Effect of clinically significant thresholds of eosinophil elevation on health care resource use in asthma.

BACKGROUND: Blood eosinophil counts correlate with exacerbations, but there is a lack of consensus on a clinically relevant definition of eosinophil count elevation. OBJECTIVE: To analyze health care resource use among patients with elevated blood eosinophil counts defined at 150 cells/µL or greater and 300 cells/µL or greater. METHODS: Data on patients who received a diagnosis of asthma between 2007 and 2016 were extracted from EMRClaims + database. Patients were defined as having elevated eosinophil counts if any test result during 3 months before follow-up found blood eosinophil count of 150 cells/µL or more or 300 cells/µL or more. Hospitalizations, emergency department visits, outpatient visits, and associated costs were compared. With logistic regression, likelihood of hospitalization was assessed in the presence of eosinophil elevation. RESULTS: Among 3687 patients who met the study criteria, 1152 received a test within 3 months before the follow-up period, of whom 644 (56%) had elevated eosinophil counts of 150 cells/µL or greater and 322 (29%) had eosinophil counts of 300 cells/µL or greater. Overall, the mean (SD) number of hospitalizations for patients with elevated eosinophil counts vs the comparator was significantly greater (0.29 [0.92] vs 0.17 [0.57], P < .001 at ≥150 cells/µL and 0.30 [0.95] vs 0.18 [0.61] at ≥300 cells/µL, P = .001). The total mean cost was significantly greater for patients with elevated eosinophil counts (at ≥150 cells/µL: $10,262 vs $7149, P < .001 and at ≥300 cells/µL: $9966 vs $7468, P = .003). CONCLUSION: Patients with asthma incurred greater health care resource use when their blood eosinophil counts were elevated at 150 cells/µL or greater and 300 cells/µL or greater as measured within 3 months of follow-up.

False-positive flag of WBC and change of mean platelet volume (MPV) caused by K3-EDTA on the DxH 900 hematology analyzer.

During the evaluation of the DxH 900 hematology analyzer (Beckman Coulter, Miami, FL), we noted that some patient samples produced a false positive white blood cell (WBC) flag, neutrophil blasts (NE-blast), despite the absence of abnormal cells. We investigated whether storage time or anticoagulants such as K2- or K3-ethylenediaminetetraacetic acid (EDTA) would affect complete blood count (CBC) tests on the DxH 900. Sixty-four whole blood samples were collected in K3-EDTA tubes, and 44 were simultaneously drawn in K2-EDTA tubes. Samples were tested at the following two intervals: within 30 min of collection (0 min) and after an additional 30 min of roller-mixing at room temperature (30 min). WBC differential dataplots in 0-min K3-EDTA tubes showed a mixed cell population between lymphocytes and neutrophils in 22 patients presenting the NE-blast flag. All 22 samples revealed normal WBC differential dataplots after 30 min of roller-mixing. The significantly lower mean neutrophil volume in specimens of 0-min K3-EDTA tubes than those of 0-min K2-EDTA, 30-min K2-EDTA and 30-min K3-EDTA tubes appear to be the cause of the false flag. Unlike blood cell counts, mean platelet volume (MPV) was significantly higher at 30 min using both EDTA tubes than that at 0 min. In conclusion, K3-EDTA can produce a false positive flag, NE-blast, on the DxH 900. MPV increases over time irrespective of EDTA salt type.

Study of the analytical performance at different concentrations of hematological parameters using Spanish EQAS data.

Background External quality assessment programs are one of the currently available tools to evaluate the analytical performance of clinical laboratories, where the measurement error (ME) obtained can be compared with quality specifications to evaluate possible deviations. The objective of this work was to analyze the ME behavior over the analytical range to assess the need to establish concentration-dependent specifications. Methods A total of 389,000 results from 585 laboratories and 2628 analyzers were collected from the Spanish external quality assessment schemes (EQAS) in hematology during the years 2015-2016. The parameters evaluated included white blood cells, red blood cells, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, platelets, prothrombin time, activated partial thromboplastin time, neutrophils, lymphocytes, monocytes, eosinophils, basophils, reticulocytes, hemoglobin A2, antithrombin, factor VIII, protein C and von Willebrand factor. The 90th percentile of ME was calculated for every concentration evaluated of each parameter. Results We found a significant variation in the analytical performance of leukocytes, platelets, neutrophils, lymphocytes, monocytes, eosinophils, basophils, prothrombin time, reticulocytes, hemoglobin A2, antithrombin and protein C. Furthermore, this ME variation may not allow complying with the same biological variability requirements within the whole analytical range studied. Conclusions Our work shows the importance of implementing concentration-dependent specifications which can help laboratories to use proper criteria for quality specifications selection and for a better external quality control results evaluation.

