Treatment of AIDS-related non-Hodgkin's lymphoma with chemotherapy (CNOP) and r-hu-G-CSF: clinical outcome and effect on HIV-1 viral load

Lack of Specific Regulatory T Cell Depletion and Cytoreduction Associated with Extensive Toxicity After Administration of Low and High Doses of Cyclophosphamide

Up to 93% of the human immunodeficiency virus (HIV) latent reservoir comprised defective proviruses, suggesting that a functional cure is possible through the elimination of a small population of cells containing intact virus, instead of the entire reservoir. Cyclophosphamide (Cy) is an established chemotherapeutic agent for immune cell cancers. In high doses, Cy is a nonselective cytoreductor, used in allogeneic stem-cell transplantation, while in a low dose, metronomic schedule, Cy selectively depletes regulatory T cells (Tregs). We administered low and high doses to simian immunodeficiency virus (SIV)-infected rhesus macaques (RM) to assess their effects on the SIV reservoirs. As a Treg-depleting agent, Cy unselectively depleted Treg and total lymphocytes, resulting in minimal immune activation and no viral reactivation. As a cytoreductive agent, Cy induced massive viral reactivation in elite controller RMs without ART. However, when administered with antiretroviral therapy (ART), Cy had substantial adverse effects, including mortality. Our study thus dissuades further investigation of Cy as an HIV cure agent.

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.

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.

Management of AIDS-related non-Hodgkin's lymphomas

The incidence of non-Hodgkin's lymphoma in individuals infected with HIV is approximately 60- to 100-fold increased over the general population. The majority of patients with AIDS-related lymphoma (ARL) present with stage III-IV disease and with B-symptoms. They often have multiple extranodal localisations, with a high incidence of central nervous system involvement. Histologically, most tumours are either diffuse large cell lymphomas or Burkitt lymphomas. Several factors, such as disrupted immune surveillance, Epstein-Barr virus infection, chronic antigenic stimulation, cytokine dysregulation and the acquisition of genetic lesions, are thought to contribute to the pathogenesis. Patients with ARL have a poor prognosis: overall survival ranges from 1.5 to 18 months. The most important adverse prognostic factors are poor performance status, a low CD4+ cell count and a history of opportunistic infections. Results of treatment with polychemotherapy compare unfavourably to results in patients without HIV infection. Since the advent of highly active antiretroviral therapy (HAART), there appears to be a decrease in the incidence of ARL. In addition, the use of HAART in combination with chemotherapy and the use of new treatment modalities may improve the outcome of this disease.

Drugs and cardiotoxicity in HIV and AIDS

The advent of potent antiretroviral drugs in recent years has had an impressive impact on mortality and disease progression in HIV-infected patients, so that issues related to long-term effects of drugs are of growing importance. Hyperlipidemia, hyperglycemia, and lipodystrophy are increasingly described adverse effects of highly active antiretroviral therapy (HAART), in particular when protease inhibitors are used. Hyperlipidemia is strikingly associated with the use of most available protease inhibitors, with an estimated prevalence of up to 50%. Because of the short observation period and the small number of cardiovascular events, epidemiological evidence for an increased risk of coronary heart disease in HIV-infected patients treated with HAART is not adequate at present; however, it is likely that shortly more data will accumulate to quantify this risk. Before starting HAART and during treatment it is reasonable to evaluate all patients for traditional coronary risk factors, including lipid profile. Among the drugs that are currently used in HIV+ patients, antibacterials, antifungals, psychotropic drugs and anti-histamines have been associated with QT prolongation or torsade de pointe, a life-threatening ventricular arrhythmia. Among the risk factors that may precipitate an asymptomatic electrocardiographic abnormality into a dangerous arrhythmia is the concomitant use of drugs that share the CYP3A metabolic pathway. Since most protease inhibitors are potent inhibitors of CYP3A, clinicians should be aware of this potentially dangerous effect of HAART. Anthracyclines are potent cytotoxic antibiotics that have been widely used for the treatment of HIV-related neoplasms. Their cardiotoxicity is well known, ranging from benign and reversible arrhythmias to progressive severe cardiomyopathy. The increased survival and quality of life of HIV+ patients emphasize the importance of a high awareness of adverse drug-related cardiac effects.

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.

Chemotherapy for human immunodeficiency virus-associated non-Hodgkin's lymphoma in combination with highly active antiretroviral therapy

PURPOSE

This study investigated the efficacy, toxicity, and pharmacokinetic interactions resulting from simultaneous combination chemotherapy and highly active antiretroviral therapy (HAART) for patients with human immunodeficiency virus (HIV)-associated non-Hodgkin's lymphoma (NHL). In addition, the effects on viral load, CD4 counts, and opportunistic infections were examined with the use of combination chemotherapy combined with HAART.

PATIENTS AND METHODS

Sixty-five patients with previously untreated and measurable disease at any stage of HIV-associated NHL of intermediate or high grade were entered onto this study at 17 different centers. The first 40 patients entered onto the study received reduced doses of cyclophosphamide and doxorubicin, combined with vincristine and prednisone (modified CHOP [mCHOP]), whereas the subsequent 25 patients entered onto the study received full doses of CHOP combined with granulocyte colony-stimulating factor (G-CSF). All patients also received stavudine, lamivudine, and indinavir.

