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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the past, studies on CD34+ cells have been based on the use of monoclonal antibodies conjugated with different fluorochromes that show different fluorescence intensity and yield variable results. Moreover, most of these studies have neither specifically focused on adult human BM samples nor have they used combinations to explore specifically the phenotype of myeloid committed CD34+ cells. The aim of the present study has been to characterize the normal human CD34+ precursor cells from adult BM in order to identify missing or extremely rare phenotypes that can be used for detecting minimal residual disease (MRD) in patients with AML. For this purpose we have utilized the fluorochrome conjugates that provide the most sensitive signals for identifying low antigenic expression, and the technique has been adapted to the characterization of cells present at very low frequencies. Normal human BM samples from 13 adult healthy volunteers have been analyzed using triple stainings at flow cytometry. The mean percentage of CD34+ cells detected was 0.72 +/- 0.33%; these cells displayed an heterogeneous light-scatter distribution. Most CD34+ cells coexpressed CD38 (96.7 +/- 5.7%), HLADR (81.6 +/- 14.0%), CD33 (84.7 +/- 18.3%), CD13 (84.6 +/- 16.2%) and CD71 antigens (65.5 +/- 9.1%). In addition, almost half of CD34+ cells were CD117+ (60 +/- 26.8%). Only a small proportion of CD34+ cells coexpressed CD4 (15.5 +/- 11.7%, CD36 (31.7 +/- 6.2%), CD61 (16.3 +/- 12.9%), CD41 (6.5 +/- 5.5%) or the lymphoid associated markers CD10 (18.6 +/- 11.8%) and CD19 (12.3 +/- 13.2%). Reactivity for the CD15 antigen was observed in a small population of CD34+HLADR+ cells (11.6 +/- 11.2%) although its intensity of expression was lower than that of the more mature granulocytic cells. No CD34+ cells displayed CD14, CD65, CD20, strong CD22, CD3 and CD56 antigens. Accordingly, most adult bone marrow CD34+ cells appeared to be committed to the myeloid lineage (CD13+/CD33+) and displayed an intermediate-to-large FSC/SSC while the lymphoid-committed CD34+ cells (CD19+, CD10+) were in a minority with low FSC/SSC values. By triple marker stainings several phenotypes of CD34+ precursor cells were found to be either undetectable or present at very low frequencies (< 1 x 10(-3)) in the normal human adult bone marrow. These data may be of great value for defining leukemia 'associated' phenotypes used to detect minimal residual disease in adult acute leukemia patients.
Leukemia 1995 Nov
PMID:Phenotypic analysis of CD34 subpopulations in normal human bone marrow and its application for the detection of minimal residual disease. 747 81

The classification of acute leukaemias is now widely based on a combined morphological, cytochemical and immunophenotyping approach. Difficulties are frequently encountered however in reaching an acceptable degree of diagnostic concordance between different laboratories because of variations in the techniques used (in terms of methodologies, reagents and equipment) and diagnostic interpretation. The International Council for Standardization in Haematology (ICSH) convened an expert panel to consider currently available diagnostic techniques with the aim of defining a minimum cytochemical and immunological diagnostic panel that could be used as core components for the classification of acute leukaemia. The proposed ICSH scheme, which attempts to balance the basic requirement for providing precise and informative diagnostic information without limiting its use to only those laboratories with sophisticated facilities, is based on three sequential levels of investigation; primary cytochemistry, intracellular phenotyping and membrane immunophenotyping. The minimum ICSH recommended cytochemistries comprise myeloperoxidase (MPO), chloroacetate esterase (ChlorE) and alpha-naphthyl acetate esterase (ANAE), and standardised methods for these cytochemistries are detailed in this communication. For cases of acute leukaemia that remain unclassified by primary cytochemistry, subsequent immunological analyses for cytoplasmic CD3, CD22, MPO and nuclear TdT are recommended. The ICSH panel considers that the use of these minimum primary cytochemical and intracellular phenotyping procedures will lead to the consistent classification of most acute leukaemias, and that the third level of investigation (membrane immunophenotyping) should be used for the purposes of confirmation, diagnostic clarification of atypical leukaemias, and the subtyping of acute lymphoblastic leukaemias (ALL). The ICSH panel also recognised that there are a number of additional technologies which can provide definitive diagnostic information, such as cytogenetics and DNA genotyping, but these were excluded from the minimum panel because of their restricted availability. While many specialised laboratories, particularly in the areas of diagnostic research, will continue to use individual investigatory protocols, it is considered that the inclusion of the ICSH scheme as core components would lead to greater consistency when comparing independent studies of acute leukaemia.
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PMID:Recommended procedures for the classification of acute leukaemias. 749 47

