Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Expression of L-selectin was determined by single- and two-colour immunofluorescence on granulocytes, peripheral blood mononuclear cells (PBMC) and blasts of bovine origin by means of a monoclonal antibody IVA94 which recognizes bovine L-selectin (CD62L). Cells were separated from peripheral blood of healthy cattle and colleagues infected with bovine leukaemia virus (BLV). BLV-infected animals comprised lymphocytotic and non-lymphocytotic cows. L-selectin was expressed on 90-98% of granulocytes in all tested animals. The percentage of PBMC expressing L-selectin was lower in cattle with persistent lymphocytosis than in non-lymphocytotic or BLV-free cattle, and inversely correlated with lymphocyte counts. The ratio of B lymphocytes stained for L-selectin was significantly decreased from 60.2 +/- 1.9% in BLV-free cattle to 43.8 +/- 3.6 and 22.5 +/- 5.7% in non-lymphocytotic and lymphocytotic cattle, respectively. B-lymphocytes stained for L-selectin exhibited about 50% reduction in L-selectin expression in BLV-infected cattle compared with BLV-free cattle, as judged by the mean fluorescence intensity (MFI). The percentage of L-selectin-positive PBMC not bearing surface immunoglobulin M (predominantly T lymphocytes) was comparable in BLV-free and BLV-infected cattle. However, L-selectin expression on T lymphocytes was reduced (about 50%) in BLV-infected cattle, as judged by the MFI. We suppose that BLV infection results in a decreased L-selectin expression on lymphocytes, and accordingly, it may contribute to deregulation of the host immune system.
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PMID:Decreased expression of L-selectin (CD62L) on lymphocytes in enzootic bovine leukaemia. 1076 82

Opportunistic infections frequently occur in patients with adult T-cell leukemia (ATL) and human T-cell leukemia virus type I (HTLV-I) carriers. However, the underlying mechanisms of such infections remain unknown. To clarify the mechanism of immunodeficiency in those infected with HTLV-I, this study analyzed the T-cell subsets in HTLV-I carriers and patients with HTLV-I-associated myelopathy/tropical spastic paraparesis and ATL using 3-color fluorescence with CD62L and CD45RA coexpression either with CD4(+) or CD8(+) T cells. The number of naive T lymphocytes was markedly suppressed in patients with ATL, particularly in those with acute form, compared with uninfected control individuals. The number of naive T cells was low in HTLV-I-infected individuals under 50 years old compared with uninfected individuals, whereas the number of memory T lymphocytes was greater in HTLV-I-infected individuals. Although the increase of memory T lymphocytes correlated with HTLV-I provirus loads, no relationship was found between naive T-cell counts and provirus loads. T-cell receptor rearrangement excision circles (TRECs), which are generated by DNA recombination during early T lymphopoiesis, were quantified to evaluate thymic function in HTLV-I-infected individuals. TREC levels were lower in HTLV-I-infected individuals than in uninfected individuals. In HTLV-I carriers less than 70 years old, an increase of Epstein-Barr virus DNA in peripheral blood mononuclear cells was observed in 6 of 16 (38%) examined, whereas it was detectable in only 1 of 11 uninfected controls. These results suggested that the low number of naive T lymphocytes was due to suppressed production of T lymphocytes in the thymus, which might account for immunodeficiency observed in HTLV-I-infected individuals.
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PMID:Impaired production of naive T lymphocytes in human T-cell leukemia virus type I-infected individuals: its implications in the immunodeficient state. 1134 46

