Long-term follow-up of high-risk allogeneic peripheral-blood stem-cell transplant recipients: graft-versus-host disease and transplant-related mortality

Newly established stem cell transplant program: 100 days follow-up of patients and its comparison with published Indian literature

Background:

Hematopoietic progenitor stem cell transplantation (HPSCT) is used as a standard treatment option to improve outcome in hematological and nonhematological disorders. It is important for new HPSCT program to look at its patient outcome data and compare it with the published data to evaluate the efficacy of program.

Aims:

The aim was to compile and collate the patient outcome data of HPSCT and compare with published reports.

Materials and Methods:

Patient demographics, indications, stem cell harvest by apheresis, dose collected, infusion, engraftment, and follow-up data were collected from hospital information system from 2010 to 2013 in a tertiary care hospital. HPSCs were mobilized with granulocyte colony-stimulating factor, and harvests were done on the 5^th day. Engraftment was decided for neutrophil when counts were 0.5 × 10⁹/L and for platelets when counts were 20 × 10⁹/L on two consecutive days without any transfusion support.

Results:

There were 133 harvests for 95 patients with various disorders; multiple myeloma was most common in autologous and acute lymphoblastic leukemia in allogeneic group. One hundred harvests were done for autologous and 33 for allogeneic HPSCT. In autologous group, of 66 patients, 60 (90.9%) received stem cell infusion at median dose of 4.63 × 10⁶ CD34⁺ cells/kg. Similarly, in allogeneic group, of 29 patients, 27 (93.10%) received infusion at median dose of 5.8 × 10⁶ CD34⁺ cells/kg. 58 (96.9%) patients and 25 (92.6%) engrafted in autologous and allogeneic group, respectively. The median time for neutrophils engraftment was 11 days in autologous group and 12 days in allogeneic group. The median time for platelet engraftment was 11.5 days in autologous group and 13 days in allogeneic group. The 100-day survival rate was 95% (n = 57) in autologous group and 77.8% (n = 21) in allogeneic group.

Conclusion:

This data analysis shows reasonably good results of HPSCTs with majority of patients surviving at 100-day follow-up.

Hemorrhagic Cystitis Requiring Bladder Irrigation is Associated with Poor Mortality in Hospitalized Stem Cell Transplant Patients

Purpose:

To evaluate the overall prognosis of post-stem cell transplant inpatients who required continuous bladder irrigation (CBI) for hematuria.

Materials and Methods:

We performed a retrospective analysis of adult stem cell transplant recipients who received CBI for de novo hemorrhagic cystitis as inpatients on the bone marrow transplant service at Washington University from 2011-2013. Patients who had a history of genitourinary malignancy and/or recent surgical urologic intervention were excluded. Multiple variables were examined for association with death.

Results:

Thirty-three patients met our inclusion criteria, with a mean age of 48 years (23-65). Common malignancies included acute myelogenous leukemia (17/33, 57%), acute lymphocytic leukemia (3/33, 10%), and peripheral T cell lymphoma (3/33, 10%). Median time from stem cell transplant to need for CBI was 2.5 months (0 days-6.6 years). All patients had previously undergone chemotherapy (33/33, 100%) and 14 had undergone prior radiation therapy (14/33, 42%). Twenty-eight patients had an infectious disease (28/33, 85%), most commonly BK viremia (19/33, 58%), cytomegalovirus viremia (17/33, 51%), and bacterial urinary tract infection (8/33, 24%). Twenty-two patients expired during the same admission as CBI treatment (22/33 or 67% of total patients, 22/28 or 79% of deaths), with a 30-day mortality of 52% and a 90-day mortality of 73% from the start of CBI.

Conclusions:

Hemorrhagic cystitis requiring CBI is a symptom of severe systemic disease in stem cell transplant patients. The need for CBI administration may be a marker for mortality risk from a variety of systemic insults, rather than directly attributable to the hematuria.

Tear Cytokines as Biomarkers for Chronic Graft-versus-Host Disease

We investigated the tear cytokine profiles in patients who underwent stem cell transplantation (SCT) and attempted to evaluate whether tear cytokines are associated with the presence of systemic chronic graft-versus-host disease (GVHD), regardless of ocular GVHD status. We also tested tear cytokines as biomarkers for chronic ocular GVHD severity. Forty-four patients who underwent SCT were enrolled and their diagnosis of chronic GVHD was confirmed. Ocular surface parameters and tear cytokine profiles were evaluated and the correlations between concentrations of cytokines and ocular surface parameters or several chronic ocular GVHD severity scales were evaluated. Tear interleukin (IL)-2, IL-10, IL-17α, interferon (IFN)-γ, IL-6, and tumor necrosis factor (TNF)-α were elevated in patients with chronic systemic GVHD compared with patients without chronic systemic GVHD. Receiver-operating characteristic curve analysis revealed that area under the curve (AUC) values for tear IL-10 (AUC = .795), IL-17α (AUC = .821), IL-6 (AUC = .912), and TNF-α (AUC = .910) were significantly correlated with the presence of chronic GVHD (all P < .001). Tear IL-10, IL-6, and TNF-α showed a stronger correlation with ocular surface parameters than other cytokines and these cytokines also correlated with several chronic ocular GVHD severity scales (all P < .05). Our data suggest the tear cytokines are useful biomarkers for the diagnosis of chronic GVHD after SCT and chronic ocular GVHD severity.

Safety and feasibility of granulocyte colony-stimulating factor (G-CSF) primed bone marrow (BM) using three days of G-CSF priming as stem cell source for pediatric allogeneic BM transplantation

There are limited data on the optimal dosing and schedule of G-CSF priming prior to BM harvest. We evaluated the safety and efficacy of three days of G-CSF of primed BM from related pediatric donors. Forty-five children were treated. All donors received 5 μg/kg per day of G-CSF as a single subcutaneous injection for three consecutive days prior to the BM harvest. The median age of the donors was seven yr (range, 0.8-18) and no donor experienced major adverse events related to G-CSF administration. The median age for the recipients was five yr (0.3-16 yr). Thirty-five patients had non-malignant disorders. The median dose of nucleated (TNC) and CD34+, CD3 cells infused per recipient weight was 5.4 × 10(8) /kg (range, 0.61-17), 4.7 × 10(6) /kg (range, 1.6-19), and 43.8 × 10(6) /kg (range, 1.8-95), respectively. All patients achieved neutrophil and platelets engraftment, at a median of 15 (range, 10-22) and 23 days (range, 13-111), respectively. At a median follow up of 60 months (range 12-100), the estimated five yr overall and EFS was 91% and 80%, respectively. Collection of BM following three days of G-CSF priming from pediatric donors is safe and results in high TNC and CD34+ cell yield.

Gene and miRNA expression profiles of hematopoietic progenitor cells vary depending on their origin

Hematopoietic progenitor cells (HPCs) from granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood (G-PB), bone marrow (BM), or umbilical cord blood (CB) have differing biological properties and differing kinetics of engraftment post-transplantation, which might be explained, at least in part, by differing gene and miRNA expression patterns. To assess the differences in gene and miRNA expression, we analyzed whole genome expression profiles as well as the expression of 384 miRNAs in CD34(+) cells isolated from 18 healthy individuals (6 individuals per subtype of HPC source). We identified 43 genes and 36 miRNAs differentially expressed in the various CD34(+) cell sources. We observed that CD34(+) cells from CB and BM showed similar gene and miRNA expression profiles, whereas CD34(+) cells from G-PB had a very different expression pattern. Remarkably, 20 of the differentially expressed genes are targets of the differentially expressed miRNAs. Of note, the majority of genes differentially expressed in CD34(+) cells from G-PB are involved in cell cycle regulation, promoting the process of proliferation, survival, hematopoiesis, and cell signaling, and are targets of overexpressed and underexpressed miRNAs in CD34(+) cells from the same source. These data suggest significant differences in gene and miRNA expression among the various HPC sources used in transplantation. We hypothesize that the differentially expressed genes and miRNAs involved in cell cycle and proliferation might explain the differing kinetics of engraftment observed after transplantation of hematopoietic stem cells obtained from these different sources.

