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PubMed2004

Quantification of fetomaternal hemorrhage: a comparative study of the manual and automated microscopic Kleihauer-Betke tests and flow cytometry in clinical samples.

OBJECTIVE: The purpose of this study was to evaluate the quantification of fetomaternal hemorrhage by the manual and automated microscopic analysis of Kleihauer-Betke stained slides and by flow cytometry. STUDY DESIGN: Blood smears were stained and evaluated manually according to the Kleihauer-Betke test. The same slides were used for automated microscopy. In addition, blood flow cytometry was performed by anti-hemaglobin F immunostaining. RESULTS: Fetomaternal hemorrhage >0.1% was detected in 4 patients by manual and automated Kleihauer-Betke test and by blood flow cytometry. Fetomaternal hemorrhage was absent according to all 3 methods in 13 patients; fetomaternal hemorrhage<0.1% was detected in 27 patients by either manual or automated Kleihauer-Betke test or both. Moderate agreement was observed between the manual and automated Kleihauer-Betke test (weighted kappa, 0.56; 95% CI, 0.33-0.78). Agreement between the manual Kleihauer-Betke test and blood flow cytometry was fair (weighted kappa, 0.40; 95% CI, 0.15-0.66). CONCLUSION: Automated microscopic detection of fetal blood cells in clinical samples provides accurate quantification that is comparable to the manual Kleihauer-Betke test in both small and large fetomaternal hemorrhage. Blood flow cytometry is capable only of quantifying fetomaternal hemorrhage of >0.1%.

Erythrocyte Volume↗

PubMed2004

Recommended reporting format for flow cytometry diagnosis of acute leukemia.

Although flow cytometry is increasingly used as a tool to diagnose hematologic malignancies, the reporting format of acute leukemia immunodiagnosis is still imprecise and sometimes vague, often reflecting old guidelines. Thus, the purpose of the present work was to make the reporting format for the immunological diagnosis of acute leukaemia easy and clear to understand. This work represents part of a more articulated series of technical guidelines that the Italian Society for Cytometry (GIC) is currently processing. Thirteen separate recommendations, covering all aspects of an acute leukemia cytometry report, are listed. According to our suggestions, the report must contain clear statements about: 1. demographic identification of patient; 2. identification of the hospital or division sending the sample; 3. type of specimen (bone marrow aspirate, peripheral blood, other biological fluids); 4. timing of observation (first diagnosis or follow-up); 5. diagnostic hypothesis made by the sender; 6. list of antigens and type of immunofluorescence analysis carried out; 7. absolute number of cells in the sample; 8. quality of the sample, in terms of viability; 9. general description of the gating procedure; 10. immunophenotype of blast cells; 11. description of cells surrounding blasts; 12. diagnostic conclusions; 13. definition of an antigen panel (when applicable) for the detection of minimal residual disease. As an example of a final report we present a case of acute myeloid leukaemia with t(8;21) translocation; in filling this report, we followed all the 13 points of the checklist described in the paper.

Antigens, Neoplasm↗

PubMed1992

EGF cell surface receptor quantitation on ocular cells by an immunocytochemical flow cytometry technique.

A method is presented for the rapid flow cytometric determination of epidermal growth factor (EGF) receptor densities on the surface of cultured ocular cells. The technique uses a biotinylated monoclonal antibody directed against the EGF receptor in conjunction with a streptavidin-bound fluorochrome and requires the specific fluorescence per cell to be measured as a function of ligand and receptor concentration. Because the measurement is noninvasive and restricted to cell surface-bound material, the cells can be kept in a physiologic environment, even at the moment of assay. Calculated receptor densities ranged from 5142/cell (infant human corneal endothelium) to 35,678/cell (infant human keratocytes) to greater than 5 x 10(5)/cell for an A431 control cell line. Species and donor age differences were noted, as was transient receptor downregulation after EGF administration. Flow cytometry represents a valuable time saving procedure for large scale applications while providing the same level of sensitivity as standard radioimmunoassays. This technique is applicable to quantitation of other growth factor cell surface receptors and could greatly expand the use of flow cytometry in the research laboratory.

Animals↗

PubMed2000

Differential diagnosis of malignant lymphomas and related disorders by specific pattern of expression of immunophenotypic markers revealed by multiparameter flow cytometry (Review).

