Neuroprotection for ischaemic stroke: translation from the bench to the bedside.

Neuroprotection seeks to restrict injury to the brain parenchyma following an ischaemic insult by preventing salvageable neurons from dying. The concept of neuroprotection has shown promise in experimental studies, but has failed to translate into clinical success. Many reasons exist for this including the heterogeneity of human stroke and the lack of methodological agreement between preclinical and clinical studies. Even with the proposed Stroke Therapy Academic Industry Roundtable criteria for preclinical development of neuroprotective agents for stroke, we have still seen limited success in the clinic, an example being NXY-059, which fulfilled nearly all the Stroke Therapy Academic Industry Roundtable criteria. There are currently a number of ongoing trials for neuroprotective strategies including hypothermia and albumin, but the outcome of these approaches remains to be seen. Combination therapies with thrombolysis also need to be fully investigated, as restoration of oxygen and glucose will always be the best therapy to protect against cell death from stroke. There are also a number of promising neuroprotectants in preclinical development including haematopoietic growth factors, and inhibitors of the nicotinamide adenine dinucleotide phosphate oxidases, a source of free radical production which is a key step in the pathophysiology of acute ischaemic stroke. For these neuroprotectants to succeed, essential quality standards need to be adhered to; however, these must remain realistic as the evidence that standardization of procedures improves translational success remains absent for stroke.

Supportive care and chelation therapy in MDS: are we saving lives or just lowering iron?

The myelodysplastic syndromes (MDS) are characterized by cytopenias and risk of transformation to acute myeloid leukemia (AML). Although new treatments are available, a mainstay in MDS remains supportive care, which aims to minimize the impact of cytopenias and transfusion of blood products. Red blood cell (RBC) transfusions place patients at risk of iron overload (IOL). In beta-thalassemia major (BTM), IOL from chronic RBC transfusions inevitably leads to organ dysfunction and death. With iron chelation therapy (ICT), survival in BTM improved from the second decade to near normal and correlated with ICT compliance. Effects of ICT in BTM include reversal of cardiac arrhythmias, improvement in left ventricular ejection fraction, arrest of hepatic fibrosis, and reduction of glucose intolerance. It is not clear whether these specific outcomes are applicable to MDS. Although retrospective, recent studies in MDS suggest an adverse effect of transfusion dependence and IOL on survival and AML transformation, and that lowering iron minimizes this impact. These data raise important points that warrant further study. ICT is potentially toxic and cumbersome, is costly, and in MDS patients should be initiated only after weighing potential risks against benefits until further data are available to better justify its use. Since most MDS patients eventually require RBC transfusions, the public health implications both of transfusion dependence and ICT in MDS are considerable. This paper summarizes the impact of cytopenias in MDS and treatment approaches to minimize their impact, with a focus on RBC transfusions and their complications, particularly with respect to iron overload.

Use of growth factors in the elderly patient with cancer: a report from the Second International Society for Geriatric Oncology (SIOG) 2001 meeting.

Over 70% of the total incidence of cancer recorded in Europe in 1996 was in the elderly population (> or =60 years). Despite such high statistics, elderly cancer patients have often been denied the treatment that younger patients routinely receive. The response of elderly cancer patients to full-dose chemotherapy treatment in several neoplasms is similar to that of younger patients, demonstrating that age should not be a barrier to the administration of potentially curative or palliative chemotherapy. In order to provide optimal treatment to elderly cancer patients, management guidelines are recommended which take into account various factors, such as the physical well-being of the patient, the type of malignancy and any conditions that may hamper compliance with chemotherapy. The evidence-based guidelines of the National Comprehensive Cancer Network (NCCN) in the US recommend that the safest and most effective treatment of cancer in older individuals may be achieved by proper patient selection based on comprehensive geriatric assessment, dose adjustment of renally excreted drugs, prophylactic use of haematopoietic growth factors in patients treated with chemotherapy of dose-intensity comparable to cyclophosphamide/doxorubicin/vincristine/prednisone (CHOP) and maintenance of haemoglobin levels > or =12 g/l. The objective of this article is to report the conclusions of the meeting of the International Society of Geriatric Oncology (SIOG) in September 2001, including the need for geriatric assessment to tailor the management of patients to their personal circumstances and general health and the importance of evidence-based guidelines for the management of elderly cancer patients cannot be over-estimated.

