Pre-existing invasive fungal infection is not a contraindication for allogeneic HSCT for patients with hematologic malignancies: a CIBMTR study.

Patients with prior invasive fungal infection (IFI) increasingly proceed to allogeneic hematopoietic cell transplantation (HSCT). However, little is known about the impact of prior IFI on survival. Patients with pre-transplant IFI (cases; n=825) were compared with controls (n=10247). A subset analysis assessed outcomes in leukemia patients pre- and post 2001. Cases were older with lower performance status (KPS), more advanced disease, higher likelihood of AML and having received cord blood, reduced intensity conditioning, mold-active fungal prophylaxis and more recently transplanted. Aspergillus spp. and Candida spp. were the most commonly identified pathogens. 68% of patients had primarily pulmonary involvement. Univariate and multivariable analysis demonstrated inferior PFS and overall survival (OS) for cases. At 2 years, cases had higher mortality and shorter PFS with significant increases in non-relapse mortality (NRM) but no difference in relapse. One year probability of post-HSCT IFI was 24% (cases) and 17% (control, P<0.001). The predominant cause of death was underlying malignancy; infectious death was higher in cases (13% vs 9%). In the subset analysis, patients transplanted before 2001 had increased NRM with inferior OS and PFS compared with later cases. Pre-transplant IFI is associated with lower PFS and OS after allogeneic HSCT but significant survivorship was observed. Consequently, pre-transplant IFI should not be a contraindication to allogeneic HSCT in otherwise suitable candidates. Documented pre-transplant IFI is associated with lower PFS and OS after allogeneic HSCT. However, mortality post transplant is more influenced by advanced disease status than previous IFI. Pre-transplant IFI does not appear to be a contraindication to allogeneic HSCT.

Hematopoietic stem cell transplantation for childhood malignancies of myeloid origin.

Myeloid malignancies in children include de novo acute/chronic myeloid leukemia (AML/CML) and secondary malignancy due to genetic predisposition or previous therapy. Generations of clinical trials for childhood myeloid disorders have resulted in improved disease characterization and outcome, and defined therapeutic strategies combining chemotherapy, biologic response modifiers and immunotherapy. With advancement in molecular genetics and the development of sensitive techniques to detect response, residual disease and relapse, therapy can be tailored in a risk-based manner using clinical and biological/molecular parameters and several 'good-risk' myeloid malignancies enjoy high cure rates with targeted therapy. However, hematopoietic stem cell transplant remains the best method of treatment intensification for poor-risk disorders such as relapsed/secondary AML, myelodysplastic syndrome and juvenile myelomonocytic leukemia. Indications for transplant and outcomes of previous clinical studies, and novel transplant strategies designed to improve safety and efficacy of the procedure are reviewed.

Challenges in small animal parturition--timing elective and emergency cesarian sections.

Given the societal emphasis placed on the deliberate breeding of purebred animals, the practitioner today is faced with issues relative to successful parturition in these animals. Today, the serious hobby breeder expects to use planned breeding management to result in a high conception and pregnancy rate and survival rates of offspring that may exceed published parameters. These clients may elect to schedule cesarean section to maximize puppy survival and assure that they have access to quality veterinary care. Using a combination of hormone assays, temperature changes in the dam and carefully timed and documented breeding management, a cesarean section can be planned. Emergency cesarean sections will still be required for the bitch that experiences dystocia or a medical condition that warrants intervention. Timed cesarean section results in a favorable medical outcome for the dam and litter and a better financial outcome for the owner.

Long-term results of children with acute myeloid leukemia: a report of three consecutive Phase III trials by the Children's Cancer Group: CCG 251, CCG 213 and CCG 2891.

The Children's Cancer Group (CCG) conducted three Phase III prospective clinical trials for children with de novo acute myeloid leukemia between the years 1979 and 1995. A total of 1903 eligible children ages birth to 21 years of age were enrolled on CCG 251 (n=485), CCG 213 (n=532) and CCG 2891 (n=886). Follow-up is ongoing, with medians of 7.9, 10.9 and 8.6 years, respectively. These three clinical trials developed dose- and time-intensive induction regimens based upon high-dose cytarabine and daunomycin and randomly assigned patients to allogeneic bone marrow transplantation in first remission if an HLA-matched related donor was identified. Despite dose- and time-intensive induction regimens, remission induction rates remained relatively stable at 77-78%. However, overall survival, event-free survival and disease-free survival (DFS) increased for patients receiving intensive-timing induction therapy in comparison to patients who received standard-timing induction, regardless of the type of postremission therapy. Outcomes were best for patients receiving intensive-timing induction followed by matched related donor allogeneic transplantation with DFS of 65+/-9% at 6 years. These three clinical trials have established a strong foundation for the development of future studies focusing on further risk group stratification and the development of novel, molecularly-targeted therapies.

