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)

The monoclonal antibody 013, which detects the cell surface glycoprotein p30/32mic2 (CD99) is a characteristic, if nonspecific, marker for peripheral neuroepithelioma and Ewing's sarcoma. 013 was first produced against a human thymus leukemia antigen and has also been found in immature terminal deoxynucleotidyl transferase (TdT)-positive T cells and in a small group of hematopoietic precursor cells in the bone marrow. 013 is reactive in lymphoblastic lymphomas and acute leukemias, as well as in a variety of other hematologic malignancies. Because the distribution of 013 positivity in hematopoietic proliferations is similar to that of TdT, we hypothesized that 013 might correlate with TdT positivity. We studied 67 lymphoblastic lymphomas and acute lymphoblastic leukemias, 6 chronic myelogenous leukemias in blast crisis, a variety of acute myeloid leukemias, 5 granulocytic sarcomas, and a spectrum of 94 diffuse lymphomas other than lymphoblastic type. With the use of heat-induced epitope retrieval and automated immunostaining, we compared the results obtained with 013 and TdT, a well-established marker of lymphoblastic lymphomas and acute lymphoblastic leukemias that can also be successfully demonstrated in tissue sections by use of a similar technique. In our study, all of the 013-positive cases were also TdT positive. 013 reacted with 44 (71%) of 62 of the TdT-positive lymphoblastic lymphomas and acute lymphoblastic leukemias cases studied. We also found 013 to be positive in one case of TdT-positive acute myeloid leukemia, in two cases of chronic myelogenous leukemia in blast crisis, and in three TdT-positive granulocytic sarcomas. 013 was negative in all of the other high-grade malignant lymphomas and in TdT-negative leukemias. With use of our technique, 013 positivity appears to be restricted to hematologic proliferations that demonstrate TdT positivity. 013 may be a helpful additional marker in the diagnosis of TdT-positive leukemias and lymphomas in conventionally processed tissue sections.
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PMID:013 (CD99) positivity in hematologic proliferations correlates with TdT positivity. 911 Feb 87

The diagnosis of leukemia cutis and distinction of early myeloid cells and blasts from lymphoblasts or other lymphoid cells can be difficult, particularly if only fixed tissue is available. O13, a monoclonal antibody that recognizes CD99, the p30/32MIC2 gene product, has been used to identify a number of cell types, including lymphoblasts, in paraffin sections. To evaluate the usefulness of CD99 immunoreactivity in the diagnosis of leukemia cutis, we analyzed cases of cutaneous involvement by acute lymphoblastic leukemia/lymphoblastic lymphoma and acute myelogenous leukemia for the presence of this marker. Without the use of antigen retrieval methods, lymphoblasts in cases of cutaneous involvement by acute lymphoblastic leukemia/lymphoblastic lymphoma were immunoreactive for CD99 in 9 of 9 cases. Myeloblasts and early myeloid cells in cases of cutaneous involvement by acute myelogenous leukemia were immunoreactive for CD99 in 12 (80%) of 15 cases. We conclude that CD99 is a sensitive but nonspecific marker for cutaneous involvement by acute lymphoblastic leukemia/lymphoblastic lymphoma and that CD99 is immunoreactive in the vast majority of cases (21 [88%] of 24 cases) of leukemia cutis.
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PMID:CD99 (p30/32MIC2) immunoreactivity in the diagnosis of leukemia cutis. 911 Feb 88

