Strategies to overcome myelotoxic therapy for the treatment of Burkitt's and AIDS-related non-Hodgkin's lymphoma.

BACKGROUND: Strategies to circumvent or lessen the myelotoxicity associated with combination chemotherapy may improve the overall outcome of the management of patients particularly in resource poor settings. OBJECTIVES: To develop effective non-myelotoxic therapies for Burkitt's Lymphoma (BL) and AIDS-related non-Hodgkin's lymphoma. DATA SOURCES: Publications, original and review articles, conference abstracts searched mainly on Pubmed indexed for medline. DATA EXTRACTION: A systematic review of the clinical problem of combination chemotherapy. Identification of clinical strategies that circumvent or lessen the myelotoxicity of combination cytotoxic chemotherapy. Length of survival, lack of clinically significant (> grade 3) myelosuppression and weight loss were used as markers of myelotoxicity. DATA SYNTHESIS: Review of published experience with some of these strategies including dose-modification of multi-agent chemotherapy; rationale for targeted therapies, and the preclinical development of a mouse model exploring the role of metronomic scheduling substantiate pragmatism and feasibility of these approaches. CONCLUSION: Myelotoxic death rates using multi-agent induction chemotherapy approach 25% for endemic Burkitt's lymphoma and range between 20% to 60% for AIDS-related malignancy. This is mostly explained by the paucity of supportive care compounded by wasting and inanition attributable to advanced cancer and HIV infection making patients more susceptible to myelosuppressive side effects of cytotoxic chemotherapy. Investigations and alternative approaches that lessen or circumvent myelotoxicity of traditional cytotoxic chemotherapy for the management of Burkitt's lymphoma and AIDS-related non-Hodgkin's lymphoma in the resource-constrained setting are warranted. Pertinent pre-clinical and clinical data are emerging to support the need for abrograting the myelosuppressive effects of traditional cytotoxic chemotherapy. This can be achieved by developing targeted anti-viral and other strategies, such as the use of bryostatin 1 and vincristine, and by developing a preclinical mouse model to frame the clinical rationale for a pilot trial of metronomic therapy for the treatment of Burkitt's and AIDS-related lymphoma. Implementation of these investigational approaches must be encouraged as viable anti-cancer therapeutic strategies particularly in the resource-constrained settings.

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.

Treatment of HIV-associated multicentric Castleman's disease with oral etoposide.

Multicentric Castleman's disease (MCD) is a lymphoproliferative disorder that can be defined based upon both clinical and pathological characteristics. The clinical features of this frequently fatal disease include fever, generalized lymphadenopathy, fatigue, splenomegaly, hepatomegaly, and pancytopenia. Recently, severe forms of this disease have been diagnosed in HIV positive patients. Human herpesvirus type 8 (HHV-8) DNA sequences have been detected in peripheral blood mononuclear cells (PBMCs) of patients with Kaposi's sarcoma and MCD, regardless of HIV infection status. Treatment and outcomes in HIV associated MCD are generally unfavorable. We recently treated two HIV-positive patients diagnosed with aggressive MCD with daily oral etoposide (50 mg). The first patient had relapsed on several occasions despite previous therapy with doxil, paclitaxel, and oral ganciclovir. The second patient was treatment naive. Both patients had HHV-8 detectable by polymerase chain reaction in PBMCs, widespread tumor, and B-type symptoms when therapy was initiated. In both cases remissions (documented by computerized tomography) have been durable, 1.5 and 6 months, respectively, with minimal side effects. Oral etoposide may be a safe, tolerable, and active agent in MCD.

HHV-8 encoded vIRF-1 represses the interferon antiviral response by blocking IRF-3 recruitment of the CBP/p300 coactivators.

Human herpes virus 8 (HHV-8) has developed unique mechanisms for altering cellular proliferative and apoptotic control pathways by incorporating viral homologs to several cellular regulatory genes into its genome. One of the important pirated genes encoded by the ORF K9 reading frame is a viral homolog of the interferon regulatory factors (IRF), a family of cellular transcription proteins that regulates expression of genes involved in pathogen response, immune modulation and cell proliferation. vIRF-1 has been shown to downregulate the interferon- and IRF-mediated transcriptional activation of ISG and murine IFNA4 gene promoters. In this study we demonstrate that vIRF-1 efficiently inhibited virus-induced expression of endogenous interferon B, CC chemokine RANTES and CXC chemokine IP-10 genes. Co-expression analysis revealed that vIRF-1 selectively blocked IRF-3 but not IRF-7-mediated transactivation. vIRF-1 was able to bind to both IRF-3 and IRF-7 in vivo as detected by coimmunoprecipitation analysis, but did not affect IRF-3 dimerization, nuclear translocation and DNA binding activity. Rather, vIRF-1 interacted with the CBP/p300 coactivators and efficiently inhibited the formation of transcriptionally competent IRF-3-CBP/p300 complexes. These results illustrate that vIRF-1 is able to block the early stages of the IFN response to virus infection by interfering with the activation of IRF-3 responsive, immediate early IFN genes.

