Reference intervals of cell population data parameters in Sysmex XN-Series and its patterns of changes from early adulthood to geriatric ages in South Korea

INTRODUCTION

Cell population data (CPD) parameters may be putative biomarkers for the screening of various diseases including some infections and myelodysplastic syndrome. This study aimed to establish the age- and sex-specific reference intervals (RIs) for the CPD parameters in the Korean population.

METHODS

The reference population for the RIs of CPD parameters comprised 124 856 subjects aged 20-99 years. CPD parameters were obtained from Sysmex XN-2000 (Kobe, Japan) datasets from 17 health promotion centers in 13 South Korean cities. We determined significant partitions for age and sex, and calculated RIs according to Clinical and Laboratory Standards Institute C28-A3 guidelines.

RESULTS

The side scattered light intensity in the neutrophil area and the lymphocyte area did not require sex-related partitioning except in those over the age of 50, among whom the lower limit (LL) and upper limit (UL) were lower in females. However, the side scattered light distribution width in the lymphocyte area required age- and sex-related partitioning, in which LL and UL were higher in females. The LL and UL of the fluorescent light distribution width were higher in males in the neutrophil area and higher in females in the lymphocyte area, but age-related partitioning was not required. The forward scattered light intensity in the neutrophil area, lymphocyte area, and monocyte area did not require age-related partitioning in males.

CONCLUSION

This study has determined comprehensive age- and sex-specific RIs for CPD parameters, which could help to prove the clinical significance of these parameters in the Sysmex XN-2000.

Parameters of the complete blood count predict in hospital mortality

INTRODUCTION

Mortality rates are used to evaluate the quality of hospital care after adjusting for disease severity and, commonly also, for age, comorbidity, and laboratory data with only few parameters of the complete blood count (CBC).

OBJECTIVE

To identify the parameters of the CBC that predict independently in-hospital mortality of acutely admitted patients.

POPULATION

All patients were admitted to internal medicine, cardiology, and intensive care departments at the Laniado Hospital in Israel in 2018 and 2019.

VARIABLES

Independent variables were patients' age, sex, and parameters of the CBC. The outcome variable was in-hospital mortality.

ANALYSIS

Logistic regression. In 2018, we identified the variables that were associated with in-hospital mortality and validated this association in the 2019 cohort.

RESULTS

In the validation cohort, a model consisting of nine parameters that are commonly available in modern analyzers had a c-statistics (area under the receiver operator curve) of 0.86 and a 10%-90% risk gradient of 0%-21.4%. After including the proportions of large unstained cells, hypochromic, and macrocytic red cells, the c-statistic increased to 0.89, and the risk gradient to 0.1%-29.5%.

CONCLUSION

The commonly available parameters of the CBC predict in-hospital mortality. Addition of the proportions of hypochromic red cells, macrocytic red cells, and large unstained cells may improve the predictive value of the CBC.

Components of the full blood count as risk factors for colorectal cancer detection: a systematic review protocol

INTRODUCTION

Colorectal cancer is the fourth most common type of cancer and the second most common cause of cancer-related deaths in the UK. The full blood count (FBC) is a blood test that may play a role in early detection of the disease. Previous studies have aimed to identify how levels of individual components, such as haemoglobin, can be used to assist the diagnosis. We aim to systematically review studies to identify whether components of the FBC are risk factors for diagnosis of colorectal cancer, critically appraise the methods used to assess the association and assess performance of the components.

METHODS AND ANALYSIS

The MEDLINE (via OVID), EMBASE (via OVID), CINAHL (via EBSCOhost) and Web of Science databases will be searched to identify studies reporting the association between the levels of at least one FBC component and the risk of a future diagnosis of colorectal cancer in undiagnosed individuals. Clincialtrials.gov and the WHO registry will be searched to identify relevant ongoing research. Search terms will include relevant Medical Subject Headings and Emtree headings, and free-text terms relating to FBC, colorectal cancer and diagnosis. No date or language restrictions will be applied. Two reviewers will independently identify the studies for inclusion and perform data extraction. Time intervals between the blood tests and diagnosis will form the subgroups for analysis.

ETHICS AND DISSEMINATION

There is no direct patient involvement and only published articles will be reviewed; no ethical approval is required. Results from this review will set a foundation for intended future work on developing a new risk score for early detection of colorectal cancer, derived using FBC data. This systematic review will also provide guidance on the analysis of time to diagnosis. The model will be freely available to UK primary care practices.

PROSPERO REGISTRATION NUMBER

CRD42019134400.

Complete blood count reference intervals from a healthy adult urban population in Kenya

BACKGROUND

There are racial, ethnic and geographical differences in complete blood count (CBC) reference intervals (RIs) and therefore it is necessary to establish RIs that are population specific. Several studies have been carried out in Africa to derive CBC RIs but many were not conducted with the rigor recommended for RI studies hence limiting the adoption and generalizability of the results.

METHOD

By use of a Beckman Coulter ACT 5 DIFF CP analyser, we measured CBC parameters in samples collected from 528 healthy black African volunteers in a largely urban population. The latent abnormal values exclusion (LAVE) method was used for secondary exclusion of individuals who may have had sub-clinical diseases. The RIs were derived by both parametric and non-parametric methods with and without LAVE for comparative purposes.

RESULTS

Haemoglobin (Hb) levels were lower while platelet counts were higher in females across the 4 age stratifications. The lower limits for Hb and red blood cell parameters significantly increased after applying the LAVE method which eliminated individuals with latent anemia and inflammation. We adopted RIs by parametric method because 90% confidence intervals of the RI limits were invariably narrower than those by the non-parametric method. The male and female RIs for Hb after applying the LAVE method were 14.5-18.7 g/dL and 12.0-16.5 g/dL respectively while the platelet count RIs were 133-356 and 152-443 x10(3) per μL respectively.

CONCLUSION

Consistent with other studies from Sub-Saharan Africa, Hb and neutrophil counts were lower than Caucasian values. Our finding of higher Hb and lower eosinophil counts compared to other studies conducted in rural Kenya most likely reflects the strict recruitment criteria and healthier reference population after secondary exclusion of individuals with possible sub-clinical diseases.

A standardized flow cytometry network study for the assessment of circulating endothelial cell physiological ranges

Circulating endothelial cells (CEC) represent a restricted peripheral blood (PB) cell subpopulation with high potential diagnostic value in many endothelium-involving diseases. However, whereas the interest in CEC studies has grown, the standardization level of their detection has not. Here, we undertook the task to align CEC phenotypes and counts, by standardizing a novel flow cytometry approach, within a network of six laboratories. CEC were identified as alive/nucleated/CD45negative/CD34bright/CD146positive events and enumerated in 269 healthy PB samples. Standardization was demonstrated by the achievement of low inter-laboratory Coefficients of Variation (CVL), calculated on the basis of Median Fluorescence Intensity values of the most stable antigens that allowed CEC identification and count (CVL of CD34bright on CEC ~ 30%; CVL of CD45 on Lymphocytes ~ 20%). By aggregating data acquired from all sites, CEC numbers in the healthy population were captured (medianfemale = 9.31 CEC/mL; medianmale = 11.55 CEC/mL). CEC count biological variability and method specificity were finally assessed. Results, obtained on a large population of donors, demonstrate that the established procedure might be adopted as standardized method for CEC analysis in clinical and in research settings, providing a CEC physiological baseline range, useful as starting point for their clinical monitoring in endothelial dysfunctions.