Paediatric reference intervals are heterogeneous and differ considerably in the classification of healthy paediatric blood samples.

The aim was to elude differences in published paediatric reference intervals (RIs) and the implementations hereof in terms of classification of samples. Predicaments associated with transferring RIs published elsewhere are addressed. A local paediatric (aged 0 days to < 18 years) population of platelet count, haemoglobin level and white blood cell count, based on first draw samples from general practitioners was established. PubMed was used to identify studies with transferable RIs. The classification of local samples by the individual RIs was evaluated. Transference was done in accordance with the Clinical and Laboratory Standards Institute EP28-A3C guideline. Validation of transference was done using a quality demand based on biological variance. Twelve studies with a combined 28 RIs were transferred onto the local population, which was derived from 20,597 children. Studies varied considerably in methodology and results. In terms of classification, up to 63% of the samples would change classification from normal to diseased, depending on which RI was applied. When validating the transferred RIs, one RI was implementable in the local population. Conclusion: Published paediatric RIs are heterogeneous, making assessment of transferability problematic and resulting in marked differences in classification of paediatric samples, thereby potentially affecting diagnosis and treatment of children. What is Known: • Reference intervals (RIs) are fundamental for the interpretation of paediatric samples and thus correct diagnosis and treatment of the individual child. • Guidelines for the establishment of adult RIs exist, but there are no specific recommendations for establishing paediatric RIs, which is problematic, and laboratories often implement RIs published elsewhere as a consequence. What is New: • Paediatric RIs published in peer-reviewed scientific journals differ considerably in methodology applied for the establishment of the RI. • The RIs show marked divergence in the classification of local samples from healthy children.

Association of neutrophil-to-lymphocyte ratio and natural killer cell activity revealed by measurement of interferon-gamma levels in a healthy population.

BACKGROUND: While a method of assaying natural killer (NK) cell activity by measuring the amount of interferon (IFN)-γ released from NK cells has been proposed, no data are available about the factors that influence IFN-γ levels related to NK cell activity. NLR has recently been reported to be a predictor of several diseases. In the present study, we investigated the pre-analytical variables for NK cell activity using measurements of IFN-γ and the relationship between NLR and NK cell activity. METHODS: The NK cell activity was assessed with the measurement of IFN-γ after stimulation with an NK cell-specific stimulant (NK Vue™ , ATgen, Sungnam, Korea). One hundred and six adult volunteers were recruited and analysis of their complete blood count data and serum C-reactive protein was done. Blood sample from 59 of the participants was also used for analysis of lymphocyte subpopulations. RESULT: Natural killer cell activity varied widely (range, 44.2-1775.6 pg/mL). NK cell activity was higher in females than in males (P = 0.014). NK cell activity decreased with increasing NLR (P = 0.004, r = -0.32) but NK cell activity showed no significant association with NK cell count or other lymphocyte subpopulations. NK cell activity levels according to CRP quartile were significantly different (P = 0.025). CONCLUSION: We have observed that NK cell activity when assessed by IFN-γ level measurement was negatively correlating with NLR. This result can be helpful in interpreting or predicting NK cell activity in the clinical environment.

Utility of Neutrophil-to-Lymphocyte Ratio (NLR) as a Predictor of Acute Infarction in New-Onset Acute Vertigo Patients Without Neurologic and Computed Tomography Abnormalities.

