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C C Stewart

Publications and source records attributed to C C Stewart.

At least 19 recordsLinked to original sources
PubMed2001

High frequency of immunophenotype changes in acute myeloid leukemia at relapse: implications for residual disease detection (Cancer and Leukemia Group B Study 8361).

Multiparameter flow cytometry (MFC) has the potential to allow for sensitive and specific monitoring of residual disease (RD) in acute myeloid leukemia (AML). The use of MFC for RD monitoring assumes that AML cells identified by their immunophenotype at diagnosis can be detected during remission and at relapse. AML cells from 136 patients were immunophenotyped by MFC at diagnosis and at first relapse using 9 panels of 3 monoclonal antibodies. Immunophenotype changes occurred in 124 patients (91%); they consisted of gains or losses of discrete leukemia cell populations resolved by MFC (42 patients) and gains or losses of antigens on leukemia cell populations present at both time points (108 patients). Antigen expression defining unusual phenotypes changed frequently: CD13, CD33, and CD34, absent at diagnosis in 3, 33, and 47 cases, respectively, were gained at relapse in 2 (67%), 15 (45%), and 17 (36%); CD56, CD19, and CD14, present at diagnosis in 5, 16, and 20 cases, were lost at relapse in 2 (40%), 6 (38%), and 8 (40%). Leukemia cell gates created in pretreatment samples using each 3-antibody panel allowed identification of relapse AML cells in only 68% to 91% of cases, but use of 8 3-antibody panels, which included antibodies to a total of 16 antigens, allowed identification of relapse AML cells in all cases. Thus, the immunophenotype of AML cells is markedly unstable; nevertheless, despite this instability, MFC has the potential to identify RD in AML if multiple antibody panels are used at all time points. (Blood. 2001;97:3574-3580)

Adolescent↗
PubMed2001

Multiparameter data acquisition and analysis of leukocytes by flow cytometry.

Each laboratory has to establish its own experience base and standard operating procedures. The intent of this discussion has been to illustrate the procedures that will lead to good flow cytometry data acquisition and analysis and to illustrate problematic areas. The most important rule of all is to recognize when there is a problem and find the correct solution. It is hoped the information provided herein will be of help in the recognition process.

Antibodies↗
PubMed2001

HLA class I antigen cell surface expression is preserved on acute myeloid leukemia blasts at diagnosis and at relapse.

Human leukocyte antigens (HLA) class I molecules restrict the interaction between cytotoxic T cells and target cells. Abnormalities in HLA class I antigen expression and/or function may provide tumor cells with a mechanism for escaping immune surveillance and resisting T cell-based immunotherapies. The potential for applying T cell-based immunotherapy in the treatment of acute myeloid leukemia (AML) has stimulated interest in analyzing HLA class I antigen expression on leukemic blasts in this disease. Little information is available in the literature. We have analyzed HLA class I antigen expression on bone marrow samples from 25 newly diagnosed AML patients by indirect immunofluorescence staining with monoclonal antibodies. Five of these patients were also studied at relapse. Leukemic blasts were resolved from normal lymphocytes by staining with antiCD45 antibody; CD45 expression is dim on leukemia cells, but bright on lymphocytes. HLA class I antigen expression was higher on leukemic blasts than on autologous lymphocytes in all but one case. Moreover, there was no significant change in HLA class I antigen expression at relapse. These results suggest that abnormalities in HLA class I antigens are infrequent in AML and should not represent a major obstacle to the application of T cell-based immunotherapies in this disease.

Acute Disease↗
PubMed2001

Stereotactic core biopsy breast and blood cell by-products: a source of material for molecular genetics research--initial experience.

Stereotactic core biopsy washings and blood drop samples, routinely discarded by-products, provide satisfactory fresh cellular material for flow cytometry and molecular genetics microsatellite polymerase chain reaction (PCR) analysis for detection of loss of DNA alleles (loss of heterozygosity). Cytokeratin-positive (epithelial) cells from the core biopsy washings were sorted by means of flow cytometry prior to PCR analysis. DNA allele loss was detected in benign breast epithelial cells in three (20%) of 15 patients.

