Cardiac toxicity of high-dose chemotherapy.

Cardiac toxicity is an uncommon but potentially serious complication of high-dose (HD) chemotherapy and little is known about incidence, severity and underlying mechanisms. We have systematically reviewed the literature of the last 30 years to summarize and appraise the published evidence on cardiac toxicity associated with HD chemotherapy. HD cyclophosphamide-containing regimens have been most commonly associated with cardiac toxicity, with a progressively decreasing incidence over time. Dosage, application regimens and coadministration of other chemotherapeutic agents emerged as risk factors. While cardiac toxicity has been rarely associated with other cytotoxic drugs, an unexpected incidence of severe cardiotoxicity resulted from reduced-intensity conditioning regimens containing melphalan and fludarabine. Predictive value of cardiologic examination of patients is limited, and patients with a slight depression of cardiac performance could tolerate HD chemotherapy. Clinical examination, resting electrocardiography and dosage adjustment in overweight patients remain the mainstay of prevention, with bidimensional echocardiography (2D echo) for patients with a history of anthracycline exposure. Strategies to decrease the long-term negative impact of anthracycline administration on cardiac performance are being investigated. New 2D echo-based techniques and circulating markers of cardiac function hold promise for allowing identification of patients at high risk for and early diagnosis of cardiac toxicity.

Recent advances in multiple myeloma immunotherapy.

Multiple myeloma (MM) responds to, but is not cured by, chemotherapy and may therefore be amenable to tumor-specific immunization in the setting of minimal residual disease. The idiotype of the monoclonal immunoglobulin expressed by the tumor provides a clear tumor-specific antigen. Patients with follicular lymphoma have unequivocally established that idiotypic vaccination, administered when patients have minimal residual disease, has an antitumor effect and potential to improve the clinical outcome. This result and preclinical studies demonstrating that MM cells display idiotypic peptides on their surface in a form suitable for recognition and killing by host T cells, foster the application of idiotypic vaccination in MM. The current vaccine production involves idiotype protein purification for each patient followed by conjugation to exogenous, immunogenic carriers in order to break immunological tolerance. Furthermore, recent advances in molecular cloning and development of novel antigen delivery systems are making it possible to streamline the production of equally or more effective idiotypic vaccines. Particularly, DNA vaccines utilising genetic carriers to target idiotype on dendritic cells in vivo have proven successful in preclinical models. Additional candidate T cell antigens, such as MUC1, the cancer-testis antigens, and telomerase have been identified as potential targets for immunization. The possibility of using whole myeloma cells as a source of tumor antigens for immunotherapy is also being actively explored. Finally, clinical studies have begun in which dendritic cells are generated ex vivo, loaded with tumor antigen(s), and reinfused to immunize patients.

Mediators of innate immunity that target immature, but not mature, dendritic cells induce antitumor immunity when genetically fused with nonimmunogenic tumor antigens.

Chemokine receptors are differentially expressed on immature and mature dendritic cells (DC). Herein, we demonstrate for the first time that murine antimicrobial peptides beta-defensins 2 and 3 bind murine CCR6, similarly to inflammatory chemokine macrophage-inflammatory protein 3alpha, and they chemoattract bone marrow-derived immature, but not mature DC. Using various chemokines or defensins fused with nonimmunogenic tumor Ags, we studied their capacity to delivery Ags to subsets of immune cells to elicit antitumor immunity. We demonstrate that DNA immunizations with fusion constructs with beta-defensin 2 or inflammatory chemokines that target immature DC, but not homeostatic chemokines secondary lymphoid tissue chemokine, CCL21, or stromal cell-derived factor 1, CXCL12, which chemoattract mature DC, elicit humoral, protective, and therapeutic immunity against two different syngeneic lymphomas.

Serum cardiac troponin I levels and ECG/Echo monitoring in breast cancer patients undergoing high-dose (7 g/m(2)) cyclophosphamide.

