Report of the International Council for Standardization in Haematology working group for standardization of reticulocyte parameters

INTRODUCTION

The International Council for Standardization in Haematology convened a working group to assess and propose improvements upon the state of standardization and harmonization of reticulocyte parameters among commercial hematology analyzers.

METHODS

An international group of laboratory hematologists prospectively collected and analyzed clinical samples using locally available IVD commercial hematology analyzers. Eight hundred and fifty-five total samples were collected at 6 sites using 9 distinct analyzer types. Samples were assessed for reticulocyte percent (RET%), immature reticulocyte fraction (IRF), and reticulocyte hemoglobin content (RHC). Method comparison and regression statistics were calculated. These analyses were used to determine whether statistical recalibration offered a potential avenue for increasing comparability between these methods.

RESULTS

While methods producing reticulocyte percent were the most comparable in this study, the state of harmonization for the IRF and RHC was reduced with pearson correlation coefficients ranging from 0.955 to 0.77 and 0.927 and 0.680, respectively. Nevertheless, use of parameters from the Passing Bablok regression substantially improved the comparability of the results. In addition, precision data was derived which also demonstrated substantial differences between analyzer systems.

CONCLUSION

While reticulocyte counting is correlated between the automated methods evaluated in this study, the current state of harmonization of other reticulocyte parameters is not as strong. A major challenge in moving this field forward is the need for commutable materials to facilitate comparisons between analyzers not co-located. A potential alternate approach to improve the current state would be instrument re-calibration. However, this is challenging both technically and due to national regulatory frameworks.

Enumeration of Fetal Red Blood Cells, Hemoglobin-Specific RBC Cells, and F Reticulocytes in Human Blood

Recent advances in analytical cytometry have improved diagnostic tools for the study of erythropoiesis in anemic patients and resolution of differential diagnosis in diseases of the erythron. This article presents three applications of red blood cell (RBC) analysis-quantitation of fetal red cells, F-cell enumeration, and F-reticulocyte analysis-which improve diagnostic precision, sensitivity, and specificity, and provide better laboratory indicators of therapeutic efficacy in a variety of hematologic and obstetric disorders. Such advances also include the measurement and quantitation of RBC hemoglobins and their relative ribonucleic acid levels. These advances not only promise to improve diagnostic accuracy and laboratory precision over techniques such as the traditional manual reticulocyte counting method and the Kleihauer-Betke stain method for evaluating fetomaternal hemorrhage (FMH), but also serve as tools for newer assays of anemia diagnosis and improved clinical outcomes. In addition to the primary methods, supporting techniques for preparing spiked controls, automating data analysis, setting up a fetal hemoglobin acquisition protocol, and assaying reticulocytes using thiazole orange are also presented. © 2019 by John Wiley & Sons, Inc.

Fischer-Tropsch synthesis. Evaluation of an aluminum small channel reactor

Fischer-Tropsch synthesis was conducted in a small channel compact heat exchange reactor that was constructed of aluminum. While limited to lower temperature-pressure regions of the Fischer-Tropsch synthesis, the reactor could be operated in an isothermal mode with nearly a constant temperature along the length of the channel. The results obtained with the compact heat exchange reactor were similar to those obtained in the isothermal continuous stirred tank reactor, with respect to both activity and selectivity. Following a planned or unplanned shutdown, the reactor could be restarted to produce essentially the same catalytic activity and selectivity as before the shutdown.

The challenge of tetradic relationships in medically interpreted pediatric primary care visits: A descriptive study of communication practices

OBJECTIVE

To examine spoken interactions between pediatricians and community-based interpreters speaking with adolescents and parents with Limited English proficiency (LEP) in primary care to identify the challenges of interpreting in a four-person or tetradic visit, its sources of co-constructed errors, and specific practices for educational intervention.

METHODS

As part of a larger study of vaccine decision-making at six clinical sites in two states, this descriptive study used discourse analysis to examine 20 routine primary care visits in a Latino Clinic in interactions between adolescents, parents, community-based interpreters, and pediatricians. Specific patterns of communication practices were identified that contributed to inaccuracies in medical interpretation

RESULTS

Practices needing improvement were tallied for simple frequencies and included: omissions; false fluency; substitutions; editorializing; added clarification, information, or questions; medical terminology; extra explanation to mother; and, cultural additions. Of these speaking practices, omissions were the most common (123 out of 292 total) and the most affected by pediatricians.

CONCLUSION

The dynamics of both pediatricians and interpreters contributed to identification of areas for improvement, with more adolescent participation in bilingual than monolingual visits.

PRACTICE IMPLICATIONS

These observations provide opportunities for mapping a communication skills training intervention based on observations for future testing of an evidence-based curriculum.

Automated analysis of flow cytometric data for measuring neutrophil CD64 expression using a multi-instrument compatible probability state model

BACKGROUND

Leuko64™ (Trillium Diagnostics) is a flow cytometric assay that measures neutrophil CD64 expression and serves as an in vitro indicator of infection/sepsis or the presence of a systemic acute inflammatory response. Leuko64 assay currently utilizes QuantiCALC, a semiautomated software that employs cluster algorithms to define cell populations. The software reduces subjective gating decisions, resulting in interanalyst variability of <5%. We evaluated a completely automated approach to measuring neutrophil CD64 expression using GemStone™ (Verity Software House) and probability state modeling (PSM).

METHODS

Four hundred and fifty-seven human blood samples were processed using the Leuko64 assay. Samples were analyzed on four different flow cytometer models: BD FACSCanto II, BD FACScan, BC Gallios/Navios, and BC FC500. A probability state model was designed to identify calibration beads and three leukocyte subpopulations based on differences in intensity levels of several parameters. PSM automatically calculates CD64 index values for each cell population using equations programmed into the model. GemStone software uses PSM that requires no operator intervention, thus totally automating data analysis and internal quality control flagging. Expert analysis with the predicate method (QuantiCALC) was performed. Interanalyst precision was evaluated for both methods of data analysis.

RESULTS

PSM with GemStone correlates well with the expert manual analysis, r(2) = 0.99675 for the neutrophil CD64 index values with no intermethod bias detected. The average interanalyst imprecision for the QuantiCALC method was 1.06% (range 0.00-7.94%), which was reduced to 0.00% with the GemStone PSM. The operator-to-operator agreement in GemStone was a perfect correlation, r(2) = 1.000.

CONCLUSION

Automated quantification of CD64 index values produced results that strongly correlate with expert analysis using a standard gate-based data analysis method. PSM successfully evaluated flow cytometric data generated by multiple instruments across multiple lots of the Leuko64 kit in all 457 cases. The probability-based method provides greater objectivity, higher data analysis speed, and allows for greater precision for in vitro diagnostic flow cytometric assays.