Adult↗
PubMed2000

Use of specimen mammography-guided FNA (fine-needle aspirates) for flow cytometric multiple marker analysis and immunophenotyping in breast cancer.

A pilot study of a novel translational research method to simultaneously assay multiple molecular markers and DNA in fine-needle aspirates (FNA) of mammographically detected breast lesions is described. Specimen mammography-guided 20-gauge FNAs obtained from 86 lesions and 22 areas of normal tissue were analyzed by multiparameter flow cytometry for DNA content, her2/neu, transforming growth factor alpha (TGF alpha), and the epithelial marker cytokeratin (CK) simultaneously. Epithelial cell her2/neu positivity was detected in 12 of 44 (27%) of invasive ductal carcinomas and 3 of 9 (33%) ductal carcinoma in situ (DCIS), 10 of 30 (33%) benign lesions, and 4 of 22 (18%) normal tissue aspirates. All lesions and normal tissue showed a similar positive rate for TGFalpha ranging from 61 to 76%. The CK(+)TGF alpha(-)her2/neu(+) immunophenotype was more frequently positive in aneuploid tumors (22%) than all other lesions (7%) (P < 0.05). Specimen mammography-guided FNAs provide fresh cells for flow cytometric multiple marker analysis and immunophenotyping of clinically occult breast lesions and normal tissue.

Adult↗
PubMed2000

Immunoreactivity of MIC2 (CD99) in acute myelogenous leukemia and related diseases.

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.

12E7 Antigen↗
PubMed2000

Flow cytometric DNA analysis of specimen mammography-guided fine-needle aspirates of ductal carcinoma in situ.

Flow cytometric studies of screening mammography detected ductal carcinoma in situ (DCIS) are limited by the lack of fresh cell samples. We have performed flow cytometric DNA analyses of specimen mammography-guided fine-needle aspirates of 50 consecutive DCIS lesions detected by screening mammography. The comedo histologic subtype had an aneuploidy rate of 39% (9 of 23); noncomedo subtypes had an aneuploidy rate of 19% (5 of 27), p=ns. Noncomedo subtypes were more likely to have low (less than 2.2%) S-phase percentages, 59% (16 of 27) as compared to comedo, 9% (2 of 23), p<0.05. High and intermediate nuclear grade DCIS lesions had an insignificantly greater rate of aneuploidy, 35% (9 of 26) and 33% (4 of 12) respectively, as compared to low nuclear grade lesions, 8% (1 of 12), p=ns. Low and intermediate nuclear grade DCIS lesions had low S-phase percentage rates of 67% and 50% respectively, as compared to the high nuclear grade lesions low S-phase percentage rate, 15%, p=ns. Aneuploidy and lesser rates of low S-phase percentages were significantly associated with necrosis and apoptosis. Our data suggest that flow cytometric DNA analysis of mammographic lesion-specific, fresh cell samples obtained by fine-needle aspiration under specimen mammographic guidance can assess mammography-detected DCIS lesions when gross fresh tissue procurement is not possible.

Adult↗
PubMed1999

Four color compensation.

Four-color immunophenotyping can now be routinely performed using either a single laser or dual laser flow cytometer. When a single laser instrument is used, the fluorochromes evaluated are usually FITC, PE, PE-TR and PE-CY5 (or PerCP). For two-laser excitation APC is generally used in place of PE-TR. Since each tandem dye construct contains PE, three of the four detectors are affected and compensation can be problematic. In this report we show that each tandem conjugated antibody, whether different batches from the same supplier or conjugates from different suppliers all require unique compensation. This inconsistency results in erroneous data, negates the use of single labeled particles as a method for providing adequate compensation and requires dual and triple labeled cells of known pattern to verify compensation. It is also shown that improper compensation can reduce or eliminate completely the detection of fluorescence emission from PECY5 conjugated antibodies. These problems are caused by a variation in energy transfer between PE and either TR or CY5 because the chemistry involved in preparation and conjugation to antibodies is not sufficiently controlled to produce reagents with uniform compensation requirements. The variation in tandem dye compensation can be addressed by either using the same tandem conjugated antibody, by using the same second step tandem reagent to an appropriate first step antibody or by using software compensation. The latter provides an easy solution because a unique compensation matrix can be produced for each antibody tandem conjugate.