BACKGROUND: Neutrophil-to-lymphocyte ratio (NLR) has been used as a predictive marker for various conditions. However, there are no previous studies about NLR as a prognostic marker for acute infarction. OBJECTIVE: To evaluate the potential utility of NLR as a predictor of acute infarction in acute vertigo patients without neurologic and computed tomography (CT) abnormalities. METHODS: We conducted a prospective, observational study in the Emergency Department (ED) between January 2015 and December 2016. All patients underwent physical examination, laboratory tests, CT, and magnetic resonance imaging (MRI). Results of the initial and follow-up MRI with clinical progress note were considered as the reference standard. Statistically, multivariate logistic regression analysis and receiver operating characteristic (ROC) curve were used. RESULTS: Thirty-five (25.9%) patients were diagnosed with acute infarction and 100 (74.1%) patients were diagnosed with peripheral vertigo. Horizontal nystagmus (p = 0.03; odds ratio 0.22) and NLR (p = 0.03; odds ratio 5.4) were significant factors for the differential diagnosis of acute infarction and peripheral vertigo. NLR > 2.8 showed the greatest area under the ROC curve (AUC; 0.819), optimal sensitivity (85.7%), and specificity (78.0%). NLR > 1.4 showed the highest sensitivity (97.1%) and relatively low specificity (41%). The absence of horizontal nystagmus increased the specificity (81.0%) and AUC (0.844). CONCLUSIONS: A combination of NLR > 2.8 and the absence of horizontal nystagmus is sufficiently specific for acute infarction in an ED patient with acute vertigo; thus, further testing with MRI is indicated. NLR < 2.8 by itself or combined with the presence of horizontal nystagmus is not sufficiently sensitive to rule out the need for further testing.

A prolonged microscopic observation improves detection of underpopulated cells in peripheral blood smears.

We evaluated an extended time in the microscopic review in samples in which the potential clinical information could be increased with respect to those that could be achieved with the usual laboratory methodologies. We used samples containing nucleated red blood cells in a small amount and cytopenic samples. For these purposes for each peripheral blood smear, the timing of eye-count differential was increased up to 20 min, regardless of the final number of cells which could be counted. In addition, an automated system for digital analysis of peripheral blood smears was employed and the number of cells counted was brought up to 1000 leukocytes. In both manual and automatic light microscopy extended observation, we obtained more diagnostic information in respect to those with routine or standard methods. Both automated and manual increase systems of the timing for microscopic review are useful tools to find diagnostic information that otherwise would be lost using normal and standard procedures. So, these methods should be used especially when there is a higher pre-test probability for discovery of pathological cells.

Investigation and Analysis of Reference Intervals for Blood Cell Parameters in a Healthy Population from Daxingan Region Inner Mongolia.

BACKGROUND: Blood cell parameters in a healthy population of different ages and genders from the Daxingan region of Inner Mongolia were evaluated to establish reference intervals (RIs) for venous blood parameters for healthy individuals from this region. METHODS: Venous blood specimens were collected from 1757 healthy individuals aged 7-65 years and analyzed by an XE-5000 automated hematology analyzer. Results were statistically analyzed by gender and age group. RIs for venous blood parameters of children were compared to the National Clinical Laboratory Procedures and those of adults were compared to the Health Industry Standards of the People's Republic of China (WST405-2012). RESULTS: In the Daxingan region, WBC, RBC, MCV, and NEUT%, MONO%, and EO% of healthy children were significantly different between genders (p < 0.05). Other parameters were not significantly different (p > 0.05). All parameters of adults were significantly different between different genders (p < 0.05) except for LYMPH% and BASO%. Comparison of mean values between children and adults of the same gender revealed significant differences in each blood cell parameter (p < 0.05). RBC, MCV, MCH, MCHC, PLT, MONO%, and BASO% of adult men were significantly different between different age groups (p < 0.05), and HGB, HCT, and EO% of adult women were significantly different between different age groups (p < 0.05). For children, only the mean of MCHC and EO% were close to the National Clinical Laboratory Procedures. Mean of RBC, HGB, PLT, LYMPH%, and MONO% were higher and the remaining parameters were lower than the National Clinical Laboratory Procedures. Compared with WST405-2012 for adults, PLT of women aged 18-40 years and NEUT% of adults were higher, whereas the mean of EO% and BASO% were significantly lower. CONCLUSIONS: RIs for venous blood parameters change with age, geographic region, ethnic group, and gender. There is a great necessity to establish RIs for venous blood parameters among the healthy population in the Daxingan region.

Complete blood count at the ED: preanalytic variables for hemoglobin and leukocytes.

