Wanted on Agave americana! Hymenobolus agaves, an overlooked introduced pathogen in the western palearctic region.

Hymenobolus agaves has been reported only in Europe and Africa on the American plant Agave americana (Asparagaceae). This fungus has never been found in the native range of its host, in arid ecosystems of northern and central Mexico and Texas, USA. It has been suggested to be a pathogen that can kill its host. The fungus grows on succulent leaf bases of the plant. The morphology - black apothecia with a hymenium that disintegrates when asci mature and dark ornamented ascospores - make this species very distinctive, but it has been collected and reported only a few times since its first description. Its systematic position has been unclear, and it has been treated as incertae sedis, that is of uncertain placement, in Leotiomycetes. With recent collections and additional data on the ecology of H. agaves, we use integrative taxonomy (DNA sequences, morphology, ecology) to show its relationships is with Cenangiaceae.

Use of a SCID mouse/human lymphoma model to evaluate cytokine-induced killer cells with potent antitumor cell activity.

C.B-17 severe combined immune deficient (SCID) mice, which lack functional B and T lymphocytes, allow xenografts and, therefore, can be used to study the biology of human malignancies. Two different human B cell lymphoma cell lines, SU-DHL-4 and OCI-Ly8, which both harbor the t(14;18) chromosomal translocation, were injected into C.B-17 SCID mice. Mice injected intravenously or intraperitoneally developed tumors and died in a dose-dependent manner. The presence of tumor cells in various murine tissues could be demonstrated by a clonogenic tumor assay, staining of frozen sections with a monoclonal antibody (mAb) against a human B cell antigen (CD19), and with the polymerase chain reaction technique. A protocol using cytotoxic effector cells was developed and used to selectively deplete the tumor cells from bone marrow. These cells were developed by growing peripheral blood mononuclear cells in the presence of interferon gamma (IFN-gamma), anti-CD3 mAb, and interleukin 2 (IL-2). The timing of IFN-gamma treatment was critical and optimal if IFN-gamma was added before IL-2 treatment. The cells that were stimulated by IFN-gamma, followed by IL-2, could be expanded by treatment with a mAb directed against CD3. These cells could be further activated by IL-1, but not by tumor necrosis factor alpha. With this protocol, a tumor cell kill of 3 logs was obtained as measured by a clonogenic assay. Interestingly, despite their high cytotoxic activity against lymphoma cells, these cells had little toxicity against a subset of normal human hematopoietic precursor cells (granulocyte/macrophage colony-forming units). These cells were further tested by treating murine bone marrow contaminated with the human lymphoma cell line SU-DHL-4, and injecting these cells into SCID mice to assay for tumor growth in vivo. The animals injected with bone marrow contaminated with SU-DHL-4 cells had enhanced survival if the bone marrow was treated with the cytokine-induced killer cells before infusion. The SCID mouse provides a useful in vivo model for evaluation of new therapeutic approaches for lymphoma treatment. The cytokine-induced killer cells generated as described here could have an important impact on bone marrow purging for autologous bone marrow transplantation as well as for adoptive immunotherapy.

The use of colony stimulating factors in clinical bone marrow transplantation.

The use of colony stimulating factors in clinical bone marrow transplantation is rapidly evolving. Both granulocyte colony stimulating factor and granulocyte macrophage colony stimulating factor have shown efficacy in bone marrow transplant patients in accelerating the rate of myeloid recovery. The use of colony stimulating factor primed peripheral blood progenitor cells appears to accelerate platelet recovery as well as myeloid recovery.

Detection of tumor cells in purged bone marrow and peripheral-blood mononuclear cells by polymerase chain reaction amplification of bcl-2 translocations.