Non-myeloablative hematopoietic stem cell transplantation is of limited value in advanced or refractory acute myeloblastic leukemia. The Mexican experience

Allogeneic hematopoietic stem cell transplantation (HSCT) is an effective strategy for preventing relapse of acute myelogenous leukemia (AML). We analyzed the outcome of 31 primary AML patients who received a reduced-intensity conditioning regimen for allogeneic HSCT in first or second remission. Thirty-one AML patients, 20 in first complete remission (FCR), 8 in second complete remission (SCR) and 3 in a partial remission (SPR) were included. All received busulfan 4 mg/kg/d/2 days, fludarabine 30 mg/m(2)/d/3 days and cyclophosphamide 350 mg/m(2)/d/3 days as conditioning regimen. The median number of CD34+ cells infused was 5.6 x 10(6)/kg and 5.2 x 10(6) in FCR and SCR group, respectively. All patients received cyclosporine-A (CsA) and methotrexate as graft vs. host disease (GvHD) prophylaxis. All patients showed myeloid engraftment (neutrophils >0.5 x 10(9)/l) after a median of 13 days in FCR group and 15 days in SCR group. Platelet recovery >20 x 10(9)/l was achieved after a median of 13 days in both groups. Relapse for 20 patients in FCR was 35% compared to 91% for 11 in SCR/SPR (p < 0.05). Conclusions. Reduced-intensity conditioning followed by allogeneic HSCT can induce stable remission in primary AML patients transplanted in FCR. A high relapse rate was documented in patients with refractory or relapsed AML.

Immune Reconstitution and Early Infectious Complications Following Nonmyeloablative Hematopoietic Stem Cell Transplantation

Non-myeloablative stem cell transplantation (NMT) has been increasingly used in compromised patients who would otherwise have been unable to undergo allotransplant. There is little understanding of the kinetics of immune reconstitution and its influence on infective complications following NMT. The aim of present study was to evaluate lymphocyte subset reconstitution over the first 12 months post-transplant in 15 adult patients receiving NMT with comparison to that of 30 patients grafted with a conventional hemopoietic stem cell transplantation (HSCT). NMT recipients were conditioned with fludarabine-based conditioning regimens. Peripheral blood stem cell (PBSC) was the source of stem cells in 13 NMT recipients and in 24 conventional HSCT recipients. Absolute numbers of helper (CD4+) T cells, naive (CD4+ CD45RA+) and memory (CD4+ CD45RO+) T cells as well as suppressor (CD8+) T cells, CD19+ B cells and NK cells were comparable in the two groups at all time points after transplantation. A median value of 200 CD4+ T cells/microl was achieved at 2 months post-transplant by the NMT and HSCT recipients. The CD4:CD8 ratio remained severely depressed throughout the study period. Almost all CD4+ lymphocytes expressed CD45RO antigen in the both groups of patients B lymphocytes showed low counts throughout the entire study period in both groups. Bacteremia and CMV antigenemia occurred respectively in 13 and 36% of the patients in the NMT group and in 15 and 39% of the patients in the HSCT group. Our preliminary data indicate that patients receiving a NMT have a lymphocyte reconstitution similar to that observed in patients who received a conventional HSCT. The incidence of bacteremia and CMV infection were not significantly different between the groups. Nevertheless, due to the small sample size, these results should be considered suggestive rather than definitive.

Antileukemia and antitumor effects of the graft-versus-host disease: a new immunovirological approach

In leukemic mice, the native host's explicit and well-defined immune reactions to the leukemia virus (a strong exogenous antigen) and to leukemia cells (pretending in their native hosts to be protected "self" elements) are extinguished and replaced in GvHD (graft-versus-host disease) by those of the immunocompetent donor cells. In many cases, the GvHD-inducer donors display genetically encoded resistance to the leukemia virus. In human patients only antileukemia and anti-tumor cell immune reactions are mobilized; thus, patients are deprived of immune reactions to a strong exogenous antigen (the elusive human leukemia-sarcoma retroviruses). The innate and adaptive immune systems of mice have to sustain the immunosuppressive effects of leukemia-inducing retroviruses. Human patients due to the lack of leukemiainducing retroviral pathogens (if they exist, they have not as yet been discovered), escape such immunological downgrading. After studying leukemogenic retroviruses in murine and feline (and other mammalian) hosts, it is very difficult to dismiss retroviral etiology for human leukemias and sarcomas. Since no characterized and thus recognized leukemogenic-sarcomagenic retroviral agents are being isolated from the vast majority of human leukemias-sarcomas, the treatment for these conditions in mice and in human patients vastly differ. It is immunological and biological modalities (alpha interferons; vaccines; adoptive lymphocyte therapy) that dominate the treatment of murine leukemias, whereas combination chemotherapy remains the main remission-inducing agent in human leukemias-lymphomas and sarcomas (as humanized monoclonal antibodies and immunotoxins move in). Yet, in this apparently different backgrounds in Mus and Homo, GvHD, as a treatment modality, appears to work well in both hosts, by replacing the hosts' anti-leukemia and anti-tumor immune faculties with those of the donor. The clinical application of GvHD in the treatment of human leukemias-lymphomas and malignant solid tumors remains a force worthy of pursuit, refinement and strengthening. Graft engineering and modifications of the inner immunological environment of the recipient host by the activation or administration of tumor memory T cells, selected Treg cells and natural killer (NKT) cell classes and cytokines, and the improved pharmacotherapy of GvHD without reducing its antitumor efficacy, will raise the value of GvHD to the higher ranks of the effective antitumor immunotherapeutical measures. Clinical interventions of HCT/HSCT (hematopoietic cell/stem cell transplants) are now applicable to an extended spectrum of malignant diseases in human patients, being available to elderly patients, who receive non-myeloablative conditioning, are re-enforced by post-transplant donor lymphocyte (NK cell and immune T cell) infusions and post-transplant vaccinations, and the donor cells may derive from engineered grafts, or from cord blood with reduced GvHD, but increased GvL/GvT-inducing capabilities (graft-versus leukemia/tumor). Post-transplant T cell transfusions are possible only if selected leukemia antigen-specific T cell clones are available. In verbatim quotation: "Ultimately, advances in separation of GvT from GvHD will further enhance the potential of allogeneic HCT as a curative treatment for hematological malignancies" (Rezvani, A.R. and Storb, R.F., Journal of Autoimmunity 30:172-179, 2008 (see in the text)). It may be added: for cure, a combination of the GvL/T effects with new targeted therapeutic modalities, as elaborated on in this article, will be necessary.

Comparison of outcomes after transplantation of G-CSF-stimulated bone marrow grafts versus bone marrow or peripheral blood grafts from HLA-matched sibling donors for patients with severe aplastic anemia

We compared outcomes of patients with severe aplastic anemia (SAA) who received granulocyte-colony stimulating factor (G-CSF)-stimulated bone marrow (G-BM) (n = 78), unstimulated bone marrow (BM) (n = 547), or peripheral blood progenitor cells (PBPC) (n = 134) from an HLA-matched sibling. Transplantations occurred in 1997 to 2003. Rates of neutrophil and platelet recovery were not different among the 3 treatment groups. Grade 2-4 acute graft-versus-host disease (aGVHD) (relative risk [RR] = 0.82, P = .539), grade 3-4 aGVHD (RR = 0.74, P = .535), and chronic GVHD (cGVHD) (RR = 1.56, P = .229) were similar after G-BM and BM transplants. Grade 2-4 aGVHD (RR = 2.37, P = .012) but not grade 3-4 aGVHD (RR = 1.66, P = .323) and cGVHD (RR = 5.09, P < .001) were higher after PBPC transplants compared to G-BM. Grade 2-4 (RR = 2.90, P < .001), grade 3-4 (RR = 2.24, P = .009) aGVHD and cGVHD (RR = 3.26, P < .001) were higher after PBPC transplants compared to BM. Mortality risks were lower after transplantation of BM compared to G-BM (RR = 0.63, P = .05). These data suggest no advantage to using G-BM and the observed higher rates of aGVHD and cGVHD in PBPC recipients warrants cautious use of this graft source for SAA. Taken together, BM is the preferred graft for HLA-matched sibling transplants for SAA.