Antibodies↗
PubMed1999

Effects of thermal exposure on immunophenotyping combined with in situ PCR, measured by flow cytometry.

BACKGROUND: The combination of in situ PCR and cell phenotyping by antibody labeling (ISPCR/Flow) allows for the identification of cell subsets carrying a particular genetic sequence. ISPCR utilizes thermal cycling for genetic amplification, which can reduce the effectiveness of surface antibody labeling. This study explored and characterized the effects of thermal exposure on antibody labeling using CD4 and CD45. METHODS: Single temperature incubations and thermal cycling exposures were performed on leukocytes labeled with either direct antibody conjugates or with biotinylated antibodies and PE-streptavidin. RESULTS: Fluorescence emission decreased above 70 degrees ( )C when cells were stained with directly conjugated antibodies or a biotinylated antibody and PE-streptavidin prior to high heat exposure. If counter stained with PE-streptavidin after heat, fluorochrome fluorescence was detectable. We tested a second CD4 clone, that provided poor results under similar labeling conditions, suggesting the combination of fixation and heat may have an epitope specific effect for the same cellular antigen. CONCLUSIONS: Immunophenotyping can be combined with ISPCR, but each antibody must be tested to determine its efficacy. The denaturation of protein above 70 degrees C appears to be the main reason for loss of fluorescence. The best procedure is to first stain cells with a biotinylated antibody to an epitope that survives fixation and thermocycling. The cells are then subjected to the desired PCR procedure. Finally they are stained with a fluorochrome conjugated streptavidin.

Antibodies↗
PubMed1999

Value of immunophenotype in intensively treated adult acute lymphoblastic leukemia: cancer and leukemia Group B study 8364.

The prognostic value of immunophenotype in adult acute lymphoblastic leukemia (ALL) has varied based on the methods used, surface markers studied, and therapy administered. From April 1991 to September 1996, samples of leukemic marrow or blood from 259 eligible and evaluable adult ALL patients entering dose-intensive Cancer and Leukemia Group B (CALGB) front-line treatment protocols were prospectively studied for immunophenotypic classification by multiparameter flow cytometry (MFC) in a central laboratory. A B-lineage (B-LIN) phenotype was expressed in 79% of cases, with one third coexpressing myeloid antigens. A T-lineage (T-LIN) phenotype was expressed in 17% of cases, with one quarter coexpressing myeloid antigens. Since the advent of more intensive CALGB therapy which incorporated cyclophosphamide and the early use of L-asparaginase into the backbone of daunorubicin, vincristine and prednisone, together with central nervous system prophylaxis for adult ALL, no significant differences in response rates, remission duration, or survival have been seen in those patients coexpressing myeloid antigens. The T-LIN phenotype was associated with younger age (P =.01), a higher male to female ratio (P =.01), higher white blood cell count (P =.001) and hemoglobin (P <.001) levels, presence of a mediastinal mass (P <. 001), and longer survival (P =.01) and disease-free survival (DFS) (P =.01) when compared to patients with a B-LIN phenotype. The 3-year probability of survival and DFS (95% confidence interval [CI]) of T-LIN adult ALL was 0.62 (0.46 to 0.76) and 0.62 (0.44 to 0. 77), respectively. Comparatively, the 3-year probability of survival and DFS (95% CI) of B-LIN adult ALL was 0.42 (0.35 to 0.50) and 0.39 (0.31 to 0.47), respectively. The number of T markers expressed in T-LIN ALL cases was shown to have prognostic significance. In particular, patients expressing six or more markers compared with patients expressing three or fewer markers had longer DFS (P =.003) and survival (P =.004). The presence of the Philadelphia chromosome was significantly associated with B-LIN ALL cases which coexpressed CD19(+), CD34(+), and CD10(+) (49%; P =.003), whereas the majority of t(4;11) cases were CD19(+), CD34(+) but CD10(-). The knowledge gained from this study of MFC of a large number of patients will permit a reduction in the number of antigens to be evaluated in future studies. Overall, this should lead to cost savings without loss of valuable information. A rational approach for future studies would be to use four-color flow cytometry (instead of the current three-color) to help further streamline the study of immunophenotype of adult ALL by MFC.