Baseline Haematology and Erythrocyte Morphological Changes of Apparently Normal Dogs Raised in Ibadan, Oyo State

This study evaluates the haematological parameters and the observed erythrocytes morphological changesin dogs raised in Ibadan, Oyo State in the south western part of Nigeria. Blood samples were collected from sixty-four apparently healthy dogs. The haematological parameters of the blood samples collected were evaluated with the quantification of the percentage erythrocyte morphological abnormalities. The result of the quantitative count of the erythrocyte morphological abnormalities were also converted using reference guide to give the numerical/descriptive clinical grade of the associated morphological abnormalities. There was a significant difference between the haematological parameters reported in this study and the commonly used dog haematological reference ranges from temperate regions used in laboratories in Nigeria. Some of the morphological abnormalities observed in this study include echinocyte (4.12±0.35%), macrocyte (2.61±0.22%) and spherocyte (2.17±0.29%) and eccentrocyte (0.39±0.06%) while other such as acanthocyte (1.39±0.19), leptocyte (0.71±0.13), schizocyte (0.703±0.104) and codocyte (0.50±0.11) were also seen. These study findings show that the associated morphological changes were all not significant and fall within the acceptable range using the reference guide for erythrocyte morphological abnormalities even when the haematological values differ significantly fromthe reference value. This study provides baseline information on the haematological parameters and the novel correlation ofthe associated erythrocyte abnormalities seen as a corresponding proof of the apparently healthy status of the dogs raised in Ibadan used for this study. The study while serving as an important means of verification of the reference range of haematological parameters also shows that clinical case interpretation using haematological baseline data from the temperate region should be used with caution in our tropical environment. This thus necessitates the need for an advocacy to build a reference range of haematological parameters that can be used as a working baseline value for the tropical environment.

Evaluation of locally established reference intervals for hematology and biochemistry parameters in Western Kenya

Background

Important differences have been demonstrated in laboratory parameters from healthy persons in different geographical regions and populations, mostly driven by a combination of genetic, demographic, nutritional, and environmental factors. Despite this, European and North American derived laboratory reference intervals are used in African countries for patient management, clinical trial eligibility, and toxicity determination; which can result in misclassification of healthy persons as having laboratory abnormalities.

Methods

An observational prospective cohort study known as the Kisumu Incidence Cohort Study (KICoS) was conducted to estimate the incidence of HIV seroconversion and identify determinants of successful recruitment and retention in preparation for an HIV vaccine/prevention trial among young adults and adolescents in western Kenya. Laboratory values generated from the KICoS were compared to published region-specific reference intervals and the 2004 NIH DAIDS toxicity tables used for the trial.

Results

About 1106 participants were screened for the KICoS between January 2007 and June 2010. Nine hundred and fifty-three participants aged 16 to 34 years, HIV-seronegative, clinically healthy, and non-pregnant were selected for this analysis. Median and 95% reference intervals were calculated for hematological and biochemistry parameters. When compared with both published region-specific reference values and the 2004 NIH DAIDS toxicity table, it was shown that the use of locally established reference intervals would have resulted in fewer participants classified as having abnormal hematological or biochemistry values compared to US derived reference intervals from DAIDS (10% classified as abnormal by local parameters vs. >40% by US DAIDS). Blood urea nitrogen was most often out of range if US based intervals were used: <10% abnormal by local intervals compared to >83% by US based reference intervals.

Conclusion

Differences in reference intervals for hematological and biochemical parameters between western and African populations highlight importance of developing local reference intervals for clinical care and trials in Africa.

Laboratory reference intervals of complete blood count for apparently healthy elderly people in Shuyang, China

BACKGROUND

Currently, there are no appropriate RIs of blood cells available for the elderly in most clinical laboratories in China. The aim of this study is to establish the RIs of complete blood cell count for apparently healthy elderly people.

METHODS

Blood specimens were collected from elderly residents by standard procedures. Complete blood counts were determined by Sysmex XE-2100 analyzer. The RIs and 95% confidence intervals were calculated by the robust method recommended by CLSI C28-A3 guideline.

RESULTS

RIs established for healthy elderly include: total WBC 3.63 - 10.3 x 10(9)/L for males and 3.64 - 10.3 x 10(9)/L for females; RBC 3.74 - 5.49 x 10(12)/L for males and 3.74 - 5.53 x 10(12)/L for females; Hb 109 - 167 g/L for males and 109 - 168 g/L for females; HCT 36.0 - 51.8% for males and 35.7 - 51.8% for females; MCV 86.0 - 105 fL for males and 86.2 - 106 fL for females; MCH 26.4 - 33.6 pg for males and 26.4 - 33.8 pg for females; MCHC 293 - 333 g/L for males and 291 - 335 g/L for females; RDW-SD 39.3 - 53.7 fL for males and 39.6 - 54.5 fL for females; RDW-CV 11.7 - 15.1% for males and 11.7 - 15.2% for females; PLT 122 - 355 x 10(9)/L for males and 122 - 350 x 10(9)/L for females; PCT 14.1 - 37.6 x 10(-1) mL/L for males and 13.9 - 37.9 x 10(-1) mL/L for females; MPV 11.3 - 15.5 fL for males and 11.3 - 15.5 fL for females; PDW 9.74 - 17.0% for males and 9.72 - 17.0% for females; platelet-LCR (P-LCR) 21.3 - 51.2% for males and 21.1 - 51.4% for females.

CONCLUSIONS

We established scientific and reasonable RIs of blood cell analysis for the healthy elderly in our region.

Development of simple equations for effective screening of spurious hemolysis in whole-blood specimens

INTRODUCTION

We aimed to identify simple but reliable indices for effective screening of spurious hemolysis in whole-blood specimens.

METHODS

Thirteen inpatient whole-blood samples were divided in two aliquots. The former was left untreated, whereas the latter was mechanically hemolyzed by forced aspiration with an insulin syringe. All aliquots were tested on Siemens Advia 2120 and Sysmex XE-2100. The hemolysis index (HI) was also assessed in centrifuged plasma.

RESULTS

The mechanical hemolysis generated a 4-40% decrease in red blood cells (RBCs). A statistically significant decrease was observed for hematocrit (Ht) and mean corpuscular volume (MCV), whereas mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and platelet count were increased. The values of hemoglobin (Hb) and white blood cells remained substantially unchanged. Two specific equations ([Ht/Hb] × √MCV and [Ht/Hb] × 100) were developed. Both equations displayed an area under the curve of ≥0.99 for identifying spurious hemolysis, much greater than that of both RBC ghosts and immature platelet fraction. A highly significant correlation was also observed between results of these equations and percentage reduction in RBCs or HI increase.

CONCLUSION

Provided that these results will be confirmed in further studies, these equations may provide a reliable means for screening spurious hemolysis in whole-blood samples.

[The reference values of indicators of total blood analysis of adult working population]

The application in laboratory diagnostics of the hematologic analyzers of different class functioning on the basis of various methods of calculation and identification of blood cells condition the need of establishing the reference intervals for the blood picture parameters. In the documents GOSTK 53002-2008, S28-A3 (CLSI) of 2008 the regulations are proposed to establish the reference intervals with detailed description of data statistical analysis. The processing of blood pictures of 1453 healthy patients the reference intervals were established for the indicators of clinical blood analysis. The results saved in the laboratory data base and obtained using analyzer Sysmex XT-2000i (Sysmex Corporation, Japan) were analyzed.

