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PubMed2005

Comparison of results of clinicians' assessments, cytologic examination of fine-needle lymph node aspirates, and flow cytometry for determination of remission status of lymphoma in dogs.

OBJECTIVE: To determine interclinician agreement when assessing remission of lymphoma in dogs and the association among results of clinicians' assessments via lymph node palpation, cytologic examination of fine-needle lymph node aspirates, and flow cytometry as determinants of remission. DESIGN: Prospective study. ANIMALS: 23 dogs with untreated lymphoma. PROCEDURE; Two clinicians independently measured large lymph nodes and cytologic examination and flow cytometry of cells from a mandibular or popliteal lymph node were performed 1 week prior to initiating treatment. Lymph node measurements with clinicians' remission assessments and cytologic examination were repeated at weeks 2, 3, and 5; flow cytometry was repeated at week 5. RESULTS: Significant correlation was identified between clinicians' remission assessments. Significant correlation between lymph node palpation and cytologic examination was identified at week 5, but not at weeks 2 and 3. Lymphoma was diagnosed in 16 of 23 (70%) dogs at initial evaluation by use of flow cytometry, although it was of limited use at subsequent evaluations and results were not diagnostic of lymphoma in any dog at week 5, including 1 dog in which lymphoma was diagnosed cytologically. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that physical examination and measurement of lymph node volume may not be sufficient for accurately determining remission, that flow cytometry alone should not be relied on as a means for diagnosis, and that cytologic examination of fine-needle lymph node aspirates should be considered as the most accurate means of determining remission status at times in which treatment modifications are considered.

Animals↗

PubMed1981

Flow cytometry analysis of lung cells from normal and acid-treated rabbits.

Lavaged lung cells from normal rabbits and rabbits given hydrochloric acid intratracheally were analyzed using flow cytometry techniques. The rabbit alveolar macrophage was characterized as a cell with relatively high light scatter and high intrinsic autofluorescence compared with the lung neutrophil with its lower light scatter and autofluorescence. The flow cytometry characteristics of these 2 cell populations were confirmed with light microscopy after cell sorting. A flow cytometry analysis of alveolar macrophage phagocytosis using fluorescent latex particles was applied to normal rabbit alveolar macrophages. These studies showed that flow cytometry can be used to study the morphologic features and function of rabbit lavage lung cell populations and may be ultimately useful in the analysis of human lung cells.

Animals↗

PubMed1994

Comparison of nucleolar organiser regions and DNA flow cytometry in the evaluation of pleural effusion.

BACKGROUND: In conventional cytological diagnosis of pleural effusions the assessment of morphological features plays an important part. However, false negative and false positive results may occur. In this study conventional cytology was compared with flow cytometric DNA analysis and the argyrophil staining technique for nucleolar organiser regions (AgNOR) to characterise benign and malignant effusions. METHODS: Pleural effusions from 71 patients (38 with benign lung disease, 33 with proven adenocarcinoma of lung) were studied by conventional cytology, flow cytometric DNA analysis, and the AgNOR technique. Tumour cell ploidy was determined by flow cytometry. In an attempt to detect the cell proliferative state, flow cytometric S phase fraction and the AgNOR technique were used. The correlations among conventional cytology, flow cytometric DNA ploidy, S phase fraction analysis, and nucleolar organiser regions were investigated. RESULTS: All the 38 benign pleural effusions were diploid. There were 17 (52%) aneuploid and 16 (48%) diploid malignant pleural effusions. Based on these results this type of DNA analysis had a sensitivity of 52% and a specificity of 100%. The mean (SD) numbers of flow cytometric S phase fractions of benign and malignant cases were 5.32 (1.67)% and 12.45 (3.93)% respectively. The mean numbers of S phase fractions of diploid malignant cases were higher than diploid benign cases. In each case the number of AgNORs was counted in 100 cells. The mean number of AgNOR dots per nucleus was 12.57 (3.64) for malignant pleural effusion cells and 3.96 (1.39) for benign pleural effusion cells. The mean number of AgNOR dots was 14.45 (3.36) for aneuploid malignant pleural effusion cells and 10.57 (2.82) for diploid malignant pleural effusion cells. The AgNOR numbers were higher in diploid malignant cells than in diploid benign cells. There was a significant correlation between the S phase fraction determined by flow cytometry and the mean number of AgNORs per nucleus in malignant cases. CONCLUSIONS: Both flow cytometry and the AgNOR methods provide comparable measurements in the diagnosis of pleural effusion. The study also indicates that the AgNOR method, which is rapid and easy to perform, may be a useful adjunct to flow cytometry, S phase fraction analysis and conventional cytology in the routine diagnosis of malignant pleural effusion.