National estimates of the use of hematopoietic stem-cell transplantation in children with cancer in the United States.

National utilization data for hematopoietic stem-cell transplantation (HSCT) for childhood cancers in the United States have not been reported. We identified cancer encounters for children aged 18 years and younger from 1997 to 2001 in US nonfederal, acute care hospitals. We compared patient, hospital, and resource use characteristics and in-patient mortality associated with HSCT and non-HSCT encounters, estimated the number of HSCT encounters by stem-cell source and cancer type, and examined resource use and mortality in each category. We identified 461,175 cancer encounters, of which 6380 (1.4%) were HSCT encounters. There was wide variation in resource use and mortality by stem-cell source and cancer type. Of note, 17% of HSCT encounters were for patients with acute lymphoblastic leukemia without remission or sarcoma, conditions for which there is little evidence of benefit from HSCT in children. These encounters were associated with high in-patient mortality and long lengths of stay. Also, we observed an increasing use of cord blood over the study period. Future research should examine potentially important sociodemographic differences in patients undergoing HSCT compared to those who do not. Additional analyses incorporating disease stage and severity are needed.

Postremission therapy for children with acute myeloid leukemia: the children's cancer group experience in the transplant era.

We reviewed consolidation therapy results and analyzed postremission outcomes for 1464 children less than 21 years old at diagnosis in five consecutive Children's Cancer Group acute myeloid leukemia trials between 1979 and 1996. Children in remission were allocated to allogeneic bone marrow transplantation (BMT) (N=373) in first remission, if a matched family donor was available. Remaining children were assigned consolidation chemotherapy (N=688) or autologous purged BMT (N=217), or withdrew from study before assignment, or with unknown data (N=186). Overall and disease-free survival were superior for children assigned allogeneic transplants. High (>50,000/microl) diagnostic white blood cell (WBC) count was prognostic for inferior outcome, but French-American-British (FAB) subtypes were not. Inv(16) is a favorable karyotypic feature for children in first remission and t(8;21) is not. Allogeneic transplantation benefit was evident in most children, including those with high or low diagnostic WBC count, each FAB subtype, and t(8;21), but was not seen in children with inv(16). Therefore, these data suggest reserving matched related donor allogeneic transplantation for children with inv(16) for second remission, but not those with t(8;21).

Childhood and maternal infections and risk of acute leukaemia in children with Down syndrome: a report from the Children's Oncology Group.

Children with Down syndrome (DS) are highly susceptible to acute leukaemia. Given the potential role of infections in the aetiology of leukaemia in children without DS, we investigated whether there was an association between early-life infections and acute leukaemia in children with DS. Maternal infections during pregnancy were also examined. We enrolled 158 incident cases of acute leukaemia in children with DS (97 acute lymphoblastic leukaemia (ALL) and 61 acute myeloid leukaemia (AML)) diagnosed at Children's Oncology Group institutions between 1997 and 2002. DS controls (N=173) were selected from the cases' primary care clinics and frequency matched on age at leukaemia diagnosis. Data were collected on demographics, child's medical history, mother's medical history, and other factors by maternal interview. Analyses were conducted using unconditional logistic regression adjusted for potential confounders. A significant negative association was observed between acute leukaemia and any infection in the first 2 years of life (adjusted odds ratio (OR)=0.55, 95% confidence interval (CI) (0.33-0.92); OR=0.53, 95% CI (0.29-0.97); and OR=0.59, 95% CI (0.28-1.25) for acute leukaemia combined, ALL, and AML respectively). The association between acute leukaemia and maternal infections during pregnancy was in the same direction but not significant. This study offers support for the hypothesis that early-life infections may play a protective role in the aetiology of acute leukaemia in children with DS.

Persistent gestational trophoblastic disease presenting as left hemiparesis in a Jamaican teenager.

A 19-year-old woman, who delivered a macerated stillborn at 32 weeks' gestation and had persistent postpartum vaginal bleeding, presented with a left hemiparesis three and a half months after delivery. A clinical diagnosis of persistent gestational trophoblastic disease (GTD) was made, based on quantitative serum beta-hCG of more than 200,000 IU/ml, cannon ball metastases on chest X-ray and two ring enhancing lesions, metastases, in the right parietal lobe on Computed Axial Tomography (CAT) scan of the brain. Despite combination chemotherapy, with methotrexate, cyclophosphamide and actinomycin D, her condition worsened and she died.

