Aging stability of complete blood count and white blood cell differential parameters analyzed by Abbott CELL-DYN Sapphire hematology analyzer

A comparative study of blood cell count in four automated hematology analyzers: An evaluation of the impact of preanalytical factors

Differential white blood cell counts are frequently used in diagnosis, patient stratification, and treatment selection to optimize therapy responses. Referral laboratories are often used but challenged with use of different hematology platforms, variable blood shipping times and storage conditions, and the different sensitivities of specific cell types. To extend the scientific literature and knowledge on the temporal commutability of blood samples between hematology analyzers, we performed a comparative ex-vivo study using four of the most utilized commercial platforms, focusing on the assessment of eosinophils given its importance in asthma management. Whole blood from healthy volunteers with and without atopy (n = 6+6) and participants with eosinophilic asthma (n = 6) were stored under different conditions (at 4, 20, 30, and 37°C, with or without agitation) and analyzed at different time points (3, 6, 24, 48 and 72h post-sampling) in parallel on the Abbott CELL-DYN Sapphire, Beckman Coulter DxH900, Siemens ADVIA 2120i and Sysmex XN-1000V. In the same blood samples, eosinophil-derived neurotoxin (EDN), eosinophil activation and death markers were analyzed. All platforms gave comparable measurements of cell differentials on fresh blood within the same day of sampling. However, by 24 hours, significant temporal and temperature-dependent differences were observed, most markedly for eosinophils. None of the platforms performed perfectly across all temperatures tested during the 72 hours, showing that handling conditions should be optimized depending on the cell type of interest and the hematology analyzer. Neither disease status (healthy vs. asthma) nor agitation of the sample affected the cell quantification result or EDN release. The eosinophil activation markers measured by flow cytometry increased with time, were influenced by temperature, and were higher in those with asthma versus healthy participants. In conclusion, hematology analyzer, time window from sampling until analysis, and temperature conditions must be considered when analyzing blood cell differentials, particularly for eosinophils, via central labs to obtain counts comparable to the values obtained in freshly sampled blood.

Investigating the effects of maltreatment and acute stress on the concordance of blood and DNA methylation methods of estimating immune cell proportions

BACKGROUND

Immune cell proportions can be used to detect pathophysiological states and are also critical covariates in genomic analyses. The complete blood count (CBC) is the most common method of immune cell proportion estimation, but immune cell proportions can also be estimated using whole-genome DNA methylation (DNAm). Although the concordance of CBC and DNAm estimations has been validated in various adult and clinical populations, less is known about the concordance of existing estimators among stress-exposed individuals. As early life adversity and acute psychosocial stress have both been associated with unique DNAm alterations, the concordance of CBC and DNAm immune cell proportion needs to be validated in various states of stress.

RESULTS

We report the correlation and concordance between CBC and DNAm estimates of immune cell proportions using the Illumina EPIC DNAm array within two unique studies: Study 1, a high-risk pediatric cohort of children oversampled for exposure to maltreatment (N = 365, age 8 to 14 years), and Study 2, a sample of young adults who have participated in an acute laboratory stressor with four pre- and post-stress measurements (N = 28, number of observations = 100). Comparing CBC and DNAm proportions across both studies, estimates of neutrophils (r = 0.948, p < 0.001), lymphocytes (r = 0.916, p < 0.001), and eosinophils (r = 0.933, p < 0.001) were highly correlated, while monocyte estimates were moderately correlated (r = 0.766, p < 0.001) and basophil estimates were weakly correlated (r = 0.189, p < 0.001). In Study 1, we observed significant deviations in raw values between the two approaches for some immune cell subtypes; however, the observed differences were not significantly predicted by exposure to child maltreatment. In Study 2, while significant changes in immune cell proportions were observed in response to acute psychosocial stress for both CBC and DNAm estimates, the observed changes were similar for both approaches.

