Jhf Falkenburg

Hematopoietic SCT in Europe: data and trends in 2011

In all, 651 from 680 centers in 48 countries reported 35u2009660 hematopoietic SCT (HSCT) in 32u2009075 patients (13u2009470 allogeneic (42%), 18u2009605 autologous (58%)) to the 2011 survey. Main indications were: leukemias; 10u2009113 (32%; 94% allogeneic); lymphoid neoplasias; non-Hodgkin’s lymphoma, Hodgkin’s lymphoma, plasma cell disorders; 18u2009433 (57%; 12% allogeneic); solid tumours; 1573 (5%; 5% allogeneic); and non-malignant disorders; 1830 (6%; 92% allogeneic). There were more unrelated donors than HLA identical sibling donors (54% versus 39%); proportion of peripheral blood as stem cell source was 99% for autologous and 73% for allogeneic HSCT. Cord blood was only used in allogeneic transplants (6% of total). In the past 10 years, the overall number of transplants has increased by 53%. Allogeneic HSCT have doubled (from 7272 to 14u2009549) while, autologous have increased by 32% and continue to increase by about 1100 HSCT per year since 2001. In the past 2 years, an increase of >2000 HSCT per year was seen. Transplant activity is shown by team size. For allogeneic HSCT, we show use of reduced-intensity conditioning versus myeloablative conditioning across Europe and use of post-transplant donor lymphocyte infusions with considerable variation across different countries.

Long-term follow-up of myeloablative allogeneic stem cell transplantation using Campath ‘in the bag’ as T-cell depletion: the Leiden experience

Graft-versus-host disease (GVHD) is a major cause of mortality and morbidity after allogeneic stem cell transplantation (alloSCT) but can be prevented by removing T-lymphocytes from the graft. Campath (anti-CD52) antibodies have been widely used in vivo for T-cell depletion following conventional and reduced intensity conditioning regimens. The use of Campath in vivo was associated with a significant reduction in GVHD but at the cost of impaired immune reconstitution. We evaluated the long-term outcome of 73 myeloablative allogeneic stem cell transplants with HLA-identical sibling donors using Campath ‘in the bag’ as method of in vitro T-cell depletion. All patients engrafted and hematopoietic recovery was uneventful, resulting in a median of 99% donor chimerism at 3 months after alloSCT. Cytomegalovirus (CMV) reactivation occurred in 53% of the patients. No CMV disease was observed probably as a result of pre-emptive (val)ganciclovir treatment. The incidence of aGVHD was low (22% grade II). No grades III–IV aGVHD was observed and extensive chronic GVHD (cGVHD) occurred in 19% of the patients. The low incidence of GVHD and successful pre-emptive antiviral therapy resulted in low TRM of 8%. Sixteen patients died due to disease relapse after alloSCT, resulting in an overall survival of 48% at 5-years after alloSCT.

Generation of leukemia-reactive cytotoxic T lymphocytes from HLA-identical donors of patients with chronic myeloid leukemia using modifications of a limiting dilution assay

Donor leukocyte transfusions (DLT) have an anti-leukemic effect in most patients with a relapse of chronic myeloid leukemia (CML) after allogeneic stem cell transplantation. However, DLT are often complicated by graft-versus-host disease. Selection of donor lymphocytes with a relative specificity for leukemic cells is desirable. The generation of leukemia-reactive cytotoxic T lymphocyte (CTL) responses between HLA-identical donors and patients in bulk cultures showed major variations, and false negative results were observed. In a modification of a limiting dilution analysis (LDA) two-fold serial dilutions of HLA-identical donor mononuclear cells (MNC) were cultured in the presence of CML cells. The anti-leukemic CTL precursor frequencies in these donors varied between <1 and 9 per 106 MNC. HLA-restricted CD4+ or CD8+ lymphocytes as well as MHC non-restricted γδ T cells were responsible for the anti-leukemic responses. A positive correlation between cytotoxicity in the various wells after 3, 4 and 5 weeks of culture could be found. The LDA may be superior to bulk cultures in selecting stable immune responses and in separating multiple different anti- leukemic T cell responses in each donor–patient combination.

Comparison of allogeneic T cell-depleted peripheral blood stem cell and bone marrow transplantation: effect of stem cell source on short- and long-term outcome.