Persistent gestational trophoblastic disease presenting as left hemiparesis in a Jamaican teenager

A 19-year-old woman, who delivered a macerated stillborn at 32 weeks' gestation and had persistent postpartum vaginal bleeding, presented with a left hemiparesis three and a half months after delivery. A clinical diagnosis of persistent gestational trophoblastic disease (GTD) was made, based on quantitative serum beta-hCG of more than 200,000 IU/ml, cannon ball metastases on chest X-ray and two ring enhancing lesions, metastases, in the right parietal lobe on Computed Axial Tomography (CAT) scan of the brain. Despite combination chemotherapy, with methotrexate, cyclophosphamide and actinomycin D, her condition worsened and she died.

Potential role of hematopoietic stem cell transplantation in children with secondary acute lymphocytic leukemia.

Secondary acute lymphocytic leukemias (ALL) are uncommon events in the pediatric patient population. There are few detailed reports on the laboratory characteristics and clinical course of patients with secondary lymphocytic leukemia. Historically, these patients have had a poor outcome. We report two patients treated at one institution who developed treatment-related secondary ALL. Both patients underwent hematopoietic stem cell transplantation, one with a compatible unrelated donor cord blood unit and one with an HLA-matched sibling donor bone marrow. One of the two patients survives disease-free 3 years after transplantation.

Mobilization and collection of peripheral blood CD34+ cells from patients with Fanconi anemia.

A potential therapeutic option for patients with Fanconi anemia is collection of peripheral blood stem cells prior to the development of severe pancytopenia. These hematopoietic cells potentially could be infused when symptomatic bone marrow failure develops, as autologous rescue after chemotherapy in the event of leukemic transformation, or as targets for gene therapy. Eight patients with Fanconi anemia were mobilized with 10 microg/kg per day of granulocyte colony-stimulating factor (median, 10 +/- 4 days) to determine the feasibility of collecting peripheral blood stem cells for future use. Six patients achieved a peripheral blood CD34+ count of > or = 6/microL and underwent apheresis. The collection goal was 2 x 10(6) CD34+ cells/kg based on a predicted weight 5 years from the date of collection. A mean of 2.6 +/- 0.9 x 10(6) CD34+ cells/kg of the weight at the time of collection were collected, which corresponded to 1.9 +/- 0.4 x 10(6) CD34+ cells/kg of the target weight. The collections required a mean of 4 +/- 3 days (range, 2-8 days) of apheresis. Six of the 8 subjects had > or = 1 x 10(6) CD34+ cells/kg cryopreserved based on both actual and target weights, and 4 subjects had > or = 2 x 10(6) CD34+ cells/kg cryopreserved based on the target weight. These results suggest that some patients with Fanconi anemia can have adequate numbers of CD34+ cells mobilized and collected from the peripheral blood prior to the onset of severe bone marrow failure, but they may require an extended mobilization and multiple days of collection.

Pediatric hematopoietic stem cell transplantation.

The successful use of allogeneic HSCT for children with malignant and nonmalignant diseases continues to be limited by the development of acute and chronic GVHD, infectious complications, delayed recovery of the immune system, acute and long-term toxicity, and relapse of disease. Significant advances have been made, particularly in the ability to identify suitable sources of HSC. Future advances will depend on a better understanding of the biology of HSC sources, GVHD, immune reconstitution, and common complications. Improved therapies are dependent on participation of children in well-designed, translational and clinical transplant studies.

Progress in the use of gene transfer methods to treat genetic blood diseases.

A report by French physician-scientists suggests a successful application of gene transfer methods in the treatment of two children with severe combined immunodeficiency (SCID) due to defective interleukin 2 receptor common gamma chain. The protocol used in this clinical trial was derived from a number of preclinical and basic studies leading to improved transduction of hematopoietic stem and primitive progenitor cells using retrovirus vectors. These improvements have also been shown to impact transduction of a long-lived progenitor cell in a chemotherapy protocol in cancer patients. The improved results of these human trials come during a period of increased scrutiny and criticism of human gene therapy trials, due, in part, to significant toxicities in some trials using adenovirus-based vectors. The potential efficacy versus toxicity of phase I trials of human gene therapy is also under question. After many years of research, however, there appears to be real evidence that genetic diseases may be successfully treated by gene transfer techniques. Future clinical studies should be based on continued progress in the understanding of the toxicology of gene delivery systems, vector technology, and target cell manipulation.

