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Engraftment failure following allogeneic bone marrow transplantation (BMT) is rare in patients with acute leukemia, after frequent conditioning with marrow-lethal chemoradiotherapy. We evaluated the efficacy of a preparatory regimen consisting of fractionated total body irradiation (TBI) (12 Gy in six fractions) and high dose etoposide (60 mg/kg) administered as an 8-h infusion for allogeneic BMT in 16 consecutive patients with acute leukemia. Although 14 patients showed complete and sustained engraftment, the remaining two patients rejected bone marrow grafts from HLA-identical sibling donors and showed subsequent recovery of host-derived hematopoiesis. Despite the limited number of patients, this observation suggests that the immunosuppressive potential of etoposide may be inferior to that of cyclophosphamide (CY) and that etoposide as an alternative to CY as an antileukemic and immunosuppressive agent in allogeneic BMT may increase the risk of graft rejection.

Immune-mediated suppression of hematopoiesis has been considered the most important mechanism in the development of idiopathic aplastic anemia (AA), mainly based on high rates of response to immunosuppressive therapy in patients with AA. However, the lack of an experimental animal model and the heterogeneity of the disease has hindered elucidation of immune mechanisms underlying AA. Recent studies on a subset of AA patients characterized by repetitive response to cyclosporine (CyA) therapy revealed a strong association of HLA-DRB1*1501 with susceptibility to such immune-mediated AA. Other studies of the T-cell clonotype in the bone marrow (BM) of the patients using the polymerase chain reaction (PCR)-single strand conformation polymorphism analysis and sequencing of T-cell receptor V beta cDNA showed dominant proliferation of a limited number of T-cells, indicating the presence of certain antigenic stimuli in the BM. More recently, we isolated a CD4+ T-cell clone that proliferated most dominantly among V beta 21+ T-cells in the BM of a CyA-dependent AA patient and was capable of killing autologous hematopoietic cells. Lysis of allogeneic hematopoietic cells by this T-cell clone required the presence of HLA-DR4 on the target cells. Further studies on such T-cell clones will help identify key molecules on hematopoietic cells that induce the development of AA.

Autologous mixed lymphocyte culture (AMLR) is an immunologic response with memory and specificity and plays a role in immune regulation. Effects of T cells activated by AMLR were studied in the regulation of in vitro erythropoiesis. AMLR-activated T cells were cocultured with autologous non-T, nonphagocytic peripheral blood mononuclear cells for assaying erythroid progenitor cells (BFU-E). T cells activated for 3 days in AMLR showed significant enhancement of in vitro colony growth by BFU-E. In contrast, activated T cells from day 7 AMLR caused significant suppression of BFU-E growth. Both enhancing and suppressing activities of AMLR-activated T cells were mediated by an la-positive and radiosensitive population within the OKT4+ subset. These observations suggest that AMLR-activated T cells may play a role in the immune-mediated regulation of in vitro erythropoiesis. It is also suggested that heterogeneous T-cell subsets may exert regulatory functions in the regulation of in vitro hematopoiesis.

T cell subsets and their immune reactivities were studied in long-term survivors after bone marrow transplantation and the results of autotransplanted and allotransplanted patients were compared. These two groups of patients (4 autotransplants and 4 allotransplants) were roughly comparable in terms of their underlying diseases, pretransplant conditioning regimens, supportive care, and posttransplant sampling days for immunological studies. Significant differences were observed between autologous and allogeneic marrow recipients in the total number of OKT3-, OKT4-, OKT8-, and OKIa1 -positive cells. Similar differences were observed between transplant patients and normal controls. Decreased OKT4 cells and increased OKT8 cells resulted in inversion of the OKT4:OKT8 ratio, which was significantly lower in allotransplanted compared with autotransplanted patients, and both groups of transplant patients showed depressed responses in comparison with normal controls. In contrast, there were no significant differences in MLR reactivities between transplanted patients and normal controls. When mitogenic responses were analyzed in relation to T cell subsets, phytohemagglutinin responsiveness showed a significant correlation with OKT4:OKT8 ratios (P less than 0.01) and the proportions of cultured OKT4 cells (P less than 0.01). These observations suggest that T lymphocyte reconstitution is still incomplete or abnormal in long-term survivors regardless of the type of graft. Furthermore, abnormalities observed in these long-term survivors were characterized by an imbalance of T cell subsets that was more profound in allotransplanted than in autotransplanted patients.

