Hematopoietic progenitor cell count, but not immature platelet fraction value, predicts successful harvest of autologous peripheral blood stem cells.

Mobilized stem cells in the peripheral blood (PB) must be efficiently harvested at the appropriate time before autologous PB stem cell (PBSC) transplantation. Enumeration of CD34+ cells in the PB before apheresis predicts the number of PBSCs that can be collected, but the cytometric techniques used are complex and expensive. Therefore, it is necessary to identify an alternative to the CD34+ cell count in PBSC harvest-time monitoring. Fully automated flow cytometry using blood cell counters now allows reliable quantification of immature myeloid cells in the PB, referred to as hematopoietic progenitor cells (HPC), and reticulated platelets, expressed as the immature platelet fraction (IPF). Immature or reticulated platelets are thought to correlate with thrombopoietic activity of the marrow. Following a chemotherapy nadir, the recovery of white blood cell and platelet counts has been used to determine the right time for apheresis. Therefore, we examined whether the HPC count and IPF value could be used to predict PBSC mobilization in 20 patients with hematological malignancies. The HPC count was found to be correlated with the CD34+ cell count (r = 0.84, P < 0.01), whereas the IPF value was not (r = 0.37, P = 0.44). Therefore, the HPC count, but not the IPF value, is a possible predictor of the timing of autologous stem cell transplantation.

Gemtuzumab ozogamicin therapy for isolated extramedullary AML relapse after allogeneic hematopoietic stem-cell transplantation.

The treatment of isolated extramedullary relapse (IEMR) after allogeneic hematopoietic stem-cell transplantation (allo-HSCT) poses a challenge for which no standard approach exists. Gemtuzumab ozogamicin (GO) is a recombinant humanized monoclonal antibody, conjugated to calicheamicin, which targets the CD33 antigen that is expressed in acute myelogenous leukemia (AML) blasts. The selectivity of GO for CD33-positive leukemic cells makes it an attractive agent for use in patients with multiple sites of IEMR after allo-HSCT, because GO does not suppress cells responsible for the putative graft-versus-leukemia (GVL) effect. Herein, we describe a 54-year-old male patient who developed AML with multiple sites of extramedullary (EM) relapse after allo-HSCT, and who exhibited apparent donor-derived hematopoiesis in the bone marrow. At approximately 120 days after allo-HSCT, the patient complained of severe lumbago. T2-weighted magnetic resonance images and fluorodeoxyglucose-positron emission tomography showed multiple mass lesions in soft tissue and bone. A biopsy specimen from a lumbar soft tissue mass confirmed EM relapse, and revealed that donor T lymphocytes were present in the relapse site and that leukemic cells expressed CD33. Therefore, to maintain the GVL effect of donor T lymphocytes, the patient was treated with GO as a single agent. He achieved complete hematological remission, and has remained in remission, with only mild liver injury, for more than 10 months since GO treatment. GO can be an effective therapy for IEMR after allo-HSCT, especially when cytotoxic T lymphocytes react to leukemic cells at the site of EM relapse.

Alteration of adipokines during peripheral blood stem cell mobilization induced by granulocyte colony-stimulating factor.

Adipokines, soluble mediators produced by adipocytes, have been shown to play a role in various physiological and pathological conditions. We investigated the involvement of adipokines in granulocyte colony-stimulating factor (G-CSF)-induced mobilization of hematopoietic stem cells in 21 healthy donors. We found that serum visfatin and resistin levels, but not leptin and adiponectin levels, were significantly elevated by G-CSF treatment. G-CSF treatment activated signaling proteins like extracellular signal-regulated kinase and stimulated secretion of visfatin from 3T3-L1 adipocytes. These findings suggest that some adipokines may play a role in G-CSF-induced mobilization of stem cells from the bone marrow into systemic circulation.

Analysis on heat stress-induced hyperphosphorylation of stathmin at serine 37 in Jurkat cells by means of two-dimensional gel electrophoresis and tandem mass spectrometry.

Two-dimensional gel electrophoresis (2-DE) and tandem mass spectrometry were successfully used for determination of a phosphorylation site of stathmin induced by heat stress to Jurkat cells of a human T lymphoblastic cell line. The cells were incubated for 30 min at 41 degrees C up to 45 degrees C in a serum free 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) buffered culture medium. The intracellular soluble proteins were separated by 2-DE, and some of the proteins increased their abundance by heat stress. Those proteins were identified to be calmodulin, protein kinase C substrate, thymosin beta-4 and F-actin capping protein beta-subunit by peptide mass fingerprinting (PMF) with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). On the contrary, protein phosphatase 2C gamma-isoform, nucleophosmin, translationally controlled tumor protein, Rho GDP-dissociation inhibitor-1, eukaryotic translation initiation factors 5A and 3A subunit 2, ubiquitin-like protein SMT 3B and chloride intracellular channel protein-1 were decreased their abundance. A protein spot of M(r) 18,000 and pI 5.9 was markedly increased at temperatures higher than 43 degrees C at which the cells were led to apoptosis. The spot was identified to be stathmin of a signal relay protein which has a function of sequestering microtubule. MALDI-quadrupole ion trap (QIT)-TOF-MS/MS and immunoblotting with a monoclonal antibody specific for a phosphorylation site of stathmin showed that the spot was a phosphorylated stathmin at serine 37 (Ser 37). The phosphorylation was suppressed by treatment of cells with olomoucine of an inhibitor specific for cyclin dependent kinase (Cdk-1). These results strongly suggest that heat stress activates Cdk-1 which phosphorylates Ser 37 on the stathmin molecule. The phosphorylation may cause the functional loss of stathmin for dynamic microtubule assembly and leads Jurkat cells to cell cycle arrest and apoptosis.