We have investigated the role of immunophenotyping in distinguishing between leukemic B-cell lymphoproliferative disorders. Circulating cells from 666 cases were analyzed with a panel of markers by flow cytometry. The diseases included: chronic lymphocytic leukemia (CLL), 400; prolymphocytic leukemia, 22; hairy cell leukemia (HCL), 40; HCL variant, 15; splenic lymphoma with villous lymphocytes, 100; follicular lymphoma, 26; lymphoplasmacytic lymphoma, 25; mantle-cell lymphoma, 20; and large cell lymphoma, 18. On the basis of the most common marker profile in CLL, CD5+, CD23+, FMC7- and weak expression (+/-) of surface immunoglobulin (SmIg) and CD22, we devised a scoring system that gives for each of these five markers a value of 1 or 0 according to whether it is typical or atypical for CLL. Scores range from 5 (typical of CLL) to 0 (atypical for CLL). Application of the scoring system to all the cases showed that 87% of CLL scored 5 and 4 and only 0.4% scored 0 or 1, whereas 89% of other B-cell leukemias and 72% of lymphomas scored 0 or 1; only one case (0.3%) scored 4 and none scored 5 (p < 0.0001). There were no differences between CLL with high and low scores but higher scores were found in cases with more typical morphology (p < 0.0015). Considering each individual marker, there was no single one that distinguished CLL from other diseases, although the most reliable were SmIg intensity and FMC7. The proposed score will facilitate the diagnosis of B-lymphoproliferative disorders and improve their classification.
Leukemia 1994 Oct
PMID:The immunological profile of B-cell disorders and proposal of a scoring system for the diagnosis of CLL. 752 97

Chronic lymphocytic leukemia (CLL) and hairy cell leukemia (HCL) are differentiated B-cell leukemias with well-described clinical, morphologic, and immunologic characteristics. We encountered two patients with indolent chronic B-cell leukemia showing overlapping features of these malignancies. The patients had progressive splenomegaly, minimal lymphadenopathy, and abnormal lymphoid cells with abundant cytoplasm and villi, which were strongly positive for surface antigens CD22 and CD11c, features associated with HCL. However, blood counts showed lymphocytosis without neutropenia and monocytopenia, and the bone marrow biopsies demonstrated tightly aggregated nodules of lymphocytes. In addition, the lymphoid cells were dual positive for CD19 and CD5, displaying weak-to-moderately positive monoclonal surface immunoglobulin, findings strongly suggestive of CLL. One patient failed to respond to therapy with chlorambucil and prednisone. The second patient showed a partial response to treatment with 2-chlorodeoxyadenosine. We compare our patients with similar variants of differentiated B-cell leukemias reported in the literature, including disorders described as hairy cell variant (HCL-V) or splenic lymphoma with villous lymphocytes (SLVL).
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PMID:CD5+ chronic B-cell leukemia with features intermediate to chronic lymphocytic leukemia and hairy cell leukemia. 752 21

Seventy-five adult patients with newly diagnosed acute lymphoblastic leukemia (ALL) were analyzed for CD34 expression on leukemic cells. CD34 was significantly associated with B-cell lineage ALL (p = 0.0002). In B-lineage ALL, CD34 positivity was significantly associated with expressions of CD9 (p = 0.001), CD19 (p = 0.00001) and CD22 (p = 0.002). CD34 was more expressed in B-ALLs with higher WBC cell count (p = 0.04), and higher percentage of peripheral blood leukemic cells (p = 0.005), total or partial monosomy of chromosome 7 (p = 0.0001) or Ph+ chromosome (p = 0.01); and less expressed in cases with hyperdiploidy (> or = 50 chromosomes) (p = 0.03). CD34 was more expressed in poor risk B-ALLs patients, defined according to Hoelzer criteria (p = 0.01). In T-lineage ALL, CD34 positivity was inversely correlated with the expression of CD10 (p = 0.05). After intensive induction therapy, 58 of 73 evaluable patients (79%) achieved a complete remission (CR). CD34 positivity was correlated with the persistence of blast cells in day 15 bone marrow aspirates (p = 0.001) and after one course of induction chemotherapy (p = 0.01). With a median follow-up of 11 months, no statistical differences were seen in leukemia-free survival and overall survival between CD34 positive and negative cases, even when stratifying by immunophenotype. We conclude that CD34 expression is associated with features of poor prognosis in adult ALL. Its study might therefore become useful in the design of future prognostic models.
Leukemia 1995 Feb
PMID:CD34 expression is associated with major adverse prognostic factors in adult acute lymphoblastic leukemia. 753 67