AC133 is a novel 5-transmembrane antigen present on a CD34((bright)) subset of human hematopoietic stem cells (HSCs) and it is also expressed on the subset of CD34 positive (CD34(+)) leukemias. But the clinical significance of AC133 expression on leukemic blasts is not yet known. We investigated the expression of AC133 antigen on blast cells of acute leukemia. Forty-one cases of acute leukemia were examined for expression of AC133, CD34, and other antigens using multicolor flow-cytometry. Samples were considered positive if at least 20% of the cells specifically stained with monoclonal antibodies (MoAbs) revealed a higher fluorescence intensity compared to cells of corresponding negative control samples (=20% cut-off level). 14/36 (38.9%) acute myelogenous leukemia (AML) samples and 6/20 (30%) acute lymphoblastic leukemia (ALL) samples were positive for AC133, the difference was not significant. All AC133 positive (AC133(+)) leukemias expressed CD34, whereas 13 of 33 CD34(+) leukemias were negative for AC133, and AC133(+)/CD34(-) leukemia was not found. Expression rates of CD31, CD62L, CD62E, CD105 and CD144 were significantly higher in AC133(+) leukemia compared to those of AC133(-) leukemia (P=0.045, P<0.001, P<0.001, P<0.001, P=0.003, respectively), but bcl-2, CXCR-1, CXCR4, VLA-4, CD106 expression rates were not significantly different between AC133(+) and AC133(-) leukemias. None of the clinical prognostic markers such as age, hemogram, lactate dehydrogenase, and chromosomal aberration were significantly different between AC133(+) and AC133(-) leukemias. CR rates of AC133(+) AML and AC133(-) AML were not significantly different, although there was a trend toward higher CR rates in AC133(-) AML (18/22[81.8%] AC133(-) AML versus 9/14[64.3%] AC133(+) AML), but the 1-year relapse rate of AC133(+) AML was significantly higher than that of AC133(-) AML (8/9 (88.9%) versus 7/19 (36.8%), P=0.016). Median disease-free survival (DFS) times of AC133(+) and AC133(-) AML were significantly different (11 and 18 months, respectively, P=0.006), although overall survival (OS) times were not significantly different (AC133(+) 15 months versus AC133(-) 20 months, respectively, P=0.06). Similar results regarding clinical outcomes were found when AC133(+)/CD34(+) and AC133(-)/CD34(+) were analyzed separately, but the difference did not attain statistical significance. In ALL, 9/11 (81.8%) AC133(-) and 2/4 (50%) AC133(+) cases achieved CR, but the difference was not significant. Four of 11 AC133(-) ALL (36.4%) and 2 of 3 AC133(+) ALL (66.7%) relapsed within 1 year. In survival analysis, median DFS time and OS time of the AC133(+) group were 7 and 18 months, respectively, and these were not significantly different from those of the AC133(-) group (median DFS 15, OS 22 months, respectively). Our results demonstrate that AC133 expression in AML blasts is associated with poor clinical outcomes in terms of higher early relapse and shorter disease-free survival, suggesting that the AC133 antigen might provide the prognostic stratification of acute leukemia. However, to verify the effect of AC133 expression on the therapeutic outcomes of adult acute leukemia, further study including more cases is needed.
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PMID:AC133 antigen as a prognostic factor in acute leukemia. 1148 69

Little is known about the requirements for human T-cell leukemia virus type I (HTLV-I) entry, including the identity of the cellular receptor(s). Recently, we have generated an HTLV-I surface glycoprotein (SU) immunoadhesin, HTSU-IgG, which binds specifically to cell-surface protein(s) critical for HTLV-I-mediated entry in cell lines. Here, expression of the HTLV-I SU binding protein on primary cells of the immune system was examined. The immunoadhesin specifically bound to adult T cells, B cells, NK cells, and macrophages. Cell stimulation dramatically increased the amount of binding, with the highest levels of binding on CD4(+) and CD8(+) T cells. Naive (CD45RA(high), CD62L(high)) CD4(+) T cells derived from cord blood cells, in contrast to other primary cells and all cell lines examined, bound no detectable HTLV-I SU. However, following stimulation, the level of HTSU-IgG binding was rapidly induced (fewer than 6 hours), reaching the level of binding seen on adult CD4(+) T cells by 72 hours. In contrast to HTLV-I virions, the soluble HTSU-IgG did not effect T-cell activation or proliferation. When incubated with human peripheral blood mononuclear cells in a mixed leukocyte reaction, HTSU-IgG inhibited proliferation at less than 1 ng/mL. These results indicate that cell-surface expression of the HTLV SU binding protein is up-regulated during in vitro activation and suggest a role for the HTLV-I SU binding proteins in the immunobiology of CD4(+) T cells.
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PMID:Regulation of the cell-surface expression of an HTLV-I binding protein in human T cells during immune activation. 1250 39

