High dose therapy and autologous stem cell transplantation for human immunodeficiency virus-associated non-Hodgkin lymphoma in the era of highly active antiretroviral therapy

Haemopoietic cell transplantation in patients living with HIV

Haemopoietic cell transplantation is established as a standard treatment approach for people living with HIV who have haematological malignancies with poor prognosis. Studies with autologous and allogeneic haemopoietic cell transplantation suggest that HIV status does not adversely affect outcomes, provided that there is adequate infection prophylaxis. Attention to possible drug-drug interactions is important. Allogeneic haemopoietic cell transplantation substantially reduces the long-term HIV reservoir when complete donor chimerism is established. When transplants from CCR5Δ32 homozygous donors are used, HIV cure is possible.

Autologous stem cell transplantation for lymphoma in HIV+ patients: higher rate of infections compared with non-HIV lymphoma

Autologous hematopoietic stem cell transplantation (ASCT) is a well-established treatment strategy in HIV-related lymphoma patients (HIV+ Ly). Nevertheless, current evidence is mainly based on reports from specialized centers, multicentre heterogeneous studies, noncomparative analyses, or registry data-based comparisons. Likewise, the risk of infections reported so far for this population, seems to be similar to that of HIV- patients, and it does not seem to impact on mortality. We report a single-center retrospective comparative analysis of AHCT procedural results, infectious complications and survival in HIV+ Ly matched with a non-HIV comparative cohort. Thirty-three HIV+ patients and 45 matched controls, who underwent ASCT between 2000 and 2016, were included. Transplant-related toxicity, event-free survival, relapse rate, and overall survival were similar in both groups. Engraftment was delayed in HIV+ Ly (neutrophils: 15 vs 12 days (p = 0.0001), and platelets 39 vs 16 days (p = 0.00001)). Bacterial infections during the pre-engraftment period were more frequent in HIV+ Ly (RR 2.24, p = 0.017), as well as viral infections in the postengraftment period (RR 3.22, p = 0.004). CMV reactivation was more frequent in HIV+ Ly (39% vs 15% p = 0.007). In conclusion, ASCT is viable and effective in HIV+ Ly, but it is associated with a higher risk of infection.

Feasibility and Efficacy of High-Dose Chemotherapy and Autologous Hematopoietic Cell Transplantation for HIV-Associated Lymphoma: A Single-Institution Experience

BACKGROUND

HIV-associated lymphomas (HAL) remain an important cause of morbidity and mortality in HIV patients, especially in the setting of treatment-refractory disease. Hematopoietic cell transplantation (HCT) is considered a curative option for patients with refractory HAL.

PATIENTS AND METHODS

We report the efficacy of autologous HCT in 20 patients with HAL [non-Hodgkin lymphoma = 14 (70%), Hodgkin lymphoma = 6 (30%)]. At the time of transplantation, the median peripheral blood CD4⁺ count was 226 cells/μL. HIV virus load was undetectable in 14 (70%) of 20 patients.

RESULTS

The median follow-up of surviving patients was 47 months (range, 20-119 months). The median time to neutrophil engraftment was 11 days. The median progression-free survival and median overall survival have not been reached. At 4 years after transplantation, progression-free survival and overall survival were 65% and 70%, respectively. Six patients died from disease relapse or progression (n = 5) and infection (n = 1). Nonrelapse mortality was 0 and 5% at 100 days and 4 years after transplantation, respectively.

CONCLUSION

Autologous HCT is an effective therapy for refractory/relapsed HAL with manageable toxicity, similar to non-HIV patients.

How I treat patients with HIV-related hematological malignancies using hematopoietic cell transplantation

Hematopoietic cell transplantation (HCT) has now been shown to be safe and effective for selected HIV-infected patients with hematological malignancies. Autologous HCT is now the standard of care for patients with HIV-related lymphomas who otherwise meet standard transplant criteria. Limited data also support use of allogeneic HCT (alloHCT) in selected HIV-infected patients who meet standard transplant criteria. We recommend enrolling patients in clinical trials that offer access to CCR5Δ32 homozygous donors, if available. HIV-infected patients requiring HCT may also be considered for participation in trials evaluating the activity of gene-modified hematopoietic stem cells in conferring resistance to HIV infection. To be considered for HCT, patients must have HIV infection that is responsive to combination antiretroviral therapy (cART). Careful planning for the peri-HCT management of the cART can avoid risk of significant drug interactions and development of cART-resistant HIV. In general, we recommend against the use of boosted proteasome inhibitors and nonnucleotide reverse transcriptase inhibitors in the cART regimen, in favor of nucleoside reverse transcriptase inhibitors and integrase inhibitors (without cobicistat). After HCT, patients must be closely monitored for development of opportunistic infections (OI), such as cytomegalovirus. Prevention of OI should include prophylactic and pre-emptive antimicrobials.