We report the results of a retrospective single-center study comparing engraftment, acute and chronic GVHD, relapse and survival in patients with malignant hematological disorders transplanted with allogeneic peripheral blood stem cells (alloPBSCT, n = 40) or bone marrow cells (alloBMT, n = 42). All transplants were T cell depleted by in vitro incubation with the Campath-1 monoclonal antibody. Primary graft failure occurred in none of the patients receiving an alloPBSCT compared with 3/42 of the recipients of an alloBMT. In addition, two patients in the alloBMT group showed no platelet engraftment. Recipients of PBSC had a more rapid recovery of neutrophils (median 14 days) compared to BM transplant recipients (median 32 days). Platelet recovery was also accelerated in PBSC recipients compared to BM recipients (11 vs 38 days). There was an increase in the incidence of grade II acute GVHD and chronic GVHD in patients after alloPBSCT (18% and 23%, respectively) compared to patients receiving alloBMT (5% and 8%, respectively). The 2-year cumulative incidence of relapse was similar in both groups (47%). At 6 months after transplantation, transplant-related mortality (TRM) was lower in PBSCT recipients than in BMT recipients. However, at a follow-up of 3 years TRM was similar in both groups. The disease-free survival rate at 3 years after transplantation did not differ between the groups (42% for PBSCT and 41% for BMT recipients). Our results indicate that T cell-depleted alloPBSCT compared to alloBMT is associated with a more rapid hematopoietic reconstitution and a decreased TRM at 6 months follow-up after transplantation. However, at a follow-up of 3 years, no sustained survival benefits were observed. Bone Marrow Transplantation (2001) 27, 1053–1058.

Similar myeloid recovery despite superior overall engraftment in NOD/SCID mice after transplantation of human CD34 + cells from umbilical cord blood as compared to adult sources

Umbilical cord blood (UCB), bone marrow (BM) and mobilized peripheral blood (mPB) are used as sources of hematopoietic stem cells for transplantation. The NOD/SCID mouse model was used to compare the lineage-specific repopulating potential of CD34+ cells derived from these sources. Six to 8 weeks after transplantation, blood, BM, spleen, liver and thymus, were harvested, and analyzed by flow cytometry using CD34, CD45, myeloid, and lymphoid lineage-specific antibodies. Fifty percent engraftment of human cells in bone marrow of mice was estimated to be reached with 0.55 × 106 CD34+ UCB cells or with 7.9 × 106 CD34+ cells from adult sources, illustrating a 10-fold superiority of UCB CD34+ cells to engraft NOD/SCID mice. Lineage-specific characterization of engrafted human cells showed that the high engraftment potential of CD34+ cells from UCB was due to a preferential B cell development (2–81%). In contrast, comparable percentages of myeloid cells were found following transplantation of CD34+ cells from UCB, BM and mPB (1–38%), and occurred at significant levels only at relatively high doses. Since the CD34 content of UCB transplants is usually at least one log lower than of transplant from adult sources, these results correspond to the clinical findings with UCB transplantation showing a relatively high overall engraftment, but delayed myeloid recovery. Bone Marrow Transplantation (2001) 28, 163–171.

The role of cytokines and hematopoietic growth factors in the autocrine/paracrine regulation of inducible hematopoiesis.

Abstractu2002To elucidate the role of hematopoietic growth factors (HGFs) and other cytokines in the autocrine or paracrine regulation of inducible hematopoiesis we studied cytokine gene expression in the bone marrow (BM) of patients after myelosuppressive treatment. Furthermore, we studied the cytokine gene expression profile in healthy individuals before and after bone marrow harvesting for the purpose of bone marrow transplantation. We speculated that the bone marrow harvesting procedure might induce changes in cytokine gene expression. No induction of G-CSF, GM-CSF, IL-1α, IL-3, IL-5, IL-8, IL-9, and IL-12 was observed in the BM of patients following intensive chemotherapy. Also, no up-regulation of expression of M-CSF, IL-1β, IL-4, IL-6, TNF-α, TGF-β, IGF-1, EDF, and EPA gene was found, illustrating that the investigated cytokines probably are not relevant in the presumed autocrine/paracrine regulation of the recovery of hematopoiesis following depletion of hematopoietic progenitor cells (HPCs). Concomitantly, elevated G-CSF plasma levels were found in these patients, suggesting that G-CSF has an endocrine regulatory role in inducible hematopoiesis. Induction of GM-CSF and IL-8, but not of G-CSF or IL-3 gene expression and up-regulation of IL-1β and IL-6 gene following BM harvesting was observed. This induction of GM-CSF and IL-8 may be attributed to tissue damage rather than to HPC depletion.