Graft-versus-host disease (GVHD) remains a major cause of morbidity and mortality in allogeneic stem cell transplantation (alloSCT). Donor T cells that accompany stem cell grafts cause GVHD by attacking recipient tissues; therefore, all patients receive GVHD prophylaxis by depletion of T cells from the allograft or through immunosuppressant drugs. In addition to providing a graft-versus-leukemia effect, donor T cells are critical for reconstituting T cell-mediated immunity. Ideally, immunity to infectious agents would be transferred from donor to host without GVHD. Most donors have been exposed to common pathogens and have an increased precursor frequency of memory T cells against pathogenic antigens. We therefore asked whether memory CD62L-CD44+ CD4+ T cells would induce less GVHD than unfractionated or naive CD4+ T cells. Strikingly, we found that memory CD4 cells induced neither clinical nor histologic GVHD. This effect was not due to the increased number of CD4+CD25+ regulatory T cells found in the CD62L-CD44+ fraction because memory T cells depletion of these cells did not cause GVHD. Memory CD4 cells engrafted and responded to antigen both in vivo and in vitro. If these murine results are applicable to human alloSCT, selective administration of memory T cells could greatly improve post-transplant immune reconstitution.
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PMID:Memory CD4+ T cells do not induce graft-versus-host disease. 1284 55

Large granular lymphocyte (LGL) leukemia is a well-recognized disease of mature T-CD8(+) or less frequently natural killer cells; in contrast, monoclonal expansions of CD4(+) T-LGL have only been sporadically reported in the literature. In the present article we have explored throughout a period of 56 months the incidence of monoclonal expansions of CD4(+) T-LGL in a population of 2.2 million inhabitants and analyzed the immunophenotype and the pattern of cytokine production of clonal CD4(+) T cells of a series of 34 consecutive cases. Like CD8(+) T-LGL leukemias, CD4(+) T-LGL leukemia patients have an indolent disease; however, in contrast to CD8(+) T-LGL leukemias, they do not show cytopenias and autoimmune phenomena and they frequently have associated neoplasias, which is usually determining the clinical course of the disease. Monoclonal CD4(+) T-LGLshowed expression of TCRalphabeta, variable levels of CD8 (CD8(-/+dim)) and a homogeneous typical cytotoxic (granzyme B(+), CD56(+), CD57(+), CD11b(+/-)) and activated/memory T cell (CD2(+bright), CD7(-/+dim), CD11a(+bright), CD28(-), CD62L(-) HLA-DR(+)) immunophenotype. In addition, they exhibited a Th1 pattern of cytokine production [interferon-gamma(++), tumor necrosis factor-alpha(++), interleukin (IL-2)(-/+), IL-4(-), IL-10(-), IL-13(-)]. Phenotypic analysis of the TCR-Vbeta repertoire revealed large monoclonal TCR-Vbeta expansions; only a restricted number of TCR-Vbeta families were represented in the 34 cases analyzed. These findings suggest that monoclonal TCRalphabeta(+)/CD4(+)/NKa(+)/CD8(-/+dim) T-LGL represent a subgroup of monoclonal LGL lymphoproliferative disorders different from both CD8(+) T-LGL and natural killer cell-type LGL leukemias. Longer follow-up periods are necessary to determine the exact significance of this clonal disorder.
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PMID:TCRalphabeta+/CD4+ large granular lymphocytosis: a new clonal T-cell lymphoproliferative disorder. 1287 95

Altered expression or function of adhesion molecules on leukaemic blasts may contribute to the evolution and biological behaviour of acute leukaemia. This work studies the expression of CD54 and CD62L by lymphoid cells and the serum level of the shed form of L-selectin (sL-selectin) in children with acute lymphoblastic leukaemia (ALL) at initial diagnosis and after first remission, and their relationship to disease activity and subtype. The study is conducted on 20 children (age range 2-10 years) newly diagnosed with ALL and admitted to Alexandria University Children's Hospital. Ten apparently healthy children of matched age and sex serve as a control group. Expression of CD54 and CD62L on mononuclear cells is detected by monoclonal antibodies using flow cytometry. Serum sL-selectin is measured by enzyme-linked immunosorbent assay (ELISA). B-cell ALL was the most common subtype (45%), followed by T-ALL (35%) and C-ALL (20%). CD54 and CD62L mean cellular expression, as well as serum sL-selectin level, were significantly higher at diagnosis than both after remission and in the control group. Univariate analysis showed that the presence of mediastinal mass, high leucocyte count, central nervous system involvement and low CD54 were significant predictors of mortality in children with ALL.
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PMID:CD54 and CD62L expression by lymphoid cells in acute lymphoblastic leukaemia in children. 1456 Jul 91