High-dose cyclophosphamide (HD-CTX) is largely employed in high-dose chemotherapy (HD-CHT) protocols. HD-CTX dose-limiting toxicity expresses itself as cardiac toxicity which is fatal in a minority of patients. The pathophysiology of HD-CTX-associated cardiotoxicity is still poorly understood. Autopsy studies in patients who died from acute HD-CTX-induced cardiac toxicity revealed hemorrhagic myocardial cell death and interstitial edema. Recently troponins, in particular troponin I (cTnI), have been found to represent a uniquely sensitive and specific marker of myocyte membrane integrity and therefore to increase in response to minimal myocardial cell damage in different settings, including doxorubicin-induced cardiotoxicity. We performed a multiparametric cardiologic monitoring in 16 consecutive breast cancer patients undergoing HD-CTX by means of serial ECG registrations and cardiac enzymes (CPK, CPK-MB and cTnI) determinations plus echocardiography in order to clarify acute cardiac events following HD-CTX administration. Neither overt cardiac toxicity nor cardiac enzymes elevation were recorded. Serial ECGs revealed in six cases little and reversible reduction of QRS voltage and/or ST abnormalities. Echo monitoring showed in four cases mild and transient increase of LV diastolic/systolic diameter/volume without decrease of FS% or EF% below normal values: in two of them abnormalities of diastolic function (E/A mitral doppler ratio) were also recorded. We conclude that our protocol of HD-CTX administration does not cause myocardial cell damage as analyzed by serum cTnI levels, thus suggesting that myocyte membrane injury may not be the first direct mechanism of HD-CTX cardiotoxicity. ECG (ie QRS voltages ) and Echo (ie E/A ratio) monitoring leads us to hypothesize that slight interstitial edema with reduction of LV diastolic compliance may be initial signs of cardiac dysfunction in this clinical setting.

Immunotherapy of multiple myeloma.

The failure of chemotherapy to cure a significant proportion of multiple myeloma (MM) patients and increasing knowledge of tumor immunology and MM biology have generated considerable interest in immunotherapy for this lethal disease. Immunotherapy for MM can be divided into three broad categories: passive antibody-mediated immunotherapy, active specific immunization (vaccination), and adoptive T-cell immunotherapy. Early clinical trials using anti-CD20 monoclonal antibodies (mAbs) have met with limited success so far but have also suggested that selected patient subgroups may benefit from this treatment. The availability of a truly tumor-specific antigen such as immunoglobulin idiotype, the recent demonstration that MM cells process and present idiotype to T lymphocytes, and formal evidence of an antitumor effect of idiotypic vaccination in follicular lymphoma provide the framework for applying idiotypic vaccination in MM. The ability to generate ex vivo functional dendritic cells has made it possible to fuse them with patients' MM cells, thus producing a different type of customized vaccine. Dendritic cells are also a pivotal reagent to generate ex vivo MM-specific cytotoxic T lymphocytes (CTLs) to be reinfused into the patient for adoptive immunotherapy. This review summarizes achievements in MM immunotherapy based on data reported since 1998.

Elimination of bcl-2-IgH-positive follicular lymphoma cells from blood transplants with high recovery of hematopoietic progenitors by the miltenyi CD34+ cell sorting system.

Contamination of autologous blood cell transplants with cells of follicular non-Hodgkin's lymphoma (F-NHL) may contribute to relapse of the malignancy after potentially curative high doses of chemotherapy and radiotherapy. In an attempt to circumvent this limitation, we have evaluated various techniques of selection of CD34+ cells to eliminate malignant cells from blood cell transplants of five patients with F-NHL undergoing high-dose sequential therapy. The contamination of F-NHL cells was evaluated using a nested PCR assay for the detection of bcl-2-IgH rearrangement with a sensitivity of one F-NHL cell in 10(5) normal cells. In two experiments with blood cell transplant fractions of 0.5 x 10(9) nucleated cells, negative selection of CD34+ cells by removal of B cells and other mature cells that naturally adhere to nylon wool fibers decreased the number of CD19+ B cells detectable by flow cytometry but failed to eliminate bcl-2-IgH-positive F-NHL cells detectable by PCR. In contrast, positive selection of CD34+ cells by the Miltenyi MiniMACS high gradient magnetic cell sorting system in five separate experiments resulted in: (1) the elimination of F-NHL cells in four out of five cases as detected both flow cytometry and bclk-2-IgH PCR; (2) a highly purified population of hematopoietic progenitors comprising 90.8% +/- 2.3% CD34+ cells; and (3) the recovery of 77.9% +/- 3.2% CD34+ cells. These favorable results were confirmed on a large-scale with a blood cell transplant comprising 5.8 x 10(9) nucleated cells in which positive selection of CD34+ cells by the Miltenyi SuperMACS system resulted in: (1) the elimination of F-NHL cells as detected both by flow cytometry and bcl-2-IgH PCR; (2) a highly purified population of hematopoietic progenitors comprising 94.6% CD34+ cells; and (3) the recovery of 62.7% CD34+ cells. These results, attained with the newly available Super MACS system, compare favorable with previous techniques because they show the feasibility of eliminating F-NHL cells from blood cell transplants without relevant nonspecific loss of hematopoietic progenitors.