Autologous hematopoietic cell transplantation for HIV-related lymphoma: results of the BMT CTN 0803/AMC 071 trial

Autologous hematopoietic cell transplant (AHCT) for HIV-infected patients is largely limited to centers with HIV-specific expertise. The Blood and Marrow Transplant Clinical Trials Network 0803/AIDS Malignancy Consortium 071 trial is a multicenter phase 2 study of AHCT for patients with HIV-related lymphoma (HRL). Eligible patients had chemotherapy-sensitive relapsed/persistent HRL, were >15 years of age, and had treatable HIV infection. Patients were prepared using carmustine, etoposide, cytarabine, and melphalan and received consistent management of peritransplant antiretroviral treatment. The primary endpoint was 1-year overall survival. Forty-three patients were enrolled; 40 underwent AHCT. Pretransplant HIV viral load was undetectable (<50 copies/mL) in 32 patients (80%); the median CD4 count was 249/μL (range, 39-797). At a median follow-up of 24.8 months, 1-year and 2-year overall survival probabilities were 87.3% (95% confidence interval [CI], 72.1-94.5) and 82% (95% CI, 65.9-91), respectively. The probability of 2-year progression-free survival was 79.8% (95% CI, 63.7-89.4). One-year transplant-related mortality was 5.2%. Median time to neutrophil and platelet recovery was 11 days and 18 days, respectively. Nine patients experienced a total of 13 unexpected grade 3-5 adverse events posttransplant (10 grade 3 and 3 grade 4 events). Twenty-two patients had at least 1 infectious episode posttransplant. At 1 year post-AHCT, median CD4(+) T-cell count was 280.3 (range, 28.8-1148.0); 82.6% had an undetectable HIV viral load. Trial patients were compared with 151 matched Center for International Bone Marrow Transplant Research controls. Outcomes between HIV-infected patients and controls were not statistically significantly different. HRL patients should be considered candidates for AHCT if they meet standard transplant criteria. The trial was registered at www.clinicaltrials.gov as #NCT01141712.

Hematopoietic stem cell transplantation for HIV cure

The apparent cure of an HIV-infected person following hematopoietic stem cell transplantation (HSCT) from an allogeneic donor homozygous for the ccr5Δ32 mutation has stimulated the search for strategies to eradicate HIV or to induce long-term remission without requiring ongoing antiretroviral therapy. A variety of approaches, including allogeneic HSCT from CCR5-deficient donors and autologous transplantation of genetically modified hematopoietic stem cells, are currently under investigation. This Review covers the experience with HSCT in HIV infection to date and provides a survey of ongoing work in the field. The challenges of developing HSCT for HIV cure in the context of safe, effective, and convenient once-daily antiretroviral therapy are also discussed.

HIV and Stem Cell Transplantation

In human immunodeficiency virus (HIV)-infected persons, the incidence of hematologic malignancies, including leukemia and lymphoma, is increased despite the use of successful antiretroviral therapy. Hematopoietic stem cell transplantation (SCT) is emerging as a safe and effective therapy for HIV-infected persons with hematologic malignancies. Management of these patients is complicated by drug-drug interactions involving antiretroviral therapy (ART) that may impact conditioning agent efficacy and metabolism of immunosuppressive medications and potentiate drug toxicities. As such, optimal strategies for ART remain controversial. We discuss recent advances, controversies, and future directions related to SCT in HIV-infected persons, including the investigation of allogeneic SCT as a strategy for HIV cure.

Outcome of patients with relapsed/refractory acquired immune deficiency syndrome-related lymphoma diagnosed 1999-2008 and treated with curative intent in the AIDS Malignancy Consortium

No comparative studies exist for relapsed/refractory (rel/rfr) acquired immune deficiency syndrome (AIDS)-related lymphoma (ARL). To determine practices over the last decade and to assess the outcomes of salvage chemotherapy with curative intent and autologous stem cell transplant (ASCT), we retrospectively evaluated treatment outcomes in patients with rel/rfr ARL who were treated in 13 national AIDS Malignancy Consortium (AMC) sites between 1999 and 2008 (n = 88). The most commonly used second-line therapies were ICE (ifosfamide/carboplatin/etoposide, n = 34), dose adjusted EPOCH (etoposide/prednisone/vincristine/cyclophosphamide/doxorubicin, n = 17) and ESHAP (etoposide/methylprednisolone/cytarabine/cisplatin, n = 11). The odds of achieving a response were lower for those with non-Hodgkin lymphoma (NHL) than for those with HL and for those with primary refractory disease than for those with relapse. Overall survival (OS) was significantly longer for those with relapsed disease compared to those with refractory disease and for those with non-Burkitt NHL compared to those with Burkitt. OS was longer in patients who underwent ASCT compared to those who did not (1-year OS: 63.2% vs. 37.2%). However, among 32 patients (36%) who achieved a complete or partial response (CR/PR) after second-line therapy, 1-year OS was not different between the two groups (87.5% for ASCT vs. 81.8% for non-ASCT). Long-term survival in some patients with rel/rfr ARL may be possible without transplant, although transplant remains the standard of care for chemotherapy sensitive disease.