Adenocarcinoma↗

PubMed1997

DNA analysis by flow cytometry in early gastric cancer.

OBJECTIVES: Flow cytometric analysis of a paraffin-embedded block of tissue provides rapid and accurate means of analyzing the DNA content of a tumor. The aim of this study was to clarify the clinical significance of flow cytometric findings in early gastric cancer(EGC). Thus we conducted this study to investigate whether DNA contents of tumor cells can correlate with known prognostic indices in patients with EGC. METHODS: The flow cytometric DNA analysis was performed with paraffin-embedded specimens from tumors of 107 patients with EGC. Flow cytometric analysis was performed using a FACScan (Becton Dickinson). In constructing the histogram, 30,000 cells were scanned from each section and results were scored. The S-phase fraction was obtained according to the CellFit cell cycle analysis (Becton Dikinson). Frequencies of aneuploidy in tumors with various clinical and pathologic parameters were compared using the chi-square test. Mean SPF/PI valuse were compared by the student t-test. RESULTS: Diploidy pattern was observed in 80 (75%) cases while aneuploidy was seen in 27(25%) cases. Aneuploidy was more frequently detected in tumors with submucosal involvement (32.7%) and lymph node (+) group (30.8%) than in the mucosal tumor (17.3%) and lymph node (-) group (24.5%), but the differences were not significant. Frequency of aneuploidy was not affected by either the histologic type or morphologic classification. On the other hand, high proliferative activities (SPF/PI) significantly correlated with the submucosal tumor invasion (66.7% vs. 45%; p < 0.05) and lymph node metastasis (28.6% vs. 7.5%; p < 0.05). CONCLUSION: Tumor aggressiveness is not directly related to DNA aneuploidy but proliferative activities are responsible for the aggressive nature of early gastric cancer. The results of this study show that DNA analysis by flow cytometry in considered to be one method of determining the biological activity of gastric cancer cells.

Adult↗

PubMed1994

Phenotype analysis of hematopoietic CD34+ cell populations derived from human umbilical cord blood using flow cytometry and cDNA-polymerase chain reaction.

A strategy to phenotype rare populations of hematopoietic cells expressing the cell-surface marker CD34 was studied. The antigenic phenotype of umbilical core blood (CB) CD34+ cells was investigated using flow cytometry and compared with the mRNA-phenotype determined by cDNA-polymerase chain reaction (cDNA-PCR) analysis. The cDNA-PCR method allowed an mRNA evaluation of small numbers of cells. Monoclonal antibodies and oligonucleotide primers that recognize myeloid, lymphoid, erythroid and platelet/megakaryocytic cell membrane antigens or corresponding mRNA transcripts were used. Evaluation by flow cytometry showed that the vast majority of CD34+ CB cells coexpressed CD38, CD18, HLA-DR, and CD33. Rare subpopulations of CD34+CD38-, CD34+CD18-, CD34+HLA-DR-, and CD34+CD33- were also identified. A large proportion of CD34+ CB cells expressed CD13, CD45R, and to a lesser extent CD71. The CD36, CD51, and CD61 antigens were identified on a small number of CD34+ cells. The three-color flow cytometry analysis showed that CD34+ cells stained with antibodies to CD61 and CD36 or CD51 can be divided into subsets that may represent progenitor cells committed to the erythroid and/or megakaryocytic lineage. A variety of other lineage-specific cell-surface antigens including pre-T-cell marker CD7 and markers of early B cells, ie, CD10 and CD19, were not coexpressed with CD34+. Using the cDNA-PCR it was seen that the mRNA phenotype of a small number of sorted CD34+ cells (purity > 98%) was negative for the markers CD2, CD14, CD16, CD20, CD21, CD22, CD41b, and glycophorin A that are expressed on differentiated cells but positive for CD34, CD7, CD19, CD36, and CD61. The results suggest that circulating CD34+CD7+ and CD34+CD19+ CB cells cannot be distinguished by flow cytometry but can be detected by cDNA-PCR. This indicates that CB either contains very low numbers of these progenitors or that the antigen density of CD7 and CD19 on CD34+ cells is below the detection limit of the flow cytometer. In contrast to flow cytometry, cDNA-PCR allows the phenotypic analysis of cells even if their number is small. Thus, the cDNA-PCR method can be useful in linking phenotype analyses, ie, markers of differentiation, to studies on gene expression within rare populations of hematopoietic stem cells.