PURPOSE: To compare bone marrow (BM) before and after purging with monoclonal antibodies (MAbs) and complement with peripheral-blood mononuclear cells (PBMNCs) for tumor-cell contamination by amplification of t(14;18) sequences using the polymerase chain reaction (PCR). PATIENTS AND METHODS: Sixty patients with non-Hodgkin's lymphoma (NHL) undergoing autologous BM transplantation were evaluated. Six BM biopsies were performed at the time of harvesting and evaluated morphologically for tumor involvement. The harvested BM was treated with a panel of anti-B-cell MAbs directed against CD9, CD10, CD19, and CD20, followed by rabbit complement. Clonogenic assays were performed before and after purging. DNA was extracted and t(14;18) sequences amplified by PCR. PBMNCs collected by apheresis for back-up purposes were similarly evaluated. RESULTS: Fifteen patients (25%) were PCR-positive before BM purging. Following MAb- and complement-mediated purging, there was a reduction in the PCR-amplified signal in 10 patients (67%). There was no reduction in colony-forming unit granulocyte-macrophage (CFU-GM) colony growth following purging. Eight of these 15 patients (53%) had morphologic evidence of BM involvement at the time of harvesting. In these eight patients, only three had a reduction in the PCR-amplified products, as compared with all seven who were morphologically negative at the time of BM harvesting (P = .026). Fourteen of these 15 patients had PBMNCs collected near the time of BM harvesting and 12 (86%) were PCR-positive. CONCLUSION: BM purging with MAbs and complement results in reduction in the number of t(14;18)-positive tumor cells, especially in those patients who have no morphologic evidence of BM disease at the time of harvesting. Purged BM was less contaminated with t(14;18)-positive cells than unpurged PBMNCs, which were frequently contaminated with tumor cells.

Fractionated total-body irradiation, etoposide, and cyclophosphamide plus autografting in Hodgkin's disease and non-Hodgkin's lymphoma.

PURPOSE: High-dose etoposide was incorporated into a regimen of fractionated total-body irradiation (FTBI) and high-dose cyclophosphamide before autologous transplant with the goal to enhance the antitumor effect of the myeloablative regimen in poor-risk lymphoid malignancies. PATIENTS AND METHODS: Ninety-six patients, 24 with recurrent or refractory Hodgkin's disease and 72 with poor-risk non-Hodgkin's lymphoma (NHL), were treated on this study. Cytoreduction with conventional therapy was attempted before administration of the preparatory regimen. The preparatory regimen consisted of 12 Gy total-body irradiation administered in 10 1.2-Gy fractions on day -8 through day -5, etoposide 60 mg/kg on day -4, and cyclophosphamide 100 mg/kg on day -2. Patients with NHL received bone marrow purged with a panel of monoclonal antibodies and complement on day 0, while patients with Hodgkin's disease received peripheral-blood stem cells alone or with unmanipulated bone marrow. RESULTS: The major morbidities of transplant were mucositis and skin toxicity. Eight patients (8.6%) died of regimen-related toxicities within 100 days of transplant. Engraftment was related to the rescue product; the median time to a neutrophil count more than 500/microL was 10 days for patients with Hodgkin's disease and 16 days for NHL patients. With a maximum follow-up duration of longer than 5 years, the 3-year actuarial survival rate is 57%. At 3 years, the actuarial freedom from progression (FFP) rate is 55% and the event-free survival rate is 47% for patients with Hodgkin's disease, while the respective figures for NHL patients are 60% and 53%. Among 32 patients with intermediate- and high-grade lymphoma transplanted subsequent to first relapse, 70% are free of lymphoma and 60% are event-free at > or = 3 years. CONCLUSION: The preparatory regimen consisting of FTBI, etoposide, and cyclophosphamide demonstrates relative efficacy in patients with Hodgkin's disease and NHL selected for high-dose therapy. Longer follow-up duration is needed to determine the rate of cure and to assess late complications. Major remaining challenges for high-dose therapy are a more inclusive strategy for all poor-risk patients and the need to reduce posttransplant relapses.

Busulfan/cyclophosphamide as conditioning regimen for allogeneic bone marrow transplantation for myelodysplasia.