Acquired aplastic anemia in children: incidence, prognosis and treatment options.

Acquired aplastic anemia is a rare disease. The incidence ranges from two to six new cases per 1 million inhabitants per annum. Bone marrow transplantation (BMT) in case of available human leucocyte antigen (HLA)-identical sibling and immunosuppressive therapy are the main therapeutic modalities currently used in pediatric patients. In large cooperative studies carried out in Europe, overall survival was not significantly different in children with aplastic anemia treated with allogeneic BMT from an HLA-identical sibling (85%) and those treated with immunosuppressive therapy (83%). Survival was significantly worse for patients treated with BMT from an alternative source (26%; p < 0.00001) versus immunosuppressive therapy. Based on these results, therapeutic strategies recommended for aplastic anemia are allogeneic BMT as a first-line therapy for children with an HLA-identical sibling, and immunosuppressive therapy in patients without. In children who do not respond, alternative therapies include BMT from unrelated or mismatched family donors and, more recently, the use of hematopoietic growth factors. Therapeutic choice in childhood severe aplastic anemia should also take into account the possible late effects, such as growth failure and other endocrine problems, that are peculiar to pediatric patients, as well as the risk of malignancies occurring mostly when irradiation is given as part of the conditioning regimen before BMT. As aplastic anemia is such a rare disease, improvements in current treatment strategies can only be achieved by joint efforts between treatment centers. Therefore, patients should be referred to experienced centers early in the course of the disease in order to offer the patient the best therapeutic options presently available.

Myeloid hematopoietic growth factors and their role in prevention and/or treatment of neonatal sepsis.

Sepsis continues to be an important cause of morbidity and mortality among both full-term and preterm infants, secondary to an immaturity in neonatal host defense. The incidence of neonatal sepsis ranges from 30% in very low birth weight infants to 0.4% in preterm neonates and 0.1% in term neonates. The dysregulation of the expression and production of hematopoietic cytokines in the neonate contributes to quantitative and qualitative deficiencies in neonatal myeloid progenitor activity and decreased availability and function of mature effector neutrophils. These abnormalities contribute in large part to the increased incidence and mortality associated with neonatal sepsis. In this review, we have summarized and analyzed the studies investigating the dysregulation, expression and production of myelopoietic growth factors in neonates, the preclinical in vivo effects of myelopoietic growth factors in neonatal animals, the preclinical in vivo effects of myelopoietic growth factors during experimental sepsis in neonatal animals, the in vitro effects of growth factors on human neonatal phagocytic immunity, and clinical results of myelopoietic growth factors in human neonates. Future studies should be focused on investigating other abnormalities of neonatal host defense and multiple and simultaneous approaches to circumvent identified defects to attempt to reduce both the incidence and severity of neonatal host defense.

Biologic response modifiers in pediatric cancer.

Biologic response modifiers are becoming an important addition to surgery, chemotherapy, and radiotherapy in the management of cancer. As this field of research grows and expands, more biologic response modifiers will be incorporated into therapeutic regimens. By stimulating the immune system to eradicate minimal residual disease, these agents may improve the disease-free and long-term survival rates of patients with a variety of malignancies. The challenge is to incorporate biologic response modifiers into the treatment armamentarium in ways that will maximize their tumorigenicity.

Myelopoietin, an engineered chimeric IL-3 and G-CSF receptor agonist, stimulates multilineage hematopoietic recovery in a nonhuman primate model of radiation-induced myelosuppression.