Adolescent↗
PubMed1999

Prospective karyotype analysis in adult acute lymphoblastic leukemia: the cancer and leukemia Group B experience.

The Cancer and Leukemia Group B (CALGB) has been conducting a prospective cytogenetic companion study (CALGB 8461) to all CALGB treatment protocols for newly diagnosed adults with acute lymphoblastic leukemia (ALL). These protocols underwent a significant change in 1988 when a new intensive chemotherapy program was introduced (CALGB 8811). We asked whether karyotype continued to represent a significant prognostic factor in adult ALL patients after the change. A total of 256 patients had adequate pretreatment cytogenetic analyses: 67 before 1988 and 189 subsequently. The complete remission (CR) rate for the whole group was 80%. Patients with t(9;22), t(4;11), -7, or +8 had significantly lower probabilities of continuous CR and survival at 5 years (.11 and.12) than patients with a normal karyotype (.38 and.37) and patients with miscellaneous cytogenetic abnormalities (.52 and.49; P <.001 for each comparison). When analyzed by treatment period, the CR rate before CALGB 8811 was 63%; subsequently, it was 86% (P <.001). Patients with cytogenetic abnormalities other than t(9;22), t(4;11), -7, or +8 had better CR rates, disease-free survival (DFS), and survivals (P =.001, P =.04, and P =.004, respectively) after the change to the more intensive chemotherapy regimens. Patients with normal cytogenetics had improved CR rate but no improved DFS or survival, whereas no significant benefit for patients with t(9;22), t(4;11), -7, or +8 was seen. In a multivariate analysis, karyotype retained its prognostic significance for DFS but not for survival; it remained the most important factor for DFS. We conclude that cytogenetic analysis at diagnosis should be used to guide treatment decisions in adults with ALL.

Adolescent↗
PubMed1999

Glucose consumption by rats decreases cytochrome P450 enzyme activity by altering hepatic lipids.

Although glucose is a ubiquitous nutrient, increased consumption of glucose decreases the metabolism of numerous drugs in humans and animals. To understand the mechanisms involved that cause decreased drug metabolism in rats that consume glucose in their water, enzyme activity and expression as well as determining the contribution of the lipids toward decreasing in vitro metabolic activity were investigated. Enzyme assays of hepatic CYP1A2, 2C6, 2C11 and 3A2 showed significant decreases in activity from glucose-treated rats compared to control. While immunodetection of CYP1A1, 2B1/2, 2C11, and 3A1/2 showed no significant difference in protein expression. Hepatic fatty acid synthase activity increased in the glucose-treated rats compared to controls. Studies with glucose-treated microsomal lipids reconstituted with microsomal proteins from control rats caused a significant decrease in benzyloxyresorufin O-dealkylase activity. The results presented here support the hypothesis that the activities of cytochrome P450 proteins are altered by modulating their catalytic activity as a result of the lipid environment rather than changing the level of expression of the individual enzymes.

Animals↗
PubMed1999

Aberrant antigen expression detected by multiparameter three color flow cytometry in intermediate and high grade B-cell lymphomas.