Antimicrobial therapy of febrile complications after high-dose chemotherapy and autologous hematopoietic stem cell transplantation--guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO)

More than 18,000 autolgous transplantation were performed in Europe in the year 2009. It as a routine procedure in experienced centres. Even if there is a low mortality rate, infections are a major issue after transplantation, occurring in more than 60 % of the patients. In this review we discuss all aspects of infections after autologous stem transplantation, including epidemiology, diagnostics, therapeutic algorithms, prophylaxis and supportive therapy.

Allogeneic hematopoietic cell transplantation in human immunodeficiency virus-positive patients with hematologic disorders: a report from the center for international blood and marrow transplant research

The role of allogeneic hematopoietic cell transplantation (alloHCT) in human immunodeficiency virus (HIV)-positive patients is not known. Using the Center for International Blood and Marrow Transplant Research database, we retrospectively evaluated 23 HIV-positive patients undergoing matched sibling donor (n = 19) or unrelated donor (n = 4) alloHCT between 1987 and 2003. The median age at alloHCT was 32 years. Indications for alloHCT were diverse and included malignant (n = 21) and nonmalignant (n = 2) hematologic disorders. Nine patients (39%) underwent transplantation after 1996, the approximate year that highly active antiretroviral therapy became standard treatment. The median time to neutrophil engraftment was 16 days (range, 7 to 30 days), and the cumulative incidences of grade II-IV acute graft-versus-host disease (aGVHD) at 100 days, chronic GVHD (cGVHD), and survival at 2 years were 30% (95% confidence interval [CI] = 14% to 50%), 28% (95% CI = 12% to 48%), and 30% (95% CI = 14% to 50%), respectively. At a median follow-up of 59 months, 6 patients were alive. Survival appears to be better in the patients undergoing alloHCT after 1996; 4 of these 9 patients survived, compared with only 2 of 14 those undergoing transplantation before 1996. These data suggest that alloHCT is feasible for selected HIV-positive patients with malignant and nonmalignant disorders. Prospective studies are needed to evaluate the safety and efficacy of this modality in specific diseases in these patients.

High-dose therapy and autologous stem cell transplantation for children with HIV-associated non-Hodgkin lymphoma

In contrast to adults, autologous stem cell transplantation (ASCT) as part of the salvage strategy after high-dose chemo/radiotherapy in human immunodeficiency virus (HIV) related Non-Hodgkin lymphoma (NHL) is not yet established for children. We report on a 13-year patient with congenital HIV infection and refractory Burkitt lymphoma, who was successfully treated by high-dose therapy (HDT) including rituximab followed by ASCT. After 26 months follow-up the patient remains in complete remission and his HIV parameters have normalized with continued highly active antiretroviral therapy (HAART). HIV infection may no longer exclude children from ASCT as part of salvage therapy.

Biology and treatment of Burkitt's lymphoma

PURPOSE OF REVIEW

Burkitt's lymphoma is a unique hematological malignancy remarkable for its biological characteristics, including aberrant expression of the MYC oncogene, and its requirement for intensive treatment regimens. This review will focus on those features, and discuss recent advances in the molecular biology and advancing treatment options for the disease.

RECENT FINDINGS

Advances in molecular biology have provided many new insights into the biology and treatment options for Burkitt's lymphoma. Microarray technology has recently been used to define a molecular gene expression signature for Burkitt's lymphoma. This signature allows for the differentiation of Burkitt's lymphoma from other forms of non-Hodgkin's lymphoma such as diffuse large B-cell lymphoma. Recent advances in the use of biological agents, such as rituximab, have also allowed for a reduction in treatment toxicities while still offering comparable survival outcomes for patients.

SUMMARY

Burkitt's lymphoma is an interesting mature B-cell non-Hodgkin's lymphoma that has numerous distinct features and clinical variants depending on factors such as geographical location, immunological status and patient's age. Although the role of the MYC oncogene has been well studied, we are only now appreciating the defining molecular characteristics of this disease, and using these advances to improve treatment options for patients.

AIDS-related cancer in the era of highly active antiretroviral therapy (HAART): a model of the interplay of the immune system, virus, and cancer. "On the offensive--the Trojan Horse is being destroyed"--Part B: Malignant lymphoma

The impact of highly active antiretroviral therapy (HAART) on the incidence of non-Hodgkin's lymphoma was less obvious initially, although primary central nervous system lymphoma (PCNSL) has dropped precipitously since the introduction of HAART. The pathogenesis of acquired immunodeficiency syndrome-related lymphoma is multifactorial. Epstein-Barr virus plays a significant role in these diseases, especially Burkitt lymphoma and PCNSL. Data regarding the effect of HAART on the natural history and treatment outcomes of these malignancies are emerging. The possibility of direct and indirect roles of human immunodeficiency virus in the carcinogenesis suggests that antiretroviral therapy may be an important component of the treatment for these malignancies. The simultaneous administration of HAART and chemotherapy does not appear to significantly alter the toxicity profile, although the information with respect to the interaction of HAART and chemotherapy is limited. The use of biological agents, for example, monoclonal antibody against CD-20, is being explored to improve the clinical outcome of this disease.