Novel therapeutic strategies for multiple sclerosis--a multifaceted adversary

Therapeutic strategies for multiple sclerosis have radically changed in the past 15 years. Five regulatory-approved immunomodulatory agents are reasonably effective in the treatment of relapsing-remitting multiple sclerosis, and appear to delay the time to progression to disabling stages. Inhibiting disease progression remains the central challenge for the development of improved therapies. As understanding of the immunopathogenesis of multiple sclerosis has advanced, a number of novel potential therapeutics have been identified, and are discussed here. It has also become apparent that traditional views of multiple sclerosis simply as a CD4+ T-cell-mediated disease of the central nervous system are incomplete. The pathogenic role of other immune components such as the innate immune system, regulatory T cells, T helper 17 cells and B cells is reaching centre stage, opening up exciting avenues and novel potential targets to affect the natural course of multiple sclerosis.

Successful treatment of refractory Langerhans cell histiocytosis by allogeneic peripheral blood stem cell transplantation

We describe a six-yr-old boy who exhibited typical signs and symptoms of LCH with EBV-associated hemophagocytic syndrome from the age of 15 months. Multiple courses of conventional chemotherapy achieved only marginal improvement over the ensuring five yr. During this period, this boy experienced recurrent episodes of hemophagocytic syndrome associated with CMV infection. Five yr after the first diagnosis of LCH, the patient was treated with allogeneic PBSCT from his HLA-identical eight-yr-old brother. PBSCT was performed using a TBI-incorporating conditioning regimen comprising TBI, busulfan, and cyclophosphamide. Diabetes insipidus, typically a permanent consequence of LCH, was well controlled by DDAVP therapy. At the time of writing, this boy is alive and well, and had been disease-free for more than two yr after the PBSCT.

A randomized double-blind trial of hydroxychloroquine for the prevention of chronic graft-versus-host disease after allogeneic peripheral blood stem cell transplantation

Hydroxychloroquine (HCQ) is an immunosuppressive lysosomotropic amine that has activity against graft-versus-host disease (GVHD). In a single-institution phase III trial, 95 recipients of allogeneic peripheral blood stem cell (PBSC) transplantation were randomized to receive, in a double-blind fashion, and in addition to prophylactic cyclosporine A (CSA), HCQ, or placebo starting 21 days pretransplant and continued until day +365. HCQ was very well tolerated and not associated with side effects. Overall, the incidence of acute GVHD (aGVHD) was 59% in both arms, and severe aGVHD occurred in 11% (HCQ) and 14% (placebo) (P = .76). Sixty percent and 78% of patients developed chronic GVHD (cGVHD) in the HCQ and the placebo arms, respectively (P = .15). With a median follow-up of 18 months, relapse-free and overall survivals (OS) were comparable in both groups. In summary, in this randomized trial, the addition of HCQ to single-agent CSA had no effects on aGVHD or cGVHD or survival.

Nonmyeloablative allogeneic stem cell transplantation in elderly patients with hematological malignancies: results from the GITMO (Gruppo Italiano Trapianto Midollo Osseo) multicenter prospective clinical trial

This study aimed to evaluate the efficacy of a nonmyeloablative conditioning consisting of fludarabine and TBI in patients aged > or =60 years.A total of 32 patients (median age 62 years; range 60-70) with hematological malignancies were treated with fludarabine (30 mg/m(2) x 3-5 days) and 200 cCy TBI followed by allogeneic hematopoietic stem cell transplantation (HSCT) from a matched-sibling donor. GVHD prophylaxis consisted of cyclosporine and mycophenolate. Neutrophil recovery occurred in all patients at a median time of 16 days (range 9-34). Six patients did not become granulocytopenic. On day +30, 10 patients had >95% donor chimerism and 19 patients had mixed chimerism. The cumulative probabilities of Grade II-IV acute GVHD and chronic GVHD were 48 and 83%, respectively. Transplant-related mortality at 100 days and 1 year was 6 and 10%, respectively. The probabilities of 2-year overall (OS) and progression-free survival (PFS) were 39 and 35%, respectively. The estimated 2-year probability of OS and PFS for patients in early disease stages were 77 and 64%, respectively, which were significantly higher than the survival and PFS estimates of 0% obtained in patients with advanced disease stages at the time of transplant. Our analysis would suggest that for patients older than 60, this regimen is well tolerated and associated with a low incidence of transplant-related mortality. The leukemic burden at time of transplant has proven to be the most important risk factor for the outcome.

A prospective study of G-CSF primed bone marrow as a stem-cell source for allogeneic bone marrow transplantation in children: a Pediatric Blood and Marrow Transplant Consortium (PBMTC) study

A prospective multicenter trial was conducted to evaluate the safety and feasibility of granulocyte colony-stimulating factor (G-CSF)-primed bone marrow (G-BM) in children receiving allogeneic bone marrow transplantation (BMT). A total of 42 children with a median age of 9.8 years (range, 0.8-17 years) were enrolled. Donors with median age of 9.2 years (range, 1.1-22 years) received 5 microg/kg per day of subcutaneous G-CSF for 5 consecutive days. BM was harvested on the fifth day. No donor experienced complications related to G-CSF administration or marrow har-vest. Median nucleated (NC) and CD34 cells infused was 6.7 x 10(8)/kg (range, 2.4-18.5 x 10(8)/kg) and 7.4 x 10(6)/kg (range, 2-27.6 x 10(6)/kg), respectively. Neutrophil and platelet engraftment was at a median of 19 days (range, 13-28 days) and 20 days (range, 9-44 days), respectively. A total of 13 (32%) patients developed grade 2 graft-versus-host disease (GVHD), and 5 (13%) of 40 evaluable patients developed chronic GVHD (3 limited and 2 extensive). Higher cell dose was not associated with increased risk of acute or chronic GVHD. Overall survival and event-free survival at 2 years were 81% and 69%, respectively. Collection of G-BM from pediatric donors is safe, and can result in high NC and CD34 cell doses that facilitate engraftment after myeloablative BMT without a discernable increase in the risk of GVHD.

Cytokines and hematopoietic stem cell mobilization

Hematopoietic stem cell transplantation (HSCT) has become the standard of care for the treatment of many hematologic malignancies, chemotherapy sensitive relapsed acute leukemias or lymphomas, multiple myeloma; and for some non-malignant diseases such as aplastic anemia and immunodeficient states. The hematopoietic stem cell (HSC) resides in the bone marrow (BM). A number of chemokines and cytokines have been shown in vivo and in clinical trials to enhance trafficking of HSC into the peripheral blood. This process, termed stem cell mobilization, results in the collection of HSC via apheresis for both autologous and allogeneic transplantation. Enhanced understanding of HSC biology, processes involved in HSC microenvironmental interactions and the critical ligands, receptors and cellular proteases involved in HSC homing and mobilization, with an emphasis on G-CSF induced HSC mobilization, form the basis of this review. We will describe the key features and dynamic processes involved in HSC mobilization and focus on the key ligand-receptor pairs including CXCR4/SDF1, VLA4/VCAM1, CD62L/PSGL, CD44/HA, and Kit/KL. In addition we will describe food and drug administration (FDA) approved and agents currently in clinical development for enhancing HSC mobilization and transplantation outcomes.

Unrelated donor or partially matched related donor peripheral stem cell transplant with CD34+ selection and CD3+ addback for pediatric patients with leukemias

Unmodified peripheral stem cell transplants are associated with an increased risk of extensive chronic GVHD. T depletion may reduce this risk, but the risk of graft failure or relapse may increase. To decrease the risks of both extensive chronic GVHD and graft failure, we added back a defined dose of CD3+ cells to CD34+ selected PSCs. Twenty-four patients were evaluable for outcome analysis. Donors were unrelated (23) or related (1). Conditioning was thiotepa, cyclophosphamide, and total body irradiation. Cyclosporine was used post transplant. Following CD34+ selection, a total of 5 x 10(5)/kg CD3+ cells were infused. Donors were matched for 12 patients. The median CD34+ dose infused was 7.1 x 10(6)/kg. Engraftment occurred in all patients at a median of 14 days (10-19). Twelve patients are alive in remission 15-34 months (median, 25) post PSCT. GVHD occurred in 17 patients, but was >grade II in only 2. Chronic GVHD occurred in 61.5% of evaluable patients, but was limited to skin and perioral cavity. Two patients relapsed, and 10 patients died of non-relapse causes. This study demonstrates that PSCT with CD34+ selection and a defined dose of CD3+ results in prompt engraftment and may limit development of extensive chronic GVHD.