PURPOSE: A non-radiation-containing regimen of busulfan and cyclophosphamide (BU/CY) was evaluated for toxicity, relapse, and long-term survival in patients who received allogeneic bone marrow transplantation (BMT) for myelodysplasia (MDS). PATIENTS AND METHODS: Thirty-eight patients with MDS, including eight with therapy-related MDS, were prepared for BMT using BU/CY. RESULTS: Fourteen patients remain in first remission 18 to 60 months posttransplant. Five patients relapsed after BMT, and four of these patients died. Eight additional patients died of acute or chronic graft-versus-host disease (GVHD), and 11 died of regimen-related toxicity, primarily systemic mycoses. Overall survival rate at 2 years was 45% (95% confidence interval [CI], 0.30 to 0.61), with a 24% probability of relapse (95% CI, 0.10 to 0.49). Regimen-related toxicity was manifested primarily as hepatic dysfunction in 72% of patients, with 16% developing overt venoocclusive disease (VOD). CONCLUSION: Non-radiation-containing preparative regimens offer long-term survival in allogeneic BMT for MDS that is comparable to that of radiation-containing regimens, and are useful in patients with therapy-related MDS. Monitoring BU levels may reduce regimen-related mortality and improve survival.

Influence of age on the outcome of 500 autologous bone marrow transplant procedures for hematologic malignancies.

PURPOSE: To determine the effect of age on the outcome of autologous bone marrow transplantation (ABMT) and/or peripheral-blood progenitor-cell (PBPC) transplantation. PATIENTS AND METHODS: A retrospective analysis was performed on 500 consecutive patients who ranged in age from 1 to 65 years (median, 40) with non-Hodgkin's lymphoma (NHL), Hodgkin's disease (HD), multiple myeloma (MM), or acute nonlymphoblastic leukemia (AML) who underwent autologous hematopoietic-cell transplant procedures at Stanford University Medical Center. RESULTS: The actuarial 5-year event-free survival (EFS) rate was 44%, the relapse rate 47%, and the regimen-related mortality (RRM) rate 8.6%. Disease status at time of transplantation, categorized as either minimal or advanced disease, was the strongest predictive factor for EFS (relative risk (RR) for advanced-disease group, 1.8; P < .0003) and relapse rate (RR for advanced-disease group, 1.9; P < .0004). Patients with minimal or advanced disease had an EFS rate of 48% and 30% and relapse rates of 43% and 72%, respectively. The EFS rate of patients less than 50 years verus > or = 50 years of age was 46% versus 34% (P = .03). Cox regression analysis showed that age was predictive for EFS (RR for patients 50 to 65 years, 1.4; P = .03). The actuarial RRM rate for these age groups was 7.4% versus 12.7% (P = .07), respectively. Multivariate analysis demonstrated that age (odds ratio [OR] for patients 50 to 65 years, 1.9; P < .05) and period of transplantation (OR for most recent years [1991 to 1995], 0.6; P = .06) were the most predictive factors for RRM. CONCLUSION: Although age greater than 50 years is associated with an inferior outcome following autologous hematopoietic-cell transplantation, it does not appear to be warranted to limit this potentially curative procedure based solely on age. The upper age limit of high-dose therapy with autologous progenitor-cell and/ or bone marrow support remains to be defined.

American Society of Clinical Oncology clinical practice guidelines for the use of chemotherapy and radiotherapy protectants.