Antigens, CD↗

PubMed1997

Rapid discrimination of bacterial species with different ampicillin susceptibility levels by means of flow cytometry.

An in vitro model for flow cytometric detection of heterogeneous drug response in exponentially growing Escherichia coli and Klebsiella pneumoniae was studied to evaluate the potential of this technology for rapid antibiotic susceptibility testing in polymicrobial samples. The cells, which exhibited 80-fold difference in in ampicillin susceptibility, were cultivated in the presence of ampicillin at a concentration equaling 1 MIC of the low-susceptibility strain (E. coli). Prior to flow cytometric analysis, the cells were fixed in 70% ethanol and stained with a DNA-specific dye. After 1 h of ampicillin incubation, the light scattering and fluorescence intensities of the susceptible cells increased 4.3-fold and 5-fold, respectively, but remained about constant for the resistant cells. The corresponding cell number increase for the resistant and the susceptible cells was 9.4 and 1.7, respectively. The two strains could be distinguished in the histograms on the basis of their light scattering and fluorescence intensities and by cell number. With an incubation of up to 3 h, the light scattering and fluorescence intensities of the susceptible cells grew stronger, at the expense of cell number. By combination of histograms, the discrimination of different cell populations could be improved. The results demonstrate the ability of flow cytometry to discriminate between species in heterogeneous cultures and suggest the potential of the technique for rapid assessment of bacterial susceptibility. However, the present results are preliminary, and the application to biological liquids and clinical samples has to be demonstrated further.

Ampicillin Resistance↗

PubMed1998

Calibration of the single cell gel electrophoresis assay, flow cytometry analysis and forward mutation in Chinese hamster ovary cells.

The induction kinetics of genetic damage were measured in one clone of a mammalian cell line (CHO AS52) with three genotoxicity assays, the single cell gel electrophoresis (Comet) assay, laser beam flow cytometry and forward mutation. The first two assays allow for the rapid analysis of genotoxic damage in individual nuclei. The alkaline Comet assay detects DNA strand breaks, alkali-labile sites and incomplete excision repair sites. Flow cytometry measures chromosome damage that results in an unequal distribution of nuclear DNA in daughter cells. We calibrated these assays to compare acute DNA damage and longer term clastogenicity with forward mutation at the gpt locus using ethyl methanesulfonate (EMS). The EMS treatments were conducted in F12 medium for 2 h. AS52 cells carry a single functional gpt gene which provides for quantitation of gpt mutants by selecting for 6-thioguanine resistance. EMS induced a concentration-dependent response with median Comet tail moment values of 1.06 microns for the negative control and 64.6 microns with 20 mM. The coefficient of variation (CV) of the negative-control with flow cytometry was 2.33; the CV value increased to 4.87 in cells treated with 20 mM EMS, EMS (8 mM) induced a mutant frequency of 779.8 x 10(-6) at a relative survival of 64.4%. Genetic response factors were calculated and the data demonstrate that the induction kinetics of genetic damage as measured by the Comet assay (15.6) and flow cytometry (14.2) were more closely related than that determined for mutation induction (7.9). These three assays measure a wide spectrum of genetic events at the level of DNA, the gene and the chromosome and demonstrate the usefulness of the Comet assay and flow cytometry as two relatively rapid procedures to detect genotoxic damage in mammalian cells.

Animals↗

PubMedDate not supplied

[Standardization and automation of HLA B27 typing by flow cytometry: validation and comparison with microlymphocytotoxicity].

One of the strongest known association between human leukocyte antigen (HLA) phenotype and disease is that of ankylosing spondylitis and HLA-B27. Thus, the determination of HLA-B27 status is an useful tool in the diagnosis of ankylosing spondylitis. To date, the 2 reference methods for HLA typing (microlymphocytotoxicity and molecular biology techniques), are costly in terms of both technician time and materials, and require a great deal of experience. In total, these techniques are not well-suited for routine application in clinical immunology laboratories. Use of flow cytometry has recently been applied for HLA-B27 typing. Nevertheless, it requires an extensive validation protocol. We developed a flow cytometry technique as standardized as possible (whole blood, automated lysing system, automated photomultiplier voltage calibration, definition of thresholds stable with time) and validated our results by comparison with microlymphocytotoxicity. In total, 326 samples were analyzed. We found 99% of concordant results between the 2 techniques, and neither false positive results nor false negative results with flow cytometry could be observed. These results illustrate the reliability of the protocol. It should be remembered that reference technique remains necessary to confirm the few results (< 1%) found in "grey zone" by flow cytometry. Standardization of flow cytometry techniques, as described in this work for HLA B27, seems to be a reasonable goal for the next decade in clinical immunology laboratories.

