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

Prognosis of AIDS-related systemic non-Hodgkin lymphoma treated with chemotherapy and highly active antiretroviral therapy depends exclusively on tumor-related factors

OBJECTIVES

To assess complete remission (CR) and survival in patients with systemic AIDS-related non-Hodgkin lymphoma (ARL) receiving highly active antiretroviral therapy (HAART).

METHODS

We analyzed the Grupo de Estudio del SIDA register of systemic ARL, which started in Jan 1994, to collect cases diagnosed at 15 institutions prospectively and with active follow-up every 6 months. The date of censorship for this study was March 2005.

RESULTS

During the study period, 210 consecutive patients were diagnosed with ARL, with a median age 39 of years, 75.7% of whom were male, and with a median baseline CD4 count of 160 cells/microL. Histologic subtypes were diffuse large B-cell lymphoma (DLCL; n = 153 [72.9%]), Burkitt and atypical Burkitt/Burkitt-like lymphoma (BL; n = 40 [19.0%]), T-cell lymphoma (TC; n = 8 [3.8%]), and miscellaneous (n = 9 [4.3%]). Chemotherapy with or without other modalities was administered to 186 (88.6%) patients. In an intent-to-treat analysis of 184 patients who received at least 1 chemotherapy course with adequate follow-up to assess their response, 119 (64.7%) achieved CR, and the median length of survival (Kaplan-Meier analysis) was 52 months (95% confidence interval [CI]: 23 to 82 months). Factors independently associated with CR were histologic subtype and International Prognostic Index (IPI) score. Factors independently associated with improved overall length of survival (OS) were CR, low IPI score, and histologic subtype. The single factor independently associated with disease-free survival was Ann Arbor stage.

CONCLUSIONS

In patients with ARL treated with HAART, CR was associated exclusively with tumor-related factors. The CR rate was poorer in patients with BL and TC subtypes and was inversely correlated with IPI score. OS was independently associated with CR, IPI score, and the histologic subtype.

RNAi in combination with a ribozyme and TAR decoy for treatment of HIV infection in hematopoietic cell gene therapy

Combinatorial therapies for the treatment of HIV infection have changed the course of the AIDS epidemic in developed nations where the antiviral drug combinations are readily available. Despite this progress, there are many problems associated with chemotherapy for AIDS including toxicities and emergence of viral mutants resistant to the drugs. Our goal has been the development of a hematopoietic gene therapy treatment for HIV infection. Like chemotherapy, gene therapy for treatment of HIV infection should be used combinatorially. We have thus combined three different inhibitory genes for treatment of HIV infection into a single lentiviral vector backbone. The inhibitory agents engage RNAi via a short hairpin RNA targeting HIV tat/rev mRNAs, a nucleolar localizing decoy that binds and sequesters the HIV Tat protein, and a ribozyme that cleaves and downregulates the CCR5 chemokine receptor used by HIV for cellular entry. This triple combination has proven to be highly effective for inhibiting HIV replication in primary hematopoietic cells, and is currently on track for human clinical application.

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.

Advances in the management of HIV-related non-Hodgkin lymphoma

PURPOSE OF REVIEW

Human immunodeficiency virus infection is associated with an increased risk of non-Hodgkin lymphoma. Even with a decrease in AIDS-defining illnesses after the advent of highly active antiretroviral therapy, HIV-associated non-Hodgkin lymphoma remains an important problem.

RECENT FINDINGS

Low CD4+ T-lymphocyte count, disease stage, performance status, serum lactate dehydrogenase, and number of extranodal sites of disease are all important prognostic factors for HIV-non-Hodgkin lymphoma. Recent studies have examined the role of infusional chemotherapy, as well as immunotherapy, in the treatment of aggressive HIV-non-Hodgkin lymphoma, and autologous stem cell transplantation for relapsed or refractory HIV-non-Hodgkin lymphoma. New developments in the association of viral infection and pathogenesis of certain subtypes of HIV-non-Hodgkin lymphoma have also recently been reported.