[Reference values of clinical donor blood analysis]

Basic hemogram parameters were analyzed in 835 blood donors (421 men and 414 women) aged 18 to 67 years) on an ADVIA 120 hematology analyzer. Reference ranges were calculated for each parameter in relation to their distribution (as X mean +/- 2alpha for normally distributed data and 2.5-97.5 per thousand for others). The findings suggest that the normal range should be extended for platelets, red blood cells, hemoglobin, and packed cell volume as compared with the earlier unified normal values, which must be taken into account when deciding whether a subject may be allowed to donate blood.

Reference intervals for eight measurands of the blood count in a large population based study

BACKGROUND

The blood count is widely used in clinical practice. Well defined reference intervals for each measurand are essential for correct clinical interpretation of results. Most previous studies have not been population-based. We therefore calculated reference intervals for several hematological measurands from a sample of the general adult population of Northeastern Germany.

METHODS AND RESULTS

We used data from 2967 healthy individuals recruited for the population-based Study of Health in Pomerania (SHIP). Reference intervals were calculated according to the guidelines of the Clinical and Laboratory Standards Institute (CLSI) using the bootstrap method for the age range from 20 to 79 years and, in addition, stratified according to age and gender with both bootstrap and quantile regression procedures. Reference ranges for erythrocytes, hemoglobin and hematocrit increased with age in women but decreased in men.

CONCLUSIONS

Our reference intervals were lower than those previously published for erythrocytes, hemoglobin, hematocrit and leukocytes but higher for Mean Corpuscular Volume (MCV) and Mean Corpuscular Hemoglobin (MCH). Different laboratory methods and study populations may lead to disparity in results.

Serial correlation of quality control data–on the use of proper control charts

BACKGROUND

Biochemical quality control (QC) data have been reported to be autocorrelated. Serial correlation may increase the rate of false alarms if the traditional exponentially weighted moving average (EWMA) control chart to monitoring the process mean is used. False alarms are the focus of this paper, where an alarm is defined as the occurrence of a QC value outside the three standard deviation control limits.

METHODS

Daily QC measurements of common biochemical (Vitros 500) and hematological (SF-3000 and Behring Coagulation Timer (BCT)) quantities were recorded during several months while methods and analyzers showed no signs of malfunctioning. The time series were examined for autocorrelation and the performance of the EWMAST chart was compared with that of the EWMA chart when autocorrelation was present.

RESULTS

Many of the time series showed significant signs of autocorrelation. Using the EWMA chart to monitor the process mean, false alarms were noted for positively autocorrelated time series, while this was seldom the case when the EWMAST chart was used. For some quantities, the EWMAST chart gave alarms. However, when the process autocorrelation and therefore the limits of the control chart were updated, the alarms given by the EWMAST chart were reduced or disappeared. In some cases the mean level changed over time, which is expected due to calibrations. This problem will be the topic of a subsequent paper.

CONCLUSIONS

Positive autocorrelation may be present in QC data. In this case the EWMAST chart should be used in place of the EWMA chart.

Stability and reproducibility of ADVIA 120-measured red blood cell and platelet parameters in dogs, cats, and horses, and the use of reticulocyte haemoglobin content (CH(R)) in the diagnosis of iron deficiency

Modern laser-based haematology analysers such as the ADVIA 120 have species-specific software and offer the possibility of assessing new haematological parameters. These parameters have yet to be evaluated, and as these analysers are often used in referral laboratories, it is important to know whether the values of haematological parameters change during sample transport. Therefore, samples of EDTA-anticoagulated blood from nine healthy dogs and EDTA- and citrate-anticoagulated blood from six healthy horses were collected and stored at room temperature for 72 and 48 hours, respectively. In canine samples, WBC and the red blood cell parameters Hb, Hb(cell), Ht, MCV, and MCHC changed significantly after only 24 hours of storage. Thus if canine blood samples need to be stored for 24 hours or longer, Hb, RBC, and MCH would appear to be more reliable parameters than Ht, Hb(cell), MCV, and MCHC. The cytoplasmic haemoglobin content (CH(R)) remained stable up to 48 hours. Both dog and horse platelet numbers were stable over time when blood was anticoagulated with EDTA. Of the platelet-derived parameters, MPC was already significantly lower 2 hours after collection of equine blood samples and was also significantly lower 24 hours after collection of canine blood samples. In contrast, MPV levels were significantly higher 48 hours after sample collection. Initial platelet numbers and platelet parameters were significantly different in citrate-anticoagulated blood and EDTA-anticoagulated blood, and platelet numbers and MPM decreased significantly in citrate-anticoagulated blood samples after only 4 hours of storage. After reference intervals for CH(R) had been established using samples from 53 non-anaemic dogs and 150 non-anaemic cats, the use of CH(R) to detect iron deficiency anaemia was tested in 63 dogs and 55 cats with different diseases. With the help of ROC curves, the optimal cut-off point was determined to be 1.22 fmol in dogs and 0.88 fmol in cats, resulting in a sensitivity of 95.2% and a specificity of 90.5% in dogs and 93.8% and 76.9% in cats, respectively.

Consistency of the initial cell acquisition procedure is critical to the standardization of CD34+ cell enumeration by flow cytometry: results of a pairwise analysis of umbilical cord blood units and cryopreserved aliquots

BACKGROUND

The CD34+ cell content is a predictive factor for engraftment and survival after umbilical cord blood (UCB) transplantation. The high variability in the CD34 assay results in different recommended cell doses for infusion across transplant centers and also limits the clinical utility of the CD34+ cell counts provided by cord blood banks (CBBs). This bi-institutional study was intended to understand the sources of this variability.

STUDY DESIGN AND METHODS

The level of CD34 agreement between the University of Minnesota (UM) and the Madrid CBB (MCBB) was evaluated on 50 UCB units before and after cryopreservation. Two cryopreserved vials per unit were thawed and processed at both laboratories. Dual-platform ISHAGE-based flow cytometry was used for CD34 enumeration.

RESULTS

Postthaw nucleated cell recoveries were similar. However, whereas CD34+ cell enumeration before freezing was 0.35 +/- 0.22 percent, the results after thawing were 0.98 +/- 0.65 and 0.57 +/- 0.39 percent at UM and MCBB, respectively. Bland-Altman plots analysis ruled out the interchangeability of MCBB and UM CD34 values. Differences in the initial cell acquisition settings accounted for most of the CD34 discrepancy, which was no longer present after normalization of the forward scatter threshold for cell acquisition.

CONCLUSIONS

The standardization of CD34+ cell enumeration by flow cytometry is strongly reliant on a consistent initial cell acquisition procedure. The interlaboratory variation can be minimized by using frozen cell aliquots as reference samples. Both requisites should be considered for CD34 testing and UCB unit selection by regulatory institutions involved with cord blood banking and transplantation.

Robust, routine haematology reference ranges for healthy adults

Accurate, reliable laboratory reference ranges are essential for effective clinical evaluation and monitoring. We present robust reference ranges established for haematology, coagulation and haematinic parameters using the Sysmex XE 2100, CA 1500 and Beckman-Coulter Access analysers. Blood samples were taken from 250 healthy laboratory personnel and routine haematology, coagulation and haematinic parameter analysis performed. Our data represent findings from an extensive study to establish reference ranges in healthy adults.

Flow cytometric CD34+ stem cell enumeration: lessons from nine years' external quality assessment within the Benelux countries

BACKGROUND

A biannual external quality assurance (EQA) scheme for flow cytometric CD34+ haematopoietic stem cell enumeration has been operational in the Benelux countries since 1996. In an evaluation of the results of 16 send-outs, we studied the effects of the methods used on assay outcome and whether or not this exercise was effective in reducing between-laboratory variation.