Azidothymidine and interferon-alpha induce apoptosis in herpesvirus-associated lymphomas.

Lymphoproliferative diseases that occur in immunocompromised patients are frequently associated with herpesviruses. These patients often fare poorly after treatment with conventional chemotherapy. We reported previously that patients with AIDS-related Burkitt's lymphoma (BL) responded to parenteral azidothymidine (AZT) and IFN-alpha. We found that EBV-positive lymphoma cells derived from these patients cultured with AZT express CD95 and undergo apoptosis. AZT-mediated apoptosis was caspase dependent and occurred despite Fas receptor blockade. In contrast, EBV-negative lymphomas were resistant to AZT-induced apoptosis, as were EBV-positive lymphomas that expressed high levels of bcl-2. Primary effusion lymphoma (PEL) cell lines infected with human herpesvirus type 8 required IFN-alpha to potentiate AZT-induced apoptosis. IFN-alpha did not up-regulate CD95 in BL or PEL but did induce expression of the death receptor ligand, CD95 ligand. AZT-sensitive lymphomas also accumulated significantly higher intracellular AZT monophosphate than did resistant lymphomas. Our data demonstrated distinct apoptotic responses to AZT and IFN-alpha in herpesvirus-associated lymphomas. EBV-positive BL cells that expressed low BCL-2 levels were sensitive to AZT alone; PEL cells required the addition of IFN-alpha to enhance apoptosis, and EBV-negative lymphomas were insensitive to both agents. AZT-sensitive BL cells transfected with BCL-2 became resistant. Susceptibility to antivirus-mediated apoptosis may be exploited to improve the therapy of certain herpesvirus-associated lymphomas.

Molecular epidemiology of human T-cell leukemia virus type I (HTLV-1) Brazil: the predominant HTLV-1s in South America differ from HTLV-ls of Japan and Africa, as well as those of Japanese immigrants and their relatives in Brazil.

To better understand the origin of human T-cell leukemia virus type l (HTLV-l) in South America, we conducted a phylogenetic study on 27 new HTLV-ls in Brazil. These were obtained from Brazilians of various ethnic origins, such as Japanese immigrants, whites, blacks and mulattos. We amplified and sequenced proviral DNAs of a part of the long terminal repeats. Phylogenetic trees revealed that all but 6 of the new isolates were not only similar to each other but also similar to HTLV-ls of other South American countries, including those from Amerindians. However, the isolates differed from the HTLV-ls of Africa and Japan. The other six isolates were from Japanese immigrants and were phylogenetically almost identical to HTLV-ls in Japan but different from the majority of South American HTLV-ls, including the other new Brazilian HTLV-ls. These findings indicate that the recent introduction of HTLV-1 from Japan is limited to Japanese immigrants. In addition, the results do not support the prevailing hypothesis that HTLV-ls in South America were introduced by blacks who were brought from Africa as slaves. Rather, these results suggest that the majority of HTLV-1s prevailing in South America have spread from Amerindians, some of whom are likely to have possessed this human retrovirus from the beginning of their settlement in South America.

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

AIDS-related primary central nervous system lymphoma (AIDS PCNSL) is a rapidly fatal disease. Conventional therapeutic modalities offer little and new approaches are needed. Previous work has shown that zidovudine (AZT) in combination with other agents is active in retroviral lymphomas. Epstein-Barr virus (EBV) is detected in tumor tissue and cerebrospinal fluid of AIDS PCNSL patients. In a preliminary in vitro study we found that an Epstein-Barr virus-positive B cell line underwent apoptosis on coculture with AZT. This effect was accentuated by the addition of ganciclovir (GCV). We treated five patients with AIDS PCNSL with a regimen consisting of parenteral zidovudine (1.6 g twice daily), ganciclovir (5 mg/kg twice daily), and interleukin 2 (2 million units twice daily). Four of five had an excellent response. Two patients are alive and free of disease 22 and 13 months later; another responded on two separate occasions, 5 months apart, and the last patient responded with a 70-80% regression of tumor but could not be maintained on therapy owing to myelosuppression. We conclude that parenteral zidovudine, ganciclovir, and interleukin 2 is an active combination for AIDS-related central nervous system lymphoma.

Danazol for paroxysmal nocturnal hemoglobinuria.