Durable remissions with autologous stem cell transplantation for high-risk HIV-associated lymphomas

The treatment of HIV-associated lymphoma has changed since the widespread use of highly active antiretroviral therapy. HIV-infected individuals can tolerate more intensive chemotherapy, as they have better hematologic reserves and fewer infections. This has led to higher response rates in patients with HIV-associated Hodgkin disease (HD) or non-Hodgkin lymphoma (NHL) treated with chemotherapy in conjunction with antiretroviral therapy. However, for patients with refractory or relapsed disease, salvage chemotherapy still offers little chance of long-term survival. In the non-HIV setting, patients with relapsed Hodgkin disease (HD) or non-Hodgkin lymphoma (NHL) have a better chance of long-term remission with high-dose chemotherapy with autologous stem cell rescue (ASCT) compared with conventional salvage chemotherapy. In a prior report we demonstrated that this approach is well tolerated in patients with underlying immunodeficiency from HIV infection. Furthermore, similar engraftment to the non-HIV setting and low infectious risks have been observed. Herein, we expand upon this early experience with the largest single institution series of 20 patients. With long-term follow-up we demonstrate that ASCT can lead to an 85% progression-free survival, which suggests that this approach may be potentially curative in select patients with relapsed HIV-associated HD or NHL.

In vivo selection for human and murine hematopoietic cells transduced with a therapeutic MGMT lentiviral vector that inhibits HIV replication

We have developed an HIV-based lentiviral vector, VRX496, which efficiently transduces human CD34+ progenitors and CD4+ T lymphocytes. VRX496 contains an antisense sequence against the HIV envelope and is currently being evaluated for safety in a clinical trial for treatment of HIV. Selective outgrowth of transduced hematopoietic cells in vivo is anticipated to increase the therapeutic efficacy of this treatment by maximizing the persistence of virus-resistant cells in the body. Although HIV resistance is selective, additional selection may aid in treatment efficacy due to the vast quantity of target cells. Therefore, we engineered VRX496 to express the P140K MGMT gene to drive potent drug-mediated in vivo selection for transduced hematopoietic long-term repopulating cells. Suboptimally transduced T cell cultures treated with O6-benzylguanine and BCNU were selected from 3 to 100%, and after selection cultures did not support HIV replication. Primary CD34+ progenitors derived from G-CSF-mobilized peripheral blood were transduced at 27 to 35% efficiency. Approximate sixfold selection was observed for transduced CD34+ progenitors, colony-forming units, and long-term culture-initiating cells. Multilineage in vivo selection was demonstrated for transduced murine hematopoietic cells in human CD34(+)-derived hematopoietic cells in NOD-SCID mice. These results establish efficient ex vivo and in vivo selection for hematopoietic cells transduced with lentiviral vectors and support the potential therapeutic benefit of this strategy in human gene therapy.

The evidence-based treatment of AIDS-related non-Hodgkin’s lymphoma

As we enter the third decade of the AIDS epidemic, it is apparent that a large number of cancers are more common in people with the human immunodeficiency virus type 1 (HIV). Non-Hodgkin's lymphoma (NHL) remains the second most common tumour in such patients. At the onset of the epidemic, dose-intense combination regimens were used but these were quickly abandoned in favour of dose-modified strategies because of difficulties in tolerating aggressive chemotherapy in the presence of underlying immunosuppression. With the improvements in supportive care including more effective anti-retroviral therapies, colony-stimulating factors and prophylaxis against opportunistic infections, we are returning to the traditional chemotherapeutic approaches similar to those utilised in the non-HIV infected individual including infusional regimens. In this review, we discuss the evidence for choosing particular therapies in patients with AIDS-related NHL.

Treatment of human immunodeficiency virus-related lymphoma with haematopoietic stem cell transplantation

The advent of highly active antiretroviral therapy (HAART) and its co-administration with chemotherapy in patients with human immunodeficiency virus (HIV)-related lymphoma has lead to the exploration of potentially curative combination chemotherapy and myeloablative therapy followed by autologous haematopoietic stem cell transplantation (ASCT). Applying the same principles used for patients with HIV-negative aggressive lymphoma, in 1998 we developed a program of high-dose therapy and ASCT at City of Hope for patients with HIV-related lymphoma and Hodgkin's disease. Our studies have primarily included patients with chemosensitive lymphoma in relapse or first remission with poor-risk features at diagnosis. Filgrastim (G-CSF)-primed peripheral blood stem cell mobilization and apheresis have been successful while patients were receiving HAART and chemotherapy. To date, ASCT has been performed in 19 patients with HIV-related lymphoid malignancies, representing the largest single-institution experience reported to date. Most patients received a chemotherapy-based conditioning regimen consisting of high-dose carmustine, etoposide and cyclophosphamide. Early infections, namely bacteremias and neutropenic fever were similar to those observed in the HIV-negative transplant setting. Opportunistic infections were rare and easily treatable. There were three early deaths, two from relapsed lymphoma and one from multi-organ failure in an older patient. The remaining 16 patients are alive and in remission. In summary, ASCT is well tolerated, can result in long-term remissions, and is potentially curative in selected HIV-related lymphoma patients with chemosensitive relapse and high-risk disease in first remission defined by the age-adjusted International Prognostic Index criteria (i.e., two or three of the following: elevated LDH, advanced stage, and poor performance status). Acquisition of resistance to HAART remains as a potential problem for HIV-positive patients who are cured of their lymphoma.