METHODS

Data were analyzed using robust multivariate regression. This approach is relatively insensitive to outliers and is used to assess the effect of methodological aspects of CD34+ cell counting on the bias and variability.

RESULTS

Five variables were associated with significant bias of absolute CD34+ cell counts: (i) unique laboratory number (ULN), (ii) gating strategy; (iii) CD34 mAb fluorochrome; (iv) type of flow cytometer, and (v) method of sample preparation. In addition, ULN and platform methodology (i.e., single vs. dual) contributed significantly to the variability of this assay. Overall, the variability in results of CD34+ cell enumeration has declined with time; in particular, after a practical workshop in which participants were trained to use the "single platform ISHAGE protocol."

CONCLUSIONS

Between-laboratory variation in CD34+ cell enumeration can be reduced by standardization of methodologies between centres. Our approach, i.e., EQA with targeted training and feedback in response to reported results, has been successful in reducing the variability of CD34+ cell enumeration between participants.

Hematology without the numbers: in-clinic blood film evaluation

Technical advances have made it possible for many private veterinary practices to purchase reasonably priced automated hematology instruments to perform in-clinic blood analyses. Although these instruments can quickly provide "numbers" to the clinician, evaluation of a well-made blood film can often provide information critical to the interpretation of those numbers. Blood film review is essential to identify important abnormalities such as neutrophilic left shifts and toxic change, neoplastic cells, hemoparasites, and erythrocyte morphologic changes that may suggest the cause of an anemia. Additionally, the blood film provides an important quality control measure for the automated hematology results. This article outlines a simple method of blood film evaluation, highlights the most common clinically important abnormalities, and reinforces the importance of blood film evaluation as a quality control measure.

Identification of inherited macrothrombocytopenias based on mean platelet volume among patients diagnosed with idiopathic thrombocytopenia

Inherited macrothrombocytopenia is a rare illness that is often misdiagnosed as idiopathic thrombocytopenia (ITP), a more widespread acquired disease. Automated blood cell counters in routine clinical use usually miss giant platelets and underestimate mean platelet volume (MPV). Incorrect diagnoses might expose patients to a risk of unnecessary treatment. The ADVIA 120 hematology counter efficiently detects large platelets based on two-dimensional laser light scatter. The present study measures and re-evaluates MPV using the ADVIA 120 in 112 patients who had initially been diagnosed with ITP. We identified 11 unrelated patients as having probable macrothrombocytopenia (average MPV of 19.2+/-3.8 fL; normal range 7.8-10.2). Functional, phenotypical and DNA analyses confirmed that three of these patients had Bernard-Soulier syndrome and one had MYH9-related disease, both of which are the most common forms of inherited macrothrombocytopenia. We stress that a conventional automated hematology analyzer had overlooked giant platelets in these patients, and that all of them had received high-dose steroid therapy and/or splenectomy before this study according to a diagnosis of ITP. Thus, checking MPV using the ADVIA 120 in thrombocytopenic patients is a useful method of correctly diagnosing inherited macrothrombocytopenia, and thus avoiding patient exposure to unnecessary and sometimes toxic treatment.

Complete blood count parameters for healthy, small-for-gestational-age, full-term newborns

No previous study has investigated the full range of complete blood count (CBC) parameters in small-for-gestational-age (SGA) newborns. The main aim of this study was to compare CBC and peripheral smear parameters in term, healthy SGA neonates and appropriate-for-gestational-age (AGA) neonates, and to establish CBC reference values for full-term SGA newborns. One hundred thirty-two healthy, term newborns (73 SGA and 59 AGA) were included. On day 1, we obtained 109 samples and on day 7 we obtained 77 samples. A CBC and peripheral smear were analyzed for each sample collected and group data were compared. We observed higher mean values for normoblast count, hemoglobin, hematocrit, and red blood cell (RBC) count in the SGA babies than in the AGA babies on day 1. The mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration values for the SGA babies were decreased because of the relatively high RBC count and relatively high mean corpuscular volume we observed in this group. Of the SGA newborns, 21.9% had neutropenia and 4.7% had absolute neutrophil counts lower than 1500/microl on day 1. On both day 1 and day 7, the SGA newborns had higher mean absolute metamyelocyte counts and higher mean I : T (immature : total neutrophil ratio) values than the AGA group. The SGA babies had a lower mean absolute lymphocyte count on day 7 than the AGA group. We detected thrombocytopenia in almost one-third of the 64 SGA newborns tested on day 1. In summary, our study clearly demonstrates that CBC parameters for healthy, full-term, SGA newborns are different from those of healthy, term AGA newborns. This is the first study that has documented different mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, metamyelocyte counts, lymphocyte counts, and I : T in SGA babies compared with AGA babies.

Laboratory Productivity and the Rate of Manual Peripheral Blood Smear Review: A College of American Pathologists Q-Probes Study of 95 141 Complete Blood Count Determinations Performed in 263 Institutions

Context.—Automated laboratory hematology analyzers are capable of performing differential counts on peripheral blood smears with greater precision and more accurate detection of distributional and morphologic abnormalities than those performed by manual examinations of blood smears. Manual determinations of blood morphology and leukocyte differential counts are time-consuming, expensive, and may not always be necessary. The frequency with which hematology laboratory workers perform manual screens despite the availability of labor-saving features of automated analyzers is unknown.

Objective.—To determine the normative rates with which manual peripheral blood smears were performed in clinical laboratories, to examine laboratory practices associated with higher or lower manual review rates, and to measure the effects of manual smear review on the efficiency of generating complete blood count (CBC) determinations.

Design.—From each of 3 traditional shifts per day, participants were asked to select serially, 10 automated CBC specimens, and to indicate whether manual scans and/or reviews with complete differential counts were performed on blood smears prepared from those specimens. Sampling continued until a total of 60 peripheral smears were reviewed manually. For each specimen on which a manual review was performed, participants indicated the patient's age, hemoglobin value, white blood cell count, platelet count, and the primary reason why the manual review was performed. Participants also submitted data concerning their institutions' demographic profiles and their laboratories' staffing, work volume, and practices regarding CBC determinations. The rates of manual reviews and estimations of efficiency in performing CBC determinations were obtained from the data.

Setting.—A total of 263 hospitals and independent laboratories, predominantly located in the United States, participating in the College of American Pathologists Q-Probes Program.

Results.—There were 95 141 CBC determinations examined in this study; participants reviewed 15 423 (16.2%) peripheral blood smears manually. In the median institution (50th percentile), manual reviews of peripheral smears were performed on 26.7% of specimens. Manual differential count review rates were inversely associated with the magnitude of platelet counts that were required by laboratory policy to trigger smear reviews and with the efficiency of generating CBC reports. Lower manual differential count review rates were associated with laboratory policies that allowed manual reviews solely on the basis of abnormal automated red cell parameters and that precluded performing repeat manual reviews within designated time intervals. The manual scan rate elevated with increased number of hospital beds. In more than one third (35.7%) of the peripheral smears reviewed manually, participants claimed to have learned additional information beyond what was available on automated hematology analyzer printouts alone.

Conclusion.—By adopting certain laboratory practices, it may be possible to reduce the rates of manual reviews of peripheral blood smears and increase the efficiency of generating CBC results.