Determination of optimal replicate number for validation of imprecision using fluorescence cell based assays: Proposed practical method

Background: Assay validation includes determination of inherent imprecision across the reportable range. However specific practical guidelines for determinations of precision for cell based fluorescence assays performed on flow cytometers are currently lacking. Methods: Replicates of 10 or 20 measurements were obtained for flow cytometric assays developed for clinical IVD use, including neutrophil CD64 expression for infection/sepsis detection, fetal red cell enumeration for fetomaternal hemorrhage detection, human equilibrative nucleoside transporter 1 (hENT1) quantitation in leukocytes for possible correlation with drug responsiveness, and CD34+ hematopoietic stem cell (HSC) enumeration of apheresis products, using up to three different instrument platforms for each assay. For each assay, the mean, 95% confidence intervals of the mean (95%CI), standard deviation and coefficient of variation (CV) of sequential replicates were determined. Results: For all assays and most instrument platforms <5 replicates were found adequate to validate assay imprecision levels below the 5-10% CV for repeatability claimed by the manufacturers of these assays. Results plotted as a novel parameter derived from the 95%CI and the cumulative mean for replicates, termed variance factor (VF), provide a data driven means for determining optimal replicate numbers. Conclusions: The novel VF can provide information to guide the practical selection of optimal replicate numbers for validation of imprecision in flow cytometric assays. The optimal number of replicates was assay and instrument platform dependent. Our findings indicate 3-4 replicates are sufficient for most flow cytometric assays and instrument combinations, rather than the higher numbers suggested by CLSI guidelines for soluble analytes. © 2013 Clinical Cytometry Society.

Use of CD157 in FLAER-based assays for high-sensitivity PNH granulocyte and PNH monocyte detection

Background: Recent Flow Cytometric guidelines to detect Paroxysmal Nocturnal Hemoglobinuria (PNH) in white blood cells recommend using FLAER-based assays to detect granulocytes and monocytes lacking expression of GPI-linked structures. However national proficiency testing results continue to suggest a need for improved testing algorithms, including the need to optimize diagnostic analytes in PNH. Methods: CD157 is another GPI-linked structure expressed on both granulocytes and monocytes and here we assess its ability to replace CD24 and CD14 in predicate 4-color granulocyte and monocyte assays respectively. We also assess a single tube, 5-color combination of FLAER, CD157, CD64, CD15 and CD45 to simultaneously detect PNH clones in granulocyte and monocyte lineages. Results: Delineation of PNH from normal phenotypes with 4- or 5-color CD157-based assays compared favorably with 4-color predicate methods and PNH clone size data were similar and highly correlated (R2 >0.99) with predicate values over a range (0.06% - 99.8%) of samples. Both CD157-based assays exhibited similar high levels of sensitivity and low background levels in normal samples. Conclusion: While CD157-based 4- and 5-color assays generated closely similar results to the predicate assays on a range of PNH and normal samples, the 5-color assay has significant advantages. Only a single 5-color WBC reagent cocktail is required to detect both PNH granulocytes and monocytes. Additionally, sample preparation and analysis time is reduced yielding significant efficiencies in technical resources and reagent costs. All 4- and 5-color reagent sets stained stabilized whole blood PNH preparations, used in external quality assurance programs. © 2013 Clinical Cytometry Society.

Toward a reference method for leukocyte differential counts in blood: comparison of three flow cytometric candidate methods

A Complete Blood Count performed by an automated hematology analyzer frequently requires a microscopic slide review. Recently, we and others have proposed combinations of monoclonal antibodies for an extended leukocyte differential by flow cytometry. The aim of this study was to compare the performance of these proposals. Ninety-two samples were analyzed at 2 sites to compare the accuracy of three published methods. Reference methods used were i) cell counter for leukocyte count and ii) microscopic review as defined by CSLI H20-A2 for cell subsets. Comparison of flow cytometers from 2 manufacturers (FC500 and CANTO/LSRII) was performed. Published protocols were adapted to three different models of flow cytometer and each provided similar results in leukocyte subset enumeration, although some discrepancies were noted for each protocol in comparison with the reference method. The conclusion is that each protocol carries advantages and disadvantages and there is no clear "winner". This study supports the fact that flow cytometry is a candidate to become a reference method for the leukocyte differential. None of the tested protocols clearly demonstrated superiority and each had demonstrable deficiencies. Additional work to develop a consensual 8 to 10 color panel is concluded to be necessary for a satisfactory reference method.

Activation of the p38 MAPK/Akt/ERK1/2 signal pathways is required for the protein stabilization of CDC6 and cyclin D1 in low-dose arsenite-induced cell proliferation

Arsenic trioxide (ATO) is a first-line anti-cancer agent for acute promyelocytic leukemia, and induces apoptosis in other solid cancer cell lines including breast cancer cells. However, as with arsenites found in drinking water and used as raw materials for wood preservatives, insecticides, and herbicides, low doses of ATO can induce carcinogenesis after long-term exposure. At 24 h after exposure, ATO (0.01-1 µM) significantly increased cell proliferation and promoted cell cycle progression from the G1 to S/G2 phases in the non-tumorigenic MCF10A breast epithelial cell line. The expression of 14 out of 96 cell-cycle-associated genes significantly increased, and seven of these genes including cell division cycle 6 (CDC6) and cyclin D1 (CCND1) were closely related to cell cycle progression from G1 to S phase. Low-dose ATO steadily increased gene transcript and protein levels of both CDC6 and cyclin D1 in a dose- and time-dependent manner. Low-dose ATO produced reactive oxygen species (ROS), and activated the p38 MAPK, Akt, and ERK1/2 pathways at different time points within 60 min. Small molecular inhibitors and siRNAs inhibiting the activation of p38 MAPK, Akt, and ERK1/2 decreased the ATO-increased expression of CDC6 protein. Inhibiting the activation of Akt and ERK1/2, but not p38 MAPK, decreased the ATO-induced expression of cyclin D1 protein. This study reports for the first time that p38 MAPK/Akt/ERK1/2 activation is required for the protein stabilization of CDC6 in addition to cyclin D1 in ATO-induced cell proliferation and cell cycle modulation from G1 to S phase.

2006 Bethesda International Consensus recommendations on the flow cytometric immunophenotypic analysis of hematolymphoid neoplasia: medical indications

The clinical indications for diagnostic flow cytometry studies are an evolving consensus, as the knowledge of antigenic definition of hematolymphoid malignancies and the prognostic significance of antigen expression evolves. Additionally the standard of care is not routinely communicated to practicing clinicians and diagnostic services, especially as may relate to new technologies. Accordingly there is often uncertainty on the part of clinicians, payers of medical services, diagnostic physicians and scientists as to the appropriate use of diagnostic flow cytometry. In an attempt to communicate contemporary diagnostic utility of immunophenotypic flow cytometry in the diagnosis and follow-up of patients with hematolymphoid malignancies, the Clinical Cytometry Society organized a two day meeting of international experts in this area to reach a consensus as to this diagnostic tool. This report summarizes the appropriate use of diagnostic flow cytometry as determined by unanimous approval of these experienced practitioners.

The costs and benefits of resource sharing: reciprocity requires resource heterogeneity

The evolution of resource sharing requires that the fitness benefits to the recipients be much higher than the costs to the giver, which requires heterogeneity among individuals in the fitness value of acquiring additional resources. We develop four models of the evolution of resource sharing by either direct or indirect reciprocity, with equal or unequal partners. Evolution of resource sharing by reciprocity requires differences between interacting individuals in the fitness value of the resource, and these differences must reverse although previous acts of giving are remembered and both participants survive. Moreover, inequality in the expected reproductive value of the interacting individuals makes reciprocity more difficult to evolve, but may still allow evolution of sharing by kin selection. These constraints suggest that resource sharing should evolve much more frequently by kin selection than by reciprocity, a prediction that is well supported by observations in the natural world.

