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Query: UMLS:C0027947 (neutropenia)
 17,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hemodialysis with first-use cellulosic dialysis membranes results in activation of the alternative pathway of complement and profound neutropenia followed by rebound leukocytosis. The neutropenia has been shown to be associated with increased expression of adhesion receptors and pulmonary sequestration of granulocytes. However, the mechanism underlying the return of the granulocytes has not been elucidated. We determined simultaneously the changes in the granulocyte adhesion receptor MAC-1 (CD11b-CD18) and the selectin LAM-1 receptor during dialysis using a complement activating and a non-complement activating membrane, in a randomized, cross-over study. With initiation of dialysis with cellulosic membranes, there was a rapid and prominent increase in the expression of MAC-1 receptors. At the nadir of granulocyte count, 15 minutes after initiation of dialysis with the complement activating membrane, there was a four-fold increase in the MAC-1 receptor expression. At the same time, there was a two-fold decrease in LAM-1 expression. There were no changes in the expression of two other granulocyte receptors CD11a and CD15 which are known not to be modulated during granulocyte activation. Granulocytes harvested during dialysis and which had high MAC-1 and low LAM-1 expression had a significantly decreased adherence to endothelial cell monolayers. Dialysis of the same patients with non-complement activating membranes resulted in no significant change in the expression of these receptors on granulocytes nor in their adherence to endothelial cells. These results shed new light on the mechanism of the cyclical granulocytopenia and rebound granulocytosis during dialysis with new cellulosic membranes.
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PMID:Modulation of granulocyte LAM-1 and MAC-1 during dialysis--a prospective, randomized controlled trial. 137 68

The growth and differentiation of selected bone marrow CD34+ cells stimulated with hematopoietic growth factors in lipid cultures were evaluated to determine whether cell types that may be useful for reducing the neutropenia associated with high-dose chemotherapy (HDC) can be produced and quantitated in vitro. CD34+ cells enriched from bone marrow were cultured for up to 5 weeks in interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) with or without stem cell factor (SCF) (also termed c-kit ligand). The mixture of IL-3, GM-CSF and G-CSF resulted in an 18-fold increase in cells after 10 to 12 days of culture and a 94-fold increase after 21 days. A 3-fold increase in colony-forming unit granulocyte-macrophage (CFU-GM) was observed after 10 days of culture. The addition of SCF during the first 10 days of culture further augmented the proliferation of cell numbers to 24-fold and colony-forming cells (CFC) to 8-fold after 10 days while cell numbers increased 130-fold after 21 days. Two-color flow cytometry defined phenotypes expressing CD11b and CD15 that represented maturation stages of neutrophils. Maturation of neutrophils in these cultures could be followed by the initial appearance after 3 to 7 days of a CD15+CD11b- phenotype representing promyelocytes, which gave rise after 2 to 3 weeks to a CD15+CD11b+ phenotype representing more mature neutrophil forms (metamyelocytes to segmented neutrophils). In contrast to normal neutrophil development, only a small fraction (10 to 15%) of the culture-derived neutrophils expressed CD16. These data define the kinetics and differentiation of neutrophils and neutrophil precursors from selected CD34+ cells in liquid cultures.
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PMID:Expansion of neutrophil precursors and progenitors in suspension cultures of CD34+ cells enriched from human bone marrow. 768 2

Hematopoietic recovery after high-dose chemotherapy is characterized by an obligate period of neutropenia of approximately 8-10 days. It is postulated that if a pool of neutrophil precursors and progenitors were expanded in vitro and reinfused, the duration of neutropenia may be substantially shortened by these cells capable of providing mature neutrophils within days of reinfusion. In this study, peripheral blood progenitor cell products were obtained from six normal donors mobilized with rhG-CSF and two patients mobilized with cyclophosphamide and rhG-CSF. CD34+ cells were isolated using the Isolex immunomagnetic bead method. A mean of 8.26 x 10(7) CD34+ cells with a mean purity of 74.5% were seeded at a concentration of 1 x 10(5)/ml into a 12 day stroma-free liquid culture using gas-permeable bags. A serum-free growth medium supplemented with PIXY321 was used. On day 7, there was a mean cellular expansion of fourfold, at which time the cells were resuspended at the initial concentration, yielding a mean culture volume of 3L (1-6 L). On day 12, there was an additional mean fold cellular expansion of 10 x, achieving an overall mean fold expansion of 41 +/- 16. Cellular characterization of the expanded cells revealed predominantly neutrophil precursors by morphology (mean 70.1%) and flow cytometric analysis. A mean of 52.3% of the expanded cells expressed CD15. Immunohistochemical staining revealed a mean of 7.1% CD41a+ megakaryocytic progenitors in the final cultured cell product. Detectable CD34+ cells were maintained only in those cultures initiated with greater than 90% CD34+ cells. Colony-forming units-granulocyte-macrophage (CFU-GM) were maintained in the 12 day culture at a level similar to the preculture number, whereas CFU mixed were depleted in all samples. On day 0, there were few CFU clusters (colonies containing fewer than 50 cells) identified, but by day 12, a mean total of 8.3 x 10(6) CFU clusters were identified. On day 12, the expanded cells were harvested and pooled using the Fenwal CS3000 Plus blood cell separator and resuspended in Plasma-Lyte-A with 1% human serum albumin. The mean harvest recovery of expanded progenitors was 91%, with a mean viability of 86%.
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PMID:Large-scale selection of CD34+ peripheral blood progenitors and expansion of neutrophil precursors for clinical applications. 881 91