Dengue and other arbovirus diseases are frequently associated with bone marrow failure. We show that dengue type 4 (DEN4) propagates in colonies derived from immature human bone marrow progenitors. DEN4 was propagated in BFU-E-derived colonies and replication was dependent on erythropoietin. DEN4 was not cytotoxic. In inoculated cultures, diffuse bursts with many clusters contained large amounts of DEN4 RNA. In contrast to dengue infection of macrophages, virus propagation in semisolid culture was sustained and not enhanced by subneutralizing amounts of antibody. DEN4 also was efficiently propagated in human hematopoietic cell lines, especially those with erythroid properties. In K562 cells, DEN4 infection persisted for months; greatly slowed cell growth, again without cytotoxicity; and resulted in cytopathic changes in cell appearance. Flaviviruses can infect human hematopoietic cells and alter their proliferative capacity.

To determine how immunosuppressant agents used for graft-versus-host disease (GVHD) prophylaxis affect natural killer (NK) cells, we examined the effects of cyclosporine (CSP), tacrolimus (TAC), mycophenolic acid (MPA, an active form of mycophenolate mofetil), and methotrexate (MTX) on the proliferation and cytotoxicity of NK cells. The proliferation of NK cells from healthy individuals in the presence of interleukin (IL)-2 and IL-15 was suppressed to 51% ± 16% of that of the controls with CSP, to 31% ± 19% with TAC, to 14% ± 6% with MPA, and to 87% ± 18% with MTX. Both CSP and TAC increased the proportion of CD16(-)CD56(bright) cells, a NK cell subset capable of secreting high amount of cytokines, and also enhanced NKp30 expression, whereas MPA markedly decreased the proportion of CD16(-)CD56(bright) cells and reduced the expression of all activating NK cell receptors, including NKG2D, NKp30, NKp44, and NKp46. MPA also reduced the cytotoxicity against K562 cells from 61% ± 15% to 17% ± 7% and that against Daudi cells from 44% ± 4% to 4% ± 4%, whereas the other 3 drugs did not diminish these cytotoxicities. The inhibition of NK cell proliferation and cytotoxicity against leukemic cell lines by MPA was partially abolished by the inclusion of guanosine in the culture. Similar to the effect of MPA on T cells, MPA inhibited the down-regulation of p27 on NK cells induced by the incubation of NK cells in the presence of IL-2. These results suggest that MPA is a potent inhibitor of NK cells, and that its inclusion in the GVHD prophylaxis regimen might diminish the graft-versus-leukemia effect of NK cells.

Introduction: Most non–small-cell lung cancer tumors with epidermal growth factor receptor mutations are responsive to EGFR tyrosine kinase inhibitors, such as gefitinib and erlotinib, but almost all such tumors ultimately acquire resistance. We previously found that a gefitinib-resistant cell line, PC-9/Met in which MET (MNNG-HOS transforming gene) is amplified, was more sensitive than its parent cell line (PC-9) to 7-ethyl-10-hydroxy-camptothecin (SN-38), an active metabolite of irinotecan. The purpose of this study was to investigate the mechanisms responsible for the increased sensitivity of the gefitinib-resistant cell line to SN-38. Methods: The sensitivity of PC-9 and PC-9/Met to SN-38 was assessed by performing water soluble tetrazolium salt (WST-1) assays. Topoisomerase I (topo I) activities were determined for the cell lines cultured in the presence of hepatocyte growth factor and for those of which MET expression was knocked down by introducing a MET-specific small interfering RNA. Results: PC-9/Met exhibited higher topo I activities, and higher topo I gene and protein expression levels than PC-9 did. Suppression of MET expression by a MET-specific small interfering RNA led to a decrease in the topo I protein expression in the PC-9/Met cells. The stimulation of PC-9 with hepatocyte growth factor caused an increase in the topo I protein level via the activation of MET. Conclusions: The increased sensitivity of PC-9/Met cells to SN-38 compared with that of PC-9 cells was partially because of topo I activities resulting from increased topo I mRNA and protein expression caused by MET signaling.

To clarify the clinical features of pulmonary Mycobacterium avium^intracellulare complex (MAC) infection, we retrospectively evaluated clinical manifestations, laboratory data, chest and maxillary sinus computed tomographic scans and induced sputum findings in 26 with MAC infection in comparison with104 patients withtuberculosis (TB) infec- tion.We found that carbohydrate antigen 19-9 (CA 19-9) and immunoglobulin A (IgA) in the serum and percentage of neutrophils in the sputum were significantly higher, and sinusitis was significantly more frequent in patients with MAC compared with patients withTB.MACinfection might be more strongly associated withimpaired upper andlower airway defense mechanism in comparison withTB. r 2003 Elsevier Science Ltd. All rights reserved.