SUMMARY

Outcomes of HIV-non-Hodgkin lymphoma are improving with the routine use of highly active antiretroviral therapy and combination chemotherapy. For aggressive HIV-non-Hodgkin lymphoma, infusional chemotherapy regimens are well tolerated and lead to complete response in about 50-75% of cases and a 2-3 years overall survival of 40-60%. The potential benefit of adding rituximab to combination chemotherapy may be offset by infectious complications in severely immunosuppressed patients. HIV-associated Burkitt lymphoma should be treated with an intensive regimen rather than standard cyclophosphamide, doxorubicin, vincristine, prednisone-like chemotherapy. Autologous stem cell transplantation should be considered for selected patients with relapsed or refractory HIV-non-Hodgkin lymphoma.

Management of patients with HIV in the intensive care unit

Because there are more than one million Americans with HIV, intensive care units continue to see frequent patients with HIV infection. In the era of highly active antiretroviral therapy, clinicians must be aware of drug toxicities and drug interactions. They must also recognize traditional opportunistic infections, as well as newer syndromes such as immune reconstitution syndrome, multicentric Castleman's disease, and primary pleural cell lymphoma.

Highly active antiretroviral therapy (HAART) improves survival in HIV-associated Hodgkin's disease: results of a multicenter study

BACKGROUND

The purpose of the study was to evaluate the outcome of Hodgkin's disease (HD) in patients infected with the human immunodeficiency virus (HIV) with respect to the use of highly active antiretroviral therapy (HAART).

MATERIALS AND METHODS

This cohort study included patients with HIV-HD diagnosed from June 1984 to February 2004. Patients treated in the pre-HAART era (1984-1996) were compared with those belonging to the HAART era (1997-2004).

RESULTS

Of 66 patients with HIV-HD, 47 (71%) presented with stage III/IV disease and 38 patients (58%) with an AIDS-defining illness. Fifty-nine of 66 patients (89.4%) underwent curative intended chemotherapy. Patients receiving HAART (n = 34) had a significantly better 2-year overall survival (OS) than those not receiving HAART (74% versus 30%, P <0.001). The 2-year OS of HAART-responders was 88% compared with 19% in patients without HAART-response (P = 0.0002). By multivariate analysis patients without HAART had a 5.6-fold higher risk for 3-year mortality [HR 5.6, 95% confidence interval (CI) 2.20-14.26]. Three-year mortality was significantly higher in patients without complete remission (HR 4.40, CI 1.77-10.99), with stage III/IV HD (HR 4.64, CI 1.31-16.49) and with CD4 cells <200/microl (HR 2.69, CI 0.99-7.33).

CONCLUSIONS

Use of HAART significantly improved the overall survival in patients with HIV-HD.

RNAi as a treatment for HIV-1 infection

Human immunodeficiency virus type 1 (HIV-1) was the first primate virus shown to be inhibited by RNA interference (RNAi). Early studies used both synthetic and promoter expressed small interfering RNAs (siRNAs) or expressed short hairpin RNAs (shRNAs) to demonstrate that this virus was susceptible to RNAi. In addition to targeting the virus itself, RNAi-mediated down-regulation of cellular targets that encode receptors required for viral entry also proved to be effective. The power of RNAi as an anti-HIV agent has propelled development of RNAi-based gene therapy approaches for the treatment of HIV infection in humans. Nevertheless, extensive in vitro experimentation has revealed potential problems of viral escape mutants and other toxicities caused by the si/shRNAs. This review covers the progress and problems in the development of RNAi for the treatment of HIV infection. Potential modalities for clinical application of RNAi in the treatment of HIV-1 infection are also described.

AIDS-related malignancies: changing epidemiology and the impact of highly active antiretroviral therapy

PURPOSE OF REVIEW

Three cancers in people with HIV denote an AIDS diagnosis: Kaposi's sarcoma, high-grade B-cell non-Hodgkin's lymphoma and invasive cervical cancer. In addition a number of other cancers occur at increased frequency in this population group but are not AIDS-defining illnesses. This review discusses the impact of highly active antiretroviral therapy on the epidemiology and outcome of AIDS-defining cancers.

RECENT FINDINGS

The incidence of both Kaposi's sarcoma and non-Hodgkin's lymphoma has declined in the era of highly active antiretroviral therapy and the outcome of both tumours has improved. Moreover, highly active antiretroviral therapy alone produces a response in a majority of antiretroviral-naïve patients with Kaposi's sarcoma. In contrast, highly active antiretroviral therapy has had little impact on the incidence of human papilloma virus-associated tumours (cervical and anal cancer) in people with HIV, although it may improve survival by reducing opportunistic infection deaths. As people with HIV live longer with highly active antiretroviral therapy, an increased incidence of other non AIDS-defining cancers that have no known association with oncogenic infections is becoming apparent.