Myelopoietins (MPOs) constitute a family of engineered, chimeric molecules that bind and activate the IL-3 and G-CSF receptors on hematopoietic cells. This study investigated the in vivo hematopoietic response of rhesus monkeys administered MPO after radiation-induced myelosuppression. Animals were total body irradiated (TBI) in 2 series, with biologically equivalent doses consisting of either a 700 cGy dose of Cobalt-60 ((60)Co) gamma-radiation or 600 cGy, 250 kVp x-irradiation. First series: On day 1 after 700 cGy irradiation, cohorts of animals were subcutaneously (SC) administered MPO at 200 microg/kg/d (n = 4), or 50 microg/kg/d (n = 2), twice daily, or human serum albumin (HSA) (n = 10). Second series: The 600 cGy x-irradiated cohorts of animals were administered either MPO at 200 microg/kg/d, in a daily schedule (n = 4) or 0.1% autologous serum (AS), daily, SC (n = 11) for 23 days. MPO regardless of administration schedule (twice a day or every day) significantly reduced the mean durations of neutropenia (absolute neutrophil count [ANC] < 500/microL) and thrombocytopenia (platelet < 20,000/microL) versus respective control-treated cohorts. Mean neutrophil and platelet nadirs were significantly improved and time to recovery for neutrophils (ANC to < 500/microL) and platelets (PLT < 20,000/microL) were significantly enhanced in the MPO-treated cohorts versus controls. Red cell recovery was further improved relative to control-treated cohorts that received whole blood transfusions. Significant increases in bone marrow-derived clonogenic activity was observed by day 14 after TBI in MPO-treated cohorts versus respective time-matched controls. Thus, MPO, administered daily was as effective as a twice daily schedule for multilineage recovery in nonhuman primates after high-dose, radiation-induced myelosuppression.

Primordial role of CD34+ 38- cells in early and late trilineage haemopoietic engraftment after autologous blood cell transplantation.

In order to better define which cell subset contained in graft products might be the most predictive of haemopoietic recovery following autologous blood cell transplantation (ABCT), the relationships between the amounts of reinfused mononuclear cells (MNC), CFU-GM, total CD34+ cells and their CD33 and CD38 subsets. and the successive stages of trilineage engraftment kinetics, were studied in 45 cancer patients, using the Spearman correlation test, a linear regression model and a log-inverse model. No relationship was found between the infused numbers of MNC, CD33+ and CD33- subsets observed and the numbers of days to reach predetermined absolute neutrophil (ANC), platelet and reticulocyte counts. The infused numbers of CFU-GM, CD34+ and CD34+ 38+ cells correlated inconstantly with haemopoietic recovery parameters. The strongest and the most constant correlations were significantly observed between the infused numbers of CD34+ 38- cells and each trilineage engraftment parameter. The log-inverse model determined a threshold dose of 0.05 x 10(6) (= 5 x 10(4)) CD34+ 38- cells/kg, below which the trilineage engraftment kinetics were significantly slower and unpredictable. Post-transplant TBI-conditioning regimens increased the low cell dose-related delay of engraftment kinetics whereas post-transplant administration of haemopoietic growth factors (HGF) seemed to abrogate this delay. This would justify clinical use of HGF only in patients transplanted with CD34+ 38- cell amounts lower than the proposed threshold value. This study suggests that the CD34+ 38- subpopulation, although essentially participating in late complete haemopoietic recovery, is also composed of committed progenitor cells involved in early trilineage engraftment.

Haemopoietic growth factors.

Haemopoietic growth factors are involved in the production of the various blood cells from progenitors in the bone marrow, making them useful in a range of clinical situations. The genes for several of them have been cloned and their production engineered by recombinant technology, making them widely available. Myeloid growth factors are used to support patients in the aftermath of chemotherapy and bone marrow transplantation and have potential application in the treatment of infectious diseases. Erythropoietin is widely used for patients with anaemia due to failure of marrow production, having established its effectiveness in chronic renal failure. Thrombopoietin has recently been described and may provide a means to alleviate thrombocytopenia. Current indications and areas of recent reappraisal are addressed in this review.

Treatment of adult acute leukemia.

In 1996 progress has been made toward a better understanding of acute leukemias, their biology, the effects of different intensity or subtype-specific chemotherapy, and the contribution of bone marrow transplantation. In acute lymphoblastic leukemia, high-dose cytarabine in induction and in postremission treatment improves the cure rate, whereas dose reduction of daunorubicin in older patients worsens response and increases mortality. After acute promyelocytic leukemia has been successfully treated by retinoids, another subtype-specific chemotherapy containing high-dose methotrexate has overcome the primarily poor prognosis of B-cell acute lymphoblastic leukemia. The leukemic stem cell of acute myeloid leukemia representing minimal residual disease, producing disease progression in the patients, and initiating long-term growth in cultures or immunodeficient mice appears as a primitive multipotent cell. Leukemic transformation is reflected either by the specific balanced chromosome translocations or by chromosome deletions or losses. They are associated with histories of cytotoxic drugs such as epipodophylotoxins and anthracyclines or alkylating agents. Alternatively, both kinds of aberrations develop spontaneously with ethnic differences in special subtypes. Cytogenetics also determine favorable and unfavorable prognosis both for chemotherapy and bone marrow transplantation. In acute lymphoblastic leukemia high-risk and nonstandard-risk patients seem to benefit from allogeneic transplantation, whereas in acute myeloid leukemia there is no adequate basis for risk-adapted stratification between treatment modalities. New prospects lie in a more successful use of the effects of treatment intensification possibly supported by autologous blood stem cell transplantation. On the basis of standardized treatment, future clinical research can address the role of biologic features of the individual leukemia such as specific chromosome aberrations, fusion genes, expression of oncogenes, and monitoring of minimal residual disease.