CONCLUSIONS

Although significant differences in immune cell proportion estimates between CBC and DNAm exist, as well as stress-induced changes in immune cell proportions, neither child maltreatment nor acute psychosocial stress alters the concordance of CBC and DNAm estimation methods. These results suggest that the agreement between CBC and DNAm estimators of immune cell proportions is robust to exposure to child maltreatment and acute psychosocial stress.

Effects of storage conditions on the stability and distribution of clinical trace elements in whole blood and plasma: Application of ICP-MS

BACKGROUND

Knowledge of trace element stability during sample handling and preservation is a prerequisite to produce reliable test results in clinical trace element analysis.

METHOD

An alkaline dissolution method has been developed using inductively coupled plasma mass spectrometry to quantify eighteen trace element concentrations: vanadium, chromium, manganese, cobalt, nickel, copper, zinc, arsenic, selenium, bromine, molybdenum, cadmium, antimony, iodine, mercury, thallium, lead, and bismuth in human blood, using a small sample volume of 0.1 mL. The study evaluated the comparative effects of storage conditions on the stability of nutritionally essential and non-essential elements in human blood and plasma samples stored at three different temperatures (4 °C, -20 °C and -80 °C) over a one-year period, and analysed at multiple time points. The distribution of these elements between whole blood and plasma and their distribution relationships are illustrated using blood samples from 66 adult donors in Queensland.

RESULTS

The refrigeration and freezing of blood and plasma specimens proved to be suitable storage conditions for many of the trace elements for periods up to six months, with essentially unchanged concentrations. Substantially consistent recoveries were obtained by preserving specimens at -20 °C for up to one year. Ultra-freezing of the specimens at -80 °C did not improve stability; but appeared to result in adsorption and/or precipitation of some elements, accompanied by a longer sample thawing time. A population sample study revealed significant differences between the blood and plasma concentrations of six essential elements and their relationships also varied significantly for different elements.

CONCLUSION

Blood and plasma specimens can be reliably stored at 4 °C for six months or kept frozen at -20 °C up to one year to obtain high quality test results of trace elements.

Influence of different methods and anticoagulants on platelet parameter measurement

Platelets are the smallest and perhaps the most versatile components of human blood. Besides their role in coagulation and the maintenance of vascular integrity, they are involved in many physiological processes, ranging from immune response and leukocyte recruitment to the production of antimicrobial peptides and immune-suppressive factors like TGF-β. These versatile abilities make platelets interesting for researchers from different disciplines. However, beside profound investigation into platelets’ physiological role, there is a need for correct, standardized and thus reproducible quantification of platelet parameters. Mean platelet volume (MPV) is a widespread prognostic marker for several conditions, such as, acute coronary syndrome, chronic kidney disease and liver cirrhosis. Platelet activation is regarded as a marker for inflammatory processes, for example in autoimmune diseases such as type-1 diabetes, systemic lupus erythematosus and rheumatoid arthritis. The monitoring of platelet function is relevant for patients receiving antiplatelet medication. Platelet parameter measurement is affected by the choice of in vitro anticoagulant, the measurement technology and the time delay after sampling. This review focuses on the pre-analytical variability that arises as a result of the use of different in vitro anticoagulants and analyzer technologies when determining platelet parameters, since, even approximately 180 years after the discovery of platelets, there is still no standardized procedure.

Stability of New Erythrocyte and Reticulocyte Parameters in Testing for Anemia on the Sysmex XN 9000

Background

New erythrocyte and reticulocyte parameters provide improved classification of anemia and monitoring of erythropoeitic activity. Parameters available on the Sysmex XN analyzers include the percentage of microcytic red blood cells (%Micro-R), percentage of macrocytic red blood cells (%Macro-R), percentage of hypochromic red blood cells (%Hypo-He), percentage of hyperchromic red blood cells (%Hyper-He), reticulocyte hemoglobin content (Ret-He), and immature reticulocyte fraction (IRF). However, use of these parameters is limited by specimen stability.

Methods

To verify the stability of the new erythrocyte and reticulocyte parameters during prolonged storage, 20 blood specimens were analyzed on the Sysmex XN-9000 hematology analyzer. The specimens included healthy patients (60%) and patients with anemia (40%). The specimens were stored at room temperature (RT) and at 4° to 8°C. Analysis was performed after 12, 24, 48, and 72 hours of storage.