Therapeutic approaches to AIDS-related malignancies

The introduction of highly active antiretroviral therapy (HAART) has changed dramatically the landscape of HIV disease. Deaths from AIDS-related diseases have been reduced by 75% since protease inhibitor therapy and combination antiretroviral therapy came into use in late 1995. While KS is declining, the situation for non-Hodgkin's lymphoma is more complex with a reduced incidence of primary central nervous system lymphoma, but a relatively stability in the number of patients developing systemic NHL. AIDS related NHL appears not to be markedly decreased by the introduction of HAART and it is the greatest therapeutic challenge in the area of AIDS oncology. The emphasis has now shifted to cure while maintaining vigilance regarding the unique vulnerability of HIV-infected hosts. Furthermore, also for the prolongation of the survival expectancy of these patients, other non AIDS-defining tumors, such as Hodgkin's disease, anal and head and neck, lung and testicular cancer, and melanoma have been recently reported with increased frequency in patients with HIV infection.

Acquired Immunodeficiency Syndrome–Related Lymphoma in the Era of Highly Active Antiretroviral Therapy

The treatment and outcome of human immunodeficiency virus (HIV) infection altered dramatically in the mid-1990s with the introduction of highly active antiretroviral therapy (HAART). Highly active antiretroviral therapy, where available, has led to a dramatic decline in mortality from HIV and a decrease in the incidence of opportunistic infections and Kaposi sarcoma. This article addresses the effects that HAART has had on acquired immunodeficiency syndrome (AIDS)-related non-Hodgkin's lymphoma (NHL). Metaanalysis of numerous cohort studies confirmed that the incidence of AIDS-related NHL has decreased since the advent of HAART. This decline is most marked for primary cerebral lymphomas and systemic immunoblastic lymphoma but has not been demonstrated for Burkitt lymphoma. In addition to genetic predisposing factors, age, nadir CD4 cell count, and lack of HAART therapy predict the development of NHL. The clinical presentation of AIDS-related NHL has not changed, but several institutions have reported an improvement in survival since the introduction of HAART. Moreover, HAART has been combined safely with systemic chemotherapy in the management of NHL, and this approach results in a more modest decrease in immune function than when chemotherapy is administered alone. This has led to a more aggressive approach to the management of AIDS-related NHL and response rates and overall survival durations that are approaching those seen in stage-matched high-grade lymphomas in the immunocompetent population.

Gene therapy for HIV/AIDS: the potential for a new therapeutic regimen

Human Immunodeficiency Virus (HIV) is the etiologic agent of Acquired Immunodeficiency Syndrome (AIDS). HIV/AIDS is a disease that, compared with the not so distant past, is now better held in check by current antiretroviral drugs. However, it remains a disease not solved. Highly active antiretroviral therapy (HAART) generally uses two non-nucleoside and one nucleoside reverse transcriptase (RT) inhibitor or two non-nucleoside RT and one protease inhibitor. HAART is far more effective than the mono- or duo-therapy of the past, which used compounds like the nucleoside reverse transcriptase inhibitor AZT or two nucleoside reverse transcriptase inhibitors. However, even with the relatively potent drug cocktails that comprise HAART, there are the issues of (i). HIV escape mutants, (ii). an apparent need to take the drugs in an ongoing manner, and (iii). the drugs' side effects that are often severe. This review speaks to the potential addition to these potent regimens of another regimen, namely the genetic modification of target hematopoietic cells. Such a new treatment paradigm is conceptually attractive as it may yield the constant intracellular expression of an anti-HIV gene that acts to inhibit HIV replication and pathogenicity. A body of preclinical work exists showing the inhibition of HIV replication and decreased HIV pathogenicity by anti-HIV genetic agents. This preclinical work used hematopoietic cell lines and primary cells as the target tissue. More recently, several clinical trials have sought to test this concept in vivo.

Treatment options of AIDS-related lymphoma

Recently, the median survival of patients with AIDS-related lymphoma has changed significantly. This effect is mainly because of changes in the use of antiviral (highly active antiretroviral therapy; HAART) or chemotherapy regimens. Several novel treatment options have been explored in patients with lymphoma. It is hoped that innovative strategies will lead to a survival benefit in these patients. In this review, we present an update of current strategies for the treatment of AIDS-related lymphoma.

Biology and management of AIDS-associated non-Hodgkin's lymphoma

The treatment of HIV-related lymphomas is evolving in the era of HAART. Standard-dose chemotherapy and dose-intensive therapies appear to be feasible. Whether outcomes are improved with combination chemotherapy and HAART remains unclear. Efforts aimed at developing pathogenic-based therapies will continue as the mechanisms of HIV lymphomagenesis are elucidated.