PURPOSE: Because toxicities associated with chemotherapy and radiotherapy can adversely affect short- and long-term patient quality of life, can limit the dose and duration of treatment, and may be life-threatening, specific agents designed to ameliorate or eliminate certain chemotherapy and radiotherapy toxicities have been developed. Variability in interpretation of the available data pertaining to the efficacy of the three United States Food and Drug Administration-approved agents that have potential chemotherapy- and radiotherapy-protectant activity-dexrazoxane, mesna, and amifostine-and questions about the role of these protectant agents in cancer care led to concern about the appropriate use of these agents. The American Society of Clinical Oncology sought to establish evidence-based, clinical practice guidelines for the use of dexrazoxane, mesna, and amifostine in patients who are not enrolled on clinical treatment trials. METHODS: A multidisciplinary Expert Panel reviewed the clinical data regarding the activity of dexrazoxane, mesna, and amifostine. A computerized literature search was performed using MEDLINE. In addition to reports collected by individual Panel members, all articles published in the English-speaking literature from June 1997 through December 1998 were collected for review by the Panel chairpersons, and appropriate articles were distributed to the entire Panel for review. Guidelines for use, levels of evidence, and grades of recommendation were reviewed and approved by the Panel. Outcomes considered in evaluating the benefit of a chemotherapy- or radiotherapy-protectant agent included amelioration of short- and long-term chemotherapy- or radiotherapy-related toxicities, risk of tumor protection by the agent, toxicity of the protectant agent itself, quality of life, and economic impact. To the extent that these data were available, the Panel placed the greatest value on lesser toxicity that did not carry a concomitant risk of tumor protection. RESULTS AND CONCLUSION: Mesna: (1) Mesna, dosed as detailed in these guidelines, is recommended to decrease the incidence of standard-dose ifosfamide-associated urothelial toxicity. (2) There is insufficient evidence on which to base a guideline for the use of mesna to prevent urothelial toxicity with ifosfamide doses that exceed 2.5 g/m(2)/d. (3) Either mesna or forced saline diuresis is recommended to decrease the incidence of urothelial toxicity associated with high-dose cyclophosphamide use in the stem-cell transplantation setting. Dexrazoxane: (1) The use of dexrazoxane is not routinely recommended for patients with metastatic breast cancer who receive initial doxorubicin-based chemotherapy. (2) The use of dexrazoxane may be considered for patients with metastatic breast cancer who have received a cumulative dosage of 300 mg/m(2) or greater of doxorubicin in the metastatic setting and who may benefit from continued doxorubicin-containing therapy. (3) The use of dexrazoxane in the adjuvant setting is not recommended outside of a clinical trial. (4) The use of dexrazoxane can be considered in adult patients who have received more than 300 mg/m(2) of doxorubicin-based therapy for tumors other than breast cancer, although caution should be used in settings in which doxorubicin-based therapy has been shown to improve survival because of concerns of tumor protection by dexrazoxane. (5) There is insufficient evidence to make a guideline for the use of dexrazoxane in the treatment of pediatric malignancies, with epirubicin-based regimens, or with high-dose anthracycline-containing regimens. Similarly, there is insufficient evidence on which to base a guideline for the use of dexrazoxane in patients with cardiac risk factors or underlying cardiac disease. (6) Patients receiving dexrazoxane should continue to be monitored for cardiac toxicity. Amifostine: (1) Amifostine may be considered for the reduction of nephrotoxicity in patients receiving cisplatin-based chemoth

Autografting in chronic myelogenous leukemia: new questions.

In the 1970s, when autografting was started, it was hard to imagine that this procedure would have an application in hematological malignancies. Autografting in patients with CML has been difficult to pursue because their bone marrow is often contaminated by Philadelphia-chromosome positive cells. In recent years, renewed interest has come from this procedure and various in vivo or in vitro techniques of manipulation of Ph-positive cells, such as collection of blood progenitor cells in the early phase of recovery after intensive conventional chemotherapy in untreated or pretreated patients, long-term bone marrow culture and chemical purging of marrow cells. Despite all these interesting trials, we do not have enough data to address the question of whether autografting in CML increases the duration of the chronic phase.

Mutations in the ras proto-oncogenes in patients with myelodysplastic syndromes.