Results

Reticulocyte parameters IRF and Ret-He were precise and stable for at least 72 hours after collection when stored at RT and 4° to 8°C. The volume-dependent parameters, %Macro-R and %Micro-R, were stable for less than 12 hours after collection at RT (mean [SD%], 6.55 [3.19%] and -20.70 [10.37%], respectively). Storage at 4° to 8°C showed a reduction in osmotic swelling. However, %Macro-R and %Micro-R were stable for less than 12 hours after collection (mean [SD%], 4.89 [2.02%] and -17.17 [8.38%], respectively). Similarly, %Hypo-He showed a mean (SD%) increase of 0.73 (4.05%) and %Hyper-He showed a decrease of -0.70 (9.72%) at less than 12 hours after storage at 4° to 8°C.

Conclusion

New reticulocyte parameters stored at RT and 4° to 8°C are suitable for testing on the Sysmex XN analyzer.

A comparison of manual counting of rabbit reticulocytes with ADVIA 2120i analyzer counting

We compared manual counting of reticulocytes in rabbits with automatic counting using an ADVIA 2120i analyzer. Reproducibility and the influence of different anticoagulants (EDTA and Li-heparin) were also examined. Blood samples of 331 rabbits (method comparison, n = 289; reproducibility, n = 33; comparison of anticoagulants, n = 9) were tested. The reticulocyte numbers of each specimen were manually determined twice for method comparison. Passing-Bablok regressions, Bland-Altman plots, and the coefficient of variation (CV) were used to evaluate statistical significance. Good correlation (rs = 0.81) was observed between manual reticulocyte counting (groups 1-4) and the ADVIA 2120i. Quantification with the ADVIA 2120i was reproducible for relative reticulocyte numbers (EDTA, CV = 4.24%; Li-heparin, CV = 3.63%) and absolute reticulocyte numbers (EDTA, CV = 5.64%; Li-heparin, CV = 3.81%). The absolute and relative reticulocyte numbers were significantly higher in Li-heparin samples than in EDTA samples (absolute, p = 0.009; relative, p = 0.016). The ADVIA 2120i is suitable for counting reticulocytes in rabbit blood samples, but reticulocyte numbers are higher by manual counting than by ADVIA 2120i counting. Therefore, microscopic confirmation of quantifications is recommended when high numbers of reticulocytes are observed. The anticoagulant of choice is EDTA.

How Long can we Store Blood Samples: A Systematic Review and Meta-Analysis

OBJECTIVE

To assess the effect of storage time and temperature on complete blood count (CBC) and comprehensive metabolic panel (CMP) testing.

METHODS

PubMed, EMBASE, the Cochrane Library of Systematic Reviews, Web of Science (WOS), China National Knowledge Infrastructure (CNKI), WanFang databases and SinoMed databases were searched up to May 2017. Clinical trials with adult whole blood samples were identified. Paired reviewers independently screened, extracted data and evaluated the quality of evidence (MINORS tool). Analyses were conducted using Revman 5.3 and Stata 14.0.

RESULTS

A total of 89 studies were confirmed. For CBC, except MPV, most parameters were stable at least for 24h. Some indices, such as WBC, PLt, HCT, HGB and MCH were stable up to 3 d. However, stable CMP test results could only be acquired within 12h. at 4°C, including GLU, AST, ALT, Na, ALB, Cl, DBIL, TC, TG and ALP. Values were less stable when stored at RT.

CONCLUSIONS

Specimens stored >12h. for CMP may generate unreliable results. For CBC, samples could reliably be stored for 24h. For longer storage, refrigeration (at 4°C) would be a better choice.