Chemotherapy of AIDS--related Kaposi's sarcoma.

Kaposi's sarcoma (KS) is the most common tumor associated with AIDS. A growing number of patients with this tumor are presenting at later stages of HIV with more rapidly progressive, extensive, or symptomatic KS or with tumors involving visceral organs. Chemotherapy treatment is effective in inducing tumor regression, reducing edema, and ameliorating symptoms caused by these tumors. Side effects and toxicities from these agents, however, can be quite pronounced, especially in patients with advanced AIDS Antiretroviral therapy, prophylaxis for opportunistic infections, and the use of hematopoietic growth factors should be routinely included in the management of these patients. Newer chemotherapeutic agents and combination regimens may be more effective or less toxic than previously evaluated regimens.

The role of hematopoietic growth factors in transfusion medicine.

Hematopoietic growth factors have already had an enormous impact on transfusion practice by eliminating or reducing the need for red blood cell transfusions in a variety of anemic states characterized by an absolute or relative decrease in erythropoietin. In addition, GM-CSF and G-CSF have stimulated the production of autologous neutrophils in febrile neutropenic patients in whom granulocyte transfusions had been considered ineffective. With the discovery of c-Mpl ligand and the promising results obtained with IL-11 and IL-3, a combination of growth factors that successfully stimulate platelet production may soon be identified. This first era in the clinical application of hematopoietic growth factors has been characterized largely by treatment of the patient to stimulate production of autologous cells or to enhance the ability of transplanted hematopoietic progenitor cells to repopulate the patient. The use of G-CSF to increase the yield of granulocytes harvested by apheresis procedures and to mobilize peripheral blood stem cells in allogeneic donors has initiated a new era in which the cell donor is treated to enhance cell production and enhance the repopulating ability of hematopoietic progenitor cells. As our understanding of hematopoiesis grows, scientists will be able to identify growth factors to overcome or correct deficient hematopoiesis. Increasingly, component transfusions will be reserved for life-threatening situations in which endogenous cell production cannot be stimulated or cell production will be too slow to prevent life-threatening events.

Hematopoietic growth factors after allogeneic marrow transplantation in animal studies and clinical trials.

The use of hematopoietic growth factors after allogeneic bone marrow transplantation (BMT) was investigated either in a preclinical canine model or in patients. G-CSF administration in dogs after high-dose total body irradiation (TBI) and transplantation of DLA-identical littermate marrow significantly accelerated recovery of peripheral blood neutrophils, monocytes and lymphocytes, but not of platelet counts, without significantly increasing the risks of graft failure or graft-versus-host disease (GVHD). GM-CSF given to patients after HLA-identical sibling BMT was well tolerated at doses < or = 250 micrograms/m2/day and resulted in significantly faster neutrophil recovery compared with matched historical controls. Risks of graft failure, GVHD or relapse were not increased. When GM-CSF was given after matched or 1-antigen mismatched unrelated BMTs, the number of febrile days and septic episodes within the first 28 days was reduced even though neutrophil recovery was not accelerated. Incidences of graft failure, GVHD or relapse were not increased. In recipients of BMT with invasive fungal infections, M-CSF in combination with conventional anti-fungal therapy may have a beneficial effect on survival. Treatment with GM-CSF in patients with graft failure appears to result in improved survival without increasing the risks of GVHD or relapse.

Successful blood stem cell collection and transplant in children weighing less than 25 kg.