Activation of the N- and K-ras proto-oncogenes is the most common molecular abnormality in myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). In retrospective studies, approximately 3-36% of MDS patients were reported to harbor a mutated ras proto-oncogene, with some series suggesting the presence of ras-mutations are associated with progressive disease and a poor prognosis. Since hematopoietic growth factors such as granulocyte colony-stimulating factor (G-CSF) are currently used for therapy in MDS but may stimulate the proliferation of leukemic cells, we assessed the frequency and significance of ras mutations in 27 MDS patients, 15 of whom underwent G-CSF therapy. Patients were analyzed for the presence of mutations in codons 12, 13, and 61 of the N- and K-ras proto-oncogenes. Only three patients (11%, two refractory anemia with excess of blasts (RAEB), one RAEB in transformation (RAEB-T)) harbored activated ras oncogenes with the mutations localized in N-ras codons 12 and 61. Patients were followed for periods of up to 4 years or until death supervened. Patients exhibiting ras mutations were no more likely to develop AML compared to ras-negative patients (1/3 vs. 10/24) or to have decreased survival (p = 0.64). These data indicate that, in this group of MDS patients, ras mutations do not appear to correlate with a poor prognosis, and do not adversely interact with exogenously administered G-CSF.

Effects of recombinant human granulocyte colony stimulating factor and granulocyte-monocyte colony stimulating factor on in vitro hemopoiesis in the myelodysplastic syndromes.

We evaluated the effects of recombinant human granulocyte colony stimulating factor (rhG-CSF) and granulocyte-monocyte colony stimulating factor (rhGM-CSF) on the in vitro proliferative, differentiative, and regenerative responsiveness of marrow cells from myelodysplastic syndrome patients (MDS) in comparison to those from normal individuals. Our studies showed decreased primary clonogenicity of myeloid (CFU-GM) and erythroid (BFU-E) hemopoietic progenitor cells from the MDS patients. rhGM-CSF had more potent stimulatory effects than rhG-CSF for MDS marrow CFU-GM growth; no enhanced cellular proliferation in the MDS patients was observed in liquid culture with either rhGM-CSF or rhG-CSF. Decreased myeloid clonal cell self-generation and/or recruitment occurred in the MDS patients upon exposure to either rhG-CSF or rhGM-CSF. rhG-CSF demonstrated more potent granulocytic differentiation effects than rhGM-CSF both for normals and MDS patients using marrow enriched for immature myeloid cells with lesser differentiation noted for MDS. Cytogenetic abnormalities, present with or without additional normal karyotypes in native marrow of four MDS patients, persisted after culture with rhG-CSF, indicating induced differentiation of both normal and abnormal clones. Although proliferative and differentiative effects were seen with both factors these data show MDS marrow cells in vitro to have predominantly differentiative responsiveness to rhG-CSF and proliferative responsiveness to rhGM-CSF.

Effects of granulocyte colony-stimulating factor therapy on in vitro hemopoiesis in myelodysplastic syndromes.

We evaluated the effects of 2 months of G-CSF treatment on in vitro hematopoiesis in 17 patients with myelodysplastic syndromes (MDS). Although in vitro marrow myeloid progenitor cell (CFU-GM) growth stimulated by G-CSF generally remained subnormal, in the majority of neutrophil responders significantly augmented incremental change (termed AIC) of CFU-GM numbers occurred after treatment, as did neutrophilic differentiation. The neutrophil non-responders had less prominent in vitro myeloid responses and lower basal neutrophil levels (p < 0.05). Following G-CSF treatment, the initially subnormal erythroid burst-forming unit (BFU-E) values underwent AIC in five of 11 patients along with increased reticulocyte responses in vivo, whereas four of the five patients who lacked AIC of BFU-E did not. Three patients with persisting cytogenetic abnormalities and increased neutrophilic differentiation in vitro also responded in vivo, suggesting that G-CSF induced in vivo cellular differentiation from the abnormal clone. Two of the three patients who developed blastic responses in vivo had increased CFU-GM growth pre- and post-therapy. These results indicate in vivo-in vitro correlations for myeloid and erythroid responses of MDS marrow cells which related to treatment with G-CSF.

The efficacy of granulocyte colony-stimulating factor following autologous bone marrow transplantation for non-Hodgkin's lymphoma with monoclonal antibody purged bone marrow.