Stem cell transplantation and gene therapy for HIV-related lymphomas

The treatment of patients with HIV-related non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD) is less successful than in the non-HIV setting, in part due to the aggressive character of these lymphomas but also due to the underlying HIV infection. High-dose therapy with stem cell transplantation has been used with success in the HIV-negative lymphoma setting for high-risk or relapsed disease. However, for patients with HIV-NHL and HIV-HD, ultimately the chance for long-term lymphoma-free survival also depends on successful control of the HIV infection. Gene therapy approaches may provide the opportunity for this long-term control. Herein, we describe the use of high-dose chemotherapy with stem cell rescue in conjunction with current and future gene therapy approaches for the treatment of HIV-associated lymphomas.

Burkitt's and Burkitt-like lymphoma

Burkitt's and Burkitt-like lymphoma (BL/BLL) are aggressive B-cell malignancies with a high proliferative rate that may be fatal within months if not treated promptly. Furthermore, treatment of BL/BLL requires comprehensive supportive care to avoid disease-related complications such as acute renal failure secondary to tumor lysis syndrome. Improvements in our understanding of the biology of BL and BLL have led to more effective therapeutic protocols. Clinical trials have demonstrated that short duration, multi-agent, dose-intensive chemotherapy regimens combined with aggressive central nervous system therapy results in long-term survival rates in children and young adults near 70% to 80%, whereas long-term disease-free survival rates in older adults remains suboptimal at 15% to 25%. Outcomes in HIV-associated BL/BLL are improved because of more effective chemotherapy regimens and enhanced HIV care. Autologous bone marrow transplantation has proven feasible in many patient populations with BL/BLL and may lead to cure in selected patients. Improved therapeutic strategies are warranted, such as integrating agents such as monoclonal antibodies to combination dose-intensive chemotherapy. Moreover, further study into the molecular biology of BL/BLL with attention to the role of c-myc dysregulation is needed to help predict prognostic factors and for the development of molecular targeted therapies. Clinical trials remain critical to determine the most effective treatment regimens that will continue to improve cure rates in this aggressive but treatable disease.

Hematologic Aspects of HIV/AIDS

This review addresses various aspects of HIV infection pertinent to hematology, including the consequences of HIV infection on specific aspects of hematopoiesis and an update on the current biologic, epidemiologic and therapeutic aspects of AIDS-related lymphoma and Hodgkin's disease. The results of the expanding use of progenitor cell transplantation in HIV infected patients are also reviewed. In Section I, Dr. Scadden reviews the basis for HIV dysregulation of blood cell production, focusing on the role of the stem cell in HIV disease. T cell production and thymic function are discussed, with emphasis placed upon the mechanisms of immune restoration in HIV infected individuals. Results of clinical and correlative laboratory studies are presented. In Section II, Dr. Levine reviews the recent epidemiologic trends in the incidence of lymphoma, since the widespread availability of highly active anti-retroviral therapy (HAART). The biologic aspects of AIDS-lymphoma and Hodgkin's disease are discussed in terms of pathogenesis of disease. Various treatment options for these disorders and the role of concomitant anti-retroviral and chemotherapeutic intervention are addressed. Drs. Zaia and Krishnan will review the area of stem cell transplantation in patients with AIDS related lymphoma, presenting updated information on clinical results of this procedure. Additionally, they report on the use of gene therapy, with peripheral blood CD34+ cells genetically modified using a murine retrovirus, as a means to treat underlying HIV infection. Results of gene transfer experiments and subsequent gene marking in HIV infected patients are reviewed.

Highly active antiretroviral therapy and allogeneic CD34(+) peripheral blood progenitor cells transplantation in an HIV/HCV coinfected patient with acute myeloid leukemia

OBJECTIVE

To evaluate the safety, feasibility, and efficacy of allogeneic stem cell transplantation (SCT) for acute myelogenous leukemia (AML) in a young female coinfected by HIV and HCV undergoing highly active antiretroviral therapy (HAART).

PATIENTS AND METHODS

A 33-year-old female HIV(+), HCV(+) in complete remission after standard chemotherapy was submitted to CD34(+) selected allogeneic transplantation from her HLA-identical HIV(-) brother after myeloablative regimen. HAART was started before transplantation, achieving a reduction of HIV load to undetectable levels. GVHD prophylaxis was carried out with cyclosporine A alone.

RESULTS

The patient achieved prompt and durable engraftment with acute GVHD grade II easily managed with steroids; CMV prophylaxis was prolonged, no clinically relevant infectious complications developed early after transplantation and during follow-up. HIV viremia was controlled by HAART although medication adherence was reduced early after transplantation and required drug adjustment. There was a gradual recovery of immune cells with normal CD4-cell count 39 months after engraftment, a significantly higher level than before transplantation. At 39 months post-transplantation follow-up the patient is alive and in continuous complete remission with undetectable levels of plasma HIV RNA on HAART.

CONCLUSION

The introduction of HAART has recently changed the paradigm of AIDS, allowing the control of HIV replication, the reduction of opportunistic infections, and the overall improvement of survival. One may therefore reconsider the current exclusion of patients with AIDS and a concomitant lethal malignancy from programs of high-dose chemotherapy and stem cell transplantation, as suggested by this report.