Automation↗

PubMed1983

Comparison of analysis of bovine surface immunoglobulin bearing and peanut agglutinin binding lymphocytes by flow cytometry and fluorescence microscopy.

Bovine peripheral blood lymphocytes were examined for their binding to anti-immunoglobulin serum, peanut agglutinin, and mu, alpha, and epsilon heavy chain specific antisera by immunofluorescence. The percentage of total lymphocytes with positive staining was determined independently by flow cytometry and fluorescence microscopy. The correlation of data from both methods was best for analysis of total surface immunoglobulin and IgM bearing cells. The percentage of lymphocytes bearing surface immunoglobulin (B cells) was determined using both whole antiserum and a F(ab')2 reagent. Quantitation by flow cytometry did not show a significant difference when the two reagents were used, whereas fluorescence microscopy revealed a significant difference (p less than .05). The mean percent of total surface immunoglobulin bearing cells was 30 +/- 3% by either method. Flow cytometry gave significantly larger values than fluorescence microscopy for samples stained with fluorescein conjugated peanut agglutinin. Peanut agglutinin binding cells comprised 70 +/- 3% by flow cytometry and 51 +/- 3% by fluorescence microscopy. Similarly, there was a significant difference between both methods when IgA bearing lymphocytes were examined. Percentages of immunoglobulin E, A, and M bearing lymphocytes as well as total B and T cells in spleen and bronchial lymph node were determined by immunofluorescence using the cytofluorograph. Peanut agglutinin binding cells were less numerous in spleen and lymph node than in peripheral blood. Immunoglobulin E bearing lymphocytes increased from 0.07% in peripheral blood to 4% in spleen and 1.9% in lymph node. In this paper we demonstrate how flow cytometry can be used to examine a large number of samples in a rapid and reproducible manner. This is the first report in which bovine lymphocytes bearing surface IgE are quantitated.

Animals↗

PubMed1990

Flow cytometry in carcinoma of the prostate.

Flow cytometry is a quantitative cytologic technique with demonstrated utility in the assessment of prostate cancer as well as other tumors. The authors summarize current data on its use in disease detection and diagnosis, prognostic evaluation, and monitoring of response to therapy. They also project future developments.

Cell Separation↗

PubMed2001

Detection of intracytoplasmic cytokines by flow cytometry in adenoids and peripheral blood lymphocytes of children.

Cytokine flow cytometry at the single-cell level has never been utilized in the study of adenoidal lymphocytes. We describe the multiparameter capability of flow cytometry to simultaneously detect an antigen on the surface of the adenoidal and peripheral blood lymphocytes and detect Th1 and Th2 cytokines within the cytoplasm of these lymphocytes. The data suggest that the percentage of cells producing interferon (IFN)-gamma are decreased in adenoidal as compared to peripheral blood lymphocytes, confirming our previous studies. The new findings show that the CD8 subset of adenoidal lymphocytes produces lower amounts of IFN-gamma as compared to peripheral blood CD8 cells. The intracytoplasmic synthesis of interleukin (IL)-2, however, appears to be similar in both adenoidal and peripheral blood lymphocytes. The CD4 subset of lymphocytes in the adenoid produces more IL-2, whereas the CD8 subset produces more IFN-gamma. Finally, as shown in our previous studies, the Th2 cytokines appear to be produced in similar quantities in both adenoidal and peripheral blood lymphocytes.

Adenoidectomy↗

PubMed2006

Syringe pumped high speed flow cytometry of oceanic phytoplankton.