Immunophenotypic profile predictive of KIT activating mutations in AML1-ETO leukemia

Translocation (8; 21)/AML1-ETO is considered a favorable cytogenetic abnormality in acute myeloid leukemia (AML). However, associated KIT activating mutations confer poor outcome. The immunophenotype associated with KIT mutations in AML1-ETO has not previously been elucidated. We retrospectively reviewed the immunophenotype by flow cytometry of 56 cases of AML with t(8; 21) and compared them with 100 cases of AML without t(8; 21). In 21 t(8; 21) cases, we sought KIT mutations by direct sequencing. Although CD19 and CD56 were aberrantly expressed in 42 (75%) of 56 and 46 (82%) of 56 cases, respectively, with t(8; 21), these markers were only expressed in 4% and 25%, respectively, without t(8; 21) (P < .001). However, the 5 KIT-mutated cases (D816H, 3; D816Y, 1; and N822K, 1) of t(8; 21) AML had diminished CD19 expression (P = .04) with definite CD56 expression (P = .30) on myeloid blasts. Our study suggests that KIT activating mutations in AML with t(8; 21) are associated with diminished CD 19 and positive CD56 expression on leukemic blasts and, thus, can be phenotypically distinguished from AML1-ETO leukemias without KIT mutations.

Comparison of intracardiac cell transplantation: autologous skeletal myoblasts versus bone marrow cells

An increasing number of patients living with cardiovascular disease (CVD) and still unacceptably high mortality created an urgent need to effectively treat and prevent disease-related events. Within the past 5 years, skeletal myoblasts (SKMBs) and bone marrow (or blood)-derived mononuclear cells (BMNCs) have demonstrated preclinical efficacy in reducing ischemia and salvaging already injured myocardium, and in preventing left ventricular (LV) remodeling, respectively. These findings have been translated into clinical trials, so far totaling over 200 patients for SKMBs and over 800 patients for BMNCs. These safety/feasibility and early phase II studies showed promising but somewhat conflicting symptomatic and functional improvements, and some safety concerns have arisen. However, the patient population, cell type, dose, time and mode of delivery, and outcome measures differed, making comparisons problematic. In addition, the mechanisms through which cells engraft and deliver their beneficial effects remain to be fully elucidated. It is now time to critically evaluate progress made and challenges encountered in order to select not only the most suitable cells for cardiac repair but also to define appropriate patient populations and outcome measures. Reiterations between bench and bedside will increase the likelihood of cell therapy success, reduce the time to development of combined of drug- and cell-based disease management algorithms, and offer these therapies to patients to achieve a greater reduction of symptoms and allow for a sustained improvement of quality of life.

Neutrophil CD64 is an improved indicator of infection or sepsis in emergency department patients

CONTEXT

Sepsis, affecting millions of individuals annually with an associated high mortality rate, is among the top 10 causes of death. In addition, improvements in diagnostic tests for detecting and monitoring sepsis and infection have been limited in the last 25 years. Neutrophil CD64 expression has been proposed as an improved diagnostic test for the evaluation of infection and sepsis.

OBJECTIVE

To evaluate the diagnostic performance of a quantitative flow cytometric assay for leukocyte CD64 expression in comparison with the standard tests for infection/sepsis in an ambulatory care setting.

DESIGN

Prospective analysis of 100 blood samples from patients from an emergency department setting in a 965-bed tertiary care suburban community hospital was performed for neutrophil CD64 expression, C-reactive protein, erythrocyte sedimentation rate, and complete blood count. The laboratory findings were compared with a clinical score for the likelihood of infection/sepsis, which was obtained by a blinded retrospective chart review.

RESULTS

The diagnostic performance, as gauged by the clinical score, varied with neutrophil CD64 (sensitivity 87.9%, specificity 71.2%, efficiency 76.8%) and outperformed C-reactive protein (sensitivity 88.2%, specificity 59.4%, efficiency 69.4%), absolute neutrophil count (sensitivity 60.0%, specificity 50.8%, efficiency 53.8%), myeloid left shift (sensitivity 68.2%, specificity 76.3%, efficiency 73.3%), and sedimentation rate (sensitivity 50.0%, specificity 65.5%, efficiency 61.0%).

CONCLUSION

Neutrophil CD64 expression quantitation provides improved diagnostic detection of infection/sepsis compared with the standard diagnostic tests used in current medical practice.

A standardized ZAP-70 assay—Lessons learned in the trenches

BACKGROUND

The disease of chronic lymphocytic leukemia (CLL) has been shown to exhibit varying clinical outcomes based on reported laboratory parameters. One of these parameters involves the measurement of the protein levels of zeta-associated protein (ZAP-70) in CLL cells. A standardized assay has not yet reached consensus in the clinical cytometry community.

METHODS

We developed a system using the 8-peak Rainbow beads as our fluorescence calibrator along with a fixed cell control. Using a panel of CD19-PE, CD5-FITC, and ZAP-70-Alexa 647, we stained normal whole blood, and blood and bone marrow from patients with CLL to determine the level of ZAP-70 expression in T-cell, B-cell, and CLL-cell populations. ZAP-70 expression was reported in molecules equivalent fluorescence (MEFL) based on the calibration of the flow cytometer with the 8-peak Rainbow beads.

RESULTS

Daily assay performance as well as operating MEFL defined ranges for ZAP-70 detection in CLL were developed. A rank-order, nonparametric approach to reference ranges was used to assign a cutoff for "negative" as well as ranges for "intermediate" and "positive" staining using T and B cells from a pool of 50 normal subjects, and CLL cells from 395 patients. The assay was validated in a multi-institutional study and has demonstrated correlation with published techniques. Since its initial development, the assay has been implemented at two additional laboratory sites and has been shown to produce reproducible, correlated data at all sites.

CONCLUSIONS

Strict adherence to standardization can yield an assay that is predictable, reliable, and reproducible as well as capable of multisite implementation. The Rainbow beads provide a common platform for system calibration. The fixed cell culture controls provide a common target to test antibody. The final level of control tests the sensitivity of ZAP-70 detection in a normal peripheral blood sample stained along with the submitted CLL patients. The acceptance/rejection of test results must meet all three levels of control before patient results are reported.

ZAP-70 expression is low in normal precursor B cells or hematogones

BACKGROUND

Zeta-associated protein (ZAP-70) expression has been associated with a less favorable prognosis in chronic lymphocytic leukemia (CLL). The role of ZAP-70 in immature B-cells is not well understood. Immature or precursor B lymphocytes (hematogones) often occur in clinical samples and coexpress CD10, CD38, and CD19 lacking surface immunoglobulin expression. The present study was carried out in an attempt to further elucidate the role of ZAP-70 in the spectrum of B-cells seen in clinical specimens.

METHODS

ZAP-70 expression was evaluated on 25 patient samples that expressed greater than 2% of CD10(+)/CD38(bright)/CD19(+) coexpression during routine evaluation. In our sample set, the hematogone expression ranged from 2 to 18% of total leukocytes and occurred in a variety of conditions, including CLL, NHL, AML, MDS, Hodgkins Disease, and Multiple Myeloma. The method of ZAP-70 detection was that routinely applied to our clinical testing of CLL samples supplemented with the determination of ZAP-70 levels in the CD38(bright)/CD19(+) coexpressing cells.

RESULTS

In all cases ZAP-70 was not expressed on the CD5 negative, CD38/CD19 coexpressing precusor B cells. In all cases hematogones were found to not express significant levels of ZAP-70.