Leukemic cells of B-lineage acute lymphoblastic leukemia (ALL) are regarded as the malignant counterparts of immature, physiologic B cell precursors (BCPs). To determine whether phenotypic differences exist between these corresponding cell types, we investigated samples of normal pediatric bone marrow (n=30) as well as of B-precursor ALL at diagnosis (n=53; common and pre-B subtype). Using three-color multiparameter flow cytometric analysis, we compared the leukemic populations with the physiologic BCPs of corresponding maturity with respect to the intensity with which they expressed a series of antigens. In some of these antigens, leukemia-associated aberrations were frequently observed. In particular, overexpression of CD10 was displayed by 65% of ALL samples, whereas 58% of leukemic cases aberrantly exhibited very low or no CD45RA expression. Regarding CD11a and CD44, 47% and 35% of ALL populations were aberrant as defined by either the absence or significant overexpression of the antigen. In contrast, antigen densities of CD49d, CD49e, and CD99 on leukemic cells were in the normal range of values for BCPs. Combining the patterns of frequently aberrant markers in a comprehensive analysis, we were able to identify individual phenotypic leukemic cell aberrations in up to 98% of investigated cases. CD10 and/or CD45RA were aberrant in 86% of cases overall, emphasizing the high discriminative potential of these two markers. Using comparative phenotype mapping based on quantitatively aberrant, leukemia-associated antigenic patterns, we were able to detect leukemic blasts among normal bone marrow cells at frequencies as low as 10(-5). We speculate that our approach may have a profound impact on the development of new strategies for minimal residual disease investigations in patients with BCP-ALL.
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PMID:Comparative phenotype mapping of normal vs. malignant pediatric B-lymphopoiesis unveils leukemia-associated aberrations. 954 13

We have recently shown that CD99 (MIC2) is differentially expressed during normal early B-cell development in the bone marrow (BM). Since immature B-cell precursors (BCP) are assumed to correspond to some extent to acute lymphoblastic leukaemia (ALL) and non-Hodgkin's lymphoma (NHL) cells with respect to patterns of phenotypic differentiation, we wondered whether the particular maturation-associated expression patterns of CD99 in the normal BCP stages were conserved also in malignant cells. Therefore we compared malignant and physiological B cells from paediatric ALL/NHL and normal BM samples with respect to CD99 expression using selective gating and semi-quantitative flow cytometry. Common-ALLs (n = 45) were similar to their corresponding, very immature BCPs (stage 1) in expressing very high levels of CD99. Most pre-B ALLs (n = 16) were also CD99hi and thus differed from the patterns found in normal cytoplasmic mu-chain+ (cmu+) pre-B cells (stage 2, CD99lo). In particular, we found that those pre-B-ALL cases which were CD34+ also showed higher CD99 expression than the CD34- cases. This prompted us to investigate the levels of CD99 in those rare normal BCPs which also coexpress CD34 and cmu; these cells, which are transitory from stage 1 to stage 2, were found also CD99hi, thus precisely reflecting the patterns of CD34+ pre-B ALLs. The blasts of Burkitt-type B-cell ALL/NHL samples (n = 13) expressed considerably less CD99, similarly to the more differentiated BCP stages 2 (cmu+) and 3 (surface mu-chain+). In summary, we found that paediatric B-lineage malignancies display remarkable synchrony regarding the levels of CD99 expression compared to their putative normal counterparts.
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PMID:CD99 (MIC2) expression in paediatric B-lineage leukaemia/lymphoma reflects maturation-associated patterns of normal B-lymphopoiesis. 1035 33

MIC2 is characteristically expressed in lymphoblastic lesions and Ewing's/primitive neuroectodermal tumor sarcomas. Although MIC2 has recently been reported in chloroma and rare terminal deoxynucleotidyl transferase-positive acute myelogenous leukemia (AML), the incidence and the significance of MIC2 (CD99) immunoreactivity in myeloid lesions is not clear. In this study, we evaluated MIC2 positivity in a variety of myeloid diseases and normal marrow to determine its incidence and distribution in myeloid diseases; its correlation with flow cytometric and cytogenetic data in AML; and its association with leukemic transformation, relapse, and chloroma formation. Paraffin sections of 11 chloromas and 94 bone marrow core biopsies from 66 patients were stained with CD99 monoclonal antibody 12E7. Of 94 bone marrow core biopsies, there were 30 AML (fragment antigen binding M0 to M6), 23 remissions, 5 relapses, 12 myeloproliferative disorders, 13 myelodysplastic syndromes, and 11 normal marrows from patients who did not have leukemia. CD99 immunoreactivity was evaluated with light microscopy. MIC2 expression was seen in leukemic blasts in 6 of 11 chloromas (55%) and 13 of 30 AML (43%) but rarely in myeloproliferative disorders, myelodysplastic syndromes, remission, and normal marrow. CD99 tended to be positive in M1-, M3-, and HLA-Dr-negative AML and negative in AML with relapse. MIC2 expression did not correlate with the karyotype independent of French-American-British Cooperative Group classification and the disease remission or occurrence of chloroma in AML. We concluded that MIC2 is commonly expressed in leukemic blasts of AML and is not predictive of leukemic transformation from myeloproliferative disorders and myelodysplastic syndromes or chloroma formation. Caution should be taken when using MIC2 as a marker for Ewing's sarcoma/ primitive neuroectodermal tumor or lymphoblastic lymphoma on paraffin sections of either soft tissue or bone marrow specimens.
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PMID:Immunoreactivity of MIC2 (CD99) in acute myelogenous leukemia and related diseases. 1078 14