Regression of a plasmablastic lymphoma in a patient with HIV on highly active antiretroviral therapy

We describe an HIV-infected 44-year-old man who presented 1 month after discontinuation of HAART therapy with a large mass extending from the mediastinum, enclosing the heart and extending through the diaphragm to the epigastric region. Biopsies subsequently revealed a highly aggressive non-Hodgkin's lymphoma (NHL) producing sheets of cells with an organoid distribution. The cells had abundant basophilic cytoplasm and a plasmacytic appearance. Although immunohistochemistry failed to show either B- or T-cell markers, antigens consistent with plasma cells were found. An immunoglobulin heavy chain clonal rearrangement was identified by PCR analysis. These studies were supportive of a diagnosis of a plasmablastic lymphoma. While awaiting the results of these tests, the patient was reinitiated on his HAART regimen. He was found on follow-up a month later to have complete resolution of his bulky mediastinal mass. He remained free of disease for 3 months with subsequent rectal and abdominal recurrence. Treatment with CHOP chemotherapy with filgrastim support was begun which resulted in another remission. Plasmablastic lymphoma is now reported in some studies to account for 2.6% of all HIV-related NHL. Originally described in 1997 in a series of 16 patients, this entity is highly associated with HIV infection in its later stages. Often, patients present with oral or jaw lesions with a rapidly progressive course. The tumors have the morphologic appearance of a plasmacytoid tumor with high proliferative index. Markers are positive mainly for LCA, CD79a, VS38C, and CD138. Co-infection with HHV-8 and EBV has not been consistently reported. Therapy with standard regimens has variable response. One case has been reported with a 3.5 year disease free survival. The regression of disease after resumption of HAART therapy alone in this patient suggests that HAART has an important role in the treatment of lymphoma in the HIV infected patient.

High-dose chemotherapy and autologous CD34-positive blood stem cell transplantation for multiple myeloma in an HIV carrier

The epidemiology and clinical outcome of multiple myeloma in human immunodeficiency virus (HIV)-positive patients is poorly documented. There are uncertainties concerning the optimal management of this rare disorder. We report on the use of myeloablative chemotherapy with autologous stem cell transplantation in an HIV-positive patient with multiple myeloma.

Prognostic factors in the treatment of human immunodeficiency virus-associated non-Hodgkin's lymphoma

Chemotherapy regimens similar to those used for non-Hodgkin's lymphoma (NHL) not associated with human immunodeficiency virus (HIV) infection have been used for patients with HIV-associated NHL with less success. In a recent trial, patients with intermediate or high-grade NHL were randomized to either low-dose chemotherapy with methotrexate, bleomycin, doxorubicin, vincristine and dexamethasone (m-BACOD) or to standard-dose m-BACOD with sargramostim (granulocyte-macrophage colony-stimulating factor, GM-CSF). With low-dose m-BACOD 41% of patients achieved a complete remission and the median survival was 35 weeks. With standard-dose m-BACOD and sargramostim, the percentage of complete remissions was 52% with a median survival of 31 weeks (P=n.s.). Myelosuppression was greater with standard-dose chemotherapy. In univariate and multivariate analyses of 21 pretreatment features of patients in this trial, four factors emerged as adversely prognostic with respect to survival: age >35 years, intravenous drug use, CD4 counts < 100/mm3 and stage III/IV disease. In an analysis using the proportional hazards model, a "favorable" group was defined by patients with 0 or 1 adverse factor (median survival 46 weeks, survival at 144 weeks 29.5%) as compared with an unfavorable group with 3 or 4 adverse factors (median survival 18 weeks, survival at 144 weeks 0). The outcome of these patients may be improving with the use of highly active antiretroviral therapy (HAART), which seems to improve immune function and tolerance of chemotherapy. A recent trial of the AIDS Malignancy Consortium found that low-dose chemotherapy (cyclophosphamide, doxorubicin, vincristine and prednisone: CHOP) and standard-dose chemotherapy had similar response rates, acceptable toxicity and minimal alterations in cyclophosphamide, doxorubicin and indinavir pharmacokinetics in HIV-associated lymphoma patients also on HAART (stavudine, lamivudine and indinavir). There is a suggestion that Burkitt-type lymphomas may tend to occur in HIV-infected patients with relatively well preserved immune function and CD4 cell counts. Recent results from our institution suggest that similar outcomes are achievable with intensive chemotherapy in patients with Burkitt's lymphomas with or without HIV infection. With improved immune status and improved bone marrow function with the use of HAART, it will probably become more possible to treat many patients with aggressive HIV-associated NHL with more intensive treatment regimens.