CONCLUSION

The presence of hematogones in clinical samples should be recognized so as to not adversely influence prognostic studies of ZAP-70 or CD38 in CLL.

Comparison of neutrophil CD64 expression, manual myeloid immaturity counts, and automated hematology analyzer flags as indicators of infection or sepsis

There is a clear need for improved indicators of infection or sepsis to increase the sensitivity and specificity of both diagnosis and therapeutic monitoring. One of the effects of inflammatory cytokines on the innate immune response is the rapid up-regulation of CD64 expression on the neutrophil membrane. We and others have hypothesized that the measurement of neutrophil CD64 expression might represent an improved diagnostic indicator of infection and sepsis. In this study we assessed the relative ability of flow cytometric neutrophil CD64 measurements, neutrophil counts, myeloid immaturity differential counts, and flagging on an automated hematology analyzer to correlate with the presence of infection, as determined by a retrospective clinical scoring system of infection or sepsis. A total of 160 blood samples were randomly selected to derive equal proportions of the 3 categories of flags on a Coulter STKS blood counter that indicate the presence of a myeloid left shift. The patients for these samples were scored by retrospective chart review and placed into 4 groups on the basis of likelihood of infection, sepsis, or severe tissue injury. Neutrophil CD64 expression demonstrated a superior sensitivity (94.1%), specificity (84.9%), and positive predictive likelihood ratio (6.24), compared with neutrophil counts (sensitivity, 79.4%; specificity, 46.8%; positive predictive likelihood ratio, 1.49), band counts (sensitivity, 87.5%; specificity, 43.5%; positive predictive likelihood ratio, 1.55), myeloid immaturity fraction (sensitivity, 94.6%; specificity, 84.5%; positive predictive likelihood ratio, 2.12), and flagging on an automated hematology analyzer (sensitivity, 94.1%; specificity, 40.5%; positive predictive likelihood ratio, 1.58). Relative to the other laboratory parameters, the neutrophil CD64 parameter also provided the best separation of the 4 clinical groups. The findings indicate that neutrophil CD64 expression as determined by quantitative flow cytometry is an improved diagnostic indicator of infection/sepsis relative to current laboratory indicators of relative or absolute myeloid cell counts or hematology analyzer flagging algorithms.

Impact of preanalytical variables on granulocytic surface antigen expression: a review

BACKGROUND

There is a gradual but steady increase in the use of granulocytic surface marker studies to diagnose several inherited and acquired blood and bone marrow disorders. Diagnosis and follow-up of patients with inflammation and infection are other areas of quantitative flow cytometric application. Despite the increased use of flow cytometry to study granulocytes, there seems to be no well-established standards regarding specimen handling for these studies.

METHODS

This review summarizes the effect of preanalytical variables on granulocytic surface markers.

RESULTS AND CONCLUSIONS

Storing specimens in sodium heparin at room temperature for up to 72 h seems satisfactory. Other anticoagulants, although acceptable, may have a shorter storage time. Storage time could be prolonged further with the use of some preservation media. Lysed whole blood is the preferred technique. Techniques should avoid major temperature change and excessive manipulation and should maintain storage and methodologic temperature with minimal fluctuation. Fixation before staining with the antibody may result in decreased expression of some surface antigens.

Improved diagnostic approaches to infection/sepsis detection

Sepsis is a major healthcare problem from the perspective of mortality and economics. Advances in diagnostic detection of infection and sepsis have been slow, but recent advances in both soluble biomarker detection and quantitative cellular measurements promise the availability of improved diagnostic techniques. Though the promise of cytokine measurements reaching clinical practice have not matured, procalcitonin levels are currently available in many countries and appear to offer enhanced diagnostic distinction between bacterial and viral etiologies. Cellular diagnostics is poised to enter clinical laboratory practice in the form of neutrophil CD64 measurements, which offer superior sensitivity and specificity to conventional laboratory assessment of sepsis. Neutrophil CD64 expression is negligible in the healthy state. However, it increases as part of the systemic response to severe infection or sepsis. The combination of cellular proteomics, as in the case of neutrophil CD64 quantification, and selected soluble biomarkers of the inflammatory response, such as procalcitonin or triggering receptor expressed on myeloid cells (TREM)-1, is predicted to remove the current subjectivity and uncertainty in the diagnosis and therapeutic monitoring of infection and sepsis.

Human monocyte CD163 expression inversely correlates with soluble CD163 plasma levels

BACKGROUND

CD163 is a monocyte/macrophage-restricted receptor involved in the clearance of hemoglobin-haptoglobin complexes and regulation of inflammatory processes. CD163 is shed from the cell surface and exists as a soluble form in plasma (sCD163). Monocyte CD163 and sCD163 are potential diagnostic tools in variety of disease states.

METHODS

We determined the relation between plasma sCD163 levels by enzyme-linked immunosorbent assay, membrane expressions of CD163, CD64, and CD14 on blood monocytes by flow cytometry, and monocyte counts in 129 random blood samples.

RESULTS

A strong inverse correlation was found between membrane CD163 expression and sCD163 levels (r = -0.65, P < 0.001). Monocyte CD163 expression and SCD163 levels did not correlate with the monocyte absolute count.

CONCLUSIONS

The inverse relation between monocyte surface CD163 expression and sCD163 levels in human blood suggests that plasma sCD163 is derived from circulating monocytes, in addition to an unknown component from tissue macrophages. The lack of correlation with the absolute monocyte number suggests that such a balance is driven by the functional state of monocytes, rather than simply by numerical changes in circulating cells. We propose that further clinical evaluations of CD163 as a diagnostic parameter should include simultaneous measurements of soluble and cell-bound forms of this antigen.

Comparative study of monocyte enumeration by flow cytometry: improved detection by combining monocyte-related antibodies with anti-CD163

Monocyte-counting performance by hematological cell counters often lacks satisfactory accuracy and precision. Flow cytometry, the alternative, is a reliable reference method for monocyte enumeration in evaluation of the performance of automated analyzers. The present study was focused on evaluation and optimization of monocyte enumeration by flow cytometry. Fifty blood samples were stained with same-color CD163, CD64, and CD14 monoclonal antibodies (MoAbs), single or in mixtures, along with different colors of anti-CD45 and anti-CD16. The percentage positive monocytes and their median fluorescence intensity (MFI) were compared between the resulting MoAb combinations. CD163(+)14 increased monocyte detection by 5% compared with CD14 alone. The CD64(+)CD163 mixture resulted in a 6% detection increase relative to CD64 alone. CD64(+)CD14 labeled 2% more monocytes than CD14 and 0.03% more compared with CD64. Combining CD14 with CD163 or CD64 increased MFI 24% and 14% relative to CD14. CD163(+)CD64 increased monocyte MFI 115% compared with CD64. We found that combining same-color antibodies improved monocyte detection, especially when anti-CD163 was added to CD64 or CD14 antibodies. The use of CD163 antibody is the recommended flow cytometric reference method for monocyte counting.