The introduction of monoclonal antibodies (mAbs) for cell immunophenotyping and use of flow cytometry with the progressively improving software for multivariate analyses have revolutionized the diagnosis and influenced the classification of hematologic neoplasms. In this review we focus on the practical application of flow cytometry in the diagnosis and classification of malignant lymphomas and related lymphoproliferative disorders with special emphasis on differential diagnosis. A general approach to the utilization of flow cytometry (FC) in hematopathology with an algorithm to diagnose the most common neoplasms is presented. We discuss precursor B-cell neoplasms, mature B-cell neoplasms (SLL/CLL, mantle cell lymphoma, marginal zone lymphoma, hairy cell leukemia, diffuse large B-cell lymphoma, plasma cell dyscrasias and lymphomas with plasmacytic differentiation), precursor T-lymphoblastic leukemia and mature (peripheral) T-cell neoplasms, including T-SLL/PLL, anaplastic cell lymphomas and large granular cell leukemia/lymphoma. The text is accompanied by characteristic FC scatterplots of the discussed entities.

Antibodies, Monoclonal↗

PubMed1996

DNA ploidy of ectopic pregnancy and first trimester spontaneous abortion investigated by flow cytometry.

BACKGROUND: To compare the success rate of DNA flow cytometry in determining the DNA ploidy status in ectopic pregnancy and first trimester spontaneous abortion. METHODS: Thirteen women with ectopic pregnancy (Group I) and 17 women with first trimester spontaneous abortion (Group II) were included into this study. DNA flow cytometric analysis was performed on all specimens. Aneuploidy was classified according to DNA index. The first trimester spontaneous abortions were also karyotyped after long-term culture of chronic villi. Student-t test and Fisher's exact test were used in statistical comparisons. RESULTS: DNA aneuploidy was found in five women with ectopic pregnancy (38.5%) versus in 12 women with first trimester spontaneous abortion (70.6%), and it was comparable. A triploidy and a tetraploidy were detected in group I. Six tubal ectopic pregnancies were unruptured at laparatomy and four of them had aneuploid DNA content. CONCLUSIONS: We believed that DNA flow cytometry was successful in determining the ploidy status of ectopic pregnancy and first trimester spontaneous abortion. In addition, it was interesting that ectopic pregnancies with aneuploid DNA content tended to be unruptured. However, this suggestion needs to be confirmed by further studies with larger numbers of cases.

Abortion, Spontaneous↗

PubMed2006

[Application of flow cytometry to the evaluation of semen quality].

OBJECTIVE: To evaluate the role of flow cytometry in semen assessment. METHODS: Semen samples from 104 infertile male patients (as the case group) and 10 fertilized donors (as the control group) were analyzed for the volume of ejaculate and sperm concentration, motility and atypical morphology by computer-assisted semen analysis (CASA), the viability, chromatin structure and mitochondrial membrane potential (MMP) of the sperm stained by SYBR-14/PI, AO and JC-1 respectively, and assessed with flow cytometry. The results were analyzed through SAS software. RESULTS: U tests indicated that the semen from the infertile patients had not only lower concentration (U = 2.51, P = 0.0143), lower motility (U = 3.44, P = 0.001) and higher rate of atypical morphology (U = -5.88, P < 0.0001), but also lower viability (U = 4.72, P < 0.0001), MMP (U = -2.53, P = 0.0309), and chromatin integrity (alpha t: U = -3.82, P = 0.0003; SD alpha t: U = -3.98, P = 0.0001; COMP alpha t: U = -3.57, P = 0.0005). The multiple stepwise regression analysis revealed that sperm motility was positively correlated with sperm membrane integrity (t = 1.66, P = 0.1016), sperm MMP (t = 3.33, P = 0.0014) and sperm acrosome integrity (t = 3.24, P = 0.0019), while sperm MMP was negatively correlated with the rates of sperm neck and tail defects (t = -3.44, P = 0.001). CONCLUSION: Flow cytometry plays a significant role in the evaluation of the quality of human sperm, and can be adopted as a useful tool in the diagnosis and treatment of male infertility.

Adult↗

PubMed2005

Detection of various platelet-associated immunoglobulins by flow cytometry in idiopathic thrombocytopenic purpura.

BACKGROUND: In 1975, Dixson reported that anti-platelet IgG on platelets from patients with idiopathic thrombocytopenic purpura (ITP) is greater than in normal people, by determining anti-platelet antibodies directly on the platelet surface with a quantitative complement lysis-inhibition-assay. Since then, platelet-associated IgG (PAIgG) has been thought of as evidence of ITP. Although platelets from ITP patients show significantly higher PAIgG values than from normal control individuals, PAIgG is not specific for autoantibody because it increases in other than immune ITP patients. METHODS: We analyzed positive platelet percentage with various platelet-associated immunoglobulins: IgG, IgM, IgA, and total immunoglobulins, in the blood from 17 normal donors and 23 ITP patients. RESULTS: The specificity for ITP disease was better in flow cytometry than in ELISA, because, other than ITP, only aplastic anemia was positive in flow cytometry; however, various disorders (aplastic anemia, chronic lymphocytic leukemia, acute myeloid leukemia, and myelodysplastic syndrome) showed positive in ELISA. Flow cytometry methods had the same sensitivity for ITP disease as ELISA. However, it is supposed that there was no nonimmune ITP in this study because the PAIgG negative patients (n = 1) showed positive results in flow cytometry. CONCLUSION: Flow cytometry method was effective for ITP screening, especially for specificity.