Enumeration of WT1-specific CD8+ T cells for clinical application using an MHC Streptamer based no-wash single-platform flow-cytometric assay

The advent of novel strategies to generate leukemia-associated-antigen (LAA)-specific T cells for adoptive immunotherapies creates a demand for standardized good laboratory practice (GLP)-compliant enumeration assays to provide a secure clinical environment-whether it is to identify potential donors, define therapeutic doses for transplantation, or monitor clinical success. Here, we introduce a no-wash assay based on single-platform cell enumeration and Streptamer staining to determine the Wilms' tumor antigen 1 (WT1)-specific T cell immunity in clinical samples. We analyzed the performance of the WT1-specific MHC Streptamers in direct comparison to CMV- and EBV-specific MHC Streptamer staining by spiking antigen-specific T cells in PBMCs. The accuracy of the assay was high for all performed experiments with a mean recovery of 94% and a linear regression of 0.988. Differences were apparent regarding the limit of detection/quantification (LOD/LOQ). While results obtained for WT1 yielded an LOD/LOQ of 0.08 ± 0.04% and 0.11 ± 0.06% (1.33 ± 0.32 cells/µl and 1.9 ± 0.14 cells/µl), the overall LOD/LOQ was notably lower and accounted to 0.02 ± 0.02% and 0.05 ± 0.03% (0.60 ± 0.03 cells/µl and 1.27 ± 0.58 cells/µl). Subsequent screening of 22 healthy individuals revealed significantly higher values for WT1 (0.04 ± 0.02% and 1.5 ± 0.9 cells/µl) than for the irrelevant HIV pol (0.016 ± 0.01% and 0.5 ± 0.4 cells/µl). In contrast, no increased frequencies were observed for WT1-specific T cells compared to HIV-specific T cells using a classical wash-protocol. These findings strongly suggest the use of no-wash single-platform assays in combination with MHC Streptamer staining for the detection of low affinity LAA-specific T cells due to its high accuracy and sensitivity. © 2017 International Society for Advancement of Cytometry.

Evaluation of di-potassium and tri-potassium EDTA evacuated tubes for routine haematological testing

BACKGROUND

The influence of blood collection devices on laboratory tests is often overlooked. We have discussed here how blood collection materials and devices can alter haematological test results, with an emphasis on blood collection tube (BCT) additives. We have compared K2 & K3-EDTA vacuum tubes of same manufacturer IMPROVACUTER ^® for CBC analysis.

METHODS

Blood was collected in both tubes simultaneously. Samples were analysed immediately after collection (<15 minutes) and after 4 hours by MEK-6318J/K Haematology Analyzer. Paired student's t-test was applied for statistical analysis. Significant differences among results and biases were compared with current quality specifications.

RESULTS

Significant differences were found in Neutrophyls (GR) and mean platelets volume (MPV) when compared. K2-EDTA vs K3-EDTA(1st time) after< 15 minutes of sample collection, for Monocytes counts (MO), MCV, MPV, and RDW when comparing K2-EDTA (first time) vs K2-EDTA(second time, after 4 hours); and for Monocytes counts (MO), MCV, MPV, PCT, and RDW when comparing K3-EDTA(1st time) vs K3-EDTA(2nd time) in order to check the stability and reproducibility of vacutainers.

CONCLUSIONS

This study assesses the use of K2& K3-EDTA vacuum tubes whether or not they represent a bias in haematological testing (CBC). The use of K2-EDTA and K3-EDTA vacuum tubes represent a clinically relevant source of variation for MCV, MPV, RDW, and PCT.

Reliability of Parameters of Complete Blood Count With Different Storage Conditions

INTRODUCTION

The complete blood count (CBC) is a frequently performed laboratory test today. This study evaluated the effects of temperature and sample storage time on parameters of CBC which could produce misleading results of clinical significance.

METHODS

In a cross-sectional study, CBC was checked in 102 randomly selected healthy individuals and baseline measurements were analyzed using the Sysmex XS 500i fully automated hematology analyzer. CBC was done on samples up to 48 hr of storage at temperatures of 4 ± 2°C, 23 ± 2°C, and 31 ± 2°C. Values were checked at time intervals of 6, 24, and 48 hr.

