Sysmex XT-2000iV Hematology Analyzer Research Articles

Repeat patient testing-quality control compared to commercial quality control material for the Sysmex XT-2000iV hematology analyzer in a multi-site veterinary laboratory.

Quality control material (QCM) for hematology in veterinary laboratories is limited, and repeat patient testing quality control (RPT-QC) is an alternative method using excess matrix-specific samples. This study aimed to determine if median differences between RPT-QC analyses for each time interval for RBC, HGB, HCT, and WBC were the same, determine if unified RPT-QC limits can be applied to a network of veterinary laboratories, compare the performance of RPT-QC to commercial QCM for the reference analyzer and evaluate the experience over a 4 month period and design, improve and implement an automated spreadsheet for RPT-QC data management. The potential to unify individual analyzer RPT-QC limits for red blood cells (RBC), hematocrit (HCT), hemoglobin (HGB), and white blood cells (WBC) on multi-site Sysmex XT-2000-iV analyzers was explored by a difference of means test and confidence interval determination for the median difference for each network analyzer in comparison to the network reference analyzer. User experience of an automated RPT-QC data management Excel spreadsheet was collected by user feedback during monthly meetings. Numbers of out-of-control results and the root causes for these for RPT-QC were compared against those of a commercial QCM over a 4-month period. Differences between individual analyzer RPT-QC limits were too large to allow for unification of network limits. The automated spreadsheet successfully highlighted out-of-control events for RPT-QC. Trends or shifts were more frequent for commercial QCM based on observed performance and a 1-2.5 s QC rule than for RPT-QC. Following routine troubleshooting, RPT-QC out-of-control events were resolved with an alternative RPT-QC sample indicating random error associated with excessive deterioration. Use of an automated spreadsheet for recording RPT-QC, documentation and troubleshooting of out-of-control events, and collating monthly summary calculations were considered an asset in laboratory quality management. RPT-QC can be successfully implemented and integrated into a multi-site veterinary laboratory. Individual analyzer RPT-QC limit generation is recommended. The deterioration of commercial QCM caused shifts or trends in QC results, which initiated more repeat analyses and investigations than did RPT-QC.

Effect of prewarming EDTA blood samples to 37°C on platelet count measured by Sysmex XT-2000iV in dogs, cats, and horses.

Pseudothrombocytopenia secondary to platelet clumping is a common cause of preanalytic error for platelet counts in dogs, cats, and horses. In human beings, it is suggested that prewarming blood samples to 37°C prior to hematology analysis will reduce platelet clumping. The purpose of the study was to evaluate the effect of prewarming EDTA blood samples to 37°C on measured platelet counts and other hematologic variables. The EDTA blood samples from dogs, cats and horses submitted to the clinical pathology laboratory at the University of Cambridge were included. Complete blood cell counts performed using a Sysmex XT-2000iV hematology analyzer were done on samples at room temperature (approximately 22°C) and following warming of the samples to 37°C in a water bath. The Wilcoxon signed rank test was used to compare hematologic variables, including platelet count, before and after sample warming to 37°C. Data are presented as median (25(th) , 75(th) percentile) increase. Blood samples from 39 dogs, 19 cats, and 10 horses were included. Sample warming to 37°C resulted in a statistically significant increase in platelet counts in dogs (11 [-2, 30] ×10(9) /L), cats (36 [14, 84] ×10(9) /L), and horses (42 [31, 79] ×10(9) /L). Sample warming did not significantly affect other hematologic variables. Prewarming EDTA blood samples to 37°C prior to hematologic analysis increased platelet counts overall in canine, feline, and equine blood, but did not abrogate platelet clumping and pseudothrombocytopenia fully in some cases. Furthermore, true pseudothrombocytopenia was not confirmed in these animals.

Validation of Sysmex XT‐2000iV generated quantitative bone marrow differential counts in untreated Wistar rats

Preclinical drug trials frequently require assessment of bone marrow toxicity in animals to evaluate hematopoietic safety. Since the gold standard, cytologic evaluation, is time consuming and requires highly trained individuals, automated methods remain intriguing. The Sysmex XT-2000iV hematology analyzer allows user-developed customizable gating. This study was conducted to validate the gating of bone marrow cell populations in Sysmex cytograms from untreated rats. B- and T-lymphocytes and myeloid cells were experimentally depleted from Charles River Wistar Han IGS (CRL: WI [Han]) rat whole bone marrow suspension using a magnetic cell sorting (MACS) method. The positively and negatively selected populations were used to verify select gates within the Sysmex cytogram. Intra- and inter-animal precision, comparability between right and left femur, as well as agreement with microscopic myelograms based on 500 counted cells, were determined. Intra-sample precision and right-to-left femur comparability confirmed that gating was reproducible and stable. In 50 tested rats, myeloid to erythroid ratios (M:E) were 1.32 ± 0.33 in males and 1.38 ± 0.29 in females by Sysmex compared to 1.36 ± 0.32 in males and 1.42 ± 0.32 in females by microscopic evaluations. Bland-Altman differences between methods was ≤ ± 0.35 units for M:E, ≤ 5.4% for maturing myeloid cells, ≤ 3.4% for proliferating myeloid cells, ≤ 6.0% for maturing myeloid cells, ≤ 3.4% for proliferating myeloid cells, and ≤ 4.1% for lymphocytes. In untreated control Charles River Wistar Han IGS (CRL: WI [Han]) rats, the Sysmex XT-2000iV produced an automated M:E and 5-part differential count equivalent to microscopic differential counts.