The aberrant expression of antigens (Ag) in lymphoproliferative disorders may cause a diagnostic problem when single parameter immunohistochemical assays are performed on frozen or paraffin sections because coexpression by relevant cells is not determined. This aberrant expression also raises the question as to whether mixed lineage (biphenotypic) lymphoid proliferations exist. Marrow (6) and extramedullary (20) tissues from 26 patients with diffuse, intermediate and high grade, B-cell lymphomas (IWF E=1, F=1, G=19, H=1 and J=4) were analyzed with 19 markers using 3-color flow cytometry. The percentages (%) of patients with double Ag coexpression in at least 20% of the CD19+ or CD20+ lymphoma cells were: stem cell (SC) Ag: CD10 = 58 and CD34 = 15; T-cell Ag: CD2 = 38, CD5 = 19 and CD7 = 19; myeloid (My) Ag: CD13 = 19 and CD33 = 8. The corresponding % with unusual triple Ag coexpression in at least 10% of the CD19+ B-cells were SC+T+ Ag: CD10CD2 = 50, CD10CD5 = 27, CD10CD7 = 38, CD34CD2 = 31, CD34CD5 = 19 and CD34CD7 = 27; T+T+ Ag: CD2CD5 = 35, CD2CD7 = 42 and CD5CD7 = 31; T+My+ Ag: CD2CD13 = 35 and CD2CD33 = 12; and My+My+ Ag: CD13CD33 = 12. Ten of 12 lymphomas tested showed clonal immunoglobulin (Ig) heavy chain gene rearrangements in the absence of clonal T-cell receptor (TCR) gene rearrangements. None (0%) of the My Ag positive cases showed immunoreactivity for myeloperoxidase. We conclude that the anomalous T and My Ag expression seen in the above B-cell lymphomas is not indicative of mixed lineage proliferation but represents the aberrant expression of these antigens by the malignant cells.

Antigens, CD↗
PubMed1998

Differential expression and function of L-selectin on CD56bright and CD56dim natural killer cell subsets.

NK cells are the first line of defense against foreign cells, virally infected cells, and tumors. The mechanisms whereby NK cells accumulate in extralymphoid sites in response to pathogenic stimuli are not well understood. The L-selectin adhesion molecule (CD62L) plays a primary role in mediating the initial interaction of leukocytes with vascular endothelium, a crucial step in the extravasation of immune effector cells into tissues. In this report, we show L-selectin to be uniquely expressed on a subset of resting human NK cells (CD56bright). Notably, CD56bright NK cells expressed L-selectin at a higher density than all other peripheral blood leukocytes. NK activation by PMA, IL-2, IL-15, or TGF-beta down-regulated L-selectin on the CD56bright subset, while increased L-selectin levels were observed in both the CD56bright and CD56dim NK subsets in response to IL-12, IL-10, or IFN-alpha. Moreover, CD56bright NK cells bound with high efficiency to physiologic L-selectin ligands on peripheral lymph node high endothelial venules (HEV). In sharp contrast, CD56dim NK cells adhered poorly to HEV and were predominantly L-selectin- or expressed L-selectin only at low density. In CD56bright cells and a subpopulation of CD56dim cells, L-selectin ligation by mAb cross-linking activated lymphocyte function-associated Ag 1 (LFA-1), a second adhesion molecule required for leukocyte extravasation. LFA-1 was expressed on both NK subsets, although its density was constitutively higher on CD56dim cells. Taken together, evidence of differential expression of L-selectin and LFA-1 on CD56bright and CD56dim NK subsets strongly suggests unique migratory properties and functions of these cells during the early immune response to foreign pathogens.

3T3 Cells↗
PubMed1998

Neutropenia associated with T-cell large granular lymphocyte leukemia: long-term response to cyclosporine therapy despite persistence of abnormal cells.

T-cell large granular lymphocyte (T-LGL) leukemia is clinically indolent, but is associated with severe neutropenia in approximately 50% of cases. The pathogenesis of the neutropenia is unclear. We report reversal of severe neutropenia associated with T-LGL leukemia in five patients treated with cyclosporine (CSA). All five had persistent neutrophil counts below 0.5 x 10(9)/L, two had agranulocytosis, and four had recurrent infections. Increased populations of LGL were present in blood and marrow, with a T-LGL immunophenotype (CD3(+)CD8(+)CD16(+/-)CD56(+/-)CD57(+)) shown by multiparameter flow cytometry, and clonal T-cell receptor (TCR) gene rearrangements in two of two pretreatment blood samples studied. CSA was initiated at doses of 1 to 1.5 mg/kg orally every 12 hours, with subsequent dose adjustments based on trough serum levels. Four patients attained normal neutrophil counts with CSA alone; one required addition of low-dose granulocyte-macrophage colony-stimulating factor. Time to attainment of 1.5 x 10(9)/L neutrophils ranged from 21 to 75 days. Attempts to taper and withdraw CSA resulted in recurrent neutropenia. Three patients have maintained normal neutrophil counts on continued CSA therapy for 2, 8, and 8.5 years. Two patients died 1.7 and 4.6 years after initiation of CSA despite normal neutrophil counts-one of metastatic melanoma and one of complications after aortofemoral bypass surgery. Despite resolution of neutropenia, increased populations of T-LGL cells have persisted in all patients during CSA therapy, as shown by morphology and flow cytometry and by the presence of clonal TCR gene rearrangements in four patients' posttreatment blood samples. We conclude that CSA is an effective therapy for neutropenia associated with T-LGL leukemia, and that resolution of neutropenia despite persistence of abnormal cells implies that CSA may inhibit T-LGL secretion of yet unidentified mediators of neutropenia.