New technology allows highly sensitive flow cytometric detection and quantitative analysis of intracellular antigens in normal and malignant hemopoietic cells. With this technology, the earliest stages of myeloid and lymphoid differentiation can easily and reliably be identified using antibodies directed against (pro-)myeloperoxidase/MPO, CD22 and CD3 antigens, respectively. Particularly for the analysis of undifferentiated acute myeloblastic leukemia (AML) cells, the immunological demonstration of intracellular MPO or its enzymatically inactive proforms is highly relevant, since other myeloid marker molecules such as CD33, CD13, or CDw65 are either not restricted to the granulomonocytic lineage or appear later in differentiation. By combining MPO staining with staining for lactoferrin (LF), undifferentiated cells can be distinguished from the granulomonocytic maturation compartment in bone marrow, since LF is selectively expressed from the myelocyte stage of differentiation onward. The list of informative intracellular antigens to be used in leukemia cell analysis will certainly expand in the near future. One candidate, intracellular CD68, has already been tested by us, and results are presented. Also dealt within this article are surface marker molecules not (as yet) widely used in leukemia cell analysis but with the potential to provide important additional information. Among them are the surface structures CD15, CD15s, CDw65, CD79a (MB-1), CD79b (B29), CD87 (uPA-R), and CD117 (c-kit).
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PMID:Flow cytometric analysis of cell-surface and intracellular antigens in leukemia diagnosis. 753 75

A case of 77-year-old female with multiple myeloma (IgG-k) developed acute myelomonocytic leukemia (AMMoL) following a myelodysplastic stage after chemotherapy with melphalancyclophosphamide combinations for 6 years. The leukemic blast cells expressed both myeloid antigens (CD11b, CD13, CD14, CD15, CD33 and CD34) and T/B lymphoid antigens (CD2, CD4, CD22 and PCA1). Cytogenetic analysis revealed a chromosome deletion -7. Analysis of immunoglobulin genes showed the heavy chain genes in germ line configuration. These findings indicate that the AMMoL was a therapy-related stem cell leukemia and was a clonal origin genetically different from multiple myeloma irrespective of plasma cell phenotype.
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PMID:Acute myelomonocytic leukemia in a patient with multiple myeloma: evidence for different clonal origin. 754 40

This study assesses the value of immunologic and ultrastructural methods in disclosing the lineage commitment of cells from acute leukemias (ALs). Two hundred and fifty-one ALs were characterized morphologically, cytochemically, and immunologically. Myeloperoxidase (MPO) positivity in > 3% of blasts was regarded as evidence of the myeloid origin of leukemic cells, cytoplasmic CD22 (cCD22) expression was taken as an indication for B-lineage acute lymphoblastic leukemia (ALL), and CD3+ (membrane or cytoplasmic) cases were classified as T-ALL. Diagnosis of minimally differentiated acute myeloid leukemia (AML-M0) was made when blast cells had undifferentiated features by light microscopy, reacted with at least one of the antibodies to myeloid-specific antigens (CD13, CD33, MPO), and lacked CD19, cCD22, and c/mCD3. Megakaryoblastic differentiation was demonstrated by the expression of CD41 and/or CD61. Following these criteria, 209 cases were classified as acute myeloid leukemia (AML) and 39 as ALL. Expression of lymphoid antigens was detected in 45% of AML cases and 30% of ALLs showed myeloid antigens. One case was regarded as a true biphenotypic leukemia because of the combined expression of MPO and CD33 for the myeloid lineage, and cCD3, CD2, and CD5 for the T-cell lineage. Two cases lacked signs of myeloid or lymphoid differentiation and were studied by electron microscopy methods. One displayed platelet peroxidase (PPO) activity and was classified as a megakaryoblastic variant, one other reacted with anti-CD33 and was considered AML-M0. We conclude that light microscopy and standard immunologic methods can accurately demonstrate the lineage orientation in greater than 99% of ALs. Integration with ultrastructural analysis can define the cell nature of virtually all cases of AL.
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PMID:Lineage identification of acute leukemias: relevance of immunologic and ultrastructural techniques. 755 58