Selected CD34+ cells from mobilized apheresis products were cultured in serum-free or serum-containing media supplemented with granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and stem cell factor (SCF; c-kit ligand). We examined the emergence of a CD15+CD11b- population, which appeared morphologically to be promyelocytes. This CD15+CD11b- population can be further expanded in culture into morphologically mature granulocytes. In an attempt to characterize this culture-derived CD15+CD11b- promyelocytic population, single cells were clone sorted into wells of a Terasaki plate containing various growth factors. We compared the growth factor requirements and kinetics of this apheresis culture-derived CD15+CD11b- population to the CD15+CD11b- population from fresh bone marrow samples. Our studies indicate that the CD15+CD11b- promyelocytic population from bone marrow and blood are equivalent in their ability to proliferate and in their requirements for growth factors. The CD15+CD11b- population in vitro shows a high proliferative capacity when compared with the other CD15/CD11b populations (CD15-CD11b-, CD15+CD11b+, CD15-CD11b+). Thus, we can manipulate CD34+ cells in vitro to proliferate and differentiate toward a mature neutrophil lineage. The CD15+CD11b- promyelocytic population derived from this culture may represent the most effective cultured cell population for therapeutic reduction of neutropenia in vivo based on both its stage of differentiation and its proliferative potential.
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PMID:Characterization of a culture-derived CD15+CD11b- promyelocytic population from CD34+ peripheral blood cells. 933 18

To test the hypothesis that low numbers of circulating neutrophils may be due to enhanced neutrophil extravasation in patients with chronic idiopathic neutropenia of adults (CINA), serum levels of endothelial cell-derived soluble cell adhesion molecules (sE-selectin, sICAM and sVCAM) usually used as indicators of endothelial cell activation, serum levels of two potent endothelial cell activators (IL-1beta and TNF-alpha), and serum levels of the chemokine interleukin-8 (IL-8) which is one of the main chemoattractant substances for neutrophils at sites of inflammation, were measured in 84 CINA patients and 30 healthy volunteers using the respective micro-ELISA methods. We found that serum sE-selectin, sICAM, sVCAM, IL-1beta and TNF-alpha concentrations were all significantly increased in the group of patients compared to controls, and were correlated inversely with the number of circulating neutrophils. Serum levels of IL-8 were also markedly increased in the patients compared to controls, and they were correlated positively with the levels of serum sE-selectin, sICAM, sVCAM, IL-1beta and TNF-alpha, and inversely with the number of circulating neutrophils. No significant differences were noted between patients and normal controls in the proportions of neutrophils carrying the cell adhesion molecules CD11a/ CD18, CD15 and CD62L. These findings suggest strongly that CINA patients have activated endothelium to which circulating neutrophils may adhere by interacting with counter-structures found on their surface. Subsequent diapedesis and subendothelial migration may be facilitated by IL-8 and possibly other chemoattractant substances. We conclude that an enhanced neutrophil extravasation may be involved, at least in part, in the determination of neutropenia in CINA patients.
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PMID:Enhanced neutrophil extravasation may be a contributing factor in the determination of neutropenia in patients with chronic idiopathic neutropenia of adults. 982 Jun 35

The initiation of hemodialysis using cuprophane membranes is followed by a rapid fall in the circulating neutrophil count. This neutropenia is caused by a transient sequestration of neutrophils in the lung due to homotypic aggregation, largely in response to generation of C5a by contact of plasma with the dialyzer. The transient nature of hemodialysis neutropenia is due to desensitization of neutrophils to stimulation by C5a, thus demonstrating desensitization in vivo. To examine the in vivo effects on surface phenotype of continuous exposure of neutrophils to C5a over 3 h, the surface expression of 22 antigens was examined by flow cytometry in patients undergoing dialysis. Neutropenia was prominent at 15 min and absent at 60 and 180 min of dialysis. CD10, CD11b, CD11c, CD13, CD18, CD35, CD45, CD66acde, and CD66b were upregulated at 15 min and remained upregulated at 180 min. CD61 and CD63 increased slightly at 15 min and returned to baseline by 180 min. CD16 and CD62L were down regulated at 15 min and normalized by 180 min. CD15s, CDw17, CD32, and CD44 were slightly down regulated at 15 min and then returned to baseline by 180 min. CD11a, CD15, CD24, CD31, and CDw65 did not change during dialysis. This study demonstrates the changes in surface phenotype of neutrophils during prolonged in vivo exposure to C5a over 3 h, during which time neutrophils become desensitized to subsequent stimulation by similar concentrations of C5a but maintain responsiveness to other chemotactic stimuli.
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PMID:Changes in neutrophil surface phenotype during hemodialysis. 982 71