SUMMARY

For those with access to highly active antiretroviral therapy, the good news from the AIDS-defining cancers - particularly Kaposi's sarcoma and non-Hodgkin's lymphoma - may be balanced by the increasing numbers of non AIDS-defining cancers.

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.

AIDS-related lymphoproliferative disease

Not long after the recognition of HIV as the causative agent of AIDS, it was evident that individuals infected with HIV developed lymphoma at a greater rate than the population at large. Approximately two thirds of AIDS-related lymphoma (ARL) cases are categorized as diffuse large B-cell type, with Burkitt lymphomas comprising 25% and other histologies a much smaller proportion. Typically, these individuals have presented with advanced extranodal disease and CD4+ lymphocyte counts of less than 200/mm3. Recent clinical trials have demonstrated a better outcome with chemotherapy for ARL since the introduction of combination antiretroviral treatment, termed highly active antiretroviral therapy (HAART). For patients with relapses, solid evidence points to the safety and utility of hematopoietic-cell transplantation as a salvage modality. Coinfection with other viruses such as Epstein-Barr virus and Kaposi sarcoma-associated herpesvirus have led to the genesis of previously rare or unrecognized lymphoma subtypes such as plasmablastic and primary effusion lymphomas. The immunosuppressive impact of treatment for patients with ARL receiving chemotherapy with HAART appears transient and opportunistic infections have become less problematic than prior to HAART. Significant progress has been made in the understanding and management of ARL but outcomes still remain inferior compared to those achieved in HIV- individuals.

T-Cell Immune Reconstitution after Hematopoietic Stem Cell Transplantation for HIV-Associated Lymphoma

BACKGROUND

One of the major concern for high-dose chemotherapy and hematopoietic stem cell transplantation (HSCT) for HIV-associated lymphoma is that posttransplant immunosuppression might worsen immune defects of HIV individuals. Since the introduction of highly active antiretroviral therapy has made HSCT possible also in these patients, we analyzed whether the immune system already compromised by HIV infection might support an efficient T-cell recovery after HSCT.

METHODS

The kinetics and the extent of T-cell reconstitution were investigated before and after HSCT in four patients with HIV-related lymphoma (one with Hodgkin's Disease and three with non-Hodgkin's lymphoma) by measuring the thymic output, the level of IL-7 and the heterogeneity of T-cell repertoire. T-cell competence was gauged at two functional levels: by determining the number of T-cell divisions and by measuring IFN-gamma production.

RESULTS

The thymus of transplanted patients can be capable of generating new T cells, but there is no relationship between increasing number of newly produced lymphocytes and modification of IL-7 level. Various T-cell subsets, expressing different T-cell receptor variable beta genes, were preferentially expanded in CD8 population and most of them showed a restricted diversity. Furthermore, CD3 lymphocytes showed heterogeneous behaviors in terms of proliferative capability and IFN-gamma production.

CONCLUSIONS

High-dose therapy and HSCT in HIV patients under highly active antiretroviral therapy does not worsen the immune defects. On the contrary, in the presence of some conditions (including the type of hematologic malignancy, the therapy compliance, and the immune status before transplantation), high-dose therapy and HSCT might support the improvement of immune conditions.

The changing face of HIV-associated lymphoma: what can we learn about optimal therapy inl the post highly active antiretroviral therapy era?