[Metaanalysis of reference values in hematology]

The reference values of the most commonly used parameters in hematology were evaluated in a metaanalysis using practices of a group of major hospitals in Switzerland and in detail review of the literature. Extensive differences of the reference values have been noted being caused mainly by selection of different patient/control collectives. Whenever possible, reference values were separately evaluated for age, gender and race. The reported reference values approximated a Gauss distribution allowing for statistical evaluation accordingly. Due to recent standardization (ICSH and NCCLS), differences caused by instrumentation and preanalytics were found to be of less importance. Our presented validated reference values in hematology should allow for better discrimination of classical hematological disease entities such as an iron deficiency anemia, thalassemia and hemolysis.

Optimized flow cytometric analysis of endothelial progenitor cells in peripheral blood

Although flow cytometry is a rapid and convenient way to measure the number of circulating endothelial progenitor cells (EPC), there is no standard technique for preparation and measurement. The aim of this study was to present an optimized preparation method for EPC measurement which should serve as a standard to facilitate the comparison of the results in stem cell investigations by different research groups. We have looked for the preparation method which delivered the best immunostaining with the directly conjugated antibodies against VEGF R2, CD133, CD34, and CD45. In order to test the sensitivity of the method, we determined the number of EPC in the peripheral blood of volunteers by flow cytometry and by cell culture assay. Furthermore, we have evaluated the influence of different durations of conservation on the EPC cell count. The pre-treatment of blood samples with 0.2% formaldehyde for 30 minutes delivers the best immunostaining, and blood samples can be stored overnight at 4 degrees C without loss of counting rate for EPC. We found an excellent correlation (r = 0.98) between the flow cytometric measurement and the cell count of the cell culture method. The presented protocol for the flow cytometric measurement of EPC in the peripheral blood can be used as a diagnostic or prognostic tool; we propose this protocol as the standard for EPC quantification.

An Evaluation of the Cell-Dyn 3200 for Counting Cells in Cerebrospinal and Other Body Fluids

This study compared the white blood cell (WBC) and red blood cell (RBC) counts obtained with the Cell-Dyn 3200 (CD 3200) with results obtained by hemocytometer, the reference method for counting cerebrospinal fluid (CSF) and other body fluid specimens. Ninety-six CSF and 65 body fluid specimens were evaluated. Background counts were maintained on the CD 3200 at 0.001 x 10(9)/L and 0.00 x 10(12)/L for WBC and RBC counts, respectively. Linearity and precision were acceptable for both the total nucleated cell (TNC) count and the RBC count. The CD 3200 WBC optical count was correlated with the TNC count obtained by the manual reference method for CSF specimens across the range of 0 x 10(9 )/L to 7.863 x 10(9)/L (r2 = 0.9867) and for body fluid specimens across the range of 0 x 10(9)/L to 14.0 x 10(9)/L (r2 = 0.9955). An r2 value of 0.9016 was obtained for the 82 CSF specimens with manual TNC counts of <0.200 x 10(9)/L. Analysis of the CSF and body fluid specimens indicated that automated RBC counts could be reported at > or = 0.003 x 10(12)/L. In this study, 7 CSF and 30 body fluid specimens had RBC counts of >0.003 x 10(12)/L, and there was good agreement with manual RBC counts, with r2 values of 0.9893 and 0.9960 obtained for CSF and other body fluids, respectively. The CD 3200 in our experience has a lower reportable range than the ranges of most automated cell counters reported in the literature. In contrast to the only other instrument with comparable reportable ranges, the CD 3200 requires a smaller sample volume without any special sample preparation, reagents, or software. By using the CD 3200 with our laboratory-specific rules for agreement between duplicate counts, we would be able to reduce our manual CSF specimen counts from 192 TNC and 192 RBC counts to 2 TNC and 178 RBC counts. For body fluid specimens, our manual counts would be reduced from 130 TNC and 130 RBC counts to 10 TNC and 4 RBC counts.

The International Consensus Group for Hematology Review: Suggested Criteria for Action Following Automated CBC and WBC Differential Analysis

In the half century since the first use of automated analyzers, manual techniques, especially microscopic examination of a stained blood film, have complemented analyzer results to provide a comprehensive hematology report on a patient's blood sample. Over the years, as the capabilities and performance of automated analyzers have improved, the respective roles of the automated analyzer and the complementary procedures have changed. Manual action (most commonly smear review) following automated analyzer results is usually triggered by determining whether the results trigger one of a series of criteria for review of results. There is little uniformity among different laboratories on criteria for action. Recognizing the long-standing need for generally accepted guidelines ("rules") which could be applied to criteria for review of CBC and differential results from automated hematology analyzers, Dr. Berend Houwen invited 20 experts to a meeting in the Spring of 2002 to discuss the issues and determine the most appropriate criteria. At this meeting, 83 rules were developed by consensus agreement. These rules were then tested in 15 laboratories on a total of 13,298 blood samples. After a detailed analysis of the data, the rules were refined and consolidated to produce 41 rules that are presented here. They include rules for first-time samples as well as delta rules for repeat samples within 72 hours from a patient. It is hoped that these rules will be useful to a large number of hematology laboratories worldwide. To facilitate validating these rules in individual laboratories before implementation in routine operation for patient samples, a suggested protocol is attached to this paper.

Hematologic Values in Healthy and Small for Gestational Age Newborns

Many of the published reports of reference values in neonates are found in older medical literature. Recognition of abnormalities in blood cell morphology and hematologic parameters depend on well-established normative data; it is essential that each neonatal medical unit have its own reference ranges. We give the umbilical cord blood complete blood count reference values from 142 healthy, appropriate for gestational age (AGA) newborns and 58 small for gestational age (SGA) newborns (term and preterm). Our data, obtained by automated blood cell counter analysis of umbilical cord blood samples taken at birth, are comparable to other previously published data. The correlation between previous data and our reference data confirms that in term AGA newborns, values for red blood cells, hemoglobin, and hematocrit are higher and mean corpuscular volume values lower than in preterm AGA newborns. Also, we found that platelet levels are reduced in SGA newborns, in accordance with the literature. These findings further support the fact that preterm SGA infants are truly growth restricted, whereas term SGA infants are most likely small but otherwise healthy babies.

Hematology of the sandbar shark, Carcharhinus plumbeus: standardization of complete blood count techniques for elasmobranchs

BACKGROUND

Standardized hematologic methods and reference intervals have not been established for cartilaginous fishes (sharks, skates, and rays) despite the large number of animals displayed in zoos and aquariums worldwide.

OBJECTIVE

The focus of this study was to validate CBC methods for sandbar shark (Carcharhinus plumbeus) blood, based on criteria established in human medicine, for the following tests: RBC count, total WBC count, PCV, hemoglobin (Hgb) concentration, and WBC differential percentages.

METHODS

Replicate CBCs were performed using blood samples from 5 captive sandbar sharks. Three protocols for RBC and total WBC counts were compared, as were different centrifugation times for PCV determination, and 2 methods for Hgb concentration. Means, minimum and maximum values, and CVs were compared to CAP and CLIA performance guidelines for human tests.

RESULTS

Total WBC counts in a diluent modified for elasmobranch blood, Hgb concentration by the cyanmethemoglobin method after removal of nuclei, and WBC differential percentages showed acceptable performance. PCV results were acceptable when tubes were centrifuged for at least 5 minutes. Total RBC counts by all 3 methods exceeded the acceptable error for manual counts of human cells.

CONCLUSIONS

Standardized CBC tests can be used as health assessment tools for elasmobranchs. Total RBC counts should be viewed as estimates.