Background Chronic cough is the only symptom of cough variant asthma (CVA) and atopic cough (AC). Cysteinyl leukotriene receptor antagonists have been shown to be effective in CVA, but there are no reports on their effectiveness in AC. To evaluate the antitussive effect of montelukast, a leukotriene receptor antagonist, in CVA and AC. Methods Seventy-five patients with chronic cough received diagnostic bronchodilator therapy with oral clenbuterol hydrochloride for 6 days. Of the 75 patients, 48 and 27 met the simplified diagnostic criteria for CVA and AC, respectively. Patients with CVA were randomly divided into 3 groups: montelukast, clenbuterol, and montelukast plus clenbuterol. Patients with AC were randomly divided into 2 groups: montelukast and placebo. The efficacy of cough treatment was assessed with a subjective cough symptom scale (0 meant “no cough” and 10 denoted “cough as bad as at first visit”). The cough scale, pulmonary function test, and peak expiratory flow rate (PEF) were evaluated before and after 2 weeks of treatment. Results In patients with CVA, 2-week treatment with montelukast, clenbuterol, and montelukast plus clenbuterol all significantly decreased cough scores and treatment with montelukast plus clenbuterol was superior to treatment with montelukast alone. In the montelukast plus clenbuterol group, PEF values in the morning and evening significantly increased after 2 weeks compared with values before treatment. In patients with AC, scores on the cough scale did not differ significantly between the montelukast group and the placebo group. Conclusions Montelukast was confirmed to suppress chronic non-productive cough in CVA, whereas it was not effective in non-productive cough in AC.

An unusual radiographic sign of crescentic cavitation appeared in a case of invasive pulmonary mucormycosis complicating the treatment of a patient with acute myelogenous leukemia and having a normal admission chest radiograph. The first manifestation was a large, wedge-shaped pleural-based consolidation, which evolved about 10 days later into a fungus ball-like lesion, usually known as the air crescent sign. Amphotericin B and 5-fluorocytosine, which were initiated immediately after appearance of the sign, proved to be effective, probably in association with hematologic improvement. Transbronchial lung biopsy was not only helpful in establishing a definitive diagnosis, but also suggested that an intracavitary mass could have resulted from pulmonary infarction. This experience thus showed that the sign may appear in greater frequency in mucormycosis as well as in aspergillosis, and may be useful as a clinical index for initiating antifungal therapy in immunocompromised patients.

The effect of peripheral blood mononuclear cells (PBMCs) from bone marrow recipients on in vitro growth of erythroid burst-forming units (BFU-E) was studied. PBMCs were obtained from 5 allogeneic, 1 syngeneic and 1 autologous bone marrow recipient(s) at different intervals after transplantation. The number of BFU-E was significantly increased when donor bone marrow cells were co-cultured with PBMCs obtained from allogeneic marrow recipients in the early post-transplant period. No effect was observed using PBMCs obtained in the later post-transplant period, PBMCs from a syngeneic marrow recipient, or PBMCs from an autologous marrow recipient. The BFU-E enhancing activity was present among T cells and was abolished by treating them with OKT3 or OKT4 antibody and complement. These observations suggest that chimeric T lymphocytes, probably of the helper/inducer subset, from allogeneic marrow recipients in the early post-transplant period have a potent enhancing effect on in vitro erythropoiesis.

To characterize the process of the establishment of complete chimerism after allogeneic peripheral blood stem cell transplantation (allo-PBSCT), we determined the origin of leukocytes in peripheral blood (PB) obtained from 23 patients in the very early period after allo-PBSCT using amplification of mini- or microsatellite regions of genomic DNA. Donor-specific alleles were amplified from the PB obtained at day 8 post-transplant for 19 allo-PBSCT patients. Among the 19 patients, 12 showed only donor-specific alleles (complete chimerism) while 7 did both donor and host-specific alleles (mixed chimerism). Although donor specific alleles were amplified in 10 of 12 patients who received allogeneic bone marrow transplantation (allo-BMT) similarly to allo-PBSCT, all of these ten showed mixed chimerism. When the chimeric state was examined in PB samples obtained serially at 2-3-day intervals post-transplant, host-specific alleles in allo-PBSCT patients were not detectable in the PB much earlier than those in allo-BMT patients. These findings indicate that the appearance of donor-derived cells associated with the disappearance of host-derived cells in the circulation occurs earlier after allo-PBSCT as compared with allo-BMT, leading to the rapid establishment of complete chimerism.