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare clonal stem-cell disorder in which blood cells lack complement inhibiting membrane proteins, and become susceptible to complement-mediated injury, leading to chronic intravascular hemolysis and pancytopenia. Glucocorticoids have been a mainstay of therapy. For patients refractory to glucocorticoids and requiring blood transfusions, an alternative therapy is needed. We studied danazol therapy in 5 patients refractory to other treatments. Four of the 5 benefited, showing rise in hematocrit and eventual cessation of transfusion requirements. Remissions lasted > or =2 years in 3 and 10 years in 1 patient. Danazol was well-tolerated without serious side effects. Danazol appears to be a good alternative treatment in PNH.

Human herpesvirus type 8 DNA sequences in cell-free plasma and mononuclear cells of Kaposi's sarcoma patients.

Human herpesvirus (HHV) type 8 has been detected in both classical and AIDS-related Kaposi's sarcoma, body-cavity lymphomas, and other types of tumors. HHV-8 has also been detected in DNA from peripheral blood mononuclear cells (PBMC) of some Kaposi's sarcoma patients and more readily in B cell fractions derived from panned cell subpopulations. Two patients were followed using several methods; in situ hybridization, solution-based polymerase chain reaction (PCR), and in situ PCR. HHV-8 was intermittently detected in plasma, and detection correlated with detection in PBMC. In situ PCR demonstrated HHV-8 sequences in both peripheral blood B lymphocytes and, to a lesser extent, T lymphocytes. HHV-8 may undergo periods of viremia while at other times it is undetectable and infects circulating B cells and some T cells.

Identification of human T cell lymphotropic virus type IIa infection in the Kayapo, an indigenous population of Brazil.

Human T cell lymphotropic virus type II (HTLV-II) infection is endemic in a number of indigenous populations in North, Central, and South America. In the present study we have employed serological and molecular methods to identify HTLV-II infection in Indian communities in the Amazon region of Brazil. Sera (1324) from 25 different Indian communities were analyzed by ELISA and Western blot. One hundred and four samples (7.8%) from a number of culturally distinct and geographically unrelated populations were found to have reactivities consistent with HTLV-II infection. Of these, 67 were from the Kayapo Indian communities, which had an overall seroprevalence rate of greater than 30%. In addition, high seroprevalence rates were observed in three other communities, the Munduruku, Arara do Laranjal and the Tyrio, suggesting that there are additional foci of endemic infection in the Amazon region. In the Kayapo, seroprevalence rates tended to increase with age, supporting the importance of sexual transmission of the virus, and family studies demonstrated that vertical transmission is also an important route of infection. Restriction fragment length polymorphism (RFLP) and nucleotide sequence analysis of a region of the env gene demonstrated that the Kayapo are infected with the HTLV-IIa subtype. Moreover, nucleotide sequence analysis of the LTR demonstrated that this belonged to a distinct HTLV-IIa phylogenetic group. The identification of HTLV-IIa in the Kayapo is, as far as we are aware, the first identified endemic focus of infection by this subtype of HTLV-II in the Americas.

Clinical spectrum of HTLV-I in south Florida.

A total of 113 patients with infection due to human T-cell leukemia virus type 1 (HTLV-I) were evaluated at the University of Miami from January 1988 to March 1993. Forty patients were identified with adult T-cell leukemia/lymphoma (ATLL) and 63 with HTLV-I-associated myelopathy (HAM). Three had concomitant ATLL and HAM. Two HAM patients co-infected with human immunodeficiency virus type 1 (HIV-I) developed clonal lymphoproliferative disease during the study period. Patients with ATLL have a poor prognosis; multiple chemotherapy regimens including high-dose cytotoxic agents have been utilized with a small impact on survival. Most of our patients are currently treated with experimental regimens. Rheumatologic or autoimmune illnesses were identified, mostly in HAM patients, and a small number developed immunodeficiencies in the absence of other definable etiologic factors. Most of the patients were immigrants from areas of endemicity in the Caribbean basin, although many Americans were also recognized. HTLV-I/II infection was diagnosed serologically and typed as HTLV-I by polymerase chain reaction (PCR) or a modified Western blot when a DNA sample was not available. In 24 of 40 patients with ATLL, Southern blot hybridization performed on DNA extracted from peripheral blood lymphocytes or tumor tissue demonstrated clonal HTLV-I integration. In South Florida, ATLL and HAM are now seen frequently. Since HTLV-I infection is associated with a 4% lifetime risk of developing ATLL and an additional 0.25% lifetime risk for developing HAM, a large pool of asymptomatically infected individuals must exist here.(ABSTRACT TRUNCATED AT 250 WORDS)

Thrombotic microangiopathy and retroviral infections: a 13-year experience.

