Study on the accuracy of automated hematology analyzers in Shanghai

The objectives of this study were to research on the accuracy of automated hematology analyzers of various types from different manufacturers and to observe the deviation among these instruments. Fresh anticoagulated blood from healthy donors on 115 hematology analyzers in 114 different hospitals were determined. RESULTS: The maximum coefficients of variation (CVs. %) among instruments of three main manufacturers (Sysmex, Beckman Coulter and Abbott) of red blood cell count (RBC), hemoglobin (Hgb), hematocrit (Hct), white blood cell count (WBC) and platelet count (Plt) were 3.2%, 3.8%, 3.6%, 9.3% and 10.8%, respectively. The maximum deviations among these parameters of different instruments were 0.74%, 1.65%, 5.45%, 7.06% and 18.55%, respectively. By improving laboratory quality management, the results of hematology analyzer determination may be more reliable than manual methods. The difference among various manufacturers was very small about RBC, Hgb, Hct, WBC and Plt the results from all kinds of instruments will tend to be comparable.     

Evaluation of the ABX Cobas Vega automated hematology analyzer and comparison with the Coulter STKS

An evaluation of the new automated hematology analyzer was performed in comparison with the Coulter STKS on 1,694 blood samples coming from the different departments of Nice University Hospital. The Cobas Vega showed very satisfactory results in terms of repeatability, reproducibility and linearity. Correlation with the STKS was excellent with the exception of the following parameters: red blood cell distribution index and the absolute values for eosinophils and basophils. Two qualities were particularly appreciable: absence of leukocyte carryover, and stability of the complete blood count and leukocyte differential count over a long period. Analysis of qualitative flags showed that the overall blood smear review rate was 47% for the Cobas Vega, not forgetting that optical microscopy detects 37% of all abnormalities. The STKS’s review rate was 49.5%. Flags commonly concerned the granulocytic lineage, 61% for the STKS and 48% for the Vega, with a false positive rate of 43.4% for the STKS compared with 22% for the Vega. The opposite phenomenon was observed with the flag for atypical lymphocytes which represented 11% of flags for the STKS and 25.6% for the Vega, with a false positive rate of 25.5% for the STKS and 34% for the Cobas Vega. This may be explained by the fact that lymphocyte abnormalities sometimes generated “granulocytic” flags on the STKS. Studies of the false negative rate carried out using light microscopy on 505 blood samples without flags on either system, detected the presence of a slight myelemia, and a few hyperbasophilic lymphocytes or plasmocytes in 18.6% of all cases. Finally, the Cobas Vega’s practicality was greatly appreciated and there was no trouble with breakdowns throughout the whole period of its use.     

Evaluation of the leukocyte differential on a new automated flow cytometry hematology analyzer

Introduction: The Hematoflow (Beckman Coulter, USA) is a new automated hematology analyzer, which provides a 16-part white blood cell count (WBC) differential. Methods: We evaluated the differential WBC count performance of the Hematoflow. 101 blood samples from patients were selected for comparison analysis. Results: The methodological comparison of the WBC differential parameters of neutrophils, lymphocytes, monocytes and eosinophils showed good correlations among 4 different analyses. More than 1% of blast cells were counted in 30 of 101 samples. A good correlation for blast cell counts obtained by Hematoflow was found with the reference manual method (r=0.9637, P 0.0001). For blast B, Hematoflow shows good correlation with reference method results but did not identify blast T. Conclusions: These results demonstrate that the Hematoflow has a comparable performance with the Sysmex XE-2100 and indicate that B cell lineage ALL can be identified by the use of the Hematoflow in an initial evaluation of acute leukemia.     

Evaluation of bone marrow aspirates using the automated hematology analyzer Sysmex XN-3000

Introduction

This study evaluated the feasibility of the Sysmex XN-3000 automated hematology analyzer for the assessment of total nucleated cells (TNC) and bone marrow (BM) cell density in routine bone marrow aspiration (BMA) samples.

Methods

A total of 54 BMA samples from 39 hematological patients were evaluated. The number of megakaryocytes was calculated by a specific gating algorithm using the body fluid mode of the WBC differential (WDF) channel. Lipid contents were calculated through a newly developed algorithm utilizing the WDF channel. The ratio of lipid particles over TNCs by the WNR channel was compared with the BM cellularity assessed by the BM biopsy. The myeloid/erythroid (M/E) ratio was calculated by measuring the number of myeloid cells in the WDF channel and the number of nucleated red blood cells (NRBCs) in the WNR channel.