RESULTS

Among CBC parameters, white blood cell, red blood cell, hemoglobin, mean cell hemoglobin (MCH), neutrophils and lymphocytes were stable at all three temperatures up to 48 hr. Monocytes, eosinophils, MCH concentration, hematocrit (Htc), and red cell distribution width-coefficient of variation showed statistically significant changes at 23 ± 2°C and 31 ± 2°C. A significant decline in platelet count (PLT) and increment in mean platelet volume and basophil count were seen at all study temperatures up to 48 hr.

CONCLUSION

This study shows that most parameters of the CBC are unaffected with the studied storage temperature up to 48 hr except for the PLT which should be performed within 6 hr of the post-collection time. To avoid changes in a few parameters such as Htc, it is best to store the sample at 4 ± 2°C if any delay is anticipated.

Deoxygenation Reduces Sickle Cell Blood Flow at Arterial Oxygen Tension

The majority of morbidity and mortality in sickle cell disease is caused by vaso-occlusion: circulatory obstruction leading to tissue ischemia and infarction. The consequences of vaso-occlusion are seen clinically throughout the vascular tree, from the relatively high-oxygen and high-velocity cerebral arteries to the relatively low-oxygen and low-velocity postcapillary venules. Prevailing models of vaso-occlusion propose mechanisms that are relevant only to regions of low oxygen and low velocity, leaving a wide gap in our understanding of the most important pathologic process in sickle cell disease. Progress toward understanding vaso-occlusion is further challenged by the complexity of the multiple processes thought to be involved, including, but not limited to 1) deoxygenation-dependent hemoglobin polymerization leading to impaired rheology, 2) endothelial and leukocyte activation, and 3) altered cellular adhesion. Here, we chose to focus exclusively on deoxygenation-dependent rheologic processes in an effort to quantify their contribution independent of the other processes that are likely involved in vivo. We take advantage of an experimental system that, to our knowledge, uniquely enables the study of pressure-driven blood flow in physiologic-sized tubes at physiologic hematocrit under controlled oxygenation conditions, while excluding the effects of endothelium, leukocyte activation, adhesion, inflammation, and coagulation. We find that deoxygenation-dependent rheologic processes are sufficient to increase apparent viscosity significantly, slowing blood flow velocity at arterial oxygen tension even without additional contributions from inflammation, adhesion, and endothelial and leukocyte activation. We quantify the changes in apparent viscosity and define a set of functional regimes of sickle cell blood flow personalized for each patient that may be important in further dissecting mechanisms of in vivo vaso-occlusion as well as in assessing risk of patient complications, response to transfusion, and the optimization of experimental therapies in development.

Elevated mean neutrophil volume represents altered neutrophil composition and reflects damage after myocardial infarction

Myocardial infarction (MI) induces an inflammatory response in which neutrophils fulfill a prominent role. Mean neutrophil volume (MNV) represents the average size of the circulating neutrophil population. Our goal was to determine the effect of MI on MNV and investigate the mechanisms behind MNV elevation. MNV of 84 MI patients was compared with the MNV of 209 stable angina patients and correlated to simultaneously measured CK levels. Fourteen pigs were subjected to temporary coronary balloon occlusion and blood was sampled at multiple time points to measure MNV. Echocardiography was performed followed by ex vivo infarct size assessment after 72 h. MNV was higher in MI patients compared to stable angina patients (602 SD26 AU vs. 580 SD20 AU, p < 0.0001) and correlated with simultaneously measured CK levels (R = 0.357, p < 0.0001). In pigs, MNV was elevated post-MI (451 SD11 AU vs. 469 SD12 AU), p < 0.0001). MNV correlated with infarct size (R = 0.705, p = 0.007) and inversely correlated with left ventricular ejection fraction (R = −0.718, p = 0.009). Cell sorting revealed an increased presence of banded neutrophils after MI, which have a higher MNV compared to mature neutrophils post-MI (495 SD14 AU vs. 478 SD11 AU, p = 0.012). MNV from coronary sinus blood was higher than MNV of neutrophils from simultaneously sampled arterial blood (463 SD7.6 AU vs. 461 SD8.6 AU, p = 0.013) post-MI. The current study shows MNV is elevated and reflects cardiac damage post-MI. MNV increases due to altered neutrophil composition and systemic neutrophil activation. MNV may be an interesting parameter for prognostic assessment in MI and provide new insights into pathological innate immune responses evoked by ischemia–reperfusion.