OBJECTIVE: The objective of this study is to determine the ways in which preanalytic factors related to physiologic status can affect the complete blood cell count (CBC) in patients referring to an emergency department (ED). METHODS: Over a 1-year period, the results of hemoglobin (Hb) level and white blood cell (WBC) counts of the first CBC tests undertaken in consecutive patients (n = 11487) referring to the ED were compared with those obtained in the same patients at a second test undertaken within 24 hours of admission. A prospective evaluation of the same differences was made in another group (group 2) of 1025 consecutive ED patients, several clinical characteristics being taken into consideration. RESULTS: Mean Hb concentrations were higher in the first (range, 8.0-15.9 g/dL) than in the second test results (median overestimation, 0.4-0.8 g/dL; P < .0001). At multivariate analysis of results in group 2 patients, fluid administration (>0.5 L) and the presence of edema played a significant role in the initial overestimation of Hb level (P = .001 and P = .045, respectively). The comparison between leukocyte counts (WBC) showed that values from the first were higher than those in the second test (median overestimation ranging from 0.42 to 3.63 × 10(9)/L cells, in the range counts from 4.0 to 30.0 × 10(9)/L). None of the clinical factors studied appeared to have affected this overestimation. CONCLUSIONS: On interpreting CBC results in patients admitted to the ED, physicians must consider the effect of physiologic variables on Hb level (mainly hydration status) and WBC count (mental and physical stress).

Real-time amplification of glyceraldehyde-3-phosphate dehydrogenase gene for quality control of leukopoor platelets.

BACKGROUND: Leukoreduction of blood products is crucial to prevent white blood cell (WBC)-associated complications during transfusion. Of the widely accepted methods for quantifying WBCs in blood components, Nageotte hemocytometry is time-consuming and laborious whereas a specialized instrument is required for flow cytometry. A reliable and affordable method to assess WBC count in blood products is of particular interest. STUDY DESIGN AND METHODS: Real-time polymerase chain reaction (PCR) of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene was developed for quantifying WBCs in leukopoor platelets (LPPs). After normalization by the cell-free prefiltrated and postfiltrated plasma DNA, the relative copy number of GAPDH gene in the platelet (PLT) concentrate and its corresponding LPPs was calculated according to the equation of 2(-ΔΔCt) of which Ct is defined as the threshold cycle. The percentage and the number of WBCs that remained in LPPs were consequently determined. This method was compared to Nageotte hemocytometry and was validated by using serially diluted PLT concentrate and 10 pairs of PLT concentrate-LPP samples. RESULTS: Consistent with the removal of WBCs after filtration, the Ct values for the LPP samples were increased when compared to their corresponding PLT concentrate. As revealed by real-time PCR of GAPDH gene, there is a correlation between the calculated and theoretical WBC count in the serially diluted PLT concentrate (correlation coefficient, 0.9532). The WBC counts for the 10 LPP samples were comparable between Nageotte and real-time PCR method and were all below 3.3 × 10(6) WBCs/L. CONCLUSION: The real-time PCR method we report in this study is applicable for routine quality assurance during leukoreduction process.

First comparative evaluation of a new leukapheresis technology in non-cytokine-stimulated donors.

BACKGROUND AND OBJECTIVES: Leukapheresis is an important source for mononuclear cells (MNCs) used in adoptive immunotherapies. Differences in the apheresis technology concerning physical conditions during cell separation and the optical detection system can affect the product's cellular content. MATERIALS AND METHODS: In a paired analysis, twenty healthy non-cytokine-stimulated donors underwent MNC collection at the Spectra Optia (Terumo BCT, Lakewood, CO, USA) and the COM.TEC (Fresenius Kabi, Bad Homburg, Germany) device. In twelve donors, apheresis was additionally performed with the Amicus (Fenwal Inc., Lake Zurich, IL, USA). Donor response to leukapheresis and product composition was compared. RESULTS: Mean yields of CD14+ (CD3+) cells were 1·64±0·70x10(9) (2·36±0·96×10(9)) in the Spectra Optia, 1·45±0·50×10(9) (3·03±1·04×10(9)) in the COM.TEC and 1·20±0·37×10(9) (2·80±1·00×10(9)) in the Amicus products, respectively. The Spectra Optia collected significantly more CD14+ monocytes than the Amicus and significantly less CD3+ T cells than the COM.TEC (P=0·002 and P=0·021). Apheresis products of the Spectra Optia showed the significantly lowest red blood cell yields while the Amicus generated products with the significantly lowest platelet contents. CONCLUSIONS: Leukaphereses with the three devices resulted in almost equal total MNC yields. MNC products of the Spectra Optia and the Amicus could be used in preference for the monocyte enrichment by the Elutra system and the leukapheresis procedures could be also favourably applied in patients with low platelet counts. The COM.TEC is more efficient in monocyte and T-cell collection with the disadvantage of high residual non-target cell content in the products.