Cloned colony-stimulating factors have been shown to accelerate myeloid recovery following autologous bone marrow transplantation. Studies with granulocyte-macrophage colony-stimulating factor (GM-CSF) have demonstrated efficacy in accelerating neutrophil recovery in patients rescued from myeloablative therapy. In our previous study, however, the subset of patients who received monoclonal antibody and complement purged bone marrow grafts followed by GM-CSF recovered neutrophil counts at the same rate as placebo-treated patients. We have now performed a phase II trial to assess whether granulocyte colony-stimulating factor (G-CSF) results in accelerated engraftment in this group of patients. Twenty-three consecutive patients with recurrent non-Hodgkin's lymphoma received G-CSF (10.5 +/- 1.2 micrograms/kg per day) following myeloablative therapy consisting of etoposide (60 mg/kg), cyclophosphamide (100 mg/kg), and either carmustine (15 mg/kg) or fractionated total body irradiation (1200 cGy). All patients received bone marrow grafts which had been purged with a panel of monoclonal antibodies directed against either B or T cell determinants plus complement. Peripheral blood mononuclear cells (PBMC) were not administered to any of the patients in this study. Twenty-one patients engrafted at a median absolute neutrophil count (ANC) greater than 500/microliters at day 12 and ANC greater than 1000/microliters at day 14. The time to myeloid engraftment was significantly shortened compared to our previous experience with either GM-CSF or placebo following identical preparatory regimens (p < 0.01). G-CSF is capable of accelerating myeloid engraftment in patients receiving monoclonal antibody purged bone marrow grafts following myeloablative therapy when compared to historical control groups treated with placebo or GM-CSF.

Long-term follow-up of 23 patients with Philadelphia chromosome-positive acute lymphoblastic leukemia treated with allogeneic bone marrow transplant in first complete remission.

Between 1984 and 1997, 23 consecutive patients with Philadelphia chromosome-positive acute lymphoblastic leukemia in first complete remission were treated with allogeneic bone marrow transplants from HLA-matched siblings. All patients but one were conditioned with fractionated total body irradiation (1320 cGy) and high-dose etoposide (60 mg/kg). One patient received high-dose cyclophosphamide instead of etoposide, and another patient received both drugs. Nine patients died following BMT, two from relapsed leukemia, and seven from transplant-related causes. The 3-year probabilities of disease-free survival and relapse are 65% and 12%, respectively. For patients transplanted after 1992, these probabilities are 81% (48-95%, 95% confidence interval) and 11% (2-50%), respectively. The relatively low relapse rate in this group of patients compared to published reports may reflect the enhanced anti-leukemic activity of etoposide in combination with FTBI compared to other conditioning regimens. The enhancement in overall survival for patients transplanted after 1992 may reflect improvements in supportive care, in particular, the prophylaxis of serious fungal and viral infections.

A feasibility study of multiple cycle therapy with melphalan, thiotepa, and paclitaxel followed by mitoxantrone, thiotepa, and paclitaxel with autologous hematopoietic cell support for metastatic breast cancer.

