system lymphoma (PNSL) is a rare type of non-Hodgkin's lymphoma confined to the nervous system. Although significant progress has been made in the treatment of PNSL over the past decade, patients with this disease are rarely cured. Until recently, whole brain radiation therapy has been the standard treatment for PNSL. However, whole brain radiation therapy is associated with a high relapse rate and late neurotoxicity after chemotherapy, especially in patients older than 60 years of age. Methotrexate-based chemotherapy has become the standard approach to treat patients with newly diagnosed PNSL. Ongoing research efforts are focused on identifying chemotherapeutic agents with good antilymphoma activity that penetrate the blood-brain barrier. The roles of intrathecal chemotherapy and blood-brain barrier disruption are not fully defined. Given the rarity of this tumor, patients with PNSL should be referred to tertiary cancer centers where ongoing clinical trials are underway to identify the optimal treatment of PNSL.

Successful treatment of posttransplantation lymphoproliferative disorder (PTLD) following renal allografting is associated with sustained CD8(+) T-cell restoration

Posttransplantation lymphoproliferative disorder (PTLD) is a life-threatening Epstein-Barr virus (EBV)-associated B-cell malignancy occurring in 1% to 2% of renal transplantation patients. Host- and PTLD-related factors determining the likelihood of tumor response following reduction of immune suppression (IS) and antiviral therapy remain largely unknown. Standard therapy for PTLD is not well established. Eleven consecutive renal transplantation patients who developed EBV-positive PTLD 8 to 94 months after allografting were uniformly treated with acyclovir and IS reduction. All PTLDs were EBV-positive diffuse large B-cell lymphomas. Ten patients (91%) obtained a durable complete response (CR), and 9 (82%) have remained in continuous CR with a median follow-up of 29 months. Five patients (45%) lost their allograft. Of these, 4 patients had PTLD affecting the transplanted kidney. Peripheral blood CD8(+) T cells increased significantly (P =.0078) from baseline in 8 responders available for analysis. One of 2 patients whose absolute CD8(+) T-cell count subsequently dropped to baseline after IS reduction relapsed. The expanded CD8(+) T cells from 2 responders specifically recognized an immunodominant peptide from the EBV lytic gene BZLF-1. Another lytic EBV gene, thymidine kinase, was expressed in all 8 PTLDs tested. IS reduction and antiviral therapy for PTLD after renal transplantation is a highly successful therapeutic combination, but the risk of graft rejection is significant, particularly in patients with PTLD involving the renal allograft. A sustained expansion of CD8(+) T cells and a cellular immune response to EBV lytic antigens may be important for PTLD clearance in renal transplantation patients.

Survival of AIDS patients with primary central nervous system lymphoma is dramatically improved by HAART-induced immune recovery

OBJECTIVE

To evaluate the impact of immune recovery induced by highly active antiretroviral therapy (HAART) on the survival of AIDS patients with primary central nervous system lymphoma (PCNSL).

METHODS

In a multicentric retrospective analysis, 29 HIV-infected patients with histologically confirmed PCNSL were identified. To evaluate median survival, Kaplan-Meier statistics were used. To explore the effects of different variables on survival, a Weibull accelerated failure time regression analysis was performed.

RESULTS

Median age at manifestation of PCNSL was 39.1 years and median CD4 cell count was 11 x 10(6) cells/l. Seventy per cent of the patients had had a prior AIDS-defining illness. Cranial radiation (CR) was given to 12 out of 29 patients. Six patients were treated with HAART. Survival time of these patients and of the patients treated with CR alone differed significantly from those receiving neither CR nor HAART (median Kaplan-Meier survival estimate: 1093, 132, and 33 days, respectively). In the multivariate regression model, HAART and CR were identified as the only variables independently associated with prolonged survival. HAART versus no HAART and CR versus no CR increased the time to event by a factor of 6.1 (95% confidence interval, 2.4-16.0; P = 0.0002) and 3.1 (95% confidence interval, 1.5-6.3; P = 0.002), respectively. Four out of six patients on HAART showed a marked immune recovery and survived for more than 1.5 years, with two patients still alive.

CONCLUSION

Data from this cohort indicate that immune recovery induced by HAART leads to dramatic improvement in survival of patients with AIDS-associated PCNSL. These findings may have important implications for future treatment strategies.

Induction of a TRAIL-mediated suicide program by interferon alpha in primary effusion lymphoma

Gammaherpes viruses are often detected in lymphomas arising in immunocompromised patients. We have found that Azidothymidine (AZT) alone induces apoptosis in Epstein Barr Virus (EBV) positive Burkitt's lymphoma (BL) cells but requires interferon alpha (IFN-alpha) to induce apoptosis in Human Herpes Virus Type 8 (HHV-8) positive Primary Effusion Lymphomas (PEL). Our analysis of a series of AIDS lymphomas revealed that IFN-alpha selectively induced very high levels of the Death Receptor (DR) tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in HHV-8 positive PEL lines and primary tumor cells whereas little or no induction was observed in primary EBV+ AIDS lymphomas and EBV-Burkitt's lines. AZT and IFN-alpha mediated apoptosis in PEL was blocked by stable overexpression of dominant negative Fas Associated Death Domain (FADD), decoy receptor 2 (DcR2), soluble TRAIL receptor fusion proteins (DR-4 and DR-5) and thymidine. Trimeric TRAIL (in place of IFN-alpha) similarly synergized with AZT to induce apoptosis in HHV-8 positive PEL cells. This is the first demonstration that IFN-alpha induces functional TRAIL in a malignancy that can be exploited to effect a suicide program. This novel antiviral approach to Primary Effusion lymphomas is targeted and may represent a highly effective and relatively non-toxic therapy.