Transplantation of CD34+ selected peripheral blood to HLA-identical sibling patients with aplastic anaemia: results from a single institution

We evaluated the use of CD34+ selected allogeneic peripheral blood as a source of hematopoietic progenitors for allogeneic transplantation in 11 patients with aplastic anemia (AA). The median age was 17 years (range, 6--9), and the median time between diagnosis and transplant 1 month (range, 1--4). Conditioning consisted of cyclophosphamide (50 mg/kg per day) on days--7 to--4 and antithymocyte globulin (30 mg/kg per day) on days--4 to--2 in nine patients. Total lymphoid irradiation was added to the preparative regimen for two. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine A and prednisone. Median doses of CD34+ and CD3+ cells infused were 3.91 x 10(6) and 0.3 x 10(6)/kg, respectively. The median time taken to achieve a neutrophil count >0.5 x 10(9)/l was 12 days and to recover a platelet count >20 x 10(9)/l, 13 days. Two patients developed acute GVHD grade I--II and one developed limited chronic GVHD. There were two treatment-related deaths. At a median follow-up of 44 months (range, 4--3), nine patients were alive with sustained and complete engraftment. This is a promising procedure in patients with AA, resulting in a rapid hematopoietic recovery, a low transplant-related mortality, and a low incidence of GVHD.

Unrelated donor hematopoietic stem cell transplantation for patients with hematologic malignancies using a nonmyeloablative conditioning regimen of fludarabine, low-dose total body irradiation, and rabbit antithymocyte globulin

Hematopoietic stem cell chimerism can be established after low-dose conditioning regimens, although the risk of donor cell rejection increases for unrelated donor transplantations. We added pretransplantation rabbit antithymocyte globulin (6 mg/kg) to an established conditioning regimen of fludarabine (90 mg/m2) and single-fraction total body irradiation (200 cGy) followed by postgrafting immunosuppression with cyclosporine A and mycophenolate mofetil for 22 patients with hematologic malignancies. One patient rejected the graft and successfully underwent transplantation with cells from a second donor by using the same conditioning regimen. The actuarial probability of developing acute graft-versus-host disease grade II to IV before day 100 was 40%, although 9 of 14 patients who survived beyond 100 days developed chronic graft-versus-host disease. These data support a hypothesis that the addition of antithymocyte globulin decreases the risk of graft-versus-host and host-versus-graft reactions when combined with a nonmyeloablative conditioning regimen of fludarabine and total body irradiation.

Transplantation of hematopoietic stem cells from the peripheral blood

Hematopoietic stem cells can be collected from the peripheral blood. These hematopoietic stem cells (HSC), or better progenitor cells, are mostly expressed as the percentage of cells than react with CD34 antibodies or that form colonies in semi-solid medium (CFU-GM). Under steady-state conditions the number of HSC is much lower in peripheral blood than in bone marrow. Mobilization with chemotherapy and/or growth factors may lead to a concentration of HSC in the peripheral blood that equals or exceeds the concentration in bone marrow. Transplantation of HSC from the peripheral blood results in faster hematologic recovery than HSC from bone marrow. This decreases the risk of infection and the need for blood-product support. For autologous stem-cell transplantation (SCT), the use of peripheral blood cells has completely replaced the use of bone marrow. For allogeneic SCT, on the other hand, the situation is more complex. Since peripheral blood contains more T-lymphocytes than bone marrow, the use of HSC from the peripheral blood increases the risk of graft-versus-host disease after allogeneic SCT. For patients with goodrisk leukemia, bone marrow is still preferred, but for patients with high-risk disease, peripheral blood SCT has become the therapy of choice.

Different efficacy of mycophenolate mofetil as salvage treatment for acute and chronic GVHD after allogeneic stem cell transplant

OBJECTIVE

The therapeutic options currently available for treating refractory graft-vs.-host disease (GVHD) are limited. Therefore, the present study evaluated the efficacy of mycophenolate mofetil (MMF) as a salvage treatment for acute and chronic GVHD in allograft patients.

METHODS

Twenty-six consecutive patients with refractory acute (13 patients) or chronic (13 patients) GVHD were enrolled. The first-line treatment for all patients with acute GVHD consisted of a combination of cyclosporine A (CyA) and steroids, while the first-line treatment for chronic GVHD was steroids with or without CyA according to the risk group. MMF was added at a dose of 1.5 or 2 g daily and the steroids were tapered in the refractory cases.

RESULTS

Four (30.8%) of 13 patients with refractory acute GVHD responded to MMF. When analyzing the overall results according to the type of acute GVHD, improvement was observed in four (30.8%) of 13 skin cases, four (44.4%) of nine liver cases, and two (22.9%) of nine gut cases. Ten (76.9%) of 13 patients with refractory chronic GVHD responded to MMF. The common side effects were gastrointestinal disturbance (26.9%) or infectious complications (23.1%). The estimated 2-yr survival rate for patients with acute GVHD and chronic GVHD was 33.3% and 53.9%, respectively.

CONCLUSIONS

MMF would appear to be effective and safe for treating refractory chronic GVHD, yet not as effective for treating refractory acute gut GVHD. Accordingly, a prospective randomized clinical trial is warranted to assess the impact of MMF in the treatment of refractory GVHD.

Adoptive immunotherapy with antigen-specific T cells in myeloma: a model of tumor-specific donor lymphocyte infusion

Although partial remissions rates of up to 60% are obtained with conventional therapeutic regimens, multiple myeloma is essentially an incurable disease with a median survival of approximately 30 months. Allogeneic stem cell transplantation (SCT) results in a high percentage of complete remissions (CRs), but it can be associated with significant treatment-related mortality. Recent clinical studies have shown that highly immunosuppressive, yet nonmyeloablative, doses of fludarabine-based chemotherapy can result in alloengraftment. However, even with a reduction in treatment-related mortality, success with allogeneic SCT is limited by the significant risk of relapse. The goal of the strategy described is to transfer tumor antigen-specific immunity induced in the stem cell donor to the allogeneic SCT recipient to reduce relapse. Donors are immunized with a well-defined vaccine, specific for the patient's tumor. The allogeneic SCT is performed with a conditioning regimen consisting of cyclophosphamide and fludarabine, and the stem cell source is blood mobilized with filgrastim, which could potentially enhance the transfer of a larger number of tumor-specific T cells in the allograft, as compared to bone marrow. Donor immunization with myeloma idiotype protein in the setting of a nonmyeloablative SCT may represent a novel strategy for the treatment of myeloma.

Comparisons between allogeneic peripheral blood stem cell transplantation and allogeneic bone marrow transplantation in adult hematologic disease: a single center experience

This retrospective study compared the outcomes in 32 adult patients with hematologic diseases (acute myeloid leukemia, acute lymphoblastic leukemia, chronic myeloid leukemia, myelodysplastic syndrome, severe aplastic anemia) who received allogeneic bone marrow transplantation (BMT, n = 14; median age, 28 years) or allogeneic peripheral blood stem cell transplantation (PBSCT, n = 18; median age, 29 years) from human leukocyte antigen-identical sibling donors. Median follow-up was 58 months in BMT recipients and 18 months in PBSCT recipients. Neutrophil (median, Day 8 vs Day 13, p < 0.001) and platelet engraftment (median, Day 9 vs Day 17, p < 0.001) was faster in the PBSCT group than in the BMT group. Patients receiving PBSCT required less platelet transfusion than those receiving BMT (median, 54 units vs 144 units, p < 0.001), but there was no significant difference in red cell transfusion. At 100 days, there was no difference in the incidence of acute graft-versus-host disease (GVHD) (42.9% vs 33.3%, p = 0.72) or grade II-IV acute GVHD (14.3% vs 5.6%, p = 0.57), and there was no difference in the cumulative incidence of chronic GVHD (20% vs 33.3%, p = 0.67). No chronic GVHD was noted in any relapsed patients (BMT, 5; PBSCT, 3), and no patients with chronic GVHD during follow-up had a relapse. Relapse was the most frequent cause of death inboth groups (BMT, 5/9, 55.6%; PBSCT, 3/4, 75%; p = 0.25); all relapses occurred within 1 year after transplantation. Overall survival was significantly better in the PBSCT group (35.7% vs 77.8%, p = 0.029), but this difference was lost if only hematologic malignancies were analyzed (30.8% vs 63.6%, p = 0.20). Our results are similar to those reported previously, with faster neutrophil and platelet engraftment and less severe acute GVHD and extensive chronic GVHD with PBSCT. Allogeneic PBSCT is a feasible and beneficial alternative to allogeneic BMT in adult hematologic disease.