Evaluation of immature granulocyte counts by the XE-IG master: upgraded software for the XE-2100 automated hematology analyzer

We evaluated an automated immature granulocyte (IG) count in the peripheral blood with the XE-IG Master (Sysmex Corporation). The XE-IG Master is the upgraded software package for the XE-2100 automated hematology analyzer. Reproducibility tests demonstrated a mean coefficient of variation of 7.02% for the IG percentage (IG%) and 6.93% for the absolute IG count. Correlations of the IG counts were assessed in two ways. A flow cytometric IG count using CD11b, CD16, and CD45 monoclonal antibodies and a manual differential count were used as reference methods. The regression equation and the correlation coefficient of the IG% for the flow cytometric reference count versus results with the XE-IG Master were: y = 0.91x + 0.10; r = 0.96. For the comparison with the manual differential count of promyelocytes, myelocytes, and metamyelocytes, the regression equation and correlation coefficient were: y = 0.81x + 1.27; r = 0.78. Samples were found to be stable up to 48 hours both at room temperature and when refrigerated. We investigated the clinical significance of the IG count as a new marker of acute inflammation. In this preliminary study, most samples with a high IG count had positive values for C-reactive protein and the erythrocyte sedimentation rate (positive sample rates were 84.0% and 95.0%, respectively) despite neutrophil counts within the normal range. Elevated IG counts correlated most closely with CD64 expression on polymorphonuclear cells and less so with the concentration of interleukin 6. Compared with other available inflammation markers, the IG count is rapidly generated with each full blood count at no extra cost and with no delay in sample analysis.

Multicenter clinical experience with flow cytometric method for fetomaternal hemorrhage detection

BACKGROUND

Enumeration of fetal red blood cells (RBCs) is important in the management of fetomaternal hemorrhage (FMH), particularly in situations of Rh incompatibility.

METHODS

We evaluated results from three institutions using the flow cytometric method (FCM) to detect fetal RBCs based on the anti-hemoglobin F (HbF) monoclonal antibody method.

RESULTS

During 1997-2001, 69 of 1248 patients (5.5%) had measurable fetal erythrocytes (RBCs) in maternal blood. Only 21 patients (1.7%) had more than 30 mL of fetal blood detected in maternal blood. Of the 11 patients with large FMH and clinical follow-up, 7 had fetal demise (64%). In positive samples, significant differences were found in the fluorescence intensity (FI) of anti-HbF antibody staining between HbF-negative erythrocytes (HbF-) and adult HbF containing erythrocytes (F cells; 4 +/- 0 versus 57 +/- 9 linear mean channels [LMC]; P < 0.001) and between HbF-cells and fetal RBCs (4 +/- 0 versus 433 +/- 136 LMC; P < 0.001). In addition, significant differences were observed in forward light scatter intensity between HbF-cells and fetal RBCs (298 +/- 15 versus 355 +/- 68 LMC, P = 0.03). The transportability of the test is also addressed by comparing results from two other laboratories. The experience of our three laboratories, as well as the results from the recently reinitiated College of American Pathologists survey, which compares FCM and manual methods, clearly documents the superiority of the FCM test over the manual Kleihauer-Betke (KB) test.

CONCLUSIONS

The FCM is a simpler, more objective, and more precise alternative to the KB method in clinical testing. The high mortality rate associated with large FMH and therapeutic implications of these results should give laboratories motivation to abandon the KB method with more robust FCM to detect FMH.

Clinical utility of CD23 and FMC7 antigen coexistent expression in B-cell lymphoproliferative disorder subclassification

BACKGROUND

CD23 and FMC7 are normal B-cell antigens utilized during diagnostic immunophenotyping of suspected lymphoproliferative disorders. However, the diagnostic utility of coexistent antigenic expression patterns with simultaneous two-color staining and flow cytometric analysis has not been studied extensively.

METHODS

Using multiparameter flow cytometry, we evaluated the expression pattern of FMC7 and CD23 in 218 cases of B-cell lymphoma from blood and bone marrow specimens.

RESULTS

The CD23(+)/FMC7(-) pattern was the most common pattern in patients with chronic lymphocytic leukemia and related variants. The widest variation of patterns was found in patients with follicular cell lymphoma, large cell lymphoma, and Waldenström's macroglobulinemia, a lymphoplasmacytoid disorder, although most cases expressed the CD23-/FMC7(+) pattern. The CD23 and FMC7 antigen, along with the CD5 coexpression pattern, provides critical adjunctive data. These data allow accurate classification of the majority of cases, thereby providing a key aspect of a reliable diagnostic algorithm. The CD23 and FMC7 antigen expression pattern, along with selected other antigens, was predictive of subtypes in >95% of lymphoproliferative cases and narrowed the differential diagnosis in the remaining cases.

CONCLUSION

The flow cytometric CD23/FMC7 expression pattern achieved by multicolor immunophenotyping facilitates accurate and reproducible classification of B-cell lymphomas and has diagnostic utility.

Diagnostic utility of red cell flow cytometric analysis

Although most of the diagnostic applications of flow cytometry bring forth examples of leukocyte immunophenotyping for immunodeficiency diseases and leukemia-lymphoma diagnosis, the same technology has improved medical assessment of diseases affecting the red cell and erythropoiesis. Flow cytometric methods were first applied to laboratory hematology with the improvement in reticulocyte counting and the creation of the immature reticulocyte fraction for better anemia evaluation and therapeutic monitoring. A more recent improvement attributable to flow cytometry is accurate detection of fetal red cells in the evaluation of FMH hemorrhage. The same method used in the detection of fetal RBCs based on HbF content measurement using monoclonal antibodies also offers the potential for enumeration of F cells, which promises to have use in therapeutic monitoring of patients with sickle cell disease and the evaluation of other hemoglobinopathies and myelodysplasia. Other clinical uses of flow cytometric RBC analysis include nonisotopic red cell survival studies, sensitive blood group typing, sensitive detection of immune-mediated hemolytic diseases, and evaluation of parasitic diseases whose life cycle involves intracellular RBC infestation. This article summarizes red cell flow cytometry, particularly as it impacts the areas of immunohematology and laboratory hematology, and points to areas of potential future contribution of this technology to diagnostic medicine.

Increased distribution and expression of CD64 on blood polymorphonuclear cells from patients with the systemic inflammatory response syndrome (SIRS)

Evidence is growing to suggest that the multiple organ damage of the systemic inflammatory response syndrome (SIRS) arises from the untoward activity of blood polymorphonuclear cells (PMNs), which upon activation acquire the IgG high affinity receptor, CD64. In the current study, flow cytometry was used to assess the prevalence of CD64-bearing PMNs and the intensity of expression of CD64 in whole blood samples from 32 SIRS patients, 11 healthy normal subjects and from eight non-SIRS patients in the intensive care unit (ICU). The percentage of PMNs expressing CD64 was higher in SIRS patients (mean 65%) than in non-SIRS patients (mean 42%; P < 0.02) and in healthy controls (mean 19%; P < 0.001) and was particularly evident in patients with SIRS and sepsis (mean 71%; P < 0.02) as opposed to SIRS alone (mean 55%). There were more CD64 molecules expressed on PMNs from patients with SIRS (median 1331 molecules/cell) in comparison with PMNs from healthy subjects (median 678 molecules/cell; P < 0.01). The highest intensity of CD64 expression was associated with PMNs from patients with both SIRS and sepsis. Functional studies revealed that the supranormal binding of PMNs from patients with SIRS to endothelial monolayers treated with TNFalpha was impeded by anti-CD64 antibodies (mean 24% inhibition; P < 0.01). Monitoring the distribution of CD64+ PMNs and their level of CD64 expression could be of assistance in the rapid discrimination of patients with SIRS from other ICU patients and in the identification of PMNs which are likely to participate in the pathological manifestations of the disease.