Dose-intensive chemotherapy appears to be important in the treatment of patients with recurrent solid tumors. Expanding upon our prior experience, we report the results of our most recent approach to administering dose-intensive therapy using four cycles of moderately high-dose chemotherapy with hematopoietic cell support for patients with metastatic breast cancer. This outpatient therapy includes high-dose melphalan, thiotepa, and paclitaxel for two cycles followed by mitoxantrone, thiotepa, and paclitaxel for two cycles, with each cycle supported with autologous peripheral blood progenitor cells (PBPCs). Between December 1994 and June 1996, 16 patients with recurrent or refractory breast cancer were enrolled in this prospective study. They had received a median of two previous chemotherapy regimens, with a median of nine prior cycles of chemotherapy. For mobilization of autologous PBPCs, patients received cyclophosphamide, 4 g/m2, followed by granulocyte colony-stimulating factor (G-CSF). PBPCs were collected by apheresis. Each day's collection was divided into four equal fractions, and each fraction was infused after each cycle of combination therapy. Cycles 1 and 2 consisted of melphalan, 80 mg/m2, thiotepa, 300 mg/m2, and paclitaxel, 200 mg/m2. Cycles 3 and 4 were comprised of mitoxantrone, 30 mg/m2, and thiotepa and paclitaxel at the same doses as in the first two cycles. The cyclophosphamide infusion was administered in the hospital, whereas all subsequent infusions of chemotherapy and PBPCs were performed on an outpatient basis. The first seven patients were randomized to receive alternate cycle G-CSF or placebo on day +1 of each cycle. Including the initial pulse of cyclophosphamide, 67 (84%) of a planned 80 total courses of chemotherapy were delivered. Of the planned 64 cycles of high-dose combination chemotherapy, 52 cycles (81%) were delivered. Treatment was discontinued for progressive disease (one patient) or morbidity (five patients). Twelve of 16 patients completed at least three cycles of therapy. Nine patients completed all four cycles. One death resulted from fungal sepsis. In 20 cycles delivered to the first seven patients, day +1 G-CSF versus placebo was administered, with a median WBC recovery of 10 versus 13 days, respectively (P = 0.048 in cycle 1). The median duration of response was almost 9 months, and the median survival was 18 months after therapy. With a median follow-up of 1.5 years and longest follow-up of 4.2 years, two patients continue to be without evidence of disease. The 3-year event-free survival, freedom from progression, and overall survival are 19%, 20%, and 31%, respectively. This four-cycle regimen of high-dose combination therapy supported with hematopoietic progenitor cells is feasible, but it is associated with a range of posttransplant complications. The efficacy of such a treatment would have to be substantially superior to that of other currently available therapies, including single autologous transplant procedures, to justify the prolonged period of treatment, multiple episodes of pancytopenia, and associated toxicities, including infectious risks. G-CSF administration after each PBPC infusion appears to accelerate time to neutrophil recovery but does not affect red cell or platelet engraftment.

Yttrium-90-labeled anti-CD20 monoclonal antibody therapy of recurrent B-cell lymphoma.

A Phase I/II dose escalation study of 90Y-murine anti-CD20 monoclonal antibody (mAb) in patients with recurrent B-cell lymphoma was performed. The primary objectives of the study were: (a) to determine the effect of the preinfusion of unlabeled anti-CD20 mAb on the biodistribution of 111In-anti-CD20 mAb; (b) to determine the maximal tolerated dose of 90Y-anti-CD20 mAb that does not require bone marrow transplantation; and (c) to evaluate the safety and antitumor effect of 90Y-anti-CD20 mAb in patients with recurrent B-cell lymphoma. Eighteen patients with relapsed low- or intermediate-grade non-Hodgkin's lymphoma were treated. Biodistribution studies with 111In-anti-CD20 mAb were performed prior to therapy. Groups of three or four patients were treated at dose levels of approximately 13.5, 20, 30, 40, and 50 mCi 90Y-anti-CD20 mAb. Three patients were retreated at the 40-mCi dose level. The use of unlabeled antibody affected the biodistribution favorably. Nonhematological toxicity was minimal. The only significant toxicity was myelosuppression. The overall response rate following a single dose of 90Y-anti-CD20 mAb therapy was 72%, with six complete responses and seven partial responses and freedom from progression of 3-29+ months following treatment. Radioimmunotherapy with

High-dose N-acetylcysteine in patients with exacerbations of chronic obstructive pulmonary disease.