Gene-expression profiling of CD34+cells from various hematopoietic stem-cell sources reveals functional differences in stem-cell activity

The replacement of bone marrow (BM) as a conventional source of stem cell (SC) by umbilical cord blood (UCB) and granulocyte-colony stimulating factor-mobilized peripheral blood SC (PBSC) has brought about clinical advantages. However, several studies have demonstrated that UCB CD34(+) cells and PBSC significantly differ from BM CD34(+) cells qualitatively and quantitatively. Here, we quantified the number of SC in purified BM, UCB CD34(+) cells, and CD34(+) PBSC using in vitro and in vivo assays for human hematopoietic SC (HSC) activity. A cobblestone area-forming cell (CAFC) assay showed that UCB CD34(+) cells contained the highest frequency of CAFC(wk6) (3.6- to tenfold higher than BM CD34(+) cells and PBSC, respectively), and the engraftment capacity in vivo by nonobese diabetic/severe combined immunodeficiency repopulation assay was also significantly greater than BM CD34(+), with a higher proportion of CD45(+) cells detected in the recipients at a lower cell dose. To understand the molecular characteristics underlying these functional differences, we performed several DNA microarray experiments using Affymetrix gene chips, containing 12,600 genes. Comparative analysis of gene-expression profiles showed differential expression of 51 genes between BM and UCB CD34(+) SC and 64 genes between BM CD34(+) cells and PBSC. These genes are involved in proliferation, differentiation, apoptosis, and engraftment capacity of SC. Thus, the molecular expression profiles reported here confirmed functional differences observed among the SC sources. Moreover, this report provides new insights to describe the molecular phenotype of CD34(+) HSC and leads to a better understanding of the discrepancy among the SC sources.

Are predictive factors clinically useful in bone marrow transplantation?

Variables that accurately predict the clinical outcome of any procedure, including bone marrow transplantation (BMT), are of paramount importance when assessing the risks and benefits of the procedure. This review of the world's literature of variables affecting overall outcome after myeloablative BMT critically appraises the value of many bone marrow transplant dogmas. There is a relative paucity of data supporting many commonly used transplant practices, including having an upper age limit for eligibility criteria, and absolute requirements for cardiac and pulmonary function pre transplant. In contrast, recently published literature suggests that several parameters occurring soon after a BMT has been performed may accurately predict transplant outcome. Ultimately, given the rapidly evolving nature of BMT, renewed clinical research of variables predictive of transplant outcome is needed.

Low-dose short-course intravenous ganciclovir as pre-emptive therapy for CMV viremia post allo-PBSC transplantation

In contrast to allogeneic bone marrow transplantation (allo-BMT), there is a paucity of data on cytomegalovirus (CMV) infection and preemptive therapy (PT) strategies following allogeneic peripheral blood stem cell (allo-PBSC) transplantation. We report here on the patterns of CMV infection in a cohort of 225 patients following sibling donor allo-PBSC transplantation. In an attempt to reduce neutropenia, we used intravenous low-dose short-course (LDSC) ganciclovir (GCV) 5 mg/kg once daily for 21 days as preemptive therapy. A total of 165 recipient-donor pairs were CMV seropositive. An initial episode of viremia (detected by shell vial/tube culture) occurred in 75/165 (45%) at a median of day +35 (17-445) post allo-PBSC. In all, 58 patients received PT with LDSC GCV. Among 58, 55 (94%) completed the 21-day course of PT. A second episode of viremia occurred in 19/58 (33%) at day+80 (50-174) and a third episode in 5/58 (9%) at day+134 (103-218). Among patients receiving LDSC GCV, 5/58(9%) developed disease (four pneumonia, one colitis) at day+211 (63-487). No patient on LDSC GCV exhibited a decline in their ANC below 500/microl and none required growth factors. LDSC GCV is extremely well tolerated and cost-effective as PT for CMV viremia following allo-PBSC transplantation.

Fewer relapses and increased chronic GVHD in patients transplanted with blood stem cells: a 5-year follow-up in a single centre study

A total of 61 consecutive adult patients with haematological malignancies with an HLA-identical or one antigen-mismatched haploidentical family donor were randomised to allogeneic transplantation with blood stem cells (BSC) or bone marrow (BM). The median observation time was 5 years. Apart from engraftment parameters and acute graft-versus-host disease (GVHD), transplant-related mortality (TRM), incidence and severity of chronic GVHD, relapse, leukaemia-free survival (LFS) and overall survival (OS) were recorded. In the BSC and BM group, respectively, TRM was 8/30 and 4/30 (P=0.405), the incidence of chronic GVHD was 15/26 and 11/30 (P=0.138), extensive chronic GVHD was 10/26 and 4/30 (P=0.034), and relapse one and 10 patients (P=0.007). In log-rank test restricted to the cases allografted from HLA-identical donors, the difference remained significant with regard to relapse incidence (P=0.039), but not extensive chronic GVHD (P=0.072). No difference in LFS and OS was observed. In conclusion, our study strongly indicates an enhanced graft-versus-leukaemia effect in BSC recipients, which is not expressed in increased survival. The increased chronic GVHD in these patients may contribute, but the relation is complex and not yet understood.

Hematopoietic stem cell graft manipulation as a mechanism of immunotherapy

Hematopoietic stem cell transplants (SCT) are used in the treatment of neoplastic diseases, in addition to congenital, autoimmune, and inflammatory disorders. Both autologous and allogeneic SCT are used, depending on donor availability and the type of disease being treated, resulting in different morbidity and outcomes. In both types of SCT, immune regulation via graft manipulation is being studied, although with highly different targeted outcomes. In general, autologous SCT have lower treatment-related morbidity and mortality, but a higher incidence of tumor relapse, and graft manipulation targets immune augmentation and/or the reduction of immune tolerance. In contrast, allogeneic SCT have a higher incidence of treatment-related morbidity and mortality and a significantly longer time of disease progression, and the targeted outcomes or graft manipulation focus on a reduction in graft versus host disease (GVHD). One source of the increased relapse rate and shorter overall survival (OS) following high dose chemotherapy (HDT) and autologous SCT is the immune tolerance that limits host response, both innate and antigen (Ag) specific, against the tumor. The immune tolerance that is observed is due in part to the tumor burden and prior cytotoxic therapy. Therefore, graft manipulation, as an adjuvant therapeutic approach in autologous SCT, is primarily focused on non-specific or specific immune augmentation using cytokines and vaccines. Recently, manipulation of the infused product as a form of cellular therapy has begun to also focus on approaches to reduce immune tolerance found in transplant patients, both prior to and following HDT and SCT. To this end, graft manipulation to reduce the presence of Fas Ligand (FasL)-expressing cells or interleukin (IL)10 and tumor growth factor (TGF)beta production has been proposed. In contrast to autologous transplantation, graft manipulation during allogeneic transplantation is used extensively. This includes limiting the infusion of T cells within the product or as a donor leukocyte infusion (DLI), resulting in a reduction in GVHD and the induction of long-term survivors. Indeed, allogeneic SCT provide the only curative therapy for patients with chronic myelogenous leukemia (CML), refractory acute leukemia, and myelodysplasia. The curative potential of allogeneic SCT is reduced, however, by the development of GVHD, a potentially lethal T-cell-mediated immune response targeting host tissues [Int. Arch. Allergy Immunol. 102 (1993) 309, J. Exp. Med. 183 (1996) 589]. The morbidity and mortality associated with GVHD limit this technology, resulting focus on those patients who have no alternative therapeutic options or who have advanced disease. Thus, allogeneic SCT provide one of the few statistically supported demonstrations of therapeutic efficacy by T cells (comparison of allogeneic to autologous transplantation). In contrast to autologous transplantation, control of GVHD following allogeneic SCT focuses on immune suppression and the induction of tolerance. Here too, graft manipulation is appropriate, and there are numerous studies of T-cell depletion to reduce GVHD, with or without the isolation and infusion of T cells as DLI. Additional strategies are examining the isolation and infusion of T cells with graft versus leukemia (GVL) activity to reduce GVHD and/or the infusion of genetically manipulated and/or selected cellular populations (monocytes or dendritic cells (DC)) to induce tolerance. Therefore, depending upon the type of transplant, the goals associated with graft manipulation can be radically different. In this review, we emphasize using graft manipulation to regulate immune tolerance and anergy in association with SCT. Although this paper focuses on hematopoietic SCT, it should be noted that these strategies are relevant to conditions other than neoplastic and congenital diseases, including solid organ transplants, and autoimmune and inflammatory diseases.