Hepatosplenic gamma/delta T-cell lymphoma in immunocompromised patients. Report of two cases and review of literature

We describe 2 male patients in whom hepatosplenic gamma/delta T-cell lymphoma (HSTL) developed 6 and 10 years after renal transplantation. The onset was abrupt with systemic symptoms, cytopenia, and hepatosplenomegaly. The histologic examination of the spleen (case 1), liver, and bone marrow revealed sinusoidal infiltrates of markedly abnormal lymphocytes. The neoplastic cells in these cases were CD2+, CD3+, CD4-, CD5-, CD7+, CD8+, CD16+, CD56+, beta F1-negative, and TIA-1-negative. Both cases displayed clonal rearrangement of the T-cell receptor (TCR) delta gene and the TCR beta gene. The spleen in case 1 was positive for Epstein-Barr virus genome and showed TCR-gamma gene rearrangement by polymerase chain reaction. Isochromosome 7 [i(7)(q10)] was found in each case. Both patients died within 4 months of diagnosis. HSTL has been reported in only 5 renal transplant recipients. HSTL may be relatively more frequent in immunocompromised patients compared with the general population.

Flow cytometric method for simultaneous assay of foetal haemoglobin containing red cells, reticulocytes and foetal haemoglobin containing reticulocytes

Level of foetal haemoglobin (HbF) containing red cells (F cells) is a parameter for monitoring sickle cell anaemia (SS) patients undergoing treatment with HbF modulating drugs (including hydroxyurea (HU)). One convenient technique for F cell assay is flow cytometry. A flow cytometric method for the simultaneous assay of F cells, reticulocytes and HbF-containing reticulocytes (F reticulocytes) is described in this paper. These three parameters can be obtained within 2 h using double colour staining flow cytometry. Glutaraldehyde fixation, Triton X-100 permeabilization, monoclonal antibody to HbF Tri-colour conjugate (MoAb-HbF-TC; deep-red fluorescence) immuno-staining and thiazole orange (TO; green fluorescence) are employed. The red cell gate was set on forward scatter (FSC) and logarithmic side scatter (logSSC) for 50 000 cells on the flow cytometer. Fluorescent signals were acquired from fluorescent channel 1 (FL1; green) and (FL4; deep-red). Coefficient of variation percent (%CVs) of intra- and inter-assay were less than 9% and 15%, respectively. EDTA, citrate, heparin and CTAD anticoagulants are all suitable; the samples can be stored at 4 degrees C for up to 6 days. The method is a simple, rapid, convenient, reproducible and useful way of determining F cell, reticulocyte and F reticulocyte levels in sickle cell and thalassaemic patients.

Diagnostic advances in defining erythropoietic abnormalities and red blood cell diseases

The majority of clinical applications of flow cytometry begin with various approaches to remove red blood cells (RBCs) from the clinical sample. However, multiparameter cytometry has and will continue to contribute much to the understanding of the pathophysiology and diagnostic accuracy in the clinical evaluation of human diseases affecting erythroid cells. This review summarizes the diagnostic advances relating to erythroid cells in the areas of immunohematology, laboratory hematology, and infectious disease with particular emphasis on medical evaluation of the anemic patient and fetomaternal hemorrhage. Semin Hematol 38:148-159.

Optimal number of reagents required to evaluate hematolymphoid neoplasias: results of an international consensus meeting

At the ISAC 2000 Congress, the Clinical Cytometry Society organized a meeting of international experts to reach consensus on the minimum number of antibodies required for a full evaluation of hematologic and lymphoid neoplasias. A questionnaire was distributed prior to the meeting to numerous experts from US and European institutions and 13 responses were received. At the meeting, 25 individuals, including most of those who returned responses, participated in the discussions and voted on the issues presented. In chronic lymphoproliferative disorders (CLD), 9 antibodies (anti-CD5, CD19, kappa, lambda, CD3, CD20, CD23, CD10, and CD45) were deemed essential for initial evaluation by 75% of the participants. There was near unanimity that additional markers (selected from CD22, FMC7, CD11c, CD103, CD38, CD25, CD79b and heavy chains for B-cell disorders, and CD4, CD7, CD8, CD2, CD56, CD16, TCRa/b, and TCRg/d for T-cell disorders) would be needed to fully characterize CLD, although not every marker would be useful in all cases. Tissue lymphomas were believed to be similar to CLD, needing a minimum of 12--16 markers. However, for some cases, CD30, bcl-2, TdT, CD71, CD1a, and CD34 were cited as useful by the participants. Markers mentioned for plasma cell disorders included kappa, lambda, CD38, CD45, CD56, CD19, CD20, CD138, and heavy chains. Of 17 voting participants, 16 agreed that between 5 to 8 markers would be essential reagents for plasma cell disorders. For acute leukemia (AL), 10 markers (CD10, CD19, CD13, CD33, CD34, CD45, CD7, CD14, CD3, and HLADR) were considered essential by 75% of participants for initial characterization of the leukemia lineage. Most (>75%) agreed that at least one more B (CD20, CD22, CD79a, IgM), T (CD1a, CD2, CD4, CD5, CD8), myeloid (CD11b, CD15, CD64, CD117, myeloperoxidase), erythroid (CD36, CD71, glycophorin A), and megakaryocytic (CD41, CD61) reagents should be included in the essential panel. However, there was no agreement as to which was optimal. Thus, approximately 13--15 of those reagents would be considered essential in all cases of AL, whereas others (CD16, CD56, CDw65, TdT, and cytoplasmic CD3) were mentioned as useful in some cases. Almost all voting participants believed that the appropriate number of markers for complete characterization of AL would average 20--24. The majority of the responders (11 of 13) indicated that fewer reagents could be used in monitoring or staging patients with previously characterized disease, but not all ventured a specific number of reagents. From the above results, we conclude that the phenotypic analysis of hematologic and lymphoid neoplasia requires a rather extensive panel of reagents. Supplementary reagents might even be necessary if they prove to become relevant for diagnostic purposes. Reducing the number of antibodies could significantly compromise the diagnostic accuracy, appropriate monitoring, or therapy of these disorders.

Diagnostic usefulness of CD23 and FMC-7 antigen expression patterns in B-cell lymphoma classification

CD23 and FMC-7 are normal B-cell antigens used during diagnostic immunophenotyping of suspected lymphoproliferative disorders, but the diagnostic usefulness of antigenic expression patterns of simultaneous 2-color staining and flow cytometric analysis has not been reported. We evaluated the FMC-7 and CD23 expression pattern in 201 cases of B-cell lymphoma from tissue biopsy specimens by multiparameter flow cytometry. The CD23-/FMC-7+ pattern was the most common pattern in large cell, mantle cell, and marginal zone lymphomas. The CD23 and FMC-7 antigen, along with the CD5 coexpression pattern, permitted accurate classification of all 71 cases of small lymphocytic, mantle cell, and marginal zone types of lymphoma. The widest variation of patterns was with follicular cell lymphoma, although most cases expressed the CD23 +/-/FMC-7+ pattern (+/-, partial or minor subset expression). The CD23 and FMC-7 antigen expression pattern was predictive of subtypes in more than 95% of lymphoma cases and could narrow the differential diagnosis in the remaining cases. We conclude the flow cytometric CD23/FMC-7 expression pattern achieved by dual staining facilitates accurate and reproducible classification of B-cell lymphomas and has diagnostic usefulness.