Adult↗
PubMed1998

Direct isolation and analysis of endogenous transjunctional ADP from Cx43 transfected C6 glioma cells.

Gap junctional communication has been implicated in numerous cellular processes. However, the repertoire of specific transjunctional substances which mediate these processes remains relatively unexplored. A few selected secondary messengers have been identified, at least indirectly (e.g., cAMP and IP3) and phenotypic complementation experiments have indicated that gap junctions enable communicating cells to distribute nucleotide pools as a shared resource. The latter would include high energy compounds such as ADP and ATP, allowing cells to share energy resources. We have utilized a nonbiased process to directly capture, identify, and quantify transjunctional compounds from C6 glioma cells, the transformed phenotype of which has been ameliorated by transfection with connexin43 (Cx43). This technique involves the direct isolation, identification, and quantitation of radioactive transjunctional molecules that travel from metabolically labeled "donor" cells to "receiver" cells. This report demonstrates that ADP and/or ATP represents over 6% of the transjunctional material derived from glucose in Cx43-transfected C6 glioma cells. Furthermore, equilibration of these high energy metabolites among first order neighbors is shown to occur in less than 20 min of communication.

Adenosine Diphosphate↗
PubMed1998

Acute myeloid leukemia with 11q23 translocations: myelomonocytic immunophenotype by multiparameter flow cytometry.

11q23 translocations (t(11q23)) are recurring cytogenetic abnormalities in both acute myeloid leukemia (AML) and acute lymphoblastic leukemia, involving the same gene, ALL1 (or MLL). Mixed lineage antigen expression has been reported in these leukemias, but its frequency and clinical significance are unknown. We immunophenotyped leukemia cells from 19 adult de novo AML patients with t(11q23) by multiparameter flow cytometry. Translocations included t(6;11)(q27;q23), t(9;11)(p22;q23), t(9;11;19)(p22;q23;q13.3), t(2;11)(11;17)(q37;q11q23;q11), t(11;17)(q23;q25), t(11;19)(q23;p13.1), t(11;19)(q23;p13.3) and t(11;22)(q23;q11). FAB types were M4 and M5. The committed stem cell and myeloid antigens HLADr, CD4dim, CD11b, CD13, CD15, CD32, CD33, CD38 and CD64 were each expressed in 80-100% of cases, and the early stem cell and lymphoid antigens CD34, CD56, CD3, CD2 and CD7 in 42, 39, 16, 5 and 5%, respectively. Antigen expression frequencies did not differ from those in 443 adequately karyotyped M4 and M5 cases without t(11q23). Fifteen patients (79%) attained complete remission (CR); median CR duration and survival were 10.0 and 15.1 months. CR duration and survival did not correlate with antigen expression. In particular, patients with t(9;11) survived longer than those with other t(11q23) (median not reached vs 7.6 months; P = 0.048), but antigen expression did not differ in the two groups. Thus frequencies of lymphoid antigen expression are similar in AML with t(11q23) and in other FAB M4 and M5 cases, treatment outcome does not differ in t(11q23) cases with and without lymphoid antigen expression, and better outcome of patients with t(9;11) compared to other t(11q23) does not correlate with differences in antigen expression. Mixed lineage antigen expression is not a distinctive feature of AML with t(11q23).

Adolescent↗