Graft-versus-host disease following allogeneic transplantation from HLA-identical sibling with antithymocyte globulin-based reduced-intensity preparative regimen

Reduced-intensity conditioning (RIC) regimens are increasingly used for allogeneic stem cell transplantation (allo-SCT). RIC has been shown to allow engraftment with minimal early transplantation-related mortality (TRM). However, in the context of RIC, predictive factors for acute and chronic graft-versus-host disease (aGVHD and cGVHD, respectively) and their effect on outcome remain unknown. In this report, we analyzed the outcome of 101 high-risk patients (70 hematologic and 31 nonhematologic malignancies) who received an HLA-identical sibling allo-SCT after RIC, including fludarabine, busulfan, and antithymocyte globulin (ATG). The cumulative incidence of grade II-IV aGVHD was 36% (95% confidence interval [CI], 27%-45%), whereas the cumulative incidence of cGVHD at 2 years was 43% (95% CI, 33%-53%). In multivariate analysis, the incidence of aGVHD was significantly associated with the ATG dose infused during conditioning (P =.0005), whereas peripheral blood as stem cell source was the only predictive factor for the development of cGVHD (P =.0007). The 1-year cumulative incidences of disease progression or relapse in patients with (n = 69) and without (n = 31) GVHD (whatever its form or grade) were 30% (95% CI, 19%-41%) and 55% (95% CI, 37%-72%), respectively (P =.02), suggesting that a potent graft-versus-tumor (GVT) effect can be achieved in high-risk patients following RIC. Moreover, the GVT effect was closely associated with GVHD without an increased risk of TRM (cumulative incidence of TRM, 18% [95% CI, 10%-25%]). Collectively, these results provide a framework for the refinement of RIC approaches designed to enhance the GVT effect with an acceptable risk of GVHD.

Stem cell mobilization

Successful blood and marrow transplant (BMT), both autologous and allogeneic, requires the infusion of a sufficient number of hematopoietic progenitor/stem cells (HPCs) capable of homing to the marrow cavity and regenerating a full array of hematopoietic cell lineages in a timely fashion. At present, the most commonly used surrogate marker for HPCs is the cell surface marker CD34, identified in the clinical laboratory by flow cytometry. Clinical studies have shown that infusion of at least 2 x 10(6) CD34(+) cells/kg recipient body weight results in reliable engraftment as measured by recovery of adequate neutrophil and platelet counts approximately 14 days after transplant. Recruitment of HPCs from the marrow into the blood is termed mobilization, or, more commonly, stem cell mobilization. In Section I, Dr. Tsvee Lapidot and colleagues review the wide range of factors influencing stem cell mobilization. Our current understanding focuses on chemokines, proteolytic enzymes, adhesion molecules, cytokines and stromal cell-stem cell interactions. On the basis of this understanding, new approaches to mobilization have been designed and are now starting to undergo clinical testing. In Section II, Dr. Michele Cottler-Fox describes factors predicting the ability to mobilize the older patient with myeloma. In addition, clinical approaches to improving collection by individualizing the timing of apheresis and adjusting the volume of blood processed to achieve a desired product are discussed. Key to this process is the daily enumeration of blood CD34(+) cells. Newer methods of enumerating and mobilizing autologous blood HPCs are discussed. In Section III, Dr. John DiPersio and colleagues provide data on clinical results of mobilizing allogeneic donors with G-CSF, GM-CSF and the combination of both as relates to the number and type of cells collected by apheresis. Newer methods of stem cell mobilization as well as the relationship of graft composition on immune reconstitution and GVHD are discussed.

Transplant-related mortality and long-term graft function are significantly influenced by cell dose in patients undergoing allogeneic marrow transplantation

We have studied the impact of cell dose on short- and long-term graft function and outcome in 905 patients undergoing an unmanipulated allogeneic bone marrow transplantation (BMT) from an HLA-identical sibling (n = 735), a one-antigen mismatched related donor (n = 35), or a matched unrelated donor (n = 135). Median number of nucleated cells infused was 3.4 x 10(8)/kg (25th percentile 2.4 x 10(8)/kg, 75th percentile 5 x 10(8)/kg). Patients were stratified according to cells infused in 3 groups: < or = 2.4 x 10(8)/kg (n = 247; low dose); >2.4 x 10(8)/kg and < or = 5 x 10(8)/kg (n = 452; intermediate dose); and >5 x 10(8)/kg (n = 206; high dose). Patients receiving high cell dose had significantly higher platelet counts on days +20, +50, +100, +180, and +365 after BMT (P <.01) and higher white blood cell counts on days +50, +100, and +180 after BMT (P <.01) as compared with other patients. The actuarial 5-year transplant-related mortality (TRM) was 41% versus 36% versus 28% (P =.01); overall survival was 45% versus 51% versus 56% (P =.0008); and disease-free survival was 41% versus 42% versus 48%, respectively, (P =.04) in patients receiving low, intermediate, or high cell dose. The cell dose effect was more pronounced in patients older than 30 years of age, with advanced disease, with chronic myeloid leukemia, and with alternative donors. In multivariate Cox analysis on TRM, cell dose was a significant predictor (P =.002; relative risk 0.6) together with donor type (P =.0001), year of transplantation (P =.0001), conditioning regimen (P =.02), and recipient age (P =.02). In conclusion, transplantation of high marrow cell dose is associated with reduced transplant mortality and improved survival and results in improved graft function both short and long term.

Transplantation with low-density autologous PBSC prepared with BDS60 for women with Stage II, III and IV breast cancer

BACKGROUND

DS60 is a novel buoyant density solution, whose density has been adjusted to enrich PBSC from subjects who have been mobilized with cytokines alone, or cytokines plus chemotherapy. This report describes the use of BDS60 to enrich autologous PBSC that were used for hematological reconstitution after myeloablative chemotherapy in women with breast cancer.

METHODS

Fifty-one consecutive patients with high-risk Stage II or III breast cancer or chemotherapy-sensitive Stage IV breast cancer were enrolled. Forty-seven completed treatment and were evaluable. After mobilization with cyclophosphamide (4.0 g/m(2) i.v. once) and filgrastim (10 microg/kg/day), the patients underwent leukapheresis and the products were enriched with BDS60 using the DACS300 Kit. Myeloablative chemotherapy, given on Day -5 through Day -2, consisted of cyclophosphamide (1.5 g/m(2)/day), thiotepa (150 mg/m(2)/day) and carboplatin (200 mg/m(2)/day).

RESULTS

Forty-one patients underwent a single leukapheresis procedure to achieve the target number of BDS60-enriched CD34+ cells for transplantation (> or = 2 x 10(6)/kg). Five of the other six patients had less than the target number of cells in the leukapheresis product and thus required 2-4 leukapheresis procedures. Median cell recovery was 76.8% for CD34+ cells, 39.1% for nucleated cells, and 17.7% for platelets. Erythrocyte contamination of the final product was negligible. The median time to sustained neutrophil count > 500/mm(3) was 9 days (range: 8-12) and the median time to platelet count > 20 000/mm(3), without transfusion support, was also 9 days (range: 6-15). There were no late graft failures. Infusion-related adverse events were mild and no adverse events were attributed to the use of BDS60 to enrich CD34+ cells.

DISCUSSION

BDS60 is an effective, rapid method for enrichment of CD34+ cells by buoyant density centrifugation and the resulting cell product is safe and effective for engraftment after myeloablative therapy.

Factors affecting long-term outcome after allogeneic haematopoietic stem cell transplantation for acute myelogenous leukaemia: a retrospective study of 172 adult patients reported to the Austrian Stem Cell Transplantation Registry

Between 1982 and 2000, 172 patients with acute myelogenous leukaemia (AML) received haematopoietic stem cell transplants (SCT) from related (n = 132) or unrelated (n = 40) donors at four Austrian transplant centres and their results were reported to the Austrian Stem Cell Transplantation Registry. Conditioning for SCT consisted of cyclophosphamide and total body irradiation in 156 (91%) patients. Graft-versus-host disease (GVHD) prophylaxis was with standard cyclosporine and methotrexate in 95 (55%) patients. Median post-transplant follow-up was 5.6 years (range, 0.2--16.7). Multivariate analysis of transplant-related mortality (TRM) identified four variables associated with a lower risk: disease status of first complete remission (CR) at SCT, patient age of 45 years and younger, transplant performed during or after 1995, and lack of acute GVHD. Variables associated with significantly improved leukaemia-free survival were: bone marrow as the stem cell source, disease status of first CR at SCT, and occurrence of chronic GVHD. In multivariate analysis, transplantation performed during or after 1995, first CR at SCT, occurrence of limited chronic GVHD and lack of acute GVHD grades III to IV were associated with increased overall survival. Based on these analyses, options for the improvement of results obtained with allogeneic SCT in patients with AML could be defined.