Combined negative and positive selection of mobilized CD34 blood cells.

We tested four negative and two positive selection methods for separation of CD34+ cells from mobilized blood cells, and analysed fold-enrichment, purity and recovery of CD34+ cells after selection procedures. The elimination of mature CD34- cells was achieved by adhesion to nylon-wool fibre (5.9 +/- 1.0 mean fold-enrichment and 65.2 +/- 2.3 mean recovery of CD34+ cells). Standard or modified Ficoll-Hypaque and Percoll density gradients, as well as phagocytosis with magnetic beads, were less effective in eliminating CD34- cells, both purity and fold-enrichment of CD34+ cells being lower than those obtained with separation by nylon-wool. Both positive selection methods tested. Ceprate and MiniMacs System, generated highly purified CD34+ cell populations ranging from 80% to 90%. The recovery of CD34+ cells was optimal with MiniMacs (77.9 +/- 3.6) and low with Ceprate (28.8 +/- 2.8). Based on these results, in two large-scale experiments we combined nylon-wool fibre and MiniMacs System in a two-step separation procedure obtaining a 36.9 +/- 2.6 mean fold-enrichment and a 50.5 +/- 0.3 mean recovery of CD34+ cells. In this way we achieved optimal enrichment and recovery of CD34+ cells, with a substantial saving of cost compared to either selection method alone.

Benefits of blood cell transplant cryopreservation with oxypolygelatine (Gelifundol) plasma substitute.

In two groups of 11 patients with poor prognosis malignancies undergoing high-dose sequential chemotherapy, we have evaluated the cryopreservation of blood cell transplants with oxypolygelatine-containing (55% oxypolygelatine, 6% hydroxyethylstarch, 5% dimethyl sulfoxide) vs standard human serum-containing (55% human serum, 6% hydroxyethylstarch, 5% dimethyl sulfoxide) cryoprotectant mixtures. Evidence is presented demonstrating that substitution of human serum proteins with oxypolygelatine has no detrimental effect either in vitro on the post-thawing recovery of hematopoietic progenitors or in vivo on the capacity of marrow reconstituting function in patients treated with myeloablative cancer therapy and autologous blood cell transplant. Oxypolygelatine is commercially available for clinical use as a plasma expander, is 30-fold less expensive than human serum albumin, is certified free of foreign serum proteins and antibodies as well as free of pyrogen, viral, mycoplasmal and bovine spongiform encephalopathy contaminants. Because of these characteristics, oxypolygelatine permits avoidance of: (1) the use of expensive serum albumin; (2) the fastidious preparation of autologous plasma or serum, and (3) the risk of infection associated with the infusion of allogeneic serum. Because of these practical advantages, we recommend the clinical use of oxypolygelatine as a substitute for human serum proteins for the routine cryopreservation of blood cell transplants.

In vitro and in vivo stability and anti-tumour efficacy of an anti-EGFR/anti-CD3 F(ab')2 bispecific monoclonal antibody.