A breast cancer patient with myelodysplastic syndrome postoperatively treated by radiation and tamoxifen administration--a case report.

A 72-year-old female developed pancytopenia 4 years after breast cancer surgery. She had received regional radiation postoperatively, and tamoxifen for 4 years. Bone marrow examination demonstrated immature myeloblasts and dysplastic cells. Myelodysplastic syndrome (MDS) of refractory anemia with excess blasts (RAEB) was diagnosed, and the patient died of cerebral hemorrhage 4 months after the diagnosis of RAEB. Radiation and the administration of tamoxifen were suspected to have played a role in the development of secondary MDS.

[Hairy cell leukemia, Japanese variant, successfully treated with cladribine].

A 67-year-old male was admitted because of lymphocytosis and huge splenomegaly. Abnormal lymphocytes had cytoplasmic hairy projections and were negative for tartrate-resistant acid phosphatase staining. The bone marrow aspirate contained many lymphocytes with the same morphology. Flow cytometric analysis revealed an increase in IgM and kappa positive B cells. They were positive for CD11c, CD19, CD20 and FMC7, and negative for CD5, CD10 and CD25. The patient was diagnosed as having hairy cell leukemia, Japanese variant. Initially interferon-alpha was administered for a month, decreasing the numbers of leukemic cells but with little effect on splenomegaly. Subsequent administration of cladribine (0.09 mg/kg, 7 days) showed a remarkable effect, and the patient has been in complete remission for 8 months.

Idiopathic pneumonia syndrome with thrombotic microangiopathy-related changes after allogeneic hematopoietic stem cell transplantation.

Idiopathic pneumonia syndrome (IPS), defined as widespread alveolar injury, is a severe complication of hematopoietic stem cell transplantation (HSCT) and a clinical syndrome with variable histopathologic correlates and multiple etiologies. Transplantation-associated thrombotic microangiopathy (TMA) is another severe complication of HSCT. TMA occurs when endothelial injury causes thrombosis and fibrin deposition in the organ microcirculation. We present a case of IPS with TMA-related changes in the lungs following HSCT. A 54-year-old woman underwent an allogeneic HSCT for refractory multiple myeloma. During transplantation, cyclosporine was administered for prophylaxis against graft-versus-host disease, but she developed respiratory failure after she was weaned off the drug. A computed tomography scan revealed ground-glass attenuation and reticular opacity in the bilateral whole-lung fields. Bronchoscopy indicated no evidence of infection, and IPS was diagnosed. High-dose steroids and etanercept were ineffective, and she died 1 month after the onset of IPS. Autopsy revealed diffuse alveolar damage, and stenosis or obstruction due to intimal thickening and thrombi resulting from endothelial injury in the arterioles of both lungs. We retrospectively diagnosed TMA based on the histological and clinical findings. To our knowledge, this is the first report suggesting the possible role of TMA in the clinical course of IPS.

Recurrent extramedullary relapse of acute myelogenous leukemia after allogeneic hematopoietic stem cell transplantation in a patient with the chromosomal abnormality t(8;21) and CD56-positivity.

Isolated extramedullary (EM) relapse of acute myelogenous leukemia (AML) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is rare. Predisposing factors include CD56 expression and the chromosomal abnormality t(8;21). We describe an AML patient showing the chromosomal abnormality t(8;21) and CD56 expression who experienced a unique EM relapse after allo-HSCT. Approximately 10 months after allo-HSCT, he experienced relapse involving the femur and lumbar vertebrae and, subsequently, an EM relapse of the stomach. Although we administered only local radiotherapy and not systemic chemotherapy, he showed no bone marrow relapse on long-term follow-up after achieving complete hematological remission. These findings suggest that the graft-versus-leukemia effect may preferentially maintain marrow remission rather than prevent EM relapse. In addition, our findings show that extended survival is possible after EM relapse following allo-HSCT in patients with marrow hematopoiesis of donor origin, and that augmentation of the graft-versus-leukemia effect may be useful.

The anti-apoptotic role of the unfolded protein response in Bcr-Abl-positive leukemia cells.