Allogeneic peripheral blood stem cell transplantation. Safety, hematologic recovery, kinetics, and complications

BACKGROUND

Hematopoietic stem cell transplants are an accepted treatment for several malignant and nonmalignant hematologic diseases. Recently, the peripheral blood, after mobilization of stem cells with growth factors, has become the source of choice for hematopoietic stem cells. We report on a series of patients who received peripheral blood stem cell transplants at the Instituto Nacional de Cancerologia (INCAN) in Mexico City.

METHODS

Between May 1995 and December 1999, 33 patients received peripheral blood stem cell transplants to treat hematologic diseases. Sixty percent of our patients had chronic myelocytic leukemia (CML). All had a matched related donor. Patients were conditioned with one of five different conditioning regimens and subsequently received one of two different graft-vs.-host disease prophylaxis regimens. Stratified Wilcoxon rank-sum, chi square, and Mann-Whitney tests were used to analyze the results.

RESULTS

In our series, median time to achieve a total neutrophil count of 0.5 x 10(9)/L was 14 days and to achieve a platelet count of 20 x 10(9)/L, 15 days. Acute graft-vs.-host disease occurred in seven patients. Chronic graft-vs.-host disease occurred in 69% of surviving patients. Survival for low-risk patients was 67% and for the high-risk group, 9%.

CONCLUSIONS

Peripheral blood stem cells produce a faster hematopoietic recovery. The rate of acute graft-vs.-host disease is not increased using the peripheral blood as source of stem cells; however, chronic graft-vs.-host disease continues to be a significant problem. Donors tolerated the procurement procedure without complications.

Donation of stem cells from blood or bone marrow: results of a randomised study of safety and complaints

Biological consequences and physical complaints were compared for donors randomly assigned either to blood stem cell (BSC) or bone marrow (BM) donation. In the period 1994-1999, 61 consecutive donors were included. The BSC donors were given G-CSF 10 microg/kg s.c., daily during 5 days before the first leukapheresis. Nineteen donors had one leukapheresis, 10 required two and one donor needed three leukaphereses in order to reach the target cell number of 2 x 10(6) CD34(+) cells/kg bw of the recipient. A median platelet nadir of 102 x 10(9)/l was reached shortly after the last leukapheresis. Three weeks post harvest, 17 of 30 BSC donors had a mild leukopenia. Six had a leukopenia lasting more than a year before returning to normal values. Both groups were monitored prospectively through a standardised questionnaire completed by the donors. BSC donation was significantly less burdensome than BM donation and was preferred by the donors. The short-term risks of BSC mobilisation and harvest seem negligible. The potential long-term effects of G-CSF are unresolved and the donors must be followed closely.

Low incidence of transplantation-related acute complications in patients with chronic myeloid leukemia undergoing allogeneic stem cell transplantation with a low-dose (550 cGy) total body irradiation conditioning regimen

Although allogeneic transplantation is a curative therapy for chronic myeloid leukemia (CML), treatment-related mortality is still a major cause of posttransplantation mortality, especially for patients older than 40 years. We investigated, in a phase II trial, the role of a low-dose (550 cGy) high-dose rate (35 cGy/min) single-exposure total body irradiation (TBI) conditioning regimen for allogeneic peripheral blood stem cell (PBSC) transplantation in patients with CML. Between June 1997 and August 2000, 30 adult patients with CML underwent cytokine-mobilized allogeneic PBSC transplantation from HLA-matched siblings following administration of cyclophosphamide (60 mg/kg per day intravenously on days -2 and -1) and single-dose TBI (550 cGy delivered at 30 cGy/min on day 0). Cyclosporine A alone was administered for prophylaxis against graft-versus-host disease (GVHD). Median patient age was 47 years (range, 21-63 years), with 23 patients (77%) older than 40 years. The preparative regimen was well tolerated. Grade 4 toxicities and oral mucositis were not observed. Graft failure did not occur. Severe acute GVHD was observed in 5 patients (17%). The median follow-up was 23 months (range, 6-39 months). Cytogenetic or hematologic relapse was detected in 3 patients (10%), 2 of whom subsequently entered remission following a taper of immunosuppression. Nonrelapse mortality occurred in 5 patients (17%), and the Kaplan-Meier estimate of survival at 2 years was 83% (95% confidence interval, 70%-97%). In summary, this low-dose TBI-based preparative regimen resulted in uniform donor engraftment, with markedly reduced organ toxicity and nonrelapse mortality, in this relatively older cohort of patients with CML.

Optimizing engraftment--source and dose of stem cells

In recent years, the use of antibodies to measure CD34(+) cells and the availability of peripheral blood (PB) and umbilical cord blood (CB) as additional stem cell sources other than bone marrow (BM) has increased interest in determining the impact of stem cell source and dose on the outcome of allogeneic stem cell transplantation. In addition to differences in their stem cell content, transplants from the three sources differ in the composition and state of activation of immune cells. As a consequence, BM, CB, and PB transplants have different kinetics of hematological recovery, the most rapid engraftment being observed with PB and the slowest with CB. Stem cell source also incurs different risks for developing graft-versus-host disease (GVHD): PB transplants show a possible increase in acute and a definite increase in chronic GVHD compared with BM. CB transplants have a favorably low risk of GVHD even in mismatched transplants. Stem cell dose in an independent factor in transplants from any source, determining engraftment, transplant-related mortality and risk of leukemic relapse. These findings are of clinical importance-an understanding of the impact of stem cell source and dose is essential to obtain optimum conditions for a successful outcome after transplant.

Allogeneic transplantation using peripheral blood stem cells

Over the past 9 years there has been a remarkable increase in the use of peripheral blood stem cells (PBSC) for allogeneic transplantation, primarily for matched sibling transplants but also increasingly for unrelated donor transplantation. In 1999 over 50% of all sibling transplants and over 25% of unrelated donor transplants reported to the European Group for Blood and Marrow Transplantation (EBMT) used PBSC. The major reason for this increasing use of PBSC relates to the rapid haemopoietic recovery seen which mirrors the advantages of using PBSC in autologous transplantation. This improvement in engraftment is a consequence of the larger number of stem cells that can be collected from G-CSF-mobilized peripheral blood compared to bone marrow. Evidence from randomized trials now shows a survival advantage for the use of PBSC in patients with advanced leukaemia. The reason for this improved survival appears primarily to relate to a reduced risk of transplant-related mortality and, possibly, a reduced risk of relapse, However, these randomized studies have also confirmed that there is an increased risk of chronic graft-versus-host disease associated with PBSC transplantation and further follow-up is required to determine the long-term impact on outcome.

Transplant dose of CD34(+) and CD3(+) cells predicts outcome in patients with haematological malignancies undergoing T cell-depleted peripheral blood stem cell transplants with delayed donor lymphocyte add-back

We sought to optimize and standardize stem cell and lymphocyte doses of T cell-depleted peripheral blood stem cell transplants (T-PBSCT), using delayed add-back of donor T cells (DLI) to prevent relapse and enhance donor immune recovery. Fifty-one patients with haematological malignancies received a T-PBSCT from an HLA-identical sibling, followed by DLI of 1 x 10(7) and 5 x 10(7) CD3(+) cells/kg on d +45 and +100 respectively. Twenty-four patients were designated as standard risk and twenty-seven patients with more advanced leukaemia were designated as high risk. Median recipient age was 38 years (range 10-56). Median (range) of CD34(+) and CD3(+) cell transplant doses were 4.6 (2.3-10.9) x 10(6)/kg and 0.83 (0.38-2) x 10(5)/kg respectively. The cumulative probability of acute GVHD was 39%. No patient died from GVHD or its consequences. The probability of developing chronic GVHD was 54% (18% extensive). The probability of relapse was 12% for the standard-risk patients and 66% for high-risk patients. In multivariate analysis, the risk factors for lower disease-free survival and overall survival were high-risk disease, CD34(+) dose < 4.6 x 10(6)/kg and CD3(+) dose < 0.83 x 10(5)/kg. Predictive factors for chronic GVHD were a T-cell dose at transplant > 0.83 x 10(5) CD3(+) cells/kg. These results further define the impact of CD34 and CD3 cell dose on transplant outcome and show that careful dosing of stem cells and lymphocytes may permit the control and optimization of transplant outcome.