Performance Evaluation of the Sysmex pocH-100i Automated Hematology Analyzer

The Sysmex pocH-100i automated hematology analyzer was evaluated at St. John's Regional Health Center, Springfield, Missouri, USA, and compared with the Sysmex KX-21N. The pocH-100i is a compact, fully automated hematology analyzer with the capability for simultaneous analysis of 17 parameters in the whole-blood mode. The touch screen liquid crystal display presents results, and the 3 histograms for white blood cell (WBC), red blood cell (RBC), and platelet (PLT) counts can be printed along with numerical results. This study was performed to provide necessary information for the US Food and Drug Administration study of allowing the product's use in the North American marketplace. The pocH-100i processes approximately 25 samples/hour, uses 2 reagents, and provides for testing in a closed-tube environment, while using only 15 microL in the whole-blood mode and 20 microL in the predilute mode. Using hydrodynamic focusing on the pocH-100i improves the accuracy for RBC and PLT measurements. Our evaluation included studies of correlation, carryover, reproducibility, linearity, and stability. Results with the pocH-100i showed good correlation with those from the KX-21N for the following parameters: WBC; numbers and percentages of lymphocytes, mixed cells (monocytes, eosinophils, and basophils), and neutrophils; RBC; hemoglobin; hematocrit; mean corpuscular volume; mean corpuscular hemoglobin; mean corpuscular hemoglobin concentration; PLT; red cell distribution width SD (RDW-SD); RDW coefficient of variation; and mean platelet volume. Carryover and reproducibility were well within the manufacturer's specifications. The pocH-100i showed linearity over the entire range for all parameters studied. A reference range for a healthy population was also established. We conclude that the overall performance of the pocH-100i is excellent and compares favorably with that of the KX-21N.

Canine and feline hematology reference values for the ADVIA 120 hematology system

BACKGROUND

The ADVIA 120 is a laser-based hematology analyzer with software applications for animal species. Accurate reference values would be useful for the assessment of new hematologic parameters and for interlaboratory comparisons.

OBJECTIVE

The goal of this study was to establish reference intervals for CBC results and new parameters for RBC morphology, reticulocytes, and platelets in healthy dogs and cats using the ADVIA 120 hematology system.

METHODS

The ADVIA 120, with multispecies software (version 1.107-MS), was used to analyze whole blood samples from clinically healthy dogs (n=46) and cats (n=61). Data distribution was determined and reference intervals were calculated as 2.5 to 97.5 percentiles and 25 to 75 percentiles.

RESULTS

Most data showed Gaussian or log-normal distribution. The numbers of RBCs falling outside the normocytic-normochromic range were slightly higher in cats than in dogs. Both dogs and cats had reticulocytes with low, medium, and high absorbance. Mean numbers of large platelets and platelet clumps were higher in cats compared with dogs.

CONCLUSIONS

Reference intervals obtained on the ADVIA 120 provide valuable baseline information for assessing new hematologic parameters and for interlaboratory comparisons. Differences compared with previously published reference values can be attributed largely to differences in methodology.

Performance Characteristics of the Coulter LH 500 Hematology Analyzer

The challenge for modern hematology laboratories is to provide accurate and reproducible results, with seamless performance between facilities, in a cost-effective manner. Beckman Coulter recently developed the Coulter LH 500 to meet the needs of smaller laboratories or serve as a backup in larger laboratories. The principal goal of this study was to validate all parameters and performance specifications of the LH 500 compared to the Coulter LH 750 predicate analyzer. A total of 245 spent clinical samples from the London Health Sciences Centre (LHSC) and 251 from the University of Pittsburgh Medical Center Health System (UPMCHS) were analyzed during the study. The samples were selected to include 75% abnormal and 25% normal blood samples. According to the results of a rank sum test, there was no significant difference between the LH 500 and LH 750 for all complete blood count parameters (P > .05) except the red cell distribution width, which showed a slight negative bias on the LH 500. Differential parameters comparing the LH 500 to a 400-cell manual differential showed correlation coefficients (r2) from 0.75 to 0.99 for all parameters except basophils. Of the samples run on the LH 500 at LHSC, the false-positive differential flagging rate was 17.32% and the false-negative rate was 3.03%. Sensitivity was 82.93%, specificity 78.95%, and efficiency 79.65%. At UPMCHS, the false-positive differential flagging rate was 13.37% and false-negative rate 2.97%. Sensitivity was 91.89%, specificity 78.91%, and efficiency 83.66%. Overall, the LH 500 performed accurately and reproducibly compared to the LH 750 and the reference procedures. It would be an excellent second instrument for larger laboratories concerned with harmonization of instrumentation and reagents or as a primary instrument for smaller hematology laboratories with limited space.

Viable CD34+ stem cell content of a cord blood graft: which measurement performed before transplantation is most representative?

BACKGROUND

Patient survival in allogeneic cord blood transplantation is critically dependent on total nucleated cell (TNC) count or total CD34+ cell count per kg of body weight. Theoretically, viable CD34+ cell measurement at the time of infusion should give a better indication of the suitability of a certain transplant. The relation between measurements on different samples and viable CD34+ cell count on the graft itself was analyzed.

STUDY DESIGN AND METHODS

Viable CD34+ cells were measured with a no-wash, single-platform technique with 7-aminoactinomycin D. Analysis was performed before freezing on the cord blood, after freezing and thawing on the cord blood unit itself, and on various samples.

RESULTS

Cord blood volume correlated poorly with viable CD34+ cell content (r=0.24) as did initial TNC count and WBC count (r=0.57 and r=0.48, respectively). In contrast, viable CD34 cell content determined before freezing correlated well with viable CD34 cell content of the graft (r=0.91) but was on average 25 percent higher than after freezing and thawing. The best correlations with the CD34+ cell content of the cord blood unit were obtained with CD34 cell measurements on a separate cryovial (r=0.95). These CD34 cell measurements on frozen samples were found to be very reproducible (r=0.96).

CONCLUSION

Viable CD34 cell count of the graft is both accurate and precise when measured on a separate sample frozen together with the cord blood unit. This measurement can be performed by the transplant center to exclude between-laboratory variability.

Five-year follow-up of routine outpatient test turnaround time: a College of American Pathologists Q-Probes study

CONTEXT

Timely reporting of outpatient tests can increase efficiency of care and improve customer satisfaction.

OBJECTIVES

We conducted a survey in 2002 to determine how quickly hospital-based laboratories turned around routine requests for 3 common assays and compared the results with a similar survey conducted in 1997.

DESIGN

One hundred eighteen laboratories prospectively recorded the collection-to-verification turnaround time for 9252 complete blood cell counts (CBCs), 8832 thyroid tests, and 9193 basic metabolic panels.

RESULTS

The median facility reported all test results by 7:00 am of the weekday immediately after the date of specimen collection. The bottom 10% of institutions reported 99% of CBCs and basic metabolic panels within 1 day and 60% of thyroid tests within 1 day. The 65 institutions that participated in both the 1997 and 2002 surveys showed significant overall improvement in turnaround time for all 3 types of tests (P <.001). In 2002, federal institutions had significantly slower turnaround times than nonfederal institutions for CBC tests (P <.001), thyroid tests (P =.03), and basic metabolic panels (P <.001). Other demographic and practice variables were not associated with turnaround time.

CONCLUSION

The turnaround time of routine outpatient tests appears to have improved between 1997 and 2002.

Does amphotericin B lipid complex (Abelcet) affect haematological parameters erroneously?