OBJECTIVE: To investigate the efficacy and tolerability of high-dose N-acetylcysteine (NAC) in the treatment of patients with exacerbations of chronic obstructive pulmonary disease (COPD). DESIGN AND PATIENTS: Randomised, double-blind, double-dummy, placebo-controlled study in 123 patients experiencing an acute exacerbation of COPD. INTERVENTIONS: NAC 1200 mg/day, 600 mg/day or placebo administered once daily for 10 days. MAIN OUTCOME MEASURES: The primary objective was to assess the proportion of patients with normalised C-reactive protein (CRP) levels. Also assessed were effects on interleukin (IL)-8 levels, lung function and symptoms. RESULTS: Both NAC 600 and 1200 mg/day were associated with a significantly higher proportion of patients achieving normalised CRP levels compared with placebo (52% and 90% vs 19% of patients; p

Bioluminescence imaging of lymphocyte trafficking in vivo.

Lymphocytes are highly mobile cells that travel throughout the body in response to a tremendous variety of stimuli. Revealing lymphocyte trafficking patterns in vivo is necessary for a complete understanding of immune function, as well as cell-cell and cell-tissue interactions in immune development and in response to insult. Although the location of cell populations in various tissues at any given point in time may be revealed by techniques such as flow cytometry and immunofluorescence, these methods are not readily amenable to the assessment of dynamic cell migration patterns in vivo. In the past 5 years, technologies for imaging molecular and cellular changes in living animals have advanced to a point where it is possible to reveal the migratory paths of these vitally important cells. Here, we review one advancement in cellular imaging, in vivo bioluminescence imaging, which addresses the problem of lymphocyte tracking. This imaging strategy has the potential to elucidate the temporal patterns of immune responses and the spatial distribution of lymphocytes within the body.

Phenotypic characterization and identification of effector cells involved in tumor cell recognition of cytokine-induced killer cells.

Cytokine-induced killer (CIK) cells are highly efficient cytotoxic effector cells capable of lysing tumor cell targets. Cultures of human CIK cells have been shown to have enhanced cytotoxicity and to proliferate more rapidly than lymphokine activated killer (LAK) cells by both in vitro and in vivo studies. In this report, we have further characterized the phenotype of CIK cells and explored the molecular structures involved in CIK-mediated cell lysis of tumor target cells. The dominant cell phenotype in CIK cell cultures expresses the alpha, beta T cell receptor (TCR-alpha/beta). In addition, CD56 is expressed on the main effector cell on a per-cell basis. Interestingly, the total number of CD56+ cells increases more than 1000-fold during the generation of CIK cells, mainly due to expansion of CD56+ cells coexpressing CD3. The higher lytic activity of CIK cells as compared to LAK cells is mainly due to the higher proliferation of CD3+CD56+ cells and to the cytotoxic activity of TCR-alpha/beta+ cells in CIK cell cultures. CIK-mediated cellular lysis is non-major histocompatibility antigen (MHC) restricted. The cytotoxic effect of CIK cells against tumor targets is blocked by antibodies directed against lymphocyte function-associated antigen (LFA-1) and its counter receptor, intercellular adhesion molecule-1 (ICAM-1).

Enrichment of bone marrow and blood progenitor (CD34+) cells by density gradients with sufficient yields for transplantation.

We have evaluated the use of iso-osmolar Percoll density gradients to enrich CD34+ hematopoietic progenitor cells and to reduce T cells for purposes of bone marrow or mobilized peripheral blood cell transplantation (BMT or PBCT). Samples from 12 normal BM donors and 11 patients undergoing mobilization of PB cells using chemotherapy and G-CSF were placed over a five-step density gradient from 40 to 50% Percoll. In BM, low-density fractions 1 to 3 (40 to 45% Percoll) accounted for 3% of starting nucleated cells with a 10- to 20-fold enrichment of hematopoietic progenitors (CD34+ cells) and a 20-fold reduction of CD4+ and CD8+ T cells. In PB, fractions 1 to 3 accounted for 20 to 30% of the starting nucleated cells with a five-fold enrichment of hematopoietic progenitors. Based on these values, such populations have been used for clinical transplantation using a single apheresis. The reduced cell numbers in the low-density fractions can facilitate tumor purging, and the reduced T cell numbers present in the marrow may ameliorate graft-vs.-host disease.