Prolonged storage-induced changes in haematology parameters referred for testing

Background

Referral of samples for the work-up of haematological disorders from remote laboratories can result in a delay in analysis.

Objective

The stability of the full blood count (FBC), differential count (DIFF), reticulocyte and peripheral blood smear (PBS) morphology during extended storage was evaluated.

Methods

Forty blood samples stored in ethylenediaminetetraacetic acid (EDTA) were analysed on an ADVIA® 120 haematology analyser. The samples (25% abnormal; 75% normal) were stored at room temperature (RT) and at 4 °C - 8 °C. Analysis of samples stored at RT was performed every 12 hours for two days. Analysis of samples stored at 4 °C - 8 °C was performed at 12 hours and subsequently every 24 hours for seven days.

Results

FBC parameters (red cell count, haemoglobin) and DIFF parameters (percentages of basophils, lymphocytes and monocytes) were stable for at least 48 hours when stored at RT. Platelets were only stable for 12 hours and the white cell count was stable for 36 hours when stored at RT. Storing samples at 4 °C - 8 °C significantly increased the stability of most parameters, in particular, mean cell volume and percentage of reticulocytes. However, DIFF parameters were associated with lower stability at 4 °C - 8 °C. PBS morphology was compromised prior to 12 hours whether stored at RT or at 4 °C - 8 °C.

Conclusion

This study provides evidence that blood samples stored in EDTA at 4 °C - 8 °C for seven days are suitable for testing on the ADVIA® 120 analyser for the FBC and percentage of reticulocyte parameters. However, storage at 4 °C - 8 °C is not a solution for samples referred for DIFF and PBS morphology review.

Verification and standardization of blood cell counters for routine clinical laboratory tests

The use of automated blood cell counters (automated hematology analyzers) for diagnostic purposes is inextricably linked to clinical laboratories. However, the need for uniformity among the various methods and parameters is increasing and standardization of the automated analyzers is therefore crucial. Standardization not only involves procedures based on reference methods but it also involves validation, verification, quality assurance, and quality control, and it includes the involvement of several participants. This article discusses the expert guidelines and provides an overview of issues involved in complete blood count parameter reference methods and standardization of reporting units.

Non-invasive haemoglobin estimation in patients with thalassaemia major

OBJECTIVES

This study aimed to validate pulse CO-oximetry-based haemoglobin (Hb) estimation in children and adults with thalassaemia major (TM) and to determine the impact of different baseline variables on the accuracy of the estimation.

METHODS

This observational study was conducted over a five-week period from March to April 2012. A total of 108 patients with TM attending the daycare thalassaemia centre of a tertiary care hospital in Muscat, Oman, were enrolled. Spot (Sp) Hb measurements were estimated using a Pronto-7(®) pulse CO-oximetry device (Masimo Corp., Irvine, California, USA). These were compared to venous samples of Hb using the CELL-DYN Sapphire Hematology Analyzer (Abbott Diagnostics, Abbott Park, Illinois, USA) to determine the reference (Ref) Hb levels. A multivariable linear regression model was used to assess the impact of baseline variables such as age, gender, weight, height, Ref Hb and blood pressure on the Hb estimations.

RESULTS

Of the 108 enrolled patients, there were 54 males and 54 females with a mean age of 21.6 years (standard deviation [SD] = 7.3 years; range: 2.5-38 years). The mean Ref Hb and Sp Hb were 9.4 g/dL (SD = 0.9 g/dL; range: 7.5-12.3 g/dL) and 11.1 g/dL (SD = 1.2 g/dL; range: 7.5-14.7 g/dL), respectively. The coefficient of determination (R(2)) was 21% with a mean difference of 1.7 g/dL (SD = 1.1 g/dL; range: -0.9-4.3 g/dL). In the multivariable model, the Ref Hb level (P = 0.001) was the only statistically significant predictor.