Technical Report: Triple-Colour Staining Flow Cytometry for Co-Distribution of Thrombospondin Receptor (CD36), Ribonucleic Acid (RNA) and Fetal Haemoglobin (HbF) in Sickle Red Blood Cells

Red blood cells (RBCs) from sickle cell patients (SS) express thrombospondin receptor (CD36), contain ribonucleic acid (RNA, recognised as reticulocytes) and fetal haemoglobin (HbF, defined as F cells) in a higher proportion than RBCs from healthy individuals. The co-distribution of CD36, RNA and HbF on the same RBCs has not been demonstrated due to a lack of detection methods. A triple-colour staining flow cytometry for the co-distribution of CD36, RNA and HbF was developed. The method can simultaneously determine CD36-expressing RBCs (CD36 cells), RNA-bearing RBCs (reticulocytes), HbF-bearing RBCs (F cells), CD36-expressing reticulocytes (CD36 reticulocytes), CD36-expressing-F cells (CD36-F cells), HbF-bearing reticulocytes (F reticulocytes) and CD36-expressing-F reticulocjrtes (CD36-F reticulocytes). Mouse monoclonal antibody against CD36 (MoAb-CD36), antibodagainst mouse-immunoglobulin conjugated to biotin (Ab-Molg-Bi), streptavidin conjugated to rhodamine phycoerythrin (StA-RFE), MoAb against HbF conjugated to Tri-Colour® (MoAb-HbF-TC), Thiazole orange (TO), Glutaraldehyde and Triton X-100 were used. The procedure takes approximately 7 hours. The numbers of CD36 cells, reticulocytes and F cells obtaining from single and triple staining were well correlated and not significantly different. Intra- and inter-assay coefficient of variation percents (%CVs) of the triple-colour staining were less than 10 and 15% respectively. EDTA blood samples stored at 4°C for less than 3 days are suitable. The method trial was then employed on blood samples from SS and healthy individuals. The method is reproducible, objective and applicable for determination of co-distribution of other membrane and intracellular markers in RBCs.

Simplified flow cytometric method for fetal hemoglobin containing red blood cells

Assay of fetal hemoglobin (HbF) and/or HbF containing red blood cells (F+ cells) is essential for monitoring sickle cell and thalassemic patients, especially during treatment with HbF stimulators. Some previous flow cytometric methods contain several washing steps. This simplified method contains no washing step and takes less than an hour to perform. The %F+ cells in five mixtures of fetal red blood cells with adult red blood cells were nonsignificantly different in the original and simplified procedure. The %F+ cells of 12 patients compared in these two procedures were also not significantly different. The intra- and interassay %CVs do not exceed 3% and 7% respectively. EDTA, citrate, or heparin is suitable as anticoagulant and the samples can be stored at 4 degrees C for up to 2 weeks. The %F+ cells and %HbF [by high-performance liquid chromatography (HPLC)] of 83 samples were highly significantly correlated regardless of diagnosis. In conclusion, this new simplified flow cytometric method for F+ cells is simple, convenient, rapid, reproducible, and could be applied for monitoring sickle cell and thalassemic patients as an alternative to HPLC, where this is unavailable. It can also be applied as a fetal cell assay in fetomaternal hemorrhage.

Proposed flow cytometric reference method for the determination of erythroid F-cell counts

BACKGROUND

Quantitation of adult erythrocytes (RBC) containing fetal hemoglobin (F cells) is of potential clinical utility in evaluating erythropoietic disorders, such as myelodysplasia and hemoglobinopathies, and in monitoring F-cell augmenting therapy. F-cell counting methodologies include fluorescence microscopy and flow cytometry. Previous flow cytometric methods have employed an isotype antibody control to distinguish F cells from non-F cells. We investigated the feasibility of using the orange autofluorescence signal (FL2) in glutaraldehyde-fixed RBC to substitute for fluorescein isothiocyanate (FITC)-labeled isotype control antibody use in F-cell quantitation.

METHODS

Our previously published method for fetal red cell detection in fetomaternal hemorrhage was used, employing a FITC-labeled anti-hemoglobin F (HbF) monoclonal antibody reagent. Blood samples with varying F-cell counts were quantitated for F cells using both immunofluorescence microscopy and flow cytometry comparing FITC-labeled isotype to FL1 thresholding defined by FL2 autofluorescence.

RESULTS

F cell percentages obtained by using an FL2 defined threshold for FL1 gating correlated well with expected values in diluted blood samples (r(2) = 0.994, slope = 1. 019, intercept = 0.24), values obtained using an isotype control (r(2) = 0.996, slope = 1.012, intercept = -0.17), and microscopic immunofluorescence counts (r(2) = 0.989, slope = 0.999, intercept = -0.72). F-cell quantitation by the isotype control and FL2 autofluorescence methods was also comparable in 40 blood samples (r(2) = 0.994, slope = 1.014, intercept = 0.03). Intra-assay, interobserver, and interinstrument precision with this autofluorescence gating method exhibited low imprecision (coefficient of variation <14%).

CONCLUSION

This novel method is a more objective and less laborious alternative for F-cell quantitation by flow cytometry compared to using an isotype control or microscopy, thereby providing a more robust methodology for clinical studies and consideration as a laboratory reference method for F-cell counting.

Myelodysplastic syndrome at a large tertiary care community hospital: analysis according to the international prognostic scoring system

The outcome of patients diagnosed myelodysplastic syndromes (MDS) between 1990 and 1997 from William Beaumont Hospital (WBH) was analyzed according to the International Prognostic Scoring System (IPSS) risk categorization. A retrospective study of 195 MDS patients wa s performed. Seventy-nine patients with MDS, in whom a karyotype was obtained and with an adequate follow-up were included in the final analysis. Cases of proliferative CMML (WBC > 12x10(9)/l) were excluded from the study. The overall median survival was 3.1 years, and median survival stratified by IPSS was 3.4, 4.1 and 0.5 years for the INT-1, INT-2 and high risk group and not yet reached for the low risk group. The overall survival by IPSS subcategorization were 6.88, 5.29, 5.30 and 2.12 years for the low, INT-1, INT-2, and high risk groups respectively. Cytogenetics were significant in predicting the overall survival. The IPSS score stratified patients into risk categories for development of AML. The risk of development into AML was 8, 8, 33 and 54% for the low, INT-1, INT-2 and high risk groups, respectively. We conclude that IPSS score can be useful in predicting survival and AML evolution in some MDS patients.