Abelcet is composed of large particles which could be misinterpreted as blood cells on measurements with blood cell counters. The direct measurement of drug suspensions on blood cell counters has been performed in an in vitro study. In an ex vivo study, the haematological parameters were compared before and during Abelcet infusions. A significant interference effect was observed in platelet counts, together with minimal differences in the WBC, RBC, and Hb parameters in the in vitro study. In the ex vivo study, there were statistically significant deviations only in RBC counts and in haemoglobin (Hb) level, while there was no difference in the other parameters. It is been reported that the drug accumulates very rapidly in the reticuloendothelial system and circulates minimally in the plasma. That is why there is a significant deviation in the direct counting of platelets, while the platelet counts taken from the patients do not differ statistically.

Performance evaluation of the Sysmex XT-2000i automated hematology analyzer

The Sysmex XT-2000i automated hematology analyzer was evaluated at Saint Louis Children's Hospital (SLCH), St. Louis, MO, USA. Complete blood count results from the Sysmex XT-2000i were compared to results from the Sysmex XE-2100 for 114 pediatric and adult patient samples. Manual differentials were performed on each specimen by 2 experienced medical technologists using guidelines established in the National Committee for Clinical Laboratory Standards (NCCLS) document H20-A. Carryover, precision, linearity, correlation, stability, and mixing-test studies were also performed. The XT-2000i results showed excellent correlation with the results from the XE-2100 for the following parameters: white blood cells; red blood cells; hemoglobin; hematocrit; mean corpuscular volume; mean corpuscular hemoglobin; mean corpuscular hemoglobin concentration; red blood cell distribution width by standard deviation; red blood cell distribution width by coefficient of variation; mean platelet volume; platelets; percent neutrophils, lymphocytes, monocytes, eosinophils, and basophils; and reticulocyte percent and number. In our evaluation of the XT-2000i the correlation coefficients for all complete blood counts and differential parameters compared well with those of the XE-2100. We concluded that the XT-2000i demonstrated comparable analytical performance to its predecessor, the XE-2100.

Evaluation of the Beckman Coulter AcT 5 diff AL hematology analyzer in a hospital setting

The Coulter AcT 5-part differential (5 diff) autoloader (AL) hematology analyzer from Beckman Coulter (Fullerton, CA, USA) was evaluated at the Florida Medical Center in Fort Lauderdale, Florida, an acute care hospital facility. The AcT 5 diff AL is a new, fully automated bench-top 5-part differential hematology analyzer with automatic loading and sampling. It is designed as a front-line instrument for small- to medium-sized laboratories or as a backup in larger laboratories. We evaluated the performance of the AcT 5 diff AL for complete blood counts (CBCs). The Coulter Onyx AL was used as the reference instrument and the 5-part differential against the reference 400-cell manual differential count (2 operators x 200 cells). A total of 140 patient samples were analyzed in the study, with most of the samples obtained from our own laboratory workload. We supplemented this dataset with pediatric and oncology samples from nearby practices. All samples were analyzed within 4 hours of collection, and the AcT 5 diff AL demonstrated excellent accuracy with correlation values (r) > 0.98 for all directly measured CBC parameters (white blood cell count, red blood cell count, hemoglobin, mean corpuscular volume, and platelets). Reproducibility studies on the AcT 5 diff AL also showed excellent results, with coefficients of variation much lower than the manufacturer's specifications. Initial differential comparisons showed good correlations for neutrophils, lymphocytes, and eosinophils (r = 0.84, 0.96, and 0.88, respectively) with a lower correlation for monocytes (r = 0.43). On subsequent review and data analysis we found differential discrepancies in 39 of the 140 samples, for which all showed multiple morphological flags, R diff flags, or poor scatterplot separations indicating that the AcT 5 diff AL differential was likely to be inaccurate and that a morphological assessment and differential was necessary. Given the acutecare setting that our laboratory serves and the skewing of the dataset of our study because of the addition of abnormal pediatric and oncology cases, these abnormal sample results were not surprising. These 39 samples all had markedly abnormal differentials with either increased numbers of immature and/or abnormal cells due to such conditions as end-stage liver disease, respiratory failure, renal failure, sepsis and pneumonia, high white blood cell leukemias, and a variety of other acute illnesses. Reanalysis of the differential data, excluding these 39 grossly abnormal samples with R flags and multiple flags, showed the AcT 5 diff AL differential gave very good correlations for neutrophils, lymphocytes, monocytes, and eosinophils (r = 0.93, 0.97, 0.66, and 0.85, respectively). Our technologists were also impressed with the reliability of the AcT 5 diff AL, its ease of use and transfer from stand-by to ready mode, the user friendliness of the software, and the clarity of the printed report. We concluded that the AcT 5 diff AL gives accurate and precise CBC and 5-part differential results and is an excellent, easy-to-use instrument ideally suited for small- to moderate-sized hospital laboratories, as a back-up in a large hospital laboratory, or for use in physician office laboratories.

External quality assessment of automated hematology analyzer performance using fresh human blood samples in Shanghai

We set out to assess the performance and degree of agreement for the different automated hematology analyzers (AHAs) currently used within the Shanghai region. Analyzers from 5 different manufacturers were represented within the 114 hospitals that participated in this project: Abbott, ABX, Beckman Coulter, Nihon Kohden, and Sysmex. We determined the results obtained on 115 hematology analyzers in the 114 different hospitals for hemoglobin (HGB), red blood cell count (RBC), white blood cell count (WBC), hematocrit (HCT), and platelet count (PLT) from fresh anticoagulated blood samples from healthy donors. The maximum coefficients of variation (CV%) among instruments of the 3 main manufacturers (Abbott, Beckman Coulter, and Sysmex) for RBC, HGB, HCT, WBC, and PLT were 3.2%, 3.8%, 3.6%, 9.3%, and 10.8%, respectively. The maximum deviations observed among these parameters from the 5 major instrument groups were 0.74% (RBC), 2.24% (HGB), 6.37% (HCT), 6.97% (WBC), and 21.06% (PLT). Implementation of the regular, local external quality assessment program in the Shanghai region using fresh blood samples has resulted in a reduction of CV% values for the major clinically important CBC parameters (RBC, HGB, HCT, WBC, and PLT) within the instrument groups over time. An important result was that the CBC parameter CVs were also well within established US Clinical Laboratory Improvement Amendments of 1988 guidelines for AHA performance. Combined with a comprehensive education program, the Shanghai external fresh blood quality assessment program has resulted in closer agreement among the various AHA manufacturers, with only very small differences for RBC, HGB, HCT, WBC, and PLT counts. The success of this program has given us increased confidence in the comparability of results and subsequent patient management using the various types of AHAs currently in use in the hospitals within the Shanghai region.

Performance characteristics of the Sysmex XT-2000i hematology analyzer

The XT-2000i is a new hematology analyzer combining aperture impedance and optical technologies. It is capable of generating a 30-parameter hematologic assay on peripheral blood at a throughput of 80 samples per hour. We have evaluated the performance characteristics of the XT-2000i analyzer and compared them with those of the state-of-the-art XE-2100 analyzer and the manual differential count. The XT-2000i compared favorably with the XE-2100 analyzer and exceeded the manufacturer's specifications in all parameters tested. The XT-2000i has a user-friendly graphical user interface, and there was virtually no downtime during the period of evaluation. This analyzer can be recommended as a backup to the XE-2100 analyzer or as a stand-alone analyzer in a laboratory with moderate volume and a broad complexity of samples.

Artifacts that may be present on a blood film

Many artifacts or pseudoartifacts may be noted during the examination of a blood film. Artifactual results also may be generated by automated hematology analyzers, which in turn may be investigated by blood film examination. Some artifacts are misdiagnosed, and this in turn leads to inappropriate investigations or treatment. An awareness of the spectrum of spurious or artifactual results may help to prevent such an unfortunate occurrence.