Biology and treatment of myelodysplastic syndromes : developments in the past decade

ConclusionsDuring the past 10 years, MDS has become a topic of considerable interest due to the development of new cytogenetic and molecular techniques and the introduction of the clinical administration of hematopoietic growth factors. The cytological and clinical classifications of the diseases comprising the syndrome are based on two main subtypes, those with a low risk of acquiring acute leukemia and those with a high risk. Which one will prove to be the simplest and most reliable classification system for the individual patient is not yet clear.Studies on clonality have shown that the myeloid cells in most of the patients studied thus far are monoclonal in nature. These methods can be used to evaluate the effect of treatment regimens.The kinetics of the in vitro growth of hematopoietic precursor cells from MDS patients is abnormal, with suboptimal colony formation. Cultures grown in the presence of certain growth factors show preferential growth of normal hematopoietic cells, which may be of clinical relevance in the future.Administration to MDS patients of hematopoietic growth factors such as GM-CSF, G-CSF, and IL-3 improves neutrophil counts in the majority of cases. The effect of erythropoietin is disappointing in most cases. At present, polyclonal hematopoiesis is rarely induced by growth factor treatment alone. More recently identified growth factors, such as MGF, might preferentially affect normal hematopoiesis at the expense of the preleukemic clones, thus changing the natural course of the disease.

High-dose Ara-C for remission induction and consolidation of previously untreated adults with ALL or lymphoblastic lymphoma

Thirty-two patients with untreated ALL (n=26) or lymphoblastic lymphoma (n=6) between 17 and 65 years of age were treated with a short remission induction course with VP16-213, amsacrine, intermediate dose Ara-C for 6 days, prednisone and intrathecal methotrexate, followed by a consolidation course with vincristine, amsacrine, high dose Ara-C for 4 days, prednisone and intrathecal methotrexate. After subsequent cranial irradiation, no further maintenance was planned. However, some patients underwent an allogeneic (n=5) or autologous (n=5) bone marrow transplantation after the consolidation treatment.Twenty-three of 32 patients (72%) achieved a complete remission. Ten of 13 patients with T-ALL or lymphoma, six of eight patients with pre-B or common ALL, and seven of 11 patients with B-ALL or Burkitts lymphoma achieved a complete remission. The median duration of remission was 24 months. Overall survival for the whole group was 35% at 5 years. The diseasefree survival was 45% at 5 years. Long-term survival for patients with B or T-ALL was approximately 60%, compared with 15% for those with common or pre BALL.Short term intensive courses including intermediate or high dose Ara-C during remission and consolidation treatment lead to results comparable to those obtained with long-term maintenance regimens. Our regimen may be sufficient for patients with T or B-ALL. Larger randomized studies are needed to investigate the relative importance of our observations.

T-Cell Dysfunction in Hairy Cell Leukemia: An Updated Review

Hairy cell leukemia (HCL) is clinically associated with severe T-cell dysfunction. Several new observations have given more insight into the abnormal T-cell responses seen in this disease. T-lymphocytes in the spleen of patients with HCL seem to be abnormally activated. On the other hand, they are non-responsive, possibly as a result of monocytopenia which may lead to inadequate antigen presentation. This, together with the lack of CD28 on T-cells, may cause T-cell dysfunction. Furthermore, there is a very restricted repertoire of the T-cell receptor-beta family, which may also result in non-responsiveness. Otherwise, T-cell clonal excess may be indicative for activated, possibly autoreactive T-cells.

Recruitment of leukemic cells from G0 phase of the cell cycle by interferons results in conversion of resistance to daunorubicin

Recruitment of leukemic cells from G 0 phase of the cell cycle by interferons results in conversion of resistance to daunorubicin