Differences in hematologic variables in rats of the same strain but different origin

Wistar rats are frequently used in toxicologic studies; however, the impact of animal source on hematologic reference intervals (RI) is not known. The purpose of this study was to compare hematologic data of Wistar rats obtained from 2 breeders and to calculate preliminary RI for the Sysmex XT-2000iV hematology analyzer. Blood collected in EDTA from 75 10-13-week-old rats (male, n = 38; female, n = 37) from breeder 1 and 60 rats (male, n = 30; female, n = 30) from breeder 2 was analyzed using a Sysmex XT-2000iV hematology analyzer. Results were analyzed for differences using a t-test or Mann-Whitney U-test. Sex-specific 95% RI were calculated for rats from both breeders. Significant breeder-specific differences were found for WBC, RBC, platelet, lymphocyte, monocyte, eosinophil, and reticulocyte counts and MCV, MCH, MPV, and plateletcrit for both sexes, and for HCT and hemoglobin concentration for female rats. The greatest differences (P < .0001) between rats from breeders 1 and 2, respectively, were found for WBC (female: 2.2-5.9 × 10(9) /L vs 4.2-9.4 × 10(9) /L 38; male: 3.4-9.5 vs 6.4-14.4 × 10(9) /L), lymphocyte (female: 1.7-4.8 × 10(9) /L vs 3.4-8.2 × 10(9) /L; male: 2.6-7.8 vs 5.2-12.4 × 10(9) /L), and platelet (female: 591-836 × 10(9) /L vs 804-1282 × 10(9) /L; male: 573-998 × 10(9) /L vs 861-1247 × 10(9) /L) counts. Differences in hematologic RI between Wistar rats obtained from different breeders underscore the need to evaluate untreated control animals for comparison, rather than using historical RI, to detect compound-related effects in preclinical safety studies. Valid RI for control animals are needed and should be verified when using a new supplier to avoid misinterpretation of data. Low reference limits for some variables, such as WBC counts, in rats from one source may preclude their use in studies in which detection of leukopenia is required.

Reference intervals forGreyhounds andLurchers using theSysmexXT‐2000iVhematology analyzer

The need for breed-specific reference intervals (RIs) for Greyhounds has been identified. As Lurchers are a sighthound cross-breed, specific RIs may also be needed for these dogs. Hematologic RIs for Greyhounds and Lurchers using the Sysmex XT-2000iV hematology analyzer have not been established. The aims of this study were to establish RIs for Greyhounds using the Sysmex XT-2000iV, to investigate whether RIs for Greyhound and nonsighthound dogs could be transferred to Lurchers, and to establish new RIs for Lurchers if transference was not possible. Data were retrieved retrospectively from a database of blood donor dogs. Greyhound RIs were established using nonparametric methods based on a reference population of 179 dogs. For the RI transference study, 38 Lurchers were selected, following guidelines proposed by the Clinical and Laboratory Standards Institute. When transference was not appropriate, new RIs were generated using the robust method. Greyhound RIs for the Sysmex hematology analyzer reflected known differences in this breed with a tendency toward higher RBC mass and lower WBC and platelet counts. RIs for hemoglobin concentration, HCT, MCV, MCH, MCHC, and WBC, neutrophil, lymphocyte, monocyte, and platelet counts for Greyhounds were suitable for transference to Lurchers. For RBC and eosinophil counts, new RIs were established. Our study suggests that Lurchers share many hematologic characteristics with Greyhounds, but had higher reference limits for RBC and eosinophil counts.