CONCLUSION

The Pronto-7(®) pulse CO-oximetry device was found to overestimate Hb levels in patients with TM and therefore cannot be recommended. Further larger studies are needed to confirm these results.

Validation of a non-invasive pulse CO-oximetry based hemoglobin estimation in normal blood donors

INTRODUCTION

Non-invasive hemoglobin estimation may increase the recruitment of blood donors. CO-oximetry hemoglobin estimation is a non-invasive method used to estimate the hemoglobin level. The primary objective of this study is to validate the pulse CO-oximetry based hemoglobin estimation in normal blood donors.

METHODS

We conducted a prospective observational study on 106 in a tertiary care hospital blood bank over a period of 4 weeks. We performed a Spot Hemoglobin concentration (Sp Hb) using Masimo Pronto-7 Pulse CO-oximetry, and compared it to a venous sample Hb concentration (Reference Hemoglobin; Ref Hb) measured using Abbott CELL-DYN Sapphire hematology analyzer. Age, gender, weight, height, blood pressure and reference hemoglobin were used in the multivariable linear regression model of the difference in measurement.

RESULTS

Total of 106 donors (98 males, 8 females) were enrolled with a mean age and Ref Hb of 27 years (SD 6.2; 18-49) and 14.2 g/dL (SD 1.2; 11.5-17) respectively. The mean Sp Hb was 14.4 g/dL (SD 1.2;11.3-16.7). The mean difference between the Sp Hb and Ref Hb was 0.2 g/dL (SD 1.2;-4.5 to 3) with a correlation coefficient of 0.46 (R(2)=21%). In the multivariable model, height (p=0.015) and Hb level (p<0.001) were statistically significant predictors. A strong correlation was found between the two CO-oximetry Hb measurements (coefficient 0.78, R(2)=60%).

CONCLUSIONS

Our study validated the use of the CO-oximetry in blood donors. Larger prospective studies are needed to confirm our results.

Effect of the addition of the antioxidant taurine on the complete blood count of whole blood stored at room temperature and at 4ºC for up to 7 days

Background

The complete blood count is one of the most common routine tests. This study aimed to evaluate possible effects of the antioxidant taurine on the complete blood count of whole blood stored at room temperature and at 4ºC over seven days.

Methods

Venous blood samples of 25 healthy males were distributed into two sets of tubes with each set of four tubes containing 50 µL of solutions with zero, 2.5 g/L, 5 g/L, 10 g/L taurine. The tubes were kept at room temperature or at 4ºC. Complete blood counts were performed on seven successive days. The mean percentage changes [Δ = (mean value - mean baseline value) / mean baseline value x 100] were calculated and compared.

Results

Complete blood count parameters exhibited different patterns of behavior which were affected by the storage temperature, time and taurine concentration. Taurine at room temperature significantly enhanced the stability of: the platelet count over seven days (Δ7 at 2.5, 5 and 10 g/L taurine were 5.45, 6.11, and 5.80 x 10⁹ cells/L, respectively); the red blood cell count over five days (Δ5 at 2.5, 5 and 10 g/L taurine were 1.59, 2.79, and 1.98 x 10¹² cells/L, respectively); mean corpuscular hemoglobin over five days (Δ5 at 2.5, 5 and 10 g/L taurine were -0.91,-1.52 and -0.84 fl respectively); and red cell distribution width over two days (Δ2 at 2.5, 5 and 10 g/L taurine were 0.90%, 1.30% and -0.1%, respectively). No additional stabilizing effects of taurine were reported for the mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, hematocrit and hemoglobin, while it negatively affected the white blood cell stability.

Conclusion

Complete blood count parameters exhibited variable stability patterns in respect to temperature, time and taurine concentration.