Chronic graft-versus-host disease after allogeneic blood stem cell transplantation

The incidence, characteristics, risk factors for, and impact of chronic graft-vs-host disease (GVHD) were evaluated in a consecutive series of 116 evaluable HLA-identical blood stem cell transplant recipients. Minimum follow-up was 18 months. Limited chronic GVHD occurred in 6% (95% confidence interval [CI], 0%-13%), and clinical extensive chronic GVHD in 71% (95% CI, 61%-80%). The cumulative incidence was 57% (95% CI, 48%-66%). In univariate analyses, GVHD prophylaxis other than tacrolimus and methotrexate, prior grades 2 to 4 acute GVHD, use of corticosteroids on day 100, and total nucleated cell dose were significant risk factors for clinical extensive chronic GVHD. On multivariate analysis, GVHD prophylaxis with tacrolimus and methotrexate was associated with a reduced risk of chronic GVHD (hazard ratio [HR], 0.35; P =.001), whereas the risk was increased with prior acute GVHD (HR, 1.67; P =.046). When adjusted for disease status at the time of transplantation, high-risk chronic GVHD had an adverse impact on overall mortality (HR, 6.6; P <.001) and treatment failure (HR, 5.2; P <.001) at 18 months. It was concluded that there is a substantial rate of chronic GVHD after HLA-identical allogeneic blood stem cell transplantation, that clinical factors may alter the risk of chronic GVHD, and that high-risk chronic GVHD adversely affects outcome.

Allogeneic peripheral blood stem cell transplantation (PBSCT) from HLA-identical sibling donors in children with hematological diseases: a single center pilot study

Between February 1995 and July 1999 25 pediatric patients (8 months to 14 years old) underwent peripheral blood stem cell transplantation (PBSCT) from an HLA-identical sibling donor. Diagnoses included ALL (17), non-ALL (6), and non-malignant disease (2). GVHD prophylaxis consisted of cyclosporine plus methotrexate (15), only cyclosporine (8), cyclosporine plus prednisone (1), or nothing (1). All donors (6 months to 41 years old) received G-CSF at 10 microg/kg/day subcutaneously for 4-5 days and on day 5 underwent large volume leukapheresis. Median number of CD34(+) and CD3(+) cells collected and infused was 6.9 x 10(6) (range 2.5-32.8) and 4.5 x 10(8) (0.5-22.1) per kg of recipient body weight respectively. Median time to achieve ANC >0.5 x 10(9)/l and platelets >20 x 10(9)/l was 10 and 12 days, respectively. Acute GVHD grade > or =II developed in 10 of 24 evaluable patients (42%). Probability of acute GVHD was 62%. Median time to discharge was 25 days (range 14-52). Among 20 evaluable patients, five (25%) developed chronic GVHD at day 100. Probability of chronic GVHD was 29% after 1 year post PBSC. At a median follow-up of 558 (9-2071) days, overall survival for the whole group is 68%. Probabilities of event-free survival, overall survival and relapse for patients with malignant hematological diseases are 53%, 59% and 24% at 5 years, respectively. This study has confirmed the feasibility and safety of mobilization and collection of PBSC products and the applicability of this procedure to the pediatric population, both donors and recipients. Studies including larger numbers of pediatric patients undergoing allogeneic PBSCT are warranted to determine the long-term outcomes of such procedures.

Acute and chronic graft-versus-host disease after allogeneic peripheral-blood stem-cell and bone marrow transplantation: a meta-analysis

PURPOSE

Controversy exists as to whether the incidence of graft-versus-host disease (GVHD) is increased after peripheral-blood stem-cell transplantation (PBSCT) when compared with bone marrow transplantation (BMT). We performed a meta-analysis of all trials comparing the incidence of acute and chronic GVHD after PBSCT and BMT reported as of June, 2000. Secondary analyses examined relapse rates after the two procedures.

METHODS

An extensive MEDLINE search of the literature was undertaken. Primary authors were contacted for clarification and completion of missing information. A review of cited references was also undertaken. Sixteen studies (five randomized controlled trials and 11 cohort studies) were included in this analysis. Data was extracted by two pairs of reviewers and analyzed for the outcomes of interest. Meta-analyses, regression analyses, and assessments of publication bias were performed.

RESULTS

Using a random effects model, the pooled relative risk (RR) for acute GVHD after PBSCT was 1.16 (95% confidence interval [CI], 1.04 to 1.28; P=.006) when compared with traditional BMT. The pooled RR for chronic GVHD after PBSCT was 1.53 (95% CI, 1.25 to 1.88; P <.001) when compared with BMT. The RR of developing clinically extensive chronic GVHD was 1.66 (95% CI, 1.35 to 2.05; P <.001). The excess risk of chronic GVHD was explained by differences in the T-cell dose delivered with the graft in a meta-regression model that did not reach statistical significance. There was a trend towards a decrease in the rate of relapse after PBSCT (RR = 0.81; 95% CI, 0.62 to 1.05).

CONCLUSION

Both acute and chronic GVHD are more common after PBSCT than BMT, and this may be associated with lower rates of malignant relapse. The magnitude of the transfused T-cell load may explain the differences in chronic GVHD risk.

Allogeneic haemopoietic cell transplants in Australia, 1996--a multi-centre retrospective comparison of the use of peripheral blood stem cells with bone marrow

A retrospective comparison was carried out on adult patients receiving HLA-identical allogeneic haemopoietic stem cell transplants from siblings in Australia in 1996, comparing bone marrow with G-CSF-mobilised peripheral blood stem cells. A total of 131 transplant recipients from nine centres were included in this study, of whom 79 received bone marrow, 44 blood stem cells and eight both. All but three of the 131 patients had cyclosporin and methotrexate as graft-versus-host disease prophylaxis. The minimum follow-up time for surviving patients is 27 months. Comparisons were carried out between the BM and PBSC groups. There were no significant differences between groups in age, sex, diagnosis, donor characteristics or pretransplant conditioning. Median time to neutrophil recovery of 0.5 x 10(9)/l was 14 days for PBSC recipients, compared to 19 days for marrow recipients (P < 0.0005). median time to platelet recovery of 20 x 10(9)/l was 17 days for PBSC recipients, compared to 28 days for marrow recipients (P < 0.0005). there were no significantly increased risks of either acute or chronic GVHD in the PBSC recipients. there were no significant differences between the groups in the incidence of major transplant-related complications, disease-free survival or overall survival.

Gastrointestinal infections in the immunocompromised host

Gastrointestinal disease is a significant cause of morbidity and mortality in the immunocompromised patient. This article focuses on the infectious gastrointestinal complications associated with the treatment of malignant disease and with solid organ transplantation but not HIV. Gastrointestinal defenses and the various mechanisms by which they are impaired are reviewed. The major pathogens and malignancies of this patient population and an approach to their diagnosis, treatment, and prevention are discussed.

A proposed objective way to assess results of randomized prospective clinical trials with acute graft-versus-host disease as an outcome of interest

The assessment of graft-versus-host disease (GVHD) as an end-point in clinical trials requires subjective judgement to distinguish morbidity caused by GVHD from morbidity caused by other complications. We developed a method based on ordinal regression for longitudinal assessment of morbidity involving the skin, liver and gut, regardless of cause as an objective end-point in randomized prospective phase III treatment or prevention trials for which GVHD is an outcome of interest. This method was validated for treatment studies by showing that morbidity was more severe among patients with grade II-IV GVHD than among those who did not have GVHD. We found no differences in morbidity involving the skin, liver and gut after the diagnosis of GVHD in a group of 30 patients who received peripheral blood stem cells and a group of 37 who received marrow in a randomized phase III clinical trial. These preliminary results suggest that objective end-points could be used in randomized clinical trials for treatment of GVHD. Further studies will be needed to determine if similar methods could be used in randomized clinical trials for prevention of GVHD.