Analysis of engraftment, graft-versus-host disease, and immune recovery following unrelated donor cord blood transplantation.

Unrelated cord blood (UCB) is being used as a source of alternative hematopoietic stem cells for transplantation with increasing frequency. From November 1994 to February 1999, 30 UCB transplant procedures were performed for both malignant and nonmalignant diseases in 27 children, aged 0.4 to 17.1 years. Patients received either HLA-matched (n = 3) or 1- or 2-antigen-mismatched (n = 27) UCB following 1 of 2 standardized preparative and graft-versus-host disease regimens (hyperfractionated total body irradiation, cyclophosphamide, and antithymocyte globulin [ATG] with cyclosporine A and methotrexate; or busulfan, melphalan, and ATG with cyclosporine A and prednisone). The median time to neutrophil and platelet engraftment was 27 days (12-60 days) and 75 days (33-158 days) posttransplantation, respectively. No correlation was noted between neutrophil and platelet engraftment and nucleated cells per kilogram, CD34(+) cells per kilogram infused, or cytomegalovirus status of recipient. The cumulative probability of acute grade 2 or greater graft-versus-host disease (GVHD) was 37.2%, and of grade 3 or greater GVHD was 8.8%. No patients developed chronic GVHD. CD4, CD19, and natural killer cell recovery was achieved at a median of 12, 6, and 2 months, respectively. CD8 recovery was delayed at a median of 9 months. Normal mitogen response was achieved at 6 to 9 months. The probability of survival, disease-free survival, and event-free survival at 1 year was 52.3% (34.1%-70.5%), 54.7% (34.5%-74.9 %) and 49.6% (29.9%-69.4%), respectively. This series of 30 UCB transplants suggests that although CD8 cell recovery is delayed, the pattern of immune reconstitution with UCB is similar to that reported for other stem cell sources. (Blood. 2000;96:2703-2711)

Efficient retrovirus-mediated transfer of the multidrug resistance 1 gene into autologous human long-term repopulating hematopoietic stem cells.

Pre-clinical studies indicate that efficient retrovirus-mediated gene transfer into hematopoietic stem cells and progenitor cells can be achieved by co-localizing retroviral particles and target cells on specific adhesion domains of fibronectin. In this pilot study, we used this technique to transfer the human multidrug resistance 1 gene into stem and progenitor cells of patients with germ cell tumors undergoing autologous transplantation. There was efficient gene transfer into stem and progenitor cells in the presence of recombinant fibronectin fragment CH-296. The infusion of these cells was associated with no harmful effects and led to prompt hematopoietic recovery. There was in vivo vector expression, but it may have been limited by the high rate of aberrant splicing of the multidrug resistance 1 gene in the vector. Gene marking has persisted more than a year at levels higher than previously reported in humans.

Osmometric and permeability characteristics of human placental/umbilical cord blood CD34+ cells and their application to cryopreservation.

The transplantation of placental/cord blood-derived HPC (e.g., CD34+ cells) has become a useful treatment for a broad spectrum of malignant and nonmalignant diseases. The ability to cryopreserve this cell type with high efficiency adds considerable flexibility to cord blood transplantation. The purpose of this study was to develop an understanding of the fundamental cryobiologic factors of these cells, including the osmotic/permeability characteristics, and to use a theoretical approach to optimize freezing procedures. To that end, biophysical parameters, including the osmotically inactive cell volume (Vb), hydraulic conductivity (Lp), and cryoprotectant permeability coefficient (P(CPA)) for DMSO and propylene glycol were measured using a modified Coulter Counter (Coulter Electronics, Inc., Hialeah, FL) at 22 degrees C. In addition, the osmotic tolerance of PCB CD34+ cells was assessed using a colony-forming assay. These experimentally determined parameters were used in a mathematical model to predict optimal cryoprotectant addition and removal procedures. The results demonstrate a Vb of 0.32 x V(iso), an average Lp of 0.17 +/- 0.03 (microm/min/atm +/- SD), and a PCPA of 0.94 +/- 0.004 or 1.0 +/- 0.004 cm/min (x10(-3)) for DMSO or propylene glycol, respectively. No significant difference was determined between the two cryoprotectants used. The osmotic tolerance limits were determined to be 200 and 600 mOsm/kg (1.29 and 0.62 x V(iso), respectively). These results indicate potential benefits of modifications to the widely used method of Rubinstein et al. Proc Natl Acad Sci USA 92:10119-10122, 1995) for cord blood CD34+ cell cryopreservation. As opposed to Rubinstein's method in which DMSO is added to cooled cell suspensions over a 15-min interval, our data indicate that better results may be obtained by introducing and removing the cryoprotectant at ambient temperature over 5 min both to increase viability by avoiding unnecessary risks from osmotic shock and to simplify the protocol. In addition, substitution of propylene glycol for DMSO may be of benefit during the actual freezing and thawing process.