Operating scheme and experience of executing internal comparisons of blood cell analysis in a clinical laboratory.

BACKGROUND: The aim of the study was to perform an internal comparison of blood cell analyses: white blood cell (WBC) and platelet (PLT) counts in a clinical laboratory. METHODS: Instrument comparison: Based on EP9-A2 of the Clinical Laboratory and Standard Institute (CLSI) and the statistics program of External Quality Assessment (EQA), we set 1/2CLIA'88 as our quality standard and used a Beckman coulter LH750 as the reference. We then compared this to another 4 blood analyzers: the Beckman Coulter Gen-S, ABX pentra 60, and the Sysmex XT2000i and XS-800i, including the Beckman Coulter Gen-S in manual mode. Personnel comparison: WBC and PLT counts were performed on five samples by 13 technicians at random. Two statistics programs were used to calculate the bias of each technician. The results were compared with the 1/2 CLIA'88 standard to evaluate staff performance. RESULTS: All instrument comparisons met our quality standards of WBC < 7.5% and PLT < 12.5%. However, five technicians did not achieve satisfactory results of the WBC count in the first assessment. The coefficient of variation (CV) among qualified staff assessing five samples ranged from 8.51% to 12.2%, but all exceeded the 1/2 CLIA'88 quality standard; however, the CVs of 2 samples among qualified staff were approximately 20%, but after strict training this variability reduced significantly to approximately 5%. CONCLUSIONS: Instrument comparisons demonstrated achievement of quality goals under rigorous calibration and quality control, but CVs were comparatively large. This improved following strict training, so a laboratory should emphasize the training and assessment of staff and evaluation of the actual situation when selecting a qualification program.

Laboratory workflow for optimizing leukocyte count and differential in synovial fluids on Sysmex XN-1000.

INTRODUCTION: Falsely elevated synovial white blood cell (WBC) counts using automated hematology analyzers have been reported particularly in the setting of joint arthroplasty. We evaluated the implementation of a laboratory workflow based on Sysmex XN-1000-automated cell counting and scattergram interpretation. METHODS: WBC and differential were measured for 76 synovial fluid samples (29 native joints and 47 with joint arthroplasties) with Sysmex XN-1000 and manual methods. All scattergrams were evaluated for possible incorrect WBC and/or differential according to our implemented workflow. A specific finding was the "banana-shape" scattergram, which indicates possible interferences. The European Bone & Joint Infection Society (EBJIS) criteria were applied to identify possible prosthetic joint infections (PJIs) in patients with joint arthroplasties. RESULTS: Correlation between automated and manual WBC counts, calculated for samples with WBC count <50 000/µL, was higher for native joints (r = 0.938) compared with patients known with arthroplasty (r = 0.906). Scattergrams classified as OK showed overall a higher correlation compared with scattergrams, which were interpreted as NOT OK. "Banana-shape" scattergrams (n = 19) showed falsely elevated automated WBC count, and the patterns were mainly seen in prosthesis patients (17/19 [89%]). Six of 47 (13%) patients with joint arthroplasties were reclassified from "confirmed" to "unlikely" PJI according to the EBJIS criteria. CONCLUSION: Our workflow based on scattergram interpretation resulted in accurate WBC counts in synovial fluid using automated/and or manual methods. It is important to identify the presence of "banana-shape" scattergrams to avoid overestimated automated WBC counts. Overall, automated synovial WBC count can be used, even for patients with arthroplasty, but after visual inspection of the scattergram to exclude possible interferences.

Performance comparison of two automated digital morphology analyzers for leukocyte differential in patients with malignant hematological diseases: Mindray MC-80 and Sysmex DI-60.