Moesin is an intracellular protein that links the cell membrane and cytoskeleton, while also mediating the formation of microtubules and cell adhesion sites as well as ruffling of the cell membrane. To determine the roles of anti-moesin Abs derived from the serum of patients with aplastic anemia (AA) in the pathophysiology of bone marrow failure, we studied the expression of moesin on various blood cells and the effects of anti-moesin Abs on the moesin-expressing cells. The proteins recognized by anti-moesin mAbs were detectable on the surface of T cells, NK cells, and monocytes from healthy individuals as well as on THP-1 cells. The peptide mass fingerprinting of the THP-1 cell surface protein and the knock-down experiments using short hairpin RNA proved that the protein is moesin itself. Both the anti-moesin mAbs and the anti-moesin polyclonal Abs purified from the AA patients’ sera stimulated THP-1 cells and the PBMCs of healthy individuals and AA patients to secrete 60–80% as much TNF-α as did LPS 100 ng/ml. Although the polyclonal Abs induced IFN-γ secretion from the PBMCs of healthy individuals only when the PBMCs were prestimulated by anti-CD3 mAbs, the anti-moesin Abs were capable of inducing IFN-γ secretion from the PBMCs of AA patients by themselves. Anti-moesin Abs may therefore indirectly contribute to the suppression of hematopoiesis in AA patients by inducing myelosuppressive cytokines from immunocompetent cells.

Background The role of angiotensin II type 2 receptor (AT2) in pulmonary fibrosis is unknown. To evaluate the influence of angiotensin II type 1 receptor (AT1) and AT2 antagonists in a mouse model of bleomycin (BLM)-induced pulmonary fibrosis. Methods We examined effects of the AT1 antagonist (AT1A) olmesartan medoxomil (olmesartan) and the AT2 antagonist (AT2A) PD-123319 on BLM-induced pulmonary fibrosis, which was evaluated by Ashcroft's pathological scoring and hydroxyproline content of lungs. We also analyzed the cellular composition and cytokine levels in bronchoalveolar lavage fluid (BALF). Results With olmesartan, the lung fibrosis score and hydroxyproline level were significantly reduced, and lymphocyte and neutrophil counts and tumor necrosis factor (TNF)-α levels in BALF were reduced on day 7. On day 14, macrophage and lymphocyte counts in BALF were reduced, accompanied by a reduction in the level of transforming growth factor (TGF)-β1. With PD-123319, the lung fibrosis score and hydroxyproline level were reduced. On day 7, macrophage, lymphocyte, and neutrophil counts in BALF were reduced, accompanied by reductions in TNF-α and monocyte chemoattractant protein (MCP)-1 levels. On day 14, macrophage, lymphocyte, and neutrophil counts in BALF were also reduced, accompanied by a reduction in the level of macrophage inflammatory protein (MIP)-2 level but not TGF-β1. Conclusion Both AT1 and AT2 are involved in promoting interstitial pneumonia and pulmonary fibrosis via different mechanisms of action.

Human interleukin-8 (IL-8) induces a rapid mobilization of hematopoietic progenitor cells (HPCs) into peripheral blood in mice and primates. Because an exact homologue of human IL-8 does not exist in mice, a chemokine, macrophage inflammatory protein-2 (MIP-2), is supposed to substitute the function of IL-8 in mice. Hence, we investigated the capacity of mouse MIP-2 to induce HPC mobilization in mice. Mouse MIP-2 induced, in either untreated or splenectomized mice, a rapid HPC mobilization, as evidenced by increased numbers of colony-forming unit granulocyte-macrophage (CFU-GM) and lineage marker (Lin)- c-kit+Sca-1 + cells. Although release of elastase from activated neutrophils was proposed to be involved in IL-8-induced HPC mobilization, mouse MIP-2 induced similar levels of HPC mobilization in elastase-deficient beige mice at a similar level to normal ones. This HPC mobilization by MIP-2 was markedly enhanced by pretreatment with granulocyte-colony-stimulating factor (G-CSF). Moreover, the combination of G-CSF and MIP-2 apparently down-regulated L-selectin expression on Lin- Sca-1 + cells in peripheral blood as well as bone marrow. Thus, MIP-2 may down-modulate the interaction between HPCs and bone marrow stroma by reducing L-selectin expression on HPCs and cause rapid mobilization of HPCs into peripheral blood.

The prognosis of relapsed acute myeloid leukemia (AML) in elderly patients is dismal, even if the AML exhibits a good prognostic karyotype, such as inv(16)(p13.1q22). We present a 72-year-old female with AML with inv(16)(p13.1q22) who suffered five episodes of relapse with temporary complete remission. Maintenance chemotherapy with oral cytarabine ocfosfate hydrate eventually produced persistent molecular complete remission of her AML that had not been induced by conventional regimens including intensive chemotherapy and low dose cytarabine therapy. The high level of tolerability to oral cytarabine ocfosfate hydrate may offer elderly patients with this type of AML a good chance for a cure. Electronic supplementary material The online version of this article (doi:10.1186/s13045-014-0100-6) contains supplementary material, which is available to authorized users.