To develop a practical immunohistochemistry panel for distinguishing lymphoblastic lymphoma from Ewing sarcoma (ES), we evaluated 17 ES and 27 lymphoblastic lymphoma and leukemia cases with antibodies to CD99, terminal deoxynucleotidyl transferase (TdT), leukocyte common antigen (LCA), CD43, CD79a, CD20, CD3, vimentin, and neuron-specific enolase (NSE). Three cases were bone lymphomas, 2 initially misdiagnosed as ES. All cases were CD99+. All lymphomas and leukemias were TdT+ compared to none of the ESs. None of the ESs expressed other lymphocytic markers, which were inconsistently expressed in the lymphomas and leukemias: CD43, 33%; LCA, 30%; CD79a, 19%; CD3, 19%; and CD20, 7%. Of the ESs, 88% were vimentin positive compared with 23% of lymphomas and leukemias. Vimentin was stronger and more diffuse in ES. NSE did not reliably stain any cases. When faced with the differential diagnosis of ES vs lymphoblastic lymphoma, an immunohistochemical panel that includes antibodies to CD99 and TdT is useful. Both epitopes are well preserved in fixed and decalcified tissue. A panel composed of antibodies to CD99 and TdT, in conjunction with other lymphocytic markers and vimentin, is highly sensitive and specific.
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PMID:Ewing sarcoma vs lymphoblastic lymphoma. A comparative immunohistochemical study. 1139 89

To investigate the occurrence of lymphoid progenitor cells in human tonsils, we studied tonsils from children and adults by immunohistochemistry by using a panel of antibodies to antigens associated with lymphoid progenitor cells, including terminal deoxynucleotidyl transferase (TdT), CD10 (CALLA), CD34, CD99 (p30/32mic2), and CD117 (c-kit), and compared them to reactive lymph nodes. Lymphoid progenitor cells, positive for TdT, CD10, and CD99, but not CD34 or CD117, were readily identified in tonsils from children and adults (TdT, 14 of 15; CD10, 15 of 15; CD99, 11 of 15), but were rarely present in lymph nodes (TdT, 1 of 8; CD10, 1 of 8; CD99, 0 of 8). Lymphoid progenitor cells in tonsils were localized to discrete foci at the periphery of lymphoid lobules adjacent to fibrous septae. Lymphoid progenitor cells are present in human tonsils, and the tonsils are a potential site of postnatal lymphopoiesis. The presence of lymphoid progenitor cells in human tonsils should not be confused with lymphoblastic lymphoma or leukemia.
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PMID:Lymphoid progenitor cells in human tonsils. 1259 13