Canine reference intervals for the Sysmex XT‐2000iV hematology analyzer

The laser-based Sysmex XT-2000iV hematology analyzer is increasingly used in veterinary clinical pathology laboratories, and instrument-specific reference intervals for dogs are not available. The purpose of this study was to establish canine hematologic reference intervals according to International Federation of Clinical Chemistry and Clinical and Laboratory Standards Institute guidelines using the Sysmex XT-2000iV hematology analyzer. Blood samples from 132 healthy purebred dogs from France, selected to represent the most prevalent canine breeds in France, were analyzed. Blood smears were scored for platelet (PLT) aggregates. Reference intervals were established using the nonparametric method. PLT and RBC counts obtained by impedance and optical methods were compared. Effects of sex and age on reference intervals were determined. The correlation between impedance (I) and optical (O) measurements of RBC and PLT counts was excellent (Pearson r=.99 and .98, respectively); however, there were significant differences between the 2 methods (Student's paired t-test, P<.0001). Differences between sexes were not significant except for HCT, PLT-I, and PLT-O. WBC, lymphocyte, and neutrophil counts decreased significantly with age (ANOVA, P<.05). Median eosinophil counts were higher in Brittany Spaniels (1.87 × 10(9) /L), Rottweilers (1.41 × 10(9) /L), and German Shepherd dogs (1.38 × 10(9) /L) than in the overall population (0.9 × 10(9) /L). PLT aggregates were responsible for lower PLT counts by the impedance, but not the optical, method. Reference intervals for hematologic analytes and indices were determined under controlled preanalytical and analytical conditions for a well-characterized population of dogs according to international recommendations.

What is your diagnosis? Discrepancy in platelet counts determined using a Sysmex XT-2000 iV hematology analyzer

What is your diagnosis? Discrepancy in platelet counts determined using a Sysmex XT-2000 iV hematology analyzer

Identification of neoplastic cells in blood using the Sysmex XT‐2000iV: a preliminary step in the diagnosis of canine leukemia

Classification of leukemias requires specialized diagnostic techniques. Automated preliminary indicators of neoplastic cells in blood would expedite selection of appropriate tests. The objective of this study was to assess the capacity of the Sysmex XT-2000iV hematology analyzer to identify neoplastic cells in canine blood samples. Blood samples (n=160) were grouped into 5 categories: acute leukemia (n=30), chronic leukemia (n=15), neoplasia without blood involvement (n=41), non-neoplastic reactive conditions (n=31), and healthy dogs (n=43). WBC counts, WBC flags, scattergrams, percentages of cells with high fluorescence intensity, and percentages of cells in the lysis-resistant region were evaluated alone or in combination to establish a "leukemic flag." Sensitivity, specificity, negative (LR-) and positive (LR+) likelihood ratios, and the number of false-negative (FN) and false-positive (FP) results were calculated, and receiver operating characteristic curves were designed for numerical values. Among single measurements and parameters, only the evaluation of scattergrams minimized FN and FP results (sensitivity 100%, specificity 94.8%, LR+ 19.17, and LR- 0.00), although their interpretation was subjective. The more objective approach based on the generation of a "leukemic flag" had a sensitivity of 100%, specificity of 87.0%, LR- of 0.00, and LR+ of 7.67. Using a novel gating strategy the Sysmex XT-2000iV may be used effectively to screen canine blood for hematopoietic neoplasia.

Comparison of flow cytometry with the Sysmex XT2000iV automated analyzer for the detection of reticulated platelets in dogs

Immature (reticulated) platelets (r-PLT) are not routinely assessed by hematology analyzers, but may be useful in the evaluation of the bone marrow response to thrombocytopenia. The aim of this study was to compare the Sysmex XT2000iV hematology analyzer with standard flow cytometry for the determination of r-PLT percentage in dogs. Blood samples were obtained from 40 healthy dogs, 12 thrombocytopenic dogs, and 6 dogs with normal platelet counts but with disorders associated with increased thrombopoiesis. The percentage of r-PLT was determined with a FACscan flow cytometer (r-PLT[F]) using CD61-phycoerythrin antibody and thiazole orange, and with the PLT-O channel of the Sysmex analyzer (r-PLT[S]). Mean platelet volume, platelet distribution width, and platelet large cell ratio were also determined on the Sysmex. Repeatability (intra-assay precision) and effect of storage were tested for the automated analyzer. The reference interval (mean+/-1.96 X SD) for r-PLT(F) was 1.91+/-1.29% (range 0.78-3.68%) and for r-PLT(S) was 0.56+/-0.82% (range 0.11-2.16%). For both flow cytometry and the Sysmex, the patient group had a significantly higher mean percentage of r-PLT compared with the control group (P<.0001, unpaired Student's t-tests). Fair correlation (r=0.71; Spearman's regression analysis) was found for r-PLT results between the 2 methods, and a negative proportional systematic bias of -6.26 was found for the Sysmex (Bland-Altman analysis). Based on receiver operating characteristic curves and a cut-off of > or =0.975%, a sensitivity of 94.7% and a specificity of 85.7% were obtained for detecting r-PLT on the Sysmex, using flow cytometry as the reference method. Blood samples stored at 4 degrees C and 25 degrees C had a significant increase in the percentage of r-PLT after 24 and 48 hours, respectively. The PLT-O channel of the Sysmex XT2000iV is capable of detecting immature platelets in healthy, thrombocytopenic, and non-thrombocytopenic ill dogs.