Impact of bone marrow transplantation for symptomatic sickle cell disease: an interim report. Multicenter investigation of bone marrow transplantation for sickle cell disease.

Fifty children who had symptomatic sickle cell disease received matched sibling marrow allografts between September 1991 and March 1999, with Kaplan-Meier probabilities of survival and event-free survival of 94% and 84%, respectively. Twenty-six patients (16 male, 10 female) had at least 2 years of follow-up after transplantation and were evaluated for late effects of transplantation and for its impact on sickle cell-related central nervous system (CNS) and pulmonary disease. Patients ranged between 3.3 and 14.0 (median, 9. 4) years of age and had a median follow-up of 57.9 (range 38-95) months after transplantation. Among 22 of 26 patients who had stable donor engraftment, complications related to sickle cell disease resolved, and none experienced further episodes of pain, stroke, or acute chest syndrome. All 10 engrafted patients with a prior history of stroke had stable or improved cerebral magnetic resonance imaging results. Pulmonary function tests were stable in 22 of the 26 patients, worse in two, and not studied in two. Seven of eight patients transplanted for recurrent acute chest syndrome had stable pulmonary function. Linear growth measured by median height standard deviation score improved from -0.7 before transplantation to -0.2 after transplantation. An adverse effect of busulfan conditioning on ovarian function was demonstrated in five of seven evaluable females who are currently at least 13 years of age. None of the four males tested had elevated serum gonadotropin levels. These data confirm that allogenic bone marrow transplantation establishes normal erythropoiesis and is associated with improved growth and stable CNS imaging and pulmonary function in most patients. (Blood. 2000;95:1918-1924)

Flow cytometric immunophenotypic characterization of pediatric and adult minimally differentiated acute myeloid leukemia (AML-M0).

We reviewed the clinicopathologic and immunophenotypic profiles of 7 pediatric and 11 adult minimally differentiated acute myelogenous leukemias (AML-M0). We also compared and evaluated myeloperoxidase in leukemic blasts using standard cytochemical and polyclonal antibody immunohistochemical stains. No distinctive clinical findings were noted in either patient group; however, thrombocytopenia typically was more prominent in adults. Adult AML-M0 also was associated with an immature myeloid profile (CD34+, terminal deoxynucleotidyl transferase positive, CD13+, and CD33+), in contrast with pediatric AML-M0, which usually lacked terminal deoxynucleotidyl transferase or CD34 but expressed bright CD33 with weak or negative CD13. Coexpression of the T-cell-associated antigen CD7 was observed in both groups. Antibody immunohistochemical stains were more sensitive than cytochemical stains for detection of myeloperoxidase activity and a useful adjunct for establishing a diagnosis of myeloid leukemia in paraffin-embedded marrow tissues.

Large-scale mobilization and isolation of CD34+ cells from normal donors.

We describe collection and purification of peripheral blood CD34+ cells from volunteer, normal donors and allogeneic stem cell donors. A total of 98 aphereses were performed on 68 volunteer donors using peripheral venous access. The mean number of nucleated cells collected was 4.6 x 10(10) which included 1.9 x 10(8) CD34+ cells corresponding to 2.7 x 10(6) CD34+ cells/kg. The number of CD34+ cells collected did not differ between males and females but did correlate with the donor's weight and the total number of nucleated cells collected. The Nexell Isolex 300i cell separator was used to isolate CD34+ cells from 30 of the collections. A mean of 0.36% of the total cells was recovered and included 43 +/- 18% of the CD34+ cells. CD34+ cells represented 85 +/- 11% of the recovered cells. The total number of CD34+ cells recovered was not influenced by the number of nucleated cells placed on the Isolex 300i. The percentage of CD34+ cells recovered was not related to the number of CD34+ cells placed on the Isolex 300i. The purity of the final product was influenced by the number of CD34+ cells but not the total number of nucleated cells. An additional 38 CD34+ cell isolations were performed on normal allogeneic stem cell donors with similar results. These observations further support the safety and feasibility of peripheral blood CD34+ cell collection and purification.