Expression of CD99 is higher on immature than on mature T cells. We postulated that this marker could be used to assess minimal residual disease (MRD) in T-lineage acute lymphoblastic leukemia (T-ALL). In diagnostic bone marrow (BM) samples from 27 children with T-ALL, expression of CD99 on leukemic lymphoblasts by flow cytometry was in median 7.7 times higher than on normal T lymphocytes from within the same sample. In 85% of cases, leukemic MFI values were higher than the mean MFI+2 s.d. of normal populations. We applied CD99 to study MRD in 39 follow-up samples from 15 consecutive T-ALL patients, and compared the results with those obtained with the well-established MRD-marker terminal deoxynucleotidyl transferase (TdT). Either antibody was combined in four-color flow cytometry with CD7, surfaceCD3, and cytoplasmicCD3. We found that CD99 was a valid complement to TdT in quantifying T-ALL MRD. Given a considerable interpatient variability, CD99 could be favorably used in nine patients, and TdT in other five patients. Both approaches showed a similar very low nonspecific background throughout 12 weeks from diagnosis (in median 0.002% of nucleated BM cells in patients with non-T ALL). We conclude that CD99 is a highly informative tool for MRD detection in T-ALL, bearing the advantage of surface expression in contrast to TdT.
Leukemia 2004 Apr
PMID:CD99 expression in T-lineage ALL: implications for flow cytometric detection of minimal residual disease. 1496 Oct 34

Myeloid sarcoma (MS) is a rare neoplasm whose knowledge is largely based on case reports and/or technically dated contributions. Ninety-two MSs in adulthood with clinical data available were evaluated both morphologically and immunohistochemically. Seventy-four cases were also studied by fluorescent in situ hybridization on tissue sections and/or conventional karyotyping on bone marrow or peripheral blood. Histologically, 50% of the tumors were of the blastic type, 43.5% either monoblastic or myelomonocytic and 6.5% corresponded to different histotypes. CD68/KP1 was the most commonly expressed marker (100%), followed by myeloperoxidase (83.6%), CD117 (80.4%), CD99 (54.3%), CD68/PG-M1 (51%), CD34 (43.4%), terminal-deoxy-nucleotidyl-transferase (31.5%), CD56 (13%), CD61/linker for activation of T cells (2.2%), CD30 (2.2%) and CD4 (1.1%). Foci of plasmacytoid monocyte differentiation were observed in intestinal cases carrying inv16. Chromosomal aberrations were detected in about 54% of cases: monosomy 7(10.8%), trisomy 8(10.4%) and mixed lineage leukemia-splitting (8.5%) were the commonest abnormalities, whereas t(8;21) was rare (2.2%). The behavior was dramatic irrespective of presentation, age, sex, phenotype and cytogenetics. Most if not all, long survivors received bone-marrow transplantation. The present report expands the spectrum of our knowledge showing that MS has frequent monoblastic/myelomonocytic differentiation, displays distinctive phenotypic profile, carries chromosomal aberrations other than t(8;21), and requires supra-maximal therapy.
Leukemia 2007 Feb
PMID:Myeloid sarcoma: clinico-pathologic, phenotypic and cytogenetic analysis of 92 adult patients. 2700 46

The aim of this study was to investigate the clinical, pathological and biological features of biphenotypic acute leukemia. The morphology of tumor cells was observed by bone marrow examination; the immunophenotype was assayed by flow cytometry and immunohistochemistry; the chromosomal aberrations were detected by conventional chromosomal analysis and RT-multiplex nested PCR. The results showed that extramedullary skin lesions and myelodysplasia occurred before the onset of overt disease. At the time of diagnosis, this case had more than 30% blasts in bone marrow with meningeal involvement. Large-sized tumor cells predominated morphologically over other cells. Flow cytometry revealed the co-expression of myeloid antigens (cMPO, CD33 and CD117) and T-lymphoid antigens (cCD3, CD5, CD7, dual expression of CD4 and CD8). Immunohistochemical staining showed that CD43 and CD99 were strong positive which define the earliest hematopoietic progenitors. Partial tandem duplication of the MLL gene could be detected with normal cytogenetic method. All above-mentioned results led to the diagnosis of biphenotypic acute leukemia. It is concluded that the biphenotypic acute leukemia is an uncommon type of leukemia which may be preceded by myelodysplastic syndrome and has aggressive clinical and biological behavior. Immunophenotype, cytogenetics and molecular analysis can contribute to early diagnosis of BAL and evaluation of prognosis.
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PMID:[Skin lesions and myelodysplastic syndrome as initial manifestations of biphenotypic acute leukemia]. 1795 70


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