Mismatches of minor histocompatibility antigens (mHas) between HLA-identical stem cell donors and recipients are known as a major risk factor for graft-versus-host disease (GVHD). We determined the alleles of 5 polymorphic molecules including HA-1 and 4 adhesion molecules in 102 patients who had undergone stem cell transplantation from HLA-identical donors and investigated the association of their mismatches with the relapse rate and incidence of GVHD. We observed relapse rates of 16.1% in patients with at least one or more incompatibilities and 39.4% in patients without incompatibilities (p = 0.018). The respective relapse rates of patients with CD62L, HA-1, CD31 exon 563, CD31 exon 125 and 49b incompatibilities were 6.1%, 14.3%, 11.7%, 20% and 40%. Only patients with CD62L incompatibilities showed a lower relapse rate than patients who received a compatible graft. Since there was no difference between patients with and without incompatibilities as far as the appearance of acute GVHD (> or = 2) was concerned, we conclude that the polymorphic CD62L molecule contributes to graft-versus-leukemia rather than the development of GVHD after HLA-identical stem cell transplantation.
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PMID:[Role of polymorphic adhesion molecules in the development of graft-versus-leukemia effect after HLA-matched allogeneic stem cell transplantation]. 1535 10

L-selectin plays a critical role in the initiation of normal leukocyte attachment to activated endothelium. It is expressed on most normal leukocytes and is also detectable on blast cells in ALL and AML. The shed form of L-selectin (sL-selectin) is found in plasma. High plasma sL-selectin levels were detectable in patients with AML and correlated with disease activity and poor prognosis. Little information is available on the clinical and prognostic significance of sL-selectin in ALL. The study was undertaken to determine sL-selectin levels during clinical course of patients with ALL and AML and to assess its role as a disease activity and prognostic factor. Heparinized plasma was obtained from 83 patients with newly diagnosed acute leukemia, including 30 with ALL, 50 with AML, 3 with biphenotypic leukemia and 19 healthy people. For some patients additional samples were taken in complete remission (CR) and relapse. sL-selectin was assayed using an ELISA method. The mean plasma sL-selectin concentration in all patients with acute leukemia was significantly higher than and in normals. Concentration of s-selectin L in patients with CR was significantly lower than at presentation and in the range of normals. sL-selectin plasma concentration in relapse was comparable to that from diagnosis. There was no significant difference in sL-selectin concentration between patients who entered CR after induction treatment and without CR. Patients with extramedullary disease had higher sL-selectin than patients without that manifestation. Monitoring of the sL-selectin concentration maybe useful for evaluating leukemia activity in both ALL and AML patients.
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PMID:[Plasma concentration of the shed form of L-selectin (sL-selectin) in patients with acute myeloblastic leukemia (AML) and acute lymphoblastic leukemia (ALL) and its relation to the clinical course]. 1577 9

Studies of gene expression profiling (GEP) have been successfully used for the identification of molecules to be employed as potential prognosticators. With the aim of identifying the immunophenotypic profile of B-CLL subsets with different prognoses, we investigated by flow cytometry the expression of 36 surface antigens in 117 cases, 113 with survival data. In analogy with GEP, results were analyzed by applying unsupervised hierarchical algorithms (surface-antigen expression profiling, SEP). Distinct immunophenotypic groups (A, B1, B2 and C) were identified, group C (57/117) with longer survivals, as compared to groups A (23/117), B1 (16/117) and B2 (21/117). The immunophenotypic signatures of these groups were characterized by the coordinated and differential over-expression of: i) CD62L, CD54 and CD49c (group C); ii) CD38 and CD49d (group A); iii) none of the above markers (group B1 and B2). Other molecules were either not expressed, widely expressed by all samples, or were variably expressed within the observed B-CLL subgroups, although without a clearly distinguishable pattern. By employing an identical approach for investigating the reactivity of B-cell panel monoclonal antibodies (B-mAbs) in B-CLLs (29 cases) and in 19 B and non-B leukemia/lymphoma cell lines, we found mAbs (B012, B001, B006, B018, B019, B020, B017) mainly unreactive in all the samples, mAbs (B002, B010, B013, B014, B015) strongly reactive in B-CLLs and B-cell lines but not in non-B-cell lines, and mAbs recognizing antigens variably expressed in cell lines and B-CLLs. A hierarchical clustering focused on B-CLLs alone, combining reactivity values for B-mAbs with the expression of CD62L and CD38, these latter antigens identified as leader markers of B-CLL subsets with different prognosis, demonstrated a correlation between CD62L expression and the reactivity of B007, B003, B011 and B005 mAbs. These mAbs may represent potentially novel markers with prognostic relevance in B-CLLs.
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PMID:Surface-antigen expression profiling (SEP) in B-cell chronic lymphocytic leukemia (B-CLL): Identification of markers with prognostic relevance. 1619 66


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