The in vitro and in vivo stability and anti-tumour efficacy of the anti-EGFR/anti-CD3 bispecific monoclonal antibody (biMAb), M26.1, were analysed. The interaction of the intact biMAb with Fc receptor I (Fc gamma RI) present on human leucocytes was not observed when the antibody was used as an F(ab')2 fragment. A CD8+ T-cell clone coated with M26.1 F(ab')2 was as effective as the intact biMAb in inducing IGROV1 target cell lysis when tested in a 51Cr-release assay. Variable levels of reduction of F(ab')2 to monovalent F(ab') were observed upon incubation with human ovarian cancer ascitic fluid (OCAF) or with human glioblastoma cavity fluid (GCF), but not with mouse or human sera. Activated lymphocytes coated with F(ab')2 and incubated in vitro with GCF or OCAF for 24 and 48 h respectively maintained their targeting. Thus, the F(ab')2, when present as a soluble molecule, but not when bound to T cells, might lose some functional activity as a consequence of partial reduction to F(ab'). In normal mice, M26.1 F(ab')2 retained full cytotoxic activity in the circulation, and clearance values were similar to those obtained with parental and other MAb F(ab')2. Treatment of IGROV1 tumour-bearing mice with activated human lymphocytes coated with the M26.1 F(ab')2 significantly prolonged survival of the animals compared with tumour-bearing untreated and control mice treated with lymphocytes or F(ab')2 alone. Together, these results suggest the clinical usefulness of bispecific M26.1 F(ab')2 as a targeting agent for local treatment of tumours such as glioma and ovarian cancers that express variable levels of epidermal growth factor receptor (EGFR).

Loco-regional immunotherapy with recombinant interleukin-2 and adherent lymphokine-activated killer cells (A-LAK) in recurrent glioblastoma patients.

Nine patients with recurrent glioblastoma were given autologous adherent lymphokine-activated killer (A-LAK) cells and interleukin-2 (IL-2) administered directly into the tumor cavity through an Ommaya tube placed during surgery/biopsy. The immunotherapy was well tolerated and the response rate was 33% (one complete response, two partial responses, four with stable disease and two with progressive disease). However, survival 18 months from initial diagnosis did not differ from that reported in the literature for patients treated conventionally. Serial determinations of IL-2 in the tumor cavity during the course of treatment revealed that IL-2 concentrations were sufficient to maintain lymphocyte activation. Since steroid medication was discontinued during treatment and A-LAK cells have greater antitumor activity than standard LAK cells, other factors are discussed that might explain the limited results.

Factors, including transforming growth factor beta, released in the glioblastoma residual cavity, impair activity of adherent lymphokine-activated killer cells.

Adherent lymphokine-activated killer (A-LAK) cells were obtained from peripheral blood lymphocytes of patients with recurrent glioblastoma. In vitro features of A-LAK cultures were assessed in comparison to those of non-adherent lymphokine-activated killer (NA-LAK) cells of the same patients with regard to cytotoxic activity, proliferation and surface markers. Only in a minority of cases did A-LAK cells show a markedly higher cytotoxicity on K562, Daudi and allogeneic glioblastoma cells. Nevertheless, A-LAK cells proliferated significantly better than NA-LAK and contained higher percentages of CD16+, CD56+ and CD25+ cells, indicating that A-LAK cells from these patients represent a subpopulation of lymphocytes enriched for activated natural killer cells. We also investigated whether immunosuppressive factor(s) were present in the tumour bed of recurrent gliomas. To this end, samples of glioblastoma cavity fluid (GCF), which accumulates in the cavity of subtotally removed tumour, were recovered and tested for the presence of immunosuppressive activity. All GCF samples analysed were shown to inhibit in vitro proliferation and antitumour cytotoxicity of 1-week-cultured A-LAK cells in a dose-dependent manner. Such GCF activity was effectively antagonized by a transforming growth factor beta (TGF beta) neutralizing antibody, indicating the involvement of TGF beta in lymphocyte inhibition. These results show that in the tumour cavity remaining after subtotal glioblastoma resection a marked immunosuppressive activity, probably due to local release of TGF beta, is present; such activity may negatively influence the therapeutic effectiveness of local cellular immunotherapy.