Immunophenotyping of posttraumatic neutrophils on a routine haematology analyser

Introduction. Flow cytometry markers have been proposed as useful predictors for the occurrence of posttraumatic inflammatory complications. However, currently the need for a dedicated laboratory and the labour-intensive analytical procedures make these markers less suitable for clinical practice. We tested an approach to overcome these limitations. Material and Methods. Neutrophils of healthy donors were incubated with antibodies commonly used in trauma research: CD11b (MAC-1), L-selectin (CD62L), FcγRIII (CD16), and FcγRII (CD32) in active form (MoPhab A27). Flow cytometric analysis was performed both on a FACSCalibur, a standard flow cytometer, and on a Cell-Dyn Sapphire, a routine haematology analyser. Results. There was a high level of agreement between the two types of analysers, with 41% for FcγRIII, 80% for L-selectin, 98% for CD11b, and even a 100% agreement for active FcγRII. Moreover, analysis on the routine haematology analyser was possible in less than a quarter of the time in comparison to the flow cytometer. Conclusion. Analysis of neutrophil phenotype on the Cell-Dyn Sapphire leads to the same conclusion compared to a standard flow cytometer. The markedly reduced time necessary for analysis and reduced labour intensity constitutes a step forward in implementation of this type of analysis in clinical diagnostics in trauma research.

Performance evaluation of the Sysmex pocH-100iV Diff hematology analyzer for analysis of canine, feline, equine, and bovine blood

BACKGROUND

The Sysmex pocH-100iV Diff is an impedance hematology analyzer recently introduced for point-of-care use in veterinary practices in Europe.

OBJECTIVE

The purpose of this study was to validate the pocH-100iV Diff for analysis of blood samples from dogs, cats, horses, and cattle.

METHODS

Fresh EDTA-blood samples from healthy and ill dogs (115), cats (94), horses (91), and cattle (78) were analyzed on the pocH-100iV Diff and the Cell-Dyn 3500. Results of the automated WBC differential counts were compared with the manual differential counts for 77 dogs, 65 cats, 40 horses, and 46 cattle. HCT were compared with PCVs obtained by microhematocrit centrifugation. Furthermore, precision, linearity, carry-over, cell aging, and clinical relevance of the pocH-100iV Diff results were assessed.

RESULTS

Most of the CBC results obtained by the pocH-100iV Diff correlated well with those of the Cell-Dyn 3500. Slightly low correlation was observed for canine MCV and hemoglobin concentration. Lymphocytes correlated well in horses and cattle, but less well in cats and dogs. The mixed cell population termed "OTHRS" (all granulocytes and monocytes for horses and cattle; neutrophils, monocytes, and basophils for cats and dogs) correlated well in all tested species. The instrument overestimated feline and canine eosinophils. In cats, platelet counts showed a strong negative bias.

CONCLUSIONS

The overall performance of the pocH-100iV Diff was excellent with the noted limitations. The automated differential count can be used as screening tool in conjunction with evaluation of a blood smear.

The effect of anticoagulant, storage temperature and dilution on cord blood hematology parameters over time

The objective of the study was to determine whether selected hematologic parameters measured on umbilical cord blood samples using an automated hematology analyzer (Sysmex XE-2100) were affected by (i) anticoagulant (the specimens were collected in EDTA vs. sodium heparin), (ii) temperature (the specimens were maintained at 4 degrees C vs. room temperature for up to 72 h) and (iii) 1 : 5 dilution vs. undiluted using the manufacturer's diluting solution. Use of heparin, instead of EDTA, had little effect on the hematologic results (n = 8) except for lower platelet and progenitor cell counts. Results were remarkably stable for 72 h at either room temperature or 4 degrees C except for modest red blood cell swelling at 24 h. Specimens of blood diluted at 1 : 5 had an immediate small, but significant change on white cell count (+13.3%), reticulocyte count (-11.2%) and reticulocyte hemoglobin content (-19.6%). Diluted samples did not change further over 4 h at room temperature. With a 1 : 5 dilution, analysis of 40 microl of cord blood stored for 3 days at room temperature may provide useful hematologic information with little phlebotomy loss.