To get more insight into the phenotypic changes of childhood acute lymphoblastic leukemia (ALL) at relapse, a detailed morphological and immunophenotypic study in 40 childhood ALL cases (32 precursor B-ALL and 8 T-ALL) was performed. Expression patterns of non-lineage specific markers (terminal deoxynucleotidyl transferase (TdT), CD34, and HLA-DR), B-lineage markers (CD10, CD19, CD20, and CD22), T-lineage markers (CD1, CD2, CD3, CD4, CD5, CD7, and CD8), and cross-lineage myeloid markers (CD14, CD15, and CD33) were compared at diagnosis and relapse. In case of low blast counts (< or = 70%) at relapse, double labeling for membrane markers and TdT was used in order to define the precise immunophenotype of the TdT+ leukemic cells. An immunological marker-shift was defined as either a conversion from positive to negative and vice versa or a difference in positivity of > or = 50%. Morphological differences between diagnosis and relapse were detected in 34% of precursor B-ALL and 14% of T-ALL. Differences in immunological marker expression were found in 72% of precursor B-ALL and in 75% of T-ALL, and generally concerned minor shifts with loss or acquisition of a few markers. The morphological shifts and immunophenotypic shifts were not correlated. Immunophenotypic shifts were found for all markers tested in precursor B-ALL, except for HLA-DR. Shifts in CD10 expression (16% of cases) were only observed in relapses occurring 30 months or more after diagnosis. In four precursor B-ALL an intra-lineage shift was found at relapse (one common ALL to null ALL and three pre-B-ALL to common ALL or null ALL) and two precursor B-ALL cases were diagnosed as acute non-lymphocytic leukemia at relapse based on morphology and immunophenotype. In T-ALL, neither intra-lineage nor inter-lineage shifts were observed, although shifts were detected in all T cell markers tested, except for the lineage specific CD3 and T cell receptor (TcR) markers. In conclusion, immunophenotypic shifts at relapse frequently occur in precursor B-ALL and T-ALL, in a small percentage leading to an intra-lineage shift (10%) or inter-lineage shift (5%). Therefore immunophenotypic monitoring of minimal residual disease in ALL patients should be based on multiple marker combinations, preferably together with polymerase chain reaction analysis of rearranged immunoglobulin and/or TcR genes or chromosome aberrations.
Leukemia 1995 Sep
PMID:Immunophenotypic changes between diagnosis and relapse in childhood acute lymphoblastic leukemia. 765 22

A portion of patients with acute myeloid leukemia also display surface antigens associated with lymphoid development (Ly+AML). The incidence of Ly+AML varies considerably between independent studies, both overall and with regard to individual antigens. On average, lymphoid-associated antigen expression is relatively low in AML. The reasons for some striking differences between conflicting reports are not clear, but are most probably due to various technical aspects including several arbitrary parameters. The data accumulated from the literature lead to the following conclusions: (i) use of different reagents against the CD surface antigens, different positive/negative cut-off levels, analysis of fresh or frozen cell material and variable sensitivities of the analytical instruments (expression of lymphoid-associated antigens was commonly weaker than myeloid-associated markers) seriously influence the results; (ii) most antigens (CD1, CD2, CD3, CD5, CD8, CD10, CD19, CD20, CD21, CD22) were expressed on less than 10% of AML cases; (iii) the CD4 and CD7 antigens, also found on normal monocytic and immature myeloid progenitor cells, were detected in 24% and 15% of AML cases, and their expression correlated with FAB M4/M5 and M1/M2 morphology, respectively; (iv) differences between pediatric and adult Ly+AML were restricted to CD4 and CD19 expression being detected more often in childhood cases; (v) there is no cytogenetic anomaly specific for Ly+AML; anomalies exclusively associated with lymphoid malignancies were not seen; aberrations involving 11q23, 14q32, and the 9;22 translocation seem to be increased; (vi) in most studies, expression of lymphoid-associated antigens (with the exception of CD7) on AML blasts lacked prognostic significance; CD7+AML appears to be a particular subset of malignant myeloid progenitors. In summary, these findings suggest that in general, Ly+AML may not represent a biologically distinct form of leukemia as these cases have similar clinical features and respond to therapy in a comparable manner.
Leukemia 1993 Apr
PMID:Acute myeloid leukemias expressing lymphoid-associated antigens: diagnostic incidence and prognostic significance. 768 17


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