Adult↗

PubMed1981

Multiparameter flow cytometry. Part II. application in hematology.

The application of flow cytometry to hematology is emerging as an important new technique in experimental and clinical leukemic research. In addition to the described methods to determine DNA, RNA, and esterase content and the stability of DNA in situ, quantitation of immunofluorescence using antibody techniques has greatly elucidated the hematopoietic cell system. Hence, flow cytometry provides new perspective for determining the origin, diagnosis, classification, staging and treatment scheduling of normal hematopoietic and malignant cell populations.

Aneuploidy↗

PubMed2000

Commercial high speed machines open new opportunities in high throughput flow cytometry (HTFC).

Two recent events have opened a new domain of flow cytometry applications which we term high throughput flow cytometry (HTFC). The release of a commercial high speed sorter in 1994 placed HTFC within the reach of anyone who could buy one of the new machines and not just the handful of advanced laboratories worldwide that had custom built their own high speed sorters. The advent in 1999 of HTFC analysis capabilities of 100000 cells/s marks the second stage in this enabling of HTFC. We describe the technical basis of HTFC. The commercial high speed sorters measure cells in dead-times three to six times shorter than conventional machines. They can sort with high yield and high purity at rates from 25000 to 60000 cells/s, depending on their settings, mainly by virtue of their use of high drop creation rates 100000 drops/s or more. Finally, one series can analyse the measured cells at rates exceeding these sort-rates and at least six times faster than conventional sorters could. The performance of the systems made by the three manufacturers can be readily assessed for single laser systems. Comparison becomes difficult for multiple beam machines, due to requirements for multi-beam sampling for each cell and due to the demands of fluorescence compensation between signals from one laser and between signals from two or three lasers. Applications are described in the field of rare cell analysis and isolation as well as from sorting of abundant cell populations.

Animals↗

PubMed1986

Flow cytometry evaluation of testicular and sperm cells obtained from bulls implanted with zeranol.

Flow cytometry of testicular and sperm cells was used to evaluate effects of pre-weaning zeranol implants on spermatogenesis. Forty five Angus-Simmental bulls were randomly assigned to three treatment groups of 15 bulls each: no implant, one implant at 30 d of age and two implants, one at 30 and the second at 120 d of age. Prior to slaughter at approximately 15 mo, semen was collected from 30 bulls, 10 of each group. Following slaughter, testes were weighed, and testicular biopsies and vas deferens sperm obtained from the same 30 bulls. Testicular and sperm cells were stained with acridine orange and measured by flow cytometry. Proportions of testicular haploid, diploid and tetraploid cells were determined by relative amounts of green (DNA) and red (RNA) fluorescence. Treatment of sperm at low pH prior to acridine orange staining potentially induces partial denaturation of DNA, detectable by the metachromatic shift from green (native DNA) to red (single-stranded DNA) fluorescence. The effect of this shift was quantified by alpha-t [alpha t = red/red + green) fluorescence]. Nonimplanted bulls had heavier (P less than .01) testicular weights than treated bulls. The proportion of haploid cells was greater (P less than .02) and diploid cells less (P less than .03) in testes of nonimplanted bulls. Sperm from implanted bulls had altered chromatin structure, indicated by higher (P less than .05) alpha t values. Flow cytometry is an effective means for detecting changes in testicular cell subpopulations and chromatin structure of sperm.

Animals↗

PubMed1983

Circadian rhythms in phases of the cell cycle in the hamster as demonstrated by flow cytometry.