To define the role of the unfolded protein response (UPR) in leukemogenesis, we investigated UPR activation in the cells expressing the representative oncogene Bcr-Abl (B-A). The expression of UPR-related proteins and mRNAs, namely, X-box-binding protein (XBP1) and glucose-regulated protein 78 (GRP78) was increased in B-A. UPR inhibition using inositol-requiring enzyme 1alpha (IRE1alpha) or activating transcription factor 6 (ATF6) dominant-negative mutants diminished the ability of Bcr-Abl to protect the cells from etoposide- and imatinib-induced apoptosis. We also noted that the expression of UPR-related genes in primary leukemia cells from Philadelphia chromosome (Ph)-positive cells was higher than that in the control by quantitative RT-PCR assay. Thus, our results suggested that UPR is a downstream target of Bcr-Abl and plays an anti-apoptotic role in Ph-positive leukemia cells.

Increased serum levels of matrix metalloproteinase-9 in acute graft-versus-host disease after allogeneic haematopoietic stem cell transplantation.

Matrix metalloproteinases (MMPs) have been implicated in a variety of normal and pathological conditions that involve matrix degradation and remodelling. We investigated the role of MMPs in acute graft-versus-host disease (aGVHD) in 29 patients who had undergone allogeneic haematopoietic stem cell transplantation. The present study showed that the serum levels of MMP-9, but not those of MMP-2, significantly correlated with the occurrence and severity of aGVHD. Moreover, immunohistochemical analysis of the cutaneous lesions of patients with aGVHD revealed an increased number of inflammatory cells positive for MMP-9. These results suggest that MMP-9 might play an important role in the pathogenesis of aGVHD.

Allogeneic peripheral blood stem cell transplantation from related donors mismatched at 2 HLA loci in the host-versus-graft direction.

In allogeneic stem cell transplantation, immune reactions can occur in 2 directions. The recipient's lymphocytes can recognize the donor's cells as "foreign" and attempt to kill them, which results in the host-versus-graft (HVG) reaction that is commonly termed graft rejection. The other direction is the graft-versus-host (GVH) reaction. When the recipient is homozygous at a mismatched human leukocyte antigen (HLA) locus, HLA disparity is present only in the former direction and not in the latter direction. If transplants harvested from such an HVG-mismatched donor can be used to achieve stable engraftment with minimal toxicity, then these donors can potentially be a useful alternative donor source. Here, we report 2 patients (1 with acute myeloblastic leukemia and another with lymphoblastic lymphoma) who were transplanted with peripheral blood stem cells (PBSCs) obtained from related donors mismatched at 2 HLA loci in the HVG direction but completely matched in the GVH direction. Our conditioning regimen, consisting of busulfan, cyclophosphamide, low-dose total body irradiation (TBI) (4 Gy), and fludarabine, achieved successful engraftment with an acceptable level of regimen-related toxicity. Our experience suggests that PBSC transplantation with an HVG-mismatched related donor and an appropriate conditioning regimen may be a therapeutic option for patients in whom early transplantation is desirable.

Elevation of serum high-mobility group box 1 protein during granulocyte colony-stimulating factor-induced peripheral blood stem cell mobilisation.

High mobility group box 1 (HMGB1) is a non-histone protein involved in maintaining the architecture of chromatin. HMGB1 also acts extracellularly as a cytokine, in processes such as inflammation, cell migration and stem cell recruitment. The involvement of HMGB1 in granulocyte colony-stimulating factor (G-CSF)-induced mobilisation of haematopoietic stem cells was investigated in 21 healthy donors. G-CSF treatment significantly elevated serum HMGB1 levels, which increased from 1.16 +/- 0.86 ng/ml, before treatment, to 31.1 +/- 5.99 ng/ml, after treatment. These findings suggest HMGB1 may play a role during the mobilisation of stem cells from the bone marrow into the systemic circulation.

Pure red-cell aplasia caused by the antibody to recombinant erythropoietin, epoetin-beta, in a Japanese patient with chronic renal failure.

A 68-year-old male with chronic renal failure and anemia received recombinant human erythropoietin (rHuEPO), epoetin beta, for approximately 1 year. Although the agent was initially effective for improving anemia, anemia refractory to EPO administration appeared and then worsened later, and pure red-cell aplasia (PRCA) was diagnosed. Anti-EPO antibody was detected by radioimmunoprecipitation (RIP) assay in the patient's serum. The antibody inhibited the proliferation of EPO-dependent cell line in a dose-dependent manner neutralizing EPO activity. The antibody also reacted with the other epoetin alfa products. The antibody did not recognize the carbohydrate moieties or denatured epoetin beta. The result suggested that the antibody recognized the conformational epitope of epoetin beta peptide molecule. Withdrawal of EPO and administration of cyclosporine decreased the titers of antibody; however, erythroid progenitor has not yet regenerated although the requirement for red blood cell transfusion is decreasing.