The Lewis(x) (Le(x)) trisaccharide (CD15) linked to proteins and glycolipids is highly expressed on the surface of normal human polymorphonuclear neutrophils (PMN) and several human neoplasias, such as breast and gastrointestinal carcinomas and chronic myeloid leukemias. FC-2.15 is an IgM murine mAb that specifically recognizes Le(x) and has been previously shown to mediate the in vitro lysis of Le(x)(+) cells by human complement. In a phase I clinical trial of FC-2.15, a temporary neutropenia was the main toxicity, and antitumor responses were observed. In order to characterize FC-2.15 further and determine the physiological relevance of Le(x) binding, the reactivity of FC-2.15 on PMN was investigated under several conditions. Flow cytometry revealed a strong reactivity of FC-2.15 with almost 100% of PMN, and Scatchard analysis demonstrated an affinity constant of 5.14 x 10(9) M(-1) and 1.11 x 10(6) antigen sites/cell. In vitro, the binding of Le(x) epitopes by FC-2.15 induced PMN homotypic aggregation, only 28.4 +/- 4.1% remaining as single cells. When PMN and the Le(x)(+) MCF-7 breast cancer cells were co-incubated, FC-2.15 induced heterotypic aggregation. In 51Cr-release assays employing human complement, FC-2.15 lysed 93.4 +/- 7.9% of PMN and 87.8 +/- 10.7% of MCF-7 cells. However, when the effect of FC-2.15 was tested in ex vivo circulating blood, no lytic activity against PMN was detected, whereas MCF-7 cells were still lysed. Blood smears demonstrated that FC-2.15 induced PMN agglutination and heterotypic aggregates when MCF-7 cells were present. A pretreatment of PMN with colchicine impaired PMN agglutination both in vitro (single PMN = 81.15 +/- 4.35%) and in ex vivo circulating blood. In the latter condition, FC-2.15-lytic activity was restored, suggesting that PMN homotypic aggregation by FC-2.15, but not lysis, is dependent on microtubule integrity and that PMN agglutination hinders their lysis. Moreover, when 51Cr-release assays were performed following agglutination, FC-2.15 cytotoxicity was restricted to isolated PMN. It is suggested that crosslinking of Le(x) epitopes by FC-2.15 induces PMN to form homotypic aggregates. It is suggested that the neutropenia observed in FC-2.15-treated patients would be due to PMN agglutination and margination, rather than lysis. In addition, FC-2.15 appears to be able to lyse Le(x)(+) tumor cells in circulation.
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PMID:Differential lytic and agglutinating activity of the anti-Lewis(x) monoclonal antibody FC-2.15 on human polymorphonuclear neutrophils and MCF-7 breast tumor cells. In vitro and ex vivo studies. 1041 63

Myelokathexis is a congenital disorder that causes severe chronic leukopenia and neutropenia. Characteristic findings include degenerative changes and hypersegmentation of mature neutrophils and hyperplasia of bone marrow myeloid cells. The associated neutropenia can be partially corrected by treatment with granulocyte colony-stimulating factor (G-CSF) or granulocyte-macrophage colony-stimulating factor (GM-CSF). These features led us to propose that accelerated apoptosis of neutrophil precursors might account for the neutropenic phenotype. Blood and bone marrow aspirates were obtained from 4 patients (2 unrelated families) with myelokathexis before G-CSF therapy and from 2 of the affected persons after G-CSF therapy (1 microg/kg per day subcutaneously for 3 weeks). Bone marrow was fractionated using immunomagnetic bead cell sorting into CD34(+), CD33(+)/CD34(-), and CD15(+)/CD34(-)/CD33(- )cell populations. Examination of these cells by flow cytometry and electron microscopy revealed abundant apoptosis in the CD15(+) neutrophil precursor population, characterized by enhanced annexin-V binding, extensive membrane blebbing, condensation of heterochromatin, and cell fragmentation. Colony-forming assays demonstrated significant reduction in a proportion of bone marrow myeloid-committed progenitor cells. Immunohistochemical analysis revealed a selective decrease in bcl-x, but not bcl-2, expression in the CD15(+)/CD34(-)/CD33(-)cell population compared with similar subpopulations of control bone marrow-derived myeloid precursors. After G-CSF therapy, apoptotic features of patients' bone marrow cells were substantially reduced, and the absolute neutrophil counts (ANC) and expression of bcl-x in CD15(+)/CD34(-)/CD33(-)cells increased. The authors concluded that myelokathexis is a disease characterized by the accelerated apoptosis of granulocytes and the depressed expression of bcl-x in bone marrow-derived granulocyte precursor cells. These abnormalities are partially corrected by the in vivo administration of G-CSF. (Blood. 2000;95:320-327)
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PMID:Myelokathexis, a congenital disorder of severe neutropenia characterized by accelerated apoptosis and defective expression of bcl-x in neutrophil precursors. 1060 19