BACKGROUND: The MC-80 (Mindray, Shenzhen, China), a newly available artificial intelligence (AI)-based digital morphology analyzer, is the focus of this study. We aim to compare the leukocyte differential performance of the Mindray MC-80 with that of the Sysmex DI-60 and the gold standard, manual microscopy. METHODS: A total of 100 abnormal peripheral blood (PB) smears were compared across the MC-80, DI-60, and manual microscopy. Sensitivity, specificity, predictive value, and efficiency were calculated according to the Clinical and Laboratory Standards Institute (CLSI) EP12-A2 guidelines. Comparisons were made using Bland-Altman analysis and Passing-Bablok regression analysis. Additionally, within-run imprecision was evaluated using five samples, each with varying percentages of mature leukocytes and blasts, in accordance with CLSI EP05-A3 guidelines. RESULTS: The within-run coefficient of variation (%CV) of the MC-80 for most cell classes in the five samples was lower than that of the DI-60. Sensitivities for the MC-80 ranged from 98.2% for nucleated red blood cells (NRBC) to 28.6% for reactive lymphocytes. The DI-60's sensitivities varied between 100% for basophils and reactive lymphocytes, and 11.1% for metamyelocytes. Both analyzers demonstrated high specificity, negative predictive value, and efficiency, with over 90% for most cell classes. However, the DI-60 showed relatively lower specificity for lymphocytes (73.2%) and lower efficiency for blasts and lymphocytes (80.1% and 78.6%, respectively) compared with the MC-80. Bland-Altman analysis indicated that the absolute mean differences (%) ranged from 0.01 to 4.57 in MC-80 versus manual differential and 0.01 to 3.39 in DI-60 versus manual differential. After verification by technicians, both analyzers exhibited a very high correlation (r = 0.90-1.00) with the manual differential results in neutrophils, lymphocytes, and blasts. CONCLUSIONS: The Mindray MC-80 demonstrated good performance for leukocyte differential in PB smears, notably exhibiting higher sensitivity for blasts identification than the DI-60.

Indirect determination of pediatric blood count reference intervals.

BACKGROUND: Determination of pediatric reference intervals (RIs) for laboratory quantities, including hematological quantities, is complex. The measured quantities vary by age, and obtaining samples from healthy children is difficult. Many widely used RIs are derived from small sample numbers and are split into arbitrary discrete age intervals. Use of intra-laboratory RIs specific to the examined population and analytical device used is not yet fully established. Indirect methods address these issues by deriving RIs from clinical laboratory databases which contain large datasets of both healthy and pathological samples. METHODS: A refined indirect approach was used to create continuous age-dependent RIs for blood count quantities and sodium from birth to adulthood. The dataset for each quantity consisted of 60,000 individual samples from our clinical laboratory. Patient samples were separated according to age, and a density function of the proportion of healthy samples was estimated for each age group. The resulting RIs were merged to obtain continuous RIs from birth to adulthood. RESULTS: The obtained RIs were compared to RIs generated by identical laboratory instruments, and to population-specific RIs created using conventional methods. This comparison showed a high concordance of reference limits and their age-dependent dynamics. CONCLUSIONS: The indirect approach reported here is well-suited to create continuous, intra-laboratory RIs from clinical laboratory databases and showed that the RIs generated are comparable to those created using established methods. The procedure can be transferred to other laboratory quantities and can be used as an alternative method for RI determination where conventional approaches are limited.

Low accuracy of manual white blood cell count in amniotic fluid.

Intra-amniotic infection (IAI) is a common cause of pre-term labour. Manual WBC count on amniotic fluid (AF) has been suggested as a diagnostic test for IAI using a threshold of 50 cells/mm(3). However, no validation studies assessing the accuracy of this method have been performed. AF samples were selected for cell count analysis. WBCs were introduced to 47 AF samples. The results from two technologists' counts were compared with the calculated expected value for WBCs in these samples. Results showed that a comparison between the technologists' WBC count to the expected WBC count yielded R(2) coefficients of 0.62 and 0.78, indicating moderate accuracy. Percentage agreement between the technologists was 67%, indicating low reproducibility. It was concluded that there was moderate correlation between the manual and the expected WBC in the spiked AF samples. Clinicians should be aware of the inaccuracy and imprecision associated with this test when evaluating a patient for IAI.

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

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

Validation of the body fluid module on the new Sysmex XN-1000 for counting blood cells in cerebrospinal fluid and other body fluids.