Peripheral blood stem cells (PBSCs) were collected for autotransplantation in 20 children (median age 4 years, range 0.5-10 years) weighing < 25 kg (median 14.5 kg, range 6.8-24 kg) with various malignant diseases: leukemias and lymphomas (n = 6), solid tumours (n = 14). Cytaphereses were carried out after standard chemotherapy (n = 10), mobilizing high-dose chemotherapy (n = 9) or radiotherapy alone (n = 1). In 13 children PBSCs were harvested after haematopoietic growth factor (HGF) administration. PBSCs were collected using a continuous flow blood separator (Cobe Spectra). In 13 patients access was through a central catheter with peripheral venous return, in 4 patients access was through a central catheter with return through a femoral catheter; one patient had femoral catheter access with peripheral venous return and two patients had both access and return through peripheral veins. For 19 patients the extracorporeal line was primed with red blood cells. The median blood flow rate was 13.8 ml/min (range 7-22 ml/min). Sixty-six procedures (mean 3.3/patient, range 1-4) were performed with a mean total collection time of 8.5 h. The median number of granulocyte-macrophage colony-forming units (CFU-GM) collected was 37.7 x 10(4)/kg (mean 107 x 10(4)/kg, range 1.05-882 x 10(4)/kg). The number of CFU-GM collected per procedure in children with HGF was 7.8-fold higher than in children without HGF (median 20.4 versus 2.6 x 10(4) CFU-GM/kg body weight, respectively). There were no consistent effects on peripheral blood counts except on platelet counts which decreased following each procedure (median decrease in platelet count was 36%).(ABSTRACT TRUNCATED AT 250 WORDS)

Haemopoietic growth factor and dose intensity in high-grade and intermediate-grade lymphoma.

Here we review the evidence that cytotoxic dose intensity is an important determinant of outcome in high- and intermediate-grade non-Hodgkin's lymphoma. The results of retrospective analyses and prospective studies support this proposition but confirmatory studies are required. We discuss the role of haemopoietic growth factors and mobilized peripheral blood progenitor cells to increase dose intensity. Studies using these modalities will enable the importance of dose intensity to be tested.

Haematopoietic growth factors and peripheral blood stem cells as supportive agents in dose intensification.

We have studied the requirements that have to be met to combine effective cancer chemotherapy with the mobilisation of peripheral blood stem cells (PBSC). We have shown that there is a differential induction of high numbers of PBSC following standard-dose chemotherapy (VIP) plus treatment with colony-stimulating factors. The combined sequential administration of interleukin 3 (IL-3) plus granulocyte-macrophage colony-stimulating factor (GM-CSF) induced maximal numbers of PBSC, including colony-forming unit-granulocyte, erythrocyte, monocyte/macrophage, megakaryocyte (CFU-GEMM) and colony-forming unit-megakaryocyte (CFU-Meg), compared with the application of GM-CSF, granulocyte colony-stimulating factor (G-CSF) or chemotherapy alone. The number of CD34+ cells was highly variable depending on the prior treatment given to the patients. Mobilised CD34+ cells--depending on the cytokines used for recruitment--had a varying cloning efficiency, and were heterogeneous as to their level of commitment. Retransfusion of G-CSF-primed progenitor cells to pilot patients following high-dose chemotherapy demonstrated that PBSC recruited by standard-dose chemotherapy plus G-CSF accelerated both neutrophil and platelet recovery.

High-dose chemotherapy with autologous stem cell support for breast cancer: a review of the Dana-Farber Cancer Institute/Beth Israel Hospital experience.

The overall median survival of women with advanced or high-risk primary breast cancer has not changed with conventional chemotherapy. Regimens employing high-dose chemotherapy with autologous stem cell support (ABMT) have been developed with the hope of optimizing tumor response and increasing survival. Early phase I studies in women with advanced refractory disease achieved high response rates of short duration. Second generation studies combined an induction phase followed by one high-dose intensification at time of maximum tumor response. The Dana-Farber Cancer Institute/Beth Israel Hospitals have developed the high-dose intensification regimen of cyclophosphamide, thiotepa, and carboplatin (CTCb) for use in women with metastatic and high-risk stage IIIB/inflammatory breast cancer. To date, approximately 19% of women with metastatic disease remain progression free using this approach, with median length of follow-up approaching 40 months. Although the median duration of follow-up for the stage IIIB women is much shorter (approximately 12 months), greater than 90% of these women are thus far disease free. With the advent of hematologic support, such as blood stem cells and colony-stimulating factors, the morbidity, mortality, and costs associated with this treatment have been substantially reduced, allowing for two or more cycles of high-dose intensification to be employed, to exploit the potential of dose-intensity to optimize response.