The infusion of ex vivo differentiated myeloid precursors may be able to shorten the period of obligatory neutropenia after high-dose chemotherapy and peripheral blood progenitor cell rescue by providing cells capable of differentiating to mature neutrophils within days of infusion. To test this hypothesis, 21 female patients with metastatic breast cancer underwent progenitor cell mobilization with cyclophosphamide, etoposide and G-CSF. CD34+ cells from one to two leukapheresis products were isolated and placed in suspension culture with a serum-free growth medium supplemented with PIXY321. The cultures were maintained for 12 days with subcultures initiated on day 7. The remaining leukapheresis products were cryopreserved in an unmanipulated state. Forty-eight hours after completing high-dose cyclophosphamide, thiotepa and carboplatin, the cryopreserved progenitors were infused, followed 1 to 24 h later by infusion of the differentiated myeloid precursors. In one patient, the cultured cells were labeled with Indium-111 with nuclear imaging performed up to 48 h post infusion. The differentiated myeloid precursors were suitable for infusion in 17 of the patients with a median 13-fold expansion of total nucleated cells. A range of 5.6 to 1066 x 10(7) nucleated cells were infused. Morphologically the cells were predominantly of myeloid lineage (63%) with a median 41% of the cells expressing CD15. No untoward effects were noted with the infusion of the cultured cells. The median days to neutrophil and platelet recovery were 8 and 10 days, respectively. There was a significant relationship (r = 0.67, P = 0.007) between the dose of differentiated myeloid precursors (CD15+ cells) and the depth and duration of neutropenia; a similar relationship, however, was also observed with the dose of cryopreserved CD34+ cells. After infusion of the radiolabeled myeloid precursors, a pattern of distribution similar to radio-labeled granulocytes was noted with uptake detected initially in the lungs and subsequently the reticulo-endothelial system. The impact of differentiated myeloid precursors on neutropenia as an adjunct to high-dose chemotherapy and peripheral blood progenitor cell rescue remains unclear from this study. Further study with controlled doses of cryopreserved progenitors and escalating doses of differentiated myeloid precursors is required.
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PMID:Clinical impact of ex vivo differentiated myeloid precursors after high-dose chemotherapy and peripheral blood progenitor cell rescue. 1101 39

Cyclic neutropenia (CN) is a congenital hematopoietic disorder characterized by remarkably regular oscillations of blood neutrophils from near normal to extremely low levels at 21-day intervals. Recurring episodes of severe neutropenia lead to repetitive and sometimes life-threatening infections. To investigate the cellular mechanism of CN, the ultrastructure and the proliferative and survival characteristics of bone marrow-derived CD34(+) early progenitors, CD33(+)/CD34(-) myeloid progenitors, and CD15(+) neutrophil precursors from CN patients and healthy volunteers were studied. The ultrastructural studies showed profound apoptotic features in bone marrow progenitor cells in CN. Colony-forming assays demonstrated a 75% decrease in the number of early myeloid-committed colonies compared with controls. Long-term culture-initiating cell assays demonstrated a 6-fold increase in production of primitive progenitor cells in CN. To determine whether accelerated apoptosis might account for the underproduction of myeloid progenitors, the hematopoietic subpopulations were labeled with fluorescein isothiocyanate-annexin V and analyzed by flow cytometry. Short-term culture of CN cells resulted in apoptosis of approximately 65% of CD34(+) cells, 80% of CD33(+)/CD34(-) cells, and more than 70% of CD15(+) cells, as compared with 20%, 7%, and 15% apoptosis in respective control subpopulations. Evidence of accelerated apoptosis of bone marrow progenitor cells was observed in all 8 patients participating in the study, regardless of the stage in the CN cycle in which bone marrow aspirations were obtained. Granulocyte colony-stimulating factor therapy of CN patients significantly improved survival of bone marrow progenitor cells. These data indicate that ineffective production of neutrophils is due to accelerated apoptosis of bone marrow myeloid progenitor cells in CN.
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PMID:Impaired survival of bone marrow hematopoietic progenitor cells in cyclic neutropenia. 2499 67


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