BACKGROUND: We evaluated the body fluid (BF) module on the new Sysmex XN-1000 for counting blood cells. METHODS: One hundred and eighty-seven BF samples [73 cerebrospinal fluid (CSF), 48 continuous ambulatory peritoneal dialysis (CAPD), 46 ascites, and 20 pleural fluid] were used for method comparison between the XN-1000 and manual microscopy (Fuchs-Rosenthal chamber and stained cytospin slides) for counting red blood cells (RBCs) and white blood cells (WBCs) (differential). RESULTS: Good agreement was found for counting WBCs (y=1.06x+0.09, n=67, R2=0.96) and mononuclear cells (MNs) (y=1.04x-0.01, n=40, R2=0.93) in CSF. However, the XN-1000 systematically counted more polymorphonuclear cells (PMNs) (y=1.48x+0.18, n=40, R2=0.99) compared to manual microscopy. Excellent correlation for RBCs >1×109/L (y=0.99x+116.56, n=26, R2=0.99) in CSF was found. For other fluids (CAPD, ascites and pleural fluid) excellent agreement was found for counting WBCs (y=1.06x+0.26, n=109, R2=0.98), MNs (y=1.06x-0.41, n=93, R2=0.96), PMNs (y=1.06x+0.81, n=93, R2=0.98) and RBCs (y=1.04x+110.04, n=43, R2=0.98). By using BF XN-check, the lower limit of quantitation (LLoQ) for WBC was defined at 5×106/L. Linearity was excellent for both the WBCs (R2=0.99) and RBCs (R2=0.99) and carry-over never exceeded 0.05%. CONCLUSIONS: The BF module on the XN-1000 is a suitable tool for fast and accurate quantification of WBC (differential) and RBC counts in CSF and other BFs in a diagnostic setting.

[Reversed clinicopathological conference (R-CPC)--interpreting laboratory data in the same way as physical findings].

Routine laboratory data are discussed by time series analysis in reversed clinicopathological conferences (R-CPC) at Shinshu University School of Medicine. We can identify fine changes in the laboratory data and the importance of negative data (without any changes) using time series analysis. Routine laboratory tests can be performed repeatedly and relatively cheaply, and time series analysis can be performed. The examination process of routine laboratory data in the R-CPC is almost the same as the process of taking physical findings. Firstly, general findings are checked and then the state of each organ is examined. Although routine laboratory data are cheap, we can obtain much more information about a patient's state than from physical examinations. In this R-CPC, several specialists in the various fields of laboratory medicine discussed the routine laboratory data of a patient, and we tried to understand the detailed state of the patient. R-CPC is an educational method to examine laboratory data and we, reconfirmed the usefulness of R-CPC to elucidate the clinical state of the patient.

Comparison of neutrophil volume distribution width to C-reactive protein and procalcitonin as a proposed new marker of acute infection.

BACKGROUND: The aim of this study was to assess the use of neutrophil distribution width (NDW) and to compare it to C-reactive protein (CRP) and procalcitonin (PCT), in the detection of early sepsis in the intensive care unit. METHODS: Subjects (N = 166) were divided into 4 groups: healthy, acute inflammatory non-infectious (AINI), localized infection, and systemic infection, according to clinical history and cultures. NDW, CRP, and PCT were compared among the different groups using multivariate analysis of variance (MANOVA). Diagnostic efficacy was assessed using receiver operating characteristic curves and areas under the curves (AUC). RESULTS: The lowest mean(NDW) was found in the healthy group (n = 41), followed by the AINI (n = 20), localized infection (n = 55), and systemic infection (n = 50) groups. AUC(NDW) was 0.877 for infected (localized + systemic) vs non-infected (healthy + AINI) groups, and 0.965 for systemic infection vs non-infected groups. A cut-off of 21.9 resulted in 90% sensitivity, 92% specificity, 90% positive predictive value, and 92% negative predictive value (AUC(NDW) = 0.965, 95% confidence interval 0.935-0.995). According to MANOVA, only NDW was able to differentiate an acute inflammatory process from early infection in postoperative patients, but not healthy from AINI subjects. CONCLUSIONS: NDW had the highest diagnostic accuracy and is available with the complete blood count with differential (CBC). It may be a promising parameter to aid in the diagnosis of acute infection in adults, provided the possibility of haematological disorders is first ruled out.