Autologous stem cell transplantation for HIV-associated lymphoma

Is peripheral stem cell mobilization followed by autologous stem cell transplantation (ASCT) feasible in patients with human immunodeficiency virus (HIV)– associated lymphoma (HIV-L)? Studies have demonstrated that, in the HIV- negative (HIV−) setting, ASCT may improve lymphoma-free survival in high-risk non-Hodgkin lymphoma (NHL) or relapsed Hodgkin disease (HD) and NHL. Given the poor prognosis of HIV-L with conventional chemotherapy, this dose-intensive approach was explored. Nine patients with HIV-HD or NHL mobilized a median of 10.6 × 106 CD34+ cells/kg and engrafted after ASCT. CD4 counts recovered to pretransplantation levels and HIV viral loads were controlled in patients compliant with antiretroviral therapy. Seven of 9 patients remain in remission from their lymphoma at a median of 19 months after transplantation. Thus, patients with HIV-L on antiretroviral therapy can engraft following ASCT. Prolonged lymphoma remissions, without significant compromise of immune function, can be seen, suggesting that ASCT can be used in selected patients with HIV-L.

Autologous stem cell transplantation for HIV-associated lymphoma

Is peripheral stem cell mobilization followed by autologous stem cell transplantation (ASCT) feasible in patients with human immunodeficiency virus (HIV)- associated lymphoma (HIV-L)? Studies have demonstrated that, in the HIV- negative (HIV(-)) setting, ASCT may improve lymphoma-free survival in high-risk non-Hodgkin lymphoma (NHL) or relapsed Hodgkin disease (HD) and NHL. Given the poor prognosis of HIV-L with conventional chemotherapy, this dose-intensive approach was explored. Nine patients with HIV-HD or NHL mobilized a median of 10.6 x 10(6) CD34(+) cells/kg and engrafted after ASCT. CD4 counts recovered to pretransplantation levels and HIV viral loads were controlled in patients compliant with antiretroviral therapy. Seven of 9 patients remain in remission from their lymphoma at a median of 19 months after transplantation. Thus, patients with HIV-L on antiretroviral therapy can engraft following ASCT. Prolonged lymphoma remissions, without significant compromise of immune function, can be seen, suggesting that ASCT can be used in selected patients with HIV-L.

Treatment of human immunodeficiency virus-related lymphoma

In newly diagnosed human immunodeficiency virus (HIV)-positive patients with non-Hodgkin's lymphoma (NHL), standard lymphoma regimens yield approximately a 50% complete response (CR) rate and an overall median survival of < or = 9 months. Treatment results of relapsed patients are extremely poor. Regimens that appear more effective than standard therapy have usually been investigated only in patients with relatively high CD4 counts. An exception is a regimen consisting of a continuous 96-hour infusion of cyclophosphamide, doxorubicin, and etoposide (CDE). A 62% CR rate was achieved in 21 patients with a median CD4 count of 87/microL, and the median overall survival was 18 months. In another study of 25 patients, didanosine (ddI) was added to CDE and was shown to cause less myelosuppression without compromising efficacy. Other studies suggest that highly active antiretroviral therapy (HAART) can be combined with intensive chemotherapy regimens, with improved efficacy attributed to less frequent dosage reduction of chemotherapeutic agents. More recently, autologous and syngeneic bone marrow transplantation have been explored in a handful of patients with acquired immunodeficiency syndrome (AIDS)-related NHL with promising results. Data on whether widespread use of HAART decreases the incidence of HIV-positive NHL are conflicting. Some clues from recent studies suggest we are close to an answer: (1) protease inhibitors significantly improve survival of HIV-positive patients with NHL; (2) only one of eight recent cases of HIV-positive men with NHL received HAART compared with greater than 70% of HIV-positive men free of NHL; and (3) no prior HAART independently predicted for AIDS-related NHL development. On the other hand, Hodgkin's disease may be increasing in frequency in HIV-positive patients as the incidence of NHL declines. It is hypothesized that more effective reconstitution of the immune system with HAART may facilitate the inversion of these incidences. Future prospective studies will hopefully answer these questions.

Approaches to gene therapy for human immunodeficiency virus infection

Much progress has been made in developing new and more efficient treatments for human immunodeficiency virus (HIV) infection, the cause of acquired immunodeficiency syndrome (AIDS). However, the scope of the HIV epidemic and the limitations of existing treatments necessitate the continued development of novel treatment strategies. Gene therapy is one such forward-looking strategy. Gene therapy approaches for HIV infection include efforts to interfere with viral replication directly by engineering HIV-resistant cells or indirectly by eliminating infected cells from the body, primarily by eliciting a therapeutic immune response to destroy HIV-infected cells. Although the prospect of gene therapy as a routine treatment for HIV infection remains distant, continuous progress is being made, which should also have implications for gene therapy strategies for a variety of other diseases. This article reviews some of the strategies for investigating the feasibility of gene transfer for the treatment of HIV infection.

HIV-associated lymphomas

Intermediate and high-grade non-Hodgkin lymphomas (NHL) with a B-cell phenotype are AIDS-defining illnesses. The incidence of systemic NHL is over 100 times increased, primary central nervous system NHL is over 3000 times increased, and Hodgkin's disease is approximately 10 times increased in the HIV-infected population. Unusual extranodal presentations of NHL and Hodgkin's disease are seen in HIV-infected individuals. High-grade histologies are common for both NHL and Hodgkin's disease in the HIV setting. Treatment approaches may be changing with the advent of highly active antiretroviral therapy, which may allow patients to tolerate more intensive treatment.