Circadian rhythmicity in the phases of the cell cycle of several epithelial tissues of the hamster was analysed by flow cytometry. Hamsters were killed every 3 hr for 24 hr to permit observation of the effect of 'time of day' on the proportion of cells in the various phases of the cell cycle. Bone marrow and epithelium from cheek pouch, oesophagus and tongue were isolated and processed to single cell suspensions for analysis. The only systematic difference in the collection of the data was the time of day when the hamsters were killed. From the resulting DNA histograms, derived by flow cytometry (which was chosen as the technique for this study because of demonstrated applicability in determining cellular properties), the G1, S, and G2 fractions were estimated. Multiple linear regression techniques were used to estimate circadian periodicity in the data. The calculated circadian rhythms in tongue and oesophagus, derived by flow cytometry, were consistent with murine rhythms previously reported, as derived by other techniques. Circadian rhythms also were demonstrated by flow cytometry to be present in the cheek pouch epithelium, as has been reported by others. Although there was considerable fluctuation in findings from the bone marrow, the fluctuation was not of circadian periodicity, perhaps because of the mixed cell population. This study validates the reliability of older techniques, such as mitotic indices, labelling indices, and uptake of tritiated thymidine, which show the rhythmic nature of cell division in vivo.

Animals↗

PubMed2006

Transgastric endoscopic ultrasound-guided fine-needle aspiration biopsy and flow cytometry of suspected lymphoma of the spleen.

BACKGROUND AND STUDY AIMS: Masses in the spleen can be sampled by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) but the diagnosis of lymphoma using EUS-FNA and flow cytometry has not been reported. We report our experience with transgastric EUS-FNA and flow cytometry in the investigation of patients with suspected lymphoma of the spleen. PATIENTS AND METHODS: All patients with splenic lesions that had been detected by computed tomography and who were referred for transgastric EUS-FNA over a 3-year period were enrolled in this study. The tissue obtained by EUS-FNA was evaluated by flow cytometry in all patients. RESULTS: Six patients with splenic masses were enrolled (four men, two women; median age 58.5 years, range 41 - 82 years). The mean size of the short axis of the lesions was 37.8 mm (SD 23.76 mm) and the mean size of the long axis was 45.6 mm (SD 31.72 mm). EUS-FNA was performed successfully in all patients and the tissue obtained was evaluated by flow cytometry. Two patients were diagnosed with lymphoma; no pathology was identified in the other four patients. Lymphoma of the spleen appeared as sharply demarcated echo-poor lesions; benign lesions appeared echo-rich in comparison with the surrounding splenic tissue. The two patients who were diagnosed with lymphoma underwent chemotherapy. Of the four patients in whom no pathology was identified, one patient subsequently underwent splenectomy for evaluation of persistent abdominal pain and was diagnosed with lymphoma; the three other patients had true-negative disease on the evidence of long-term follow-up (mean 8 months; range 6 - 12 months). No complications related to the EUS-FNA procedure were encountered in any patient. CONCLUSIONS: EUS-FNA of spleen masses is a safe technique that aids in the diagnosis of lymphoma when used in conjunction with flow cytometry.

Adult↗

PubMed1996

Use of a high affinity DNA ligand in flow cytometry.

To investigate the feasibility of using oligonucleotides in flow cytometry we describe a model system consisting of human neutrophil elastase (HNE) coated on 3.3 micro beads and a high affinity DNA ligand for HNE isolated by in vitro selection (SELEX). In this system the fluoresceinated DNA ligand was equally effective as an anti- HNE antibody in detecting HNE on beads. The location on and the chemistry of attachment of fluorescein to the DNA ligand is critical for the sensitivity of detection. DNA constructs in which fluorescein was conjugated via an ethylene glycol tether to either the 5'-end or near the 3'-end gave much higher signals than did probes with fluorescein directly conjugated to either end. Second-step staining with strepavidin-conjugated phycoerythrin was accomplished using a biotinylated DNA ligand in the initial staining of HNE beads. These data suggest that instead of, or in addition to, antibodies high affinity oligonucleotide probes can be useful in diagnostic applications based on flow cytometry.

Animals↗

PubMed1999

Diagnosis of disorders of platelet function by flow cytometry.

The platelet membrane glycoprotein (GP) IIb/IIIa, GPIX were detected by immunogold assay and flow cytometry, respectively, in two cases of Glannzmann's thrombasthenia (GT). The immunogold assay showed that the GP IIb/IIIa gold granules in GT were decreased obviously, compared with that in normal controls. Flow cytometry results showed that GP IIb/IIIa in two cases of GT was 0.1% and 0.5% of normal control, respectively. While GPIX showed no difference between the GT and normal control. The patients' father showed no bleeding symptoms, whose GP IIb/IIIa accounted for 36.99% of normal control. The experiment results suggested that flow cytometry is a quick, simple and sensitive method for the diagnosis of GP disorders.

Adult↗

PubMed1995

Use of hydroethidine and flow cytometry to assess the effects of leukocytes on the malarial parasite Plasmodium falciparum.