BACKGROUND: Nanophytoplankton (2-20 microm) are less numerous than picophytoplankton (<2 microm) in the oceans but their biomass and production are comparable and sometimes higher. The accuracy of cytometry-based enumeration of phytoplankton ultimately depends on cell abundance and sample flow rate. Commercial flow cytometers in which sheath and core streams are driven by air pressure cannot produce sufficiently high, stable sample flow rate. The present study demonstrates the applicability of a syringe pump for flow cytometric enumeration of oceanic nanophytoplankton on two meridional transects across the Atlantic Ocean. METHODS: Commercially available syringe pumps were used to deliver live phytoplankton samples into a flow cell of standard flow cytometers (FACSort, FACSCalibur, BD) with increased flow rate of > 1.0 ml min(-) (1) compared to the normal air pressure sample delivery of < 0.1 ml min(-) (1). An auxiliary application of syringe pump flow cytometry for calibrating 0.5 microm bead concentration standards is also discussed. RESULTS: The results demonstrated that flow cytometry of samples injected at rates above 0.1 ml min(-) (1) is achievable and worthwhile. Counts of phytoplankton in air and syringe pumped samples agreed closely. Syringe pumping of samples offered a broader range of flow rates up to 0.8-1.0 ml min(-) (1) without detrimental effect on flow cytometric enumeration of cells. The increased number of coincidences at high flow rates led to an approximate 10% decrease of Cyanobacteria counts when the acquisition rate approached 1,000 particles s(-) (1), but seemed to have a lesser effect on counting rarer phytoplankton. The syringe pump flow cytometry allowed enumeration of phytoplankton groups at concentrations of 5-100 cells ml(-) (1), cell concentrations equivalent to those of Cyanobacteria in the twilight deep ocean. CONCLUSION: The proposed syringe pump modification of a FACS instrument represents a significant improvement for accurate enumeration of the less abundant phytoplankton and so gives better estimations of phytoplankton distribution and standing stocks.

Atlantic Ocean↗

PubMed1996

Surface antigen expression on CD34+ cord blood cells: comparative analysis by flow cytometry and limiting dilution (LD) RT-PCR of chymopapain-treated or untreated cells.

Expression of antigens coexpressed on cord blood (CB) CD34+ cells was evaluated by flow cytometry analysis and reverse transcriptase polymerase chain reaction (RT-PCR). Antigen expression was also comparatively analyzed by flow cytometry and limiting dilution (LD) RT-PCR to investigate effects of chymopapain on epitopes of several cell surface markers: LD RT-PCR allows detection of the expression of antigens degraded by chymopapain which are not identified by flow cytometry. Monoclonal antibodies (MoAbs) that recognize chymopapain resistant epitopes on several coexpressed cell surface markers were identified: these included MoAbs directed against CD11a, CD13, CD18, CD38, CD45RO, CD51, HLA-DR, Thy-1, c-kit, flt-3 (STK-1), and mdr-1. Interestingly, chymopapain treatment caused enhanced staining with MoAbs against HLA-DR, Thy-1, flt-3, mdr-1, and CD51. The frequency (LD RT-PCR) of CD18, CD38, Thy-1, and c-kit RT-PCR signals on pure sorted CD34+ CD18-, CD34+ CD38-, CD34+ Thy-1-, and CD34+ c-kit- cells, respectively, was similar in corresponding subsets treated or not with chymopapain. In contrast, the frequency of CD33 RT-PCR signals on sorted CD34+ CD33- cells was higher in chymopapain-treated samples than in untreated samples and thus confirmed at the transcriptional level that the epitope recognized by anti-CD33 is chymopapain sensitive. Our findings extend data on the phenotypic profile of CB CD34+ cells and show that several key cell surface markers of hematopoietic progenitor cells are chymopapain resistant. In addition, the results of the present study demonstrate that the RT-PCR can be applied to the analysis of multiple RNA species in small numbers of hematopoietic progenitor cells and show that LD RT-PCR allows the identification and frequency determination of rare cells which are undetectable by flow cytometry.

Antibodies, Monoclonal↗

PubMed2002

Effects of chemical and physical agents on viability and infectivity of Encephalitozoon intestinalis determined by cell culture and flow cytometry.

We combined tissue culture and flow cytometry to assess the activities of various temperatures, chemicals, and disinfectants on the viability and infectivity of spores of Encephalitozoon intestinalis. Surfanios and benzalkonium chloride, disinfectants currently used in the hospital, were remarkably efficient in destroying spore viability and infectivity.

Animals↗

PubMed1991

Calibration of fluorescence intensities to quantify antibody binding surface determinants of cell subpopulations by flow cytometry.