RESULTS

The complete response rates were 30% and 48% among patients who received mCHOP and full-dose CHOP combined with HAART, respectively. Grade 3 or 4 neutropenia occurred in 25% of patients receiving mCHOP and 12% of those receiving full-dose CHOP combined with G-CSF (25% v 12%). There were similar numbers of patients with grade 3 or 4 hyperbilirubinemia (12% and 17%), constipation and abdominal pain (18% and 17%), and transaminase elevation (48% and 52%) on the modified and full-dose arms of the study, respectively. Doxorubicin clearance and indinavir concentration curves were similar among patients on this study and historical controls, whereas cyclophosphamide clearance was 1.5-fold reduced as compared with control values. Human immunodeficiency virus (HIV) load declined from a median baseline value of 29,000 copies/mL to a median minimum value on therapy of 500 copies/mL.

CONCLUSION

Either modified-dose or full-dose CHOP chemotherapy for HIV-NHL, delivered with HAART, is effective and tolerable.

Changing incidence and survival in patients with aids-related non-Hodgkin's lymphomas in the era of highly active antiretroviral therapy (HAART)

To determine role of highly active antiretroviral therapy (HAART) and additional factors in incidence and outcome of patients with AIDS-related non-Hodgkin's lymphomas (NHL) we retrospectively analyzed 257 cases of AIDS-related NHL (24 low-grade, 168 high-grade B-cell, 6 high-grade T-cell, and 59 primary CNS lymphomas (PCNSL) among 2004 patients with HIV-infection treated at the University Hospital of Frankfurt, Germany from January 1983 to May 1999. Data were evaluated by univariate and multivariate analyses, using overall survival as end point. Patients received CHOP-like therapy as standard treatment. Until May 1999 incidence of all diagnosed cases of NHL was decreasing (1991-94: 14.2% versus 1995-5/99: 12.8%). Mainly, the incidence of low-grade NHL and PCNSL clearly decreased whereas the incidence of high-grade B-cell NHL increased compared to all diagnosed cases of NHL (1983-86: 53.3% versus 1995-5/99: 78.6%). One-year survival probability of all screened patients with AIDS related NHL was 54%, while 5-year survival rate remained 5%. We found age <25 years, development of NHL in the years before 1990, IVDU, CD4 counts <150/microl, PCNSL as well as NHL as the AIDS index disease, to be highly significant independent predictors of poor survival, including increased hazard ratios. In the era of HAART incidence of NHL is decreasing, mainly the incidence of low-grade NHL and PCNSL. Overall survival of patients has been prolonged with HAART. This development is mainly due to improvement of antiretroviral therapy, rather than to any fundamental changes in the chemotherapeutic treatment of NHL. Therefore, new treatment approaches for AIDS-related NHL should focus on more efficient antiretroviral therapy in association with combination chemotherapy.

Glucocorticoids suppress human immunodeficiency virus type-1 long terminal repeat activity in a cell type-specific, glucocorticoid receptor-mediated fashion: direct protective effects at variance with clinical phenomenology

Glucocorticoid administration and/or excess secretion have been associated with increased Human Immunodeficiency Virus Type-1 (HIV-1) replication and AIDS progression. The HIV-1 long terminal repeat (LTR) promoter contains glucocorticoid-responsive element (GRE)-like sequences that could mediate a positive effect of glucocorticoids on HIV-1. In addition, we recently demonstrated that the HIV-1 accessory protein Vpr is a potent coactivator of the glucocorticoid receptor, which, like the host coactivator p300, potentiates the effect of glucocorticoids on GRE-containing, glucocorticoid-responsive genes. Such an effect may increase the sensitivity of several host target tissues to glucocorticoids by several fold, and may, thus, contribute to a positive effect of glucocorticoids on the HIV-1-LTR in infected host cells. In this study, we determined the direct effect of glucocorticoids on HIV-1-LTR by examining the ability of dexamethasone to modulate the activity of this promoter coupled to the luciferase reporter gene in human cell lines. Dexamethasone markedly inhibited Tat-stimulated, p300- or Vpr-enhanced luciferase activities in a cell-type specific, dose-dependent, and glucocorticoid receptor-mediated fashion. This effect of dexamethasone was not potentiated by Vpr, was antagonized by the glucocorticoid receptor antagonist RU 486 and required the DNA-binding domain of the receptor. These data suggest that the inhibitory effect of glucocorticoids on the HIV-1-LTR may be exerted via non-GRE-dependent inhibition of the strongly positive host transcription factor NF-kappaB, which interacts with the DNA- and ligand-binding domains of the receptor. Alternatively, it is also possible that dexamethasone-activated glucocorticoid receptor competes with other transcription factors for their binding sites on the promoter region or squelches transcription factors shared by HIV-1-LTR and glucocorticoid-responsive promoters. We conclude that glucocorticoids suppress, rather than stimulate, the HIV-1 promoter, thus acting, protectively for the host. Their apparent negative clinical association with AIDS is most likely due to immunosuppression of the host.