Cell analysis system based on compact disk technology

BACKGROUND

A cell analysis system was developed to enumerate and differentiate magnetically aligned cells selected from whole blood. The cellular information extracted is similar to the readout of musical information from a compact disk (CD). Here we describe the optical design and data processing of the system. The performance of the system is demonstrated using fluorescent-labeled cells and beads. Materials and Methods System performance was demonstrated with 6-microm polystyrene beads labeled with magnetic nanoparticles and allophycocyanin (APC) and immunomagnetically aligned leukocytes, fluorescently labeled with Oxazine750 and CD4-APC, CD8-Cy5.5, and CD14-APC/Cy7 in whole blood.

RESULTS

The sensitivity of the system was demonstrated using APC-labeled beads. With this system, beads containing 333 APC molecules could easily be resolved from the background. This level of sensitivity was not achievable with a commercial flow cytometer. A maximum of 20,000 immunomagnetically labeled cells could be aligned and analyzed in between 0.6 m of Ni lines, distributed over a surface area of 18 mm(2) and extracted from a blood volume that depended on the height of the chamber. The utility of the system was demonstrated by performing a three-color CD4-CD8-CD14 assay.

CONCLUSIONS

We built a cell analysis system based on immunomagnetic cell selection and alignment and analysis of fluorescent signals employing CD-technology that is as good or better than current commercial analyzers. The cell analysis can be performed in whole blood or any other type of cell suspension without extensive sample preparation.

Studies on the characterisation of the cause of leucoreduction failures, with particular reference to extra gatal events

The causes of leucodepletion failure are multifactoral and can be related to haematological variability in blood donors or donation, defective filters, poor specimen handling or ageing, and/or the presence of non-adhering leucocyte/platelets. Since refiltering removes all types of leucocytes, including the populations appearing as extra gated events, we have developed a practical method for refiltering the failed leucodepleted components on standard filters and back-flushing the second filter to assess the nature of the WBC sub-population. In practice, recovered leucocytes from red cell filters and whole blood mainly consist of neutrophils. Those from platelet and plasma filters were mainly lymphocyte with considerable differences depending on the type of leucodepletion process. Atypical leucocytes are often seen in some pre-/post-cellular leucofiltered components. These appear characteristically as small WBC with a lower affinity for filter matrix, or as cell fragment, pinched leucocyte or apoptotic cells. Different reagents in use show variable sensitivity in identifying these extra gatal events. Storage of leucodepleted samples also induces different types of abnormality in leucocyte dot plot. A useful practical approach for characterisation of the nature of leucocyte sub-populations causing failure in leucodepleted components is provided.

Improvement of the precision in CFU-GM and BFU-E counting by flow cytometry-based standardization of short-term culture assays

The counting of colony-forming units granulocyte-macrophage (CFU-GM) and burst-forming units erythrocyte (BFU-E) provides substantial in vitro information about the graft quality after peripheral stem cell transplantation (PBSCT). By using different techniques for culturing and scoring, high inter- and intralaboratory coefficients of variation (CV) are frequently reported. We minimized the imprecision by using flow cytometry-based incorporation of constant numbers of CD34(+) cells per culture dish instead of the formerly used mononuclear cells. Our results show acceptable CVs for CFU-GM (12.3%) and for BFU-E (13.3%) based on this seeding technique, which contributes to fulfilling the demands of a quality assurance system in stem cell laboratories.

Measurement of hematological, clinical chemistry, and infection parameters from hirudinized blood collected in universal blood sampling tubes

Hirudin, the anticoagulatory polypeptide of the leech Hirudo medicinalis, strongly inhibits thrombus formation by specifically interacting with thrombin. For diagnostic purposes, hirudin should be superior to other anticlotting compounds because it only minimally alters the mineral, protein, and cellular blood constituents. To test this hypothesis, hirudinized and routinely processed venous blood from 80 healthy volunteers and patients was subjected to a variety of automated blood tests. A strong correlation was found between the results of automated complete blood counts obtained from K(2)-ethylenediaminetetraacetic acid (EDTA) anticoagulated and hirudinized blood (1000 antithrombin units [ATU] hirudin/ml). In addition, clinical chemistry and serological infection parameters (asparlat amintransferase [ASAT], lactate dehydrogenase [LDH], sodium, and so on, and antibodies against hepatitis B and C and human immunodeficiency virus [HIV]1/2, respectively) correlated well when measured in serum as compared with hirudinized plasma. Contrary to single clotting factors, global coagulation parameters (activated partial thromboplastin time [aPTT], prothrombin time [PT]) could not be measured in hirudinized blood. Recombinant hirudin neither interfered with immunophenotyping of mononuclear cells using FACScan analysis, nor did it alter the detection of Wilms' tumor gene expression by RT-PCR technology even at high doses (5000 ATU hirudin). Thus, a hirudin-containing blood sampling tube can be designed as a universal blood sampling tube (UBT) for testing the majority of diagnostic blood parameters.

Laboratory evaluation of the Sysmex SE-9500 automated haematology analyser

The Sysmex SE-9c500 is a new, fully automated haematology analyser, providing a complete blood count (CBC), including a five-part differential count (DC), with flagging of morphological abnormalities. The SE-9500 was evaluated according to guidelines published by the International Committee for Standardisation in Haematology (ICSH). The results demonstrated minimal carryover (< 0.01%) and excellent linearity for WBC, RBC, HGB and platelet (PLT) (r > 0.995). Samples were stable with regard to CBC parameters after storage for up to 48 h at room temperature (RT) and 4 degrees C. Imprecision was generally acceptable for all CBC parameters (CV < 5%). Correlation between the SE-9500 and reference methods was excellent (r > 0.97) for all the major CBC parameters (WBC, RBC, HGB, PLT). There was minimal interference for WBC, RBC, HGB and PLT at high concentrations of bilirubin (BIL=224 micromol/l) or triglyceride (TG=7.78 mmol/l). SE-9500 reference values for CBC parameters are presented. Our results indicate that the SE-9500 is an excellent tool for routine haematological examination.

Comparison of blood counts in venous, fingertip and arterial blood and their measurement variation

We compared routine blood pictures in venous, fingertip and arterial blood and their measurement variation. A pair of venous and fingertip blood samples were simultaneously collected from 24 volunteers, and another pair of venous and arterial samples from another 12 volunteers. The volunteers were healthy adults, aged 20-22 years, with males and females in equal numbers. Three aliquots of blood were taken from each person for three measurements of blood counts, including haemoglobin concentration and haematocrit, using an automatic haematology analyser. Compared to arterial blood, there was a significant increase of erythrocyte count (2.7%) and haematocrit (3.1%) in the venous blood. The total and large leucocyte counts were significantly higher (9.2% and 12.6%, respectively) in the fingertip blood than in the venous blood. There were a decreasing number of leucocytes in the fingertip blood with repeated sampling. The intermeasurement variation for total leucocyte or haemoglobin measurement was significantly larger as measured with the fingertip blood or arterial blood than with the venous blood. The intermeasurement coefficients of variation of haemoglobin (1.3%) and small leucocyte ratio or platelet (approximately 4.0%) measurements with venous and arterial blood were the smallest and largest, respectively. Volume of arterial plasma was diminished by 2-3% after microcirculation. Elevation of total leucocyte count in the fingertip blood was mainly due to the increase of granulocytes. Measurement with venous blood was of better precision than with fingertip or arterial blood.