Eleven of fifty serum samples collected from patients with a diagnosis of thrombotic microangiopathy (TMA), from 1979 to 1991, tested positive for antiretroviral antibodies. Seven had human immunodeficiency virus (HIV) infection, and four had human lymphotrophic virus, type I (HTLV-I) infection. All patients were treated with plasma exchange and/or infusion, but only two of the HIV-infected patients obtained a complete response (CR) and one of them died after a few months. Combined results from the literature indicate that most patients with HIV infection survive less than one year from the initial diagnosis of TMA. In the setting of HIV infection, TMA is a treatable condition, but survival for most patients is less than 12 months. Three of the four HTLV-I infected patients with TMA had a CR. These observations strongly suggest that both HIV and HTLV-I infections are associated with TMA, but rigorous epidemiologic studies will be needed to determine the relative risk for each. Retroviral infections should be considered in patients with TMA, especially if the patient has associated risk factors and demographic characteristics.

Establishment of human T-cell leukemia virus type I T-cell lymphomas in severe combined immunodeficient mice.

Human T-cell leukemia virus type I (HTLV-I) is recognized as the etiologic agent of adult T-cell leukemia (ATL), a disease endemic in certain regions of southeastern Japan, Africa, and the Caribbean basin. Although HTLV-I can immortalize T lymphocytes in culture, factors leading to tumor progression after HTLV-I infection remain elusive. Previous attempts to propagate the ATL tumor cells in animals have been unsuccessful. Severe combined immunodeficient (SCID) mice have previously been used to support the survival of human lymphoid cell populations when inoculated with human peripheral blood lymphocytes (PBL). SCID mice were injected intraperitoneally with PBL from patients diagnosed with ATL, HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), or from asymptomatic HTLV-I-seropositive patients. Many of these mice become persistently infected with HTLV-I. Furthermore, after human reconstitution was established in these mice, HTLV-I-infected cells displayed a proliferative advantage over uninfected human cells. Lymphoblastic lymphomas of human origin developed in animals injected with PBL from two ATL patients. The tumor cells represented outgrowth of the original ATL leukemic clone in that they had monoclonal or oligoclonal integrations of the HTLV-I provirus identical to the leukemic clone and predominantly expressed the cell surface markers, CD4 and CD25. In contrast, cell lines derived by HTLV immortalization of T cells in vitro did not persist or form tumors when inoculated into SCID mice, indicating differences between in vitro immortalized cells and ATL leukemic cells. This system represents the first small animal model to study HTLV-I tumorigenesis in vivo.

Association of '(tropical) ataxic neuropathy' with HTLV-II.

Jamaican Neuropathy of the ataxic type (tropical ataxic neuropathy [TAN] and spastic type (tropical spastic paraparesis [TSP]) have been recognized for over a century in Jamaica. The recent association of TSP with HTLV-I (TSP/HAM) is now well established. We now present evidence for a possible association between a TAN-like illness with HTLV-II in four females aged 34-49. All presented with ataxic gait and all four have prominent mental changes. Three of the four also have minor motor deficits with urinary frequency and two have nocturnal leg cramps. All have serum antibody and all had PCR evidence of HTLV-II infection. Antibody to HTLV-II is present in CSF from two subjects. The distinctive picture of prominent ataxia and altered mental status in these subjects contrasts with a predominantly myelopathic picture seen in TSP/HAM.

Spastic ataxia associated with human T-cell lymphotropic virus type II infection.

Human T-cell lymphotropic virus type one (HTLV-1) is associated with tropical spastic paraparesis or HTLV-I--associated myelopathy. We report 2 women with a spastic ataxic illness similar to HTLV-I--associated myelopathy infected solely with HTLV-II. Identification of HTLV-II infection was made serologically, by polymerase chain reaction, and by viral culture (in 1 woman). One woman, treated with 200 mg of danazol orally, three times daily, had pronounced improvement in ambulation, nocturnal spasticity, and nighttime urinary frequency. It appears that infection with HTLV-II may cause an illness similar to HTLV-I--associated myelopathy, but distinguished by the presence of ataxia.

Human T lymphotropic virus type I-associated myelopathy. A report of 10 patients born in the United States.

Human T lymphotropic virus type I (HTLV-I)-associated myelopathy (HAM) (tropical spastic paraparesis/HAM) has rarely been reported in the United States. We present 10 well-documented cases with positive Western immunoblot test results and polymerase chain reactions for HTLV-I. The clinical and laboratory features of these American-born patients resemble those previously reported series of tropical spastic paraparesis and HAM from the Caribbean and Japan, but important differences were observed. In our study there were equal numbers of whites and blacks and of men and women. Age at onset was younger than that reported from the Caribbean and Japan. Rate of progression to paraparesis varied but was more rapid than previously reported. Half were transfusion recipients but six had multiple sexual partners, with one regularly interacting with prostitutes and reporting a history of drug abuse. Although more rapid progression was seen in the transfusion recipients, this did not explain the earlier age of onset in this group of patients. The HTLV-I, and the associated myelopathy, are endemic in Florida, suggesting that immigration from, and proximity, to the Caribbean basin are contributing risk factors.