The DNA binding protein BTEB mediates acetaldehyde-induced, jun N-terminal kinase-dependent alphaI(I) collagen gene expression in rat hepatic stellate cells

Alcohol-induced cirrhosis results partially from the excessive production of collagen matrix proteins, which, predominantly alphaI(I) collagen, are produced and secreted by activated hepatic stellate cells (HSC). The accumulation of alphaI(I) collagen in HSC during cirrhosis is largely due to an increase in alphaI(I) collagen gene expression. Acetaldehyde, the major active metabolite of alcohol, is known to stimulate alphaI(I) collagen production in HSC. However, the mechanisms responsible for it remain unknown. The aim of this study was to elucidate the mechanisms by which alphaI(I) collagen gene expression is induced by acetaldehyde in rat HSC. In the present study, the acetaldehyde response element was located in a distal GC box, previously described as the UV response element, in the promoter of the alphaI(I) collagen gene (-1484 to -1476). The GC box was predominantly bound by the DNA binding transcription factor BTEB (basic transcription element binding protein), expression of which was acetaldehyde and UV inducible. Blocking BTEB protein expression significantly reduced the steady-state levels of the acetaldehyde-induced alphaI(I) collagen mRNA, suggesting that BTEB is required for this gene expression. Further studies found that acetaldehyde activated Jun N-terminal kinase (JNK) 1 and 2 and activator protein 1 (AP-1) transactivating activity. Inhibition of JNK activation resulted in the reduction of the acetaldehyde-induced BTEB protein abundance and alphaI(I) collagen mRNA levels, indicating that the expression of both genes is JNK dependent in HSC. Taken together, these studies demonstrate that BTEB mediates acetaldehyde-induced, JNK-dependent alphaI(I) collagen gene expression in HSC.

Platelet-derived growth factor is a principal inductive factormodulating mannose 6-phosphate/insulin-like growth factor-II receptorgene expression via a distal E-box in activated hepatic stellate cells

Hepatic stellate cells (HSCs) become activated during the earlystages of hepatic injury associated with fibrogenesis. The mannose 6-phosphate/insulin-like growth factor-II receptor (M6P/IGFIIR) plays animportant role in early fibrogenesis by participating in the activationof latent transforming growth factor-beta, a potent inducer of thematrix proteins in activated stellate cells that produce the hepaticnodule. Platelet-derived growth factor (PDGF), a potent HSC mitogen, isreleased early in hepatic injury and activates several signallingpathways in HSCs. In this study we examined the role of PDGF-BB in HSCregulation of M6P/IGFIIR gene expression. Several promoter elementswere found and characterized that modulate M6P/IGFIIR expression inactivated stellate cells. The presence of a distal CACGTG E-box at-2695 was required for M6P/IGFIIR expression in transfectedstellate cells. When the distal E-box was removed there was no significant M6P/IGFIIR promoter activity. The distal E-box-binding protein responded specifically to PDGF-BB with increased binding. This coincided with PDGF-BB up-regulation of M6P/IGFIIR mRNA transcript levels. Downstream elements include two proximal (-2 to-48) CACGTG E-boxes that bind a different protein to the distal(-2695) E-box. The proximal E-boxes respond moderately to PDGF-BB. The promoter segment encompassing -144 to +109 is able to respond dramatically to serum but is refractory to PDGF-BB. However, a constitutively bound protein binding to the -611/-716 fragment appears to be a repressor that suppresses inductive changes in protein binding occurring downstream of -611. These results indicate that the M6P/IGFIIR promoter responds primarily and specifically to PDGF-BB through a distal E-box element and possibly through two proximal E-box elements.

1,25-Dihydroxyvitamin D(3) stimulates activator protein-1-dependent Caco-2 cell differentiation

1,25-Dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) is a potential chemopreventive agent for human colon cancer. We have reported that 1,25(OH)(2)D(3) specifically activated protein kinase C-alpha (PKC-alpha) and also caused a reduction in proliferation while increasing apoptosis and differentiation in CaCo-2 cells, a cell line derived from a human colon cancer. The mechanisms by which this secosteroid influences these important cellular processes, however, remain unclear. The transcription factor, activator protein-1 (AP-1), regulates many genes involved in these processes. Therefore, we asked whether 1,25(OH)(2)D(3) activated AP-1 in CaCo-2 cells and, if so, by what mechanisms? 1,25(OH)(2)D(3) caused a time-dependent increase in AP-1 DNA binding activity and significantly enhanced the protein and mRNA abundance of c-Jun, a component of AP-1. 1, 25(OH)(2)D(3) also induced a rapid and transient activation of ERK2 (where ERK is extracellular signal-regulated kinase) and a more persistent activation of JNK1 (where JNK Jun N-terminal kinase). Transfection experiments revealed that 1,25(OH)(2)D(3) also increased AP-1 gene-transactivating activity. This AP-1 activation was completely blocked by PD 098059, a specific mitogen-activated protein kinase/ERK kinase inhibitor, as well as by a dominant negative JNK or a dominant negative Jun, indicating that the AP-1 activation induced by 1,25(OH)(2)D(3) was mediated by ERK and JNK. Using a specific inhibitor of the Ca(2+)-dependent PKC isoforms, Gö6976, and CaCo-2 cells stably transfected with antisense PKC-alpha cDNA, demonstrated that PKC-alpha mediated the AP-1 activation induced by this secosteroid. Inhibition of JNK activation or c-Jun protein expression significantly reduced 1, 25(OH)(2)D(3)-induced alkaline phosphatase activity, a marker of CaCo-2 cell differentiation, in secosteroid-treated cells. Taken together, the present study demonstrated that 1,25(OH)(2)D(3) stimulated AP-1 activation in CaCo-2 cells by a PKC-alpha- and JNK-dependent mechanism leading to increases in cellular differentiation.

Performance evaluation of a hematology blood counter with five-part leukocyte differential capability

The summarized data and other studies to date indicate that performance of the Pentra 60 is comparable to other hematology analyzers for all CBC and 5-Diff parameters. Comparative studies indicate good correlation for all the reportable CBC parameters, lymphocyte counts, and neutrophil counts with 24 hr stability on blood samples. Good intermethod correlations on monocyte and eosinophil counts were observed. Only basophil counts showed poor intermethod correlations, but this is expected on a statistical basis, and the counts are similar to those reported for other hematology analyzer performance studies. The combination of the MDSS and stepper motor fluidic system allows for low-volume blood sampling, compact size, and low operational noise level. The Pentra 60 is well suited for physician's office laboratories, medical clinics, small- or medium-size hospitals with less than 100 CBCs per day, and larger hospitals or reference laboratories that need back-up for a high-end automated hematology analyzer.

Metabolic oxidative stress activates signal transduction and gene expression during glucose deprivation in human tumor cells

The mechanism of glucose deprivation-induced activation of Lyn kinase (Lyn), c-Jun N-terminal kinase 1 (JNK1) and increased expression of basic fibroblast growth factor (bFGF) and c-Myc was investigated in MCF-7/ADR adriamycin-resistant human breast carcinoma cells. Glucose deprivation significantly increased steady state levels of oxidized glutathione content (GSSG) and intracellular prooxidants (presumably hydroperoxides) as well as caused the activation of Lyn, JNK1, and the accumulation of bFGF and c-Myc mRNA. The suppression of GSSG accumulation and prooxidant production by treatment with the thiol antioxidant, N-acetylcysteine, also suppressed all the increases in kinase activation and gene expression observed during glucose deprivation. In addition, glucose deprivation was shown to induce oxidative stress in IMR90 SV40 transformed human fibroblasts, indicating that this phenomena is not limited to the MCF-7/ADR cell line. These and previous observations from our laboratory show that glucose deprivation-induced oxidative stress in MCF-7/ADR cells activates signal transduction involving Lyn, JNK1, and mitogen activated protein kinases (ERK1/ERK2) which results in increased bFGF and c-Myc mRNA accumulation. These results provide support for the hypothesis that alterations in intracellular oxidation/reduction reactions link changes in glycolytic metabolism to signal transduction and gene expression in these human tumor cells.