Results

XN-3000 counts and microscopic results showed a linear correlation in TNC (R² = .98, p < .001), megakaryocytes (R² = .59, p = .002), NRBC (R² = .84, p < .001), and M/E ratio (R² = .59, p < .001). There were significant differences in the lipid/TNC ratios of hypercellular, normocellular, and hypocellular BMs measured by XN-3000 (p < .001). Receiver-operating characteristic analysis detected cut-off values of the lipid/TNC ratio of >0.4054 for hypoplasia and <0.157 for hyperplasia. The sensitivity and specificity for hypoplasia were 100% and 88%, and for hyperplasia were 89% and 86%, respectively.

Conclusion

XN-3000 provides a quantitative assessment of BM cellularity, supporting the qualitative assessment by myelogram and BM biopsy.     

Evaluation of nitrogen analyzers.

Commercial N2 analyzers are in current use in tests for pulmonary closing volume. To determine whether differences between instruments might lead to inconsistencies in the measurement of closing volume, we compared the performances of 3 different N2 analyzers. The tests involved measurement of accuracy under constant and varying conditions, response to transient changes in N2 concentration, long-term stability, and an assessment of mechanical integrity. There were moderate differences in accuracy among the 3 instruments that can be essentially eliminated at N2 concentrations less than 40 per cent by changing the calibration procedure for one of the instruments. There were also moderate differences in instrument stability, dependence on environmental conditions, and mechanical quality.     

Normal hematological values of the african neonate

Summary A longitudinal study of normal hematological values of the newborn infant was undertaken in an effort to provide baseline data for assessing the African Neonate with hematological problems. There were 402 neonates, consisting of 304 full-term, 51 preterm and 47 post-term infants. The Hematocrit (Hct), Hemoglobin (Hb), Red Blood Cell Count (RBC), Reticulocyte count (Retic) and Nucleated Red Blood Cell Count (NRBC) were serially determined. The red cell indices, Mean corpuscular Hemoglobin (MCH), Mean Corpuscular volume (MCV) and Mean corpuscular Hemoglobin Concentration (MCHC) were calculated for each neonate. Our results showed that African neonates have lower hematological values than their North American and European counterparts. This was neither a reflection of an intrauterine anemia nor was it due to variables resulting from the timing of cord blood sampling. On the first day of life, the mean Hct was 45.4%; mean Hb was 15.46 gm/dl; and the RBC was 4.02×10⁶ cells/mm². The Retics, NRBC and other red blood cell indices do not differ from those of neonates reported from other parts of the world. We suggest therefore that the low hematological values of the African neonate may be intrinsic.     

Variation with age of reference values for P-cobalamins

P-cobalamins were recorded on plasma from 279 persons (age interval 20-80 years) who participated in a population survey. The values obtained showed a decrease in the mean and a broadening of the reference interval with age. The justification of employing one reference interval, 200-650 pmol/l, is discussed.     

Evaluation of hematological parameters in children with FMF

Clinical Rheumatology - In this study, we aimed to investigate whether neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), and mean platelet volume (MPV) might be helpful in the...     

Comparison of spirometric reference values

Lung-function reference values play a vital role in the management of respiratory disorders. There are many proposed reference equations for pediatric spirometry. Recently, spirometric reference equations were proposed, using data from people aged 8-80 years living in the US compiled by the third National Health and Nutrition Examination Survey. Our objective was to compare the predictive value of wider age-range reference equations to established pediatric reference equations for the pediatric population. Spirometry, height, and weight were obtained from 70 normal children aged 6-18 years. The difference between measured and predicted values as suggested by different reference equations was compared. Predicted values from general equations significantly differed from those generated from pediatric equations and from measured values in this population. The difference between measured and predicted values from the wider age-range equations varied between 7-16% for forced expired volume in 1 sec (FEV1) and forced vital capacity (FVC). The difference between measured and predicted values for the pediatric equations varied between 1-4%. Although wider age-range equations provide continuity through age ranges, their predictive accuracy may be low in the pediatric age group, especially for the youngest, smallest children. Extrapolating reference equations beyond the age range of subjects used to generate then is not recommended.