AIDS and cancer in the era of highly active antiretroviral therapy (HAART)

Combination therapy with protease inhibitors and nucleoside analogues dramatically suppresses plasma HIV-1 RNA and delays progression to AIDS, but the impact on HIV-associated malignancy remains to be established. Observational and time-trend data indicate that the incidence of Kaposi's sarcoma (KS) and primary brain lymphoma have decreased, but suggest that current therapies have not had a proportionate effect on systemic non-Hodgkin's lymphomas (NHL). As opportunistic infection and mortality are yielding to advances in antiretroviral therapy, lymphoma may increase in importance as a cause of AIDS-related morbidity and mortality. Further improvements in the long-term consequences of HIV infection will depend on better prevention and treatment of this serious malignant complication.

Clinical aspects and management of AIDS-related lymphoma

The incidence of non-Hodgkin's lymphoma (NHL) is increased by approximately 100-fold in patients with advanced HIV infection. Clinical presentations may include systemic lymphoma, primary central nervous system (CNS) lymphoma, and primary effusion lymphoma. Systemic lymphoma is the most common presentation, is almost always of intermediate or high-grade histology and B-cell phenotype, and usually involves extranodal sites. The disease is potentially curable with combination chemotherapy used for immunocompetent patients with lymphoma, although cure is achieved in only approximately 10-35% of patients. Primary CNS lymphoma may be difficult to distinguish from cerebral infection. The prognosis is very poor, although approximately 10% of patients selected for therapy may survive beyond 1 year with brain irradiation. Attention to infection prophylaxis and antiretroviral therapy is important. Evidence suggests that highly active antiretroviral therapy (HAART) has resulted in a decreased incidence of lymphoma, and that patients with systemic lymphoma treated in the post-HAART era have a better prognosis.

AIDS oncology

Kaposi's sarcoma, non-Hodgkin's lymphoma, Hodgkin's disease, and squamous cell carcinoma are among the malignancies seen with increased frequency in patients infected with HIV. The outlook for patients with these malignancies has improved significantly with the utilization of highly active antiretroviral therapy (HAART) and more aggressive cytotoxic therapies. Novel biologic therapies with lesser side effects are currently being evaluated. This article reviews the current knowledge about HIV malignancies, their epidemiology, pathogenesis, clinical manifestations, and treatment.

Inhibition of murine AIDS by alternate administration of azidothymidine and fludarabine monophosphate

Anti-HIV-1 combination therapies, including protease and reverse transcriptase inhibitors, can reduce plasma viremia to undetectable levels within the first 2 weeks of treatment. This reduction is followed by a slower decline that primarily results from the presence of viral reservoirs such as CD4+ memory cells, dendritic cells, and macrophages. For this reason, we evaluated a new drug combination therapy that includes a lympholytic drug: (2-fluoro-ara-AMP, fludarabine) to eliminate cells already infected and an antiviral drug (azidothymidine [AZT]) to protect cells not yet infected. We used C57BL/6 mice infected with the retroviral complex LP-BM5, which developed severe immunodeficiency (i.e., murine AIDS), to select the most effective fludarabine regimen to inhibit disease progression, and then to evaluate the efficacy and toxicity of the fludarabine and AZT combinations. The results obtained show that intraperitoneal administration of fludarabine at 3 mg/mouse twice a day for 4 weeks is the most effective regimen in reducing splenomegaly, lymphadenopathy, hypergammaglobulinemia, and proviral DNA content in spleen and lymph nodes and in restoring the architecture of lymph nodes. Subsequently, we evaluated the combined or sequential administration of fludarabine and AZT. The data reported in this paper show that the sequential administration of the two drugs provides additive antiviral effects that reduce spleen and lymph node weights to normal values and proviral DNA content by approximately 95% in all infected organs; the phenotypes of blood T and B cells moved toward control values, although the number of B cells was significantly reduced by fludarabine treatment. Finally, we evaluated the outcome of the disease after suspension or continuation of different treatment regimens. In all treatment groups, the disease progressed and increased proviral DNA content was found in infected organs, but animals receiving the sequential administration of fludarabine and AZT were less affected than those receiving only fludarabine or the simultaneous administration of both. The results obtained suggest that fludarabine could be part of a new therapeutic approach aiming at eradicating HIV from those cells that have been already infected and that are not protected by highly active antiretroviral therapy (HAART).