Flow cytometry was evaluated as a method of assessing in vitro the effects of leukocytes on blood-stage Plasmodium falciparum. Hydroethidine is converted by metabolizing cells to ethidium, a nucleic acid fluorochrome. After incubation with hydroethidine, viable and dead leukocytes and parasitized and uninfected erthrocytes could all be identified on the basis of fluorescence intensity and size. Leukocytes can therefore be eliminated from further analysis; this allows assessment, at any parasite developmental stage, of the level of parasitemia within erythrocytes in the presence of any of several types of leukocytes. Whether leukocytes actually kill intraerythrocytic parasites can therefore be determined and the level of cytotoxicity can be assessed. The ability of leukocytes to prevent merozoites from invading new erythrocytes, i.e., inhibition of parasite invasion, can also be assessed by this method. When erythrocytes containing schizont-stage parasites were cocultured with different leukocyte populations and the level of parasitemia was determined after merozoite release and invasion, only cultures containing gamma delta T cells inhibited parasite invasion. The different blood-stage forms of the parasite vary in nucleic acid content, which allows each of the developmental stages to be distinguished by flow cytometry; this permits assessment of changes in parasite development in the presence of leukocytes. Monocyte-derived macrophages (MDMs) appeared to have an effect on parasite development. In this instance, when erythrocytes containing ring-form parasites were cocultured with MDMs and harvested 24 h later, the parasites in cultures containing MDMs were at the late schizont stage, whereas parasites in control cultures were early trophozoites; this finding suggests that MDMs accelerate parasite development. Together, these results indicate that flow cytometry is potentially useful for measuring the following effects mediated by leukocytes: (i) level of cytotoxicity, (ii) changes in parasite development, and (iii) inhibition of parasite invasion.

Animals↗

PubMed1992

Reticulocyte quantification by flow cytometry, image analysis, and manual counting.

Reticulocyte counting by flow cytometry with thiazole orange was compared to manual or automated counting of new methylene blue stained blood smears. Forty-nine samples were compared for manual counting from randomly chosen clinical samples. Two hundred and eighty-nine samples from bone marrow transplant patients were compared during the period before and through chemo-irradiation and engraftment. The slopes of correlation plots were less than 1 when flow cytometric data were the dependent variable, suggesting that thiazole orange is less sensitive than new methylene blue. In a third study, 407 samples from bone marrow transplant patients were compared after increasing the thiazole orange concentration. The reticulocyte fluorescence distribution was divided into four groups of the brightest (youngest) 40, 60, 80, and 100% of reticulocytes. The slopes from regression analysis were 0.25, 0.49, 0.78, and 1.14, respectively. This demonstrates that thiazole orange is more sensitive than new methylene blue because the window of analysis includes an increased fraction of mature reticulocytes. In addition, the precision of each assay as measured. The rank order of precision from high to low was flow cytometry > image analysis >> manual counting.

Benzothiazoles↗

PubMed1986

DNA flow cytometry of histological material from human gastric cancer.

DNA flow cytometry was performed on fixed embedded histological material from 56 radical gastrectomies for human gastric cancer. The ploidy and proportion of cells in the DNA synthetic phase of the cell cycle (S phase fraction) were estimated and the results correlated with histological features. DNA aneuploidy was encountered in 73 per cent of cases. Aneuploid and diploid tumours both had significantly higher fractions of cells in S phase than normal mucosa. S phase fractions for aneuploid tumours were higher than diploid tumours. There was a trend for tumours exhibiting an infiltrating mode of growth and poor tubule formation to have a diploid DNA content and low S phase fraction. No difference was observed between the results obtained from tumours with or without lymph node metastases. Early uniform fixation greatly improved the quality of the flow cytometry results measurable by a reduction in the mean coefficient of variation.

Cell Division↗

PubMed1987

DNA analysis of breast tumour fine needle aspirates using flow cytometry.

Cellular DNA was analysed by flow cytometry in fine needles aspirates (FNA) from both benign and malignant breast lesions in order to determine the feasibility of flow cytometric analysis. In 22 of 26 (84%) benign and 69 of 74 (93%) malignant aspirates, sufficient cells were present to produce good quality DNA histograms. DNA in all 22 benign lesions was diploid. In contrast, of the 69 cancers with sufficient cells for analysis, 40.6% had a diploid DNA content alone, whilst 59.4% had an additional DNA aneuploid line. These results indicate that the majority of FNAs provide sufficient material for flow cytometric analysis of DNA profiles. Such aspirates taken in a sequential manner may also prove to be an ideal method of studying tumour response to therapy.

Adult↗