Epidemiological data indicate that the risk of developing non-Hodgkin lymphoma (NHL) in HIV positive individuals is related to age and CD4 count (i.e. degree of immunosuppression). The prognosis of patients with HIV-NHL has been shown to be linked to several features including age, stage, modified IPI, prior AIDS diagnosis, CD4 count, immunoblastic pathology, LDH, and HAART use. These features are, as would be expected, a mixture of prognostic factors relating to both the HIV, and to the NHL. Population studies indicate that the incidence of associated (HIV-NHL) may be reducing with the advent of HAART, although not all studies concur. However, most population-based studies have not as yet shown a significant improvement in the survival of patients with HIV-NHL with HAART. The optimal chemotherapy for these patients is unknown, although it is generally accepted that CNS prophylaxis is mandatory. There is currently no good evidence of any survival benefit with increased dose intensity from large RCT. However, it must be borne in mind that the large randomised studies comparing differing dose intensities were undertaken before the advent of effective HAART. There is some evidence that there may be a subset of good prognosis patients who may benefit from more intensive therapy. Given that the prognosis of patients with HIV can now be considerably improved with HAART, we cannot necessarily assume that the same results would apply with regard to chemotherapy dose intensity. There is some evidence that there is a survival benefit from the addition of HAART to chemotherapy, although this is retrospective. It is likely, however, that the reason for this is that the HAART improves the prognosis of the patients from their HIV, and therefore reduces the number of patients dying from other HIV-related illnesses whilst in remission from their lymphoma, as was seen in large numbers of patients in the earlier chemotherapy trials. It must not be forgotten that the prognosis of the patient's NHL is intimately linked to their prognosis with respect to the HIV. Although the number of patients with HIV-NHL is currently few, there is a need for more trials of chemotherapy, particularly now in the HAART era, when the prognosis from the point of view of the HIV has improved so much. In particular, the issue of dose intensity needs revisiting for patients whose overall prognosis can be improved by commencing HAART. Patients with HIV-NHL should be managed at specialist centres, and where possible should be managed as part of RCT.

Current strategies for the treatment of diffuse large B cell lymphoma

PURPOSE OF REVIEW

This paper reviews the improvement in the treatment of patients with diffuse large B cell lymphoma.

RECENT FINDINGS

The outcome in these patients has become better with longer survival because of two major developments: (1) increasing the dose of active drugs and shortening the time between cycles, resulting in dose-dense or dose-intense regimens, and (2) combining rituximab with chemotherapy. Both strategies have been associated with higher response rates, longer event-free survival, and longer overall survival, particularly in patients without adverse prognostic parameters. A combination of both is currently being tested for these poor-risk patients.

SUMMARY

Although improvement has been made in low-risk patients, much work has to be done for patients with high-risk lymphoma. It may come with a better definition of genetic abnormalities specifically associated with refractoriness to chemotherapy.

AIDS-Related Burkitt's Lymphoma Versus Diffuse Large-Cell Lymphoma in the Pre–Highly Active Antiretroviral Therapy (HAART) and HAART Eras: Significant Differences in Survival With Standard Chemotherapy

Purpose

To compare outcomes of patients with HIV-Burkitt's lymphoma (HIV-BL) and HIV-diffuse large-cell lymphoma (HIV-DLCL) after treatment with CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) or M-BACOD (methotrexate, bleomycin, cyclophosphamide, etoposide) in pre–highly active antiretroviral therapy (HAART) versus HAART eras.

Patients and Methods

Three hundred sixty-three patients with AIDS-related lymphoma diagnosed from 1982 to 2003 were reviewed retrospectively, including 262 in the pre-HAART (HIV-BL, 117; HIV-DLCL, 145) and 101 in the HAART era (HIV-BL, 18; HIV-DLCL, 83). Pre-HAART included those who did not receive HAART, and HAART era included those diagnosed after January 1997 who received HAART.

Results

There were no significant differences between groups in terms of age, sex, history of injection drug use, prior AIDS, lactate dehydrogenase level, and disease stage at diagnosis. Compared with HIV-BL, HIV-DLCL was associated with significantly lower CD4 counts in the pre-HAART but not the HAART era. Although the overall median survival was similar for both groups in the pre-HAART era (HIV-BL, 6.4 months v HIV-DLCL, 8.3 months; P = .43), survival was significantly worse in patients with HIV-BL in the HAART era (HIV-BL, 5.7 months v HIV-DLCL, 43.2 months; P = .0003). Failure to attain complete remission and CD4 count less than 100 cells/mm3 independently predicted for poor survival in the pre-HAART era. In comparison, histology of HIV-BL and no attainment of complete remission were independent poor prognostic factors in the HAART era.

Conclusion

Survival of patients with HIV-DLCL has improved in the HAART era, along with CD4 count, whereas survival of similarly treated patients with HIV-BL remained poor. The current practice of using the same regimen for both groups of patients should be re-evaluated.