Quantitative indirect immunofluorescence analysis by flow cytometry was used to determine the mean number of antibody binding sites per cell in a small subpopulation of rat brain cells expressing low levels of a cell surface differentiation antigen recognized by monoclonal antibody (Mab) RB13-6 (Kindler-Röhrborn et al.: Differentiation 30:53-60, 1985). For these non-disjunct distributions of fluorescence intensities, the cut-off border between antigen-positive and antigen-negative cells was defined by a statistical test. To eliminate the influence of accidental disturbances leading to incorrect statistical decisions, the curves for antigen-negative cells were fitted according to cell number and shape. The flow cytometer was calibrated with the use of a clonal cell line for which the average number of Mab RB13-6 binding sites per cell had previously been determined by radioimmunoassay and Scatchard-plot analysis. Using this analytical procedure, both the proportion of Mab binding brain cells and the mean number of Mab binding sites per Mab binding cell could be determined as a function of developmental stage.

Animals↗

PubMed1991

Sequential DNA flow cytometry in metastatic malignant melanoma.

Sequential flow cytometry was performed on 73 metastatic malignant melanomas, derived from 804 primary tumors. Tumor thickness was confirmed an excellent prognostic parameter in primary melanoma, but did not allow reliable predictions in metastatic disease. Also, aneuploidy and genetic heterogeneity, both common in metastatic melanoma, were equally distributed among patients differing in survival time. However, a remarkable acceleration was observed in the generation of abnormal cell lines in patients dying early of metastatic disease.

DNA, Neoplasm↗

PubMed2005

Flow cytometry in breast cancer: cell yield using two different fine needle aspiration devices.

The aim of the study was to compare the quality of breast aspirates obtained by two methods of fine needle aspiration cytology (FNAC): the auto-vacuum device and the syringe pistol holder, using flow cytometry. Both techniques were used in 44 fresh surgical specimens. Subsequently, these specimens were fixed and mounted in paraffin. Both the aspirates and the de-waxed histology material were prepared for flow cytometry using a FACScan. Flow cytometry showed that the means for DNA index and S-phase fraction were similar for aspirates obtained with both techniques. Mean aneuploidy was significantly higher in the auto-vacuum device aspirates than in the surgical specimen (43.4 SD +/- 23 vs. 27.9 SD +/- 17; p = 0.04). Mean DNA index and S-phase fraction were similar in cells from aspirates and surgical specimens. It is concluded that both FNAC methods are of similar efficacy in collecting aspirates for flow cytometry.

Aneuploidy↗

PubMed2004

[Application of flow cytometry in the differential diagnosis of lymphoma/leukemia with aberrant antigen expression].

OBJECTIVE: To investigate the application of flow cytometry in the differential diagnosis of lymphoma/leukemia with aberrant antigen expression. METHODS: The results of flow cytometry of 30 lymphoma/leukemia cases with aberrant antigen expression, of which 3 cases being lymphomas, 8 B-cell leukemia, 1 T-cell leukemia, 17 acute non-lymphoid leukemia and 1 acute non-lymphoid leukemia involving lymph nodes were analyzed. Immunohistochemistry (EnVision) for CD79a, CD3 and MPO was performed on all cases. RESULTS: Eleven cases of B-cell lymphoma/leukemia were cytoplasmic CD79a (cCD79a)-positive, cytoplasmic CD3 (cCD3epsilon) and cytoplasmic MPO (cMPO)-negative. Five of these cases were positive for CD5 and 2 for CD5, 1 or 2 for myeloid marker(s). The T-cell leukemia cases were cCD3epsilon-positive, cCD79a and cMPO-negative, they also co-expressed CD13 and CD33. The mantle cell lymphoma cases were positive for CD3, CD13 and CD33. Of the 8 B-cell leukemia cases, 4 were positive for CD5, 3 for CD13 and 1 for CD13 and CD33. The 18 acute non-lymphoid leukemia cases (including 1 acute non-lymphoid leukemia case involving lymph nodes) were cMPO-positive and cCD79a and cCD3epsilon-negative. Eight of the 18 expressed T-cell markers (including 1 case of acute non-lymphoid leukemia involving lymph nodes), 8 expressed B-cell markers, 2 expressed both T and B-cell markers. CONCLUSIONS: Flow cytometry can demonstrate aberrant antigen expression in lymphoma/leukemia cells and is helpful in delineating their cell origin. The technique is thus useful in the differential diagnosis of lymphoma/leukemia.

Antigens, CD↗