Comparison of the performance of the IDEXX SediVue Dx® with manual microscopy for the detection of cells and 2 crystal types in canine and feline urine.

BACKGROUND: Microscopic evaluation of urine is inconsistently performed in veterinary clinics. The IDEXX SediVue Dx® Urine Sediment Analyzer (SediVue) recently was introduced for automated analysis of canine and feline urine and may facilitate performance of urinalyses in practice. OBJECTIVE: Compare the performance of the SediVue with manual microscopy for detecting clinically relevant numbers of cells and 2 crystal types. SAMPLES: Five-hundred thirty urine samples (82% canine, 18% feline). METHODS: For SediVue analysis (software versions [SW] 1.0.0.0 and 1.0.1.3), uncentrifuged urine was pipetted into a cartridge. Images were captured and processed using a convolutional neural network algorithm. For manual microscopy, urine was centrifuged to obtain sediment. To determine sensitivity and specificity of the SediVue compared with manual microscopy, thresholds were set at ≥5/high power field (hpf) for red blood cells (RBC) and white blood cells (WBC) and ≥1/hpf for squamous epithelial cells (sqEPI), non-squamous epithelial cells (nsEPI), struvite crystals (STR), and calcium oxalate dihydrate crystals (CaOx Di). RESULTS: The sensitivity of the SediVue (SW1.0.1.3) was 85%-90% for the detection of RBC, WBC, and STR; 75% for CaOx Di; 71% for nsEPI; and 33% for sqEPI. Specificity was 99% for sqEPI and CaOx Di; 87%-90% for RBC, WBC, and nsEPI; and 84% for STR. Compared to SW1.0.0.0, SW1.0.1.3 had increased sensitivity but decreased specificity. Performance was similar for canine versus feline and fresh versus stored urine samples. CONCLUSIONS AND CLINICAL IMPORTANCE: The SediVue exhibits good agreement with manual microscopy for the detection of most formed elements evaluated, but improvement is needed for epithelial cells.

Validation of Sysmex XT-2000iV analyzer-generated quantitative bone marrow differential counts in cynomolgus monkeys, Beagle dogs, and CD-1 mice.

BACKGROUND: In a previous study, the validation of rat bone marrow (BM) collection, processing, and analysis using the Sysmex XT-2000iV (Sysmex Corporation, Kobe, Japan) hematology analyzer showed that the Sysmex hematology analyzer produced BM differential counts that were comparable to those obtained with microscopic differential counts. OBJECTIVE: This study was conducted to expand the validation of the Sysmex TNCC (total nucleated cell count) and 5-part BM differential in cynomolgus monkeys, Beagle dogs, and CD-1 mice, which are alternate species that are also frequently used in preclinical safety studies. METHODS: The Sysmex 5-part BM differential counts were generated with a two-step process, whereby proliferating and maturing erythroid and myeloid cells were determined by preset gating and lymphocytes were determined using species-specific B- and T-lymphocyte antibodies and a magnetic cell-sorting method (MACS). Agreement with microscopic myelograms with 500-cell differential counts was determined from BM suspensions of 62 cynomolgus monkeys, 47 Beagle dogs, and 44 CD-1 mice. RESULTS: The correlation coefficients between methods for myeloid to erythroid (M:E) ratios in all three species was > 0.928. The Bland-Altman differences between methods were approximately ± 0.3 units for the M:E ratio in dogs and mice, and +0.6 and -0.4 in monkeys. The upper limits of agreement for all three species were ≤7% for maturing myeloid cells, ≤6% for maturing erythroid cells, and ≤4% for proliferating myeloid cells, proliferating erythroid cells, and lymphocytes. CONCLUSIONS: The Sysmex XT-2000iV produces an automated M:E ratio and a 5-part differential count equivalent to microscopic differential counts in cynomolgus monkeys, Beagle dogs, and CD-1 mice.

Comparison of Enterprise Point-of-Care and Nova Biomedical Critical Care Xpress analyzers for determination of arterial pH, blood gas, and electrolyte values in canine and equine blood.

BACKGROUND: Point-of-care analyzers can provide a rapid turnaround time for critical blood test results. Agreement between the Enterprise Point-of-Care (EPOC) and bench-top laboratory analyzers is important to determine the clinical reliability of the EPOC. OBJECTIVES: The aim of the study was (1) to evaluate the precision (repeatability) of blood gas values measured by the EPOC and (2) to determine the level of agreement between the EPOC and Nova Critical Care Express (Nova CCX) for the assessment of arterial pH, blood gases, and electrolyte variables in canine and equine blood. METHODS: Arterial blood samples from dogs were analyzed on the EPOC and Nova CCX analyzers to determine precision and agreement of pH, PaCO2 , PaO2 , and HCT. The same analytes plus Na+ , K- , and Cl- were analyzed for agreement using equine blood. Statistical analyses included assessment of precision using the coefficient of variation (CV%), and agreement using the Deming regression, Pearson correlation, and Bland-Altman plots. RESULTS: Both analyzers provided precise results of pH, PaCO2 , PaO2, and HCT, meeting CV% quality requirement values. In both species, Deming regression results were acceptable and correlation values were above 0.93 for arterial pH and blood gases, but lower for sodium and chloride. Bland-Altman plots demonstrated varying degrees of bias, but good agreement between the 2 analyzers was seen when arterial blood gases and electrolytes were measured, except for PaCO2 and Cl-. CONCLUSION: The EPOC analyzer provides consistent, reliable results for canine arterial blood gas values and for equine arterial blood gas and electrolyte values. Cl- results could be acceptable with the application of a correction factor, but the PaCO2 results were more variable.

Evaluation of the delta neutrophil index from an automated blood cell analyser in septic dogs.

Immature granulocytes (IG) are a marker of severe inflammatory states in human beings and animals, and have been linked to a diagnosis of sepsis and poor prognosis. The delta neutrophil index (DNI), automatically calculated by a haematological analyser, provides an estimate of circulating IG. In particular, an increased DNI value has been associated with the severity of sepsis, and mortality, in critically ill human beings. The aims of this study were to determine the DNI reference interval (RI) in healthy dogs, and to evaluate its diagnostic and prognostic significance in dogs with sepsis. A total of 118 dogs with sepsis undergoing a complete blood cell count (CBC) at the time of hospital admission were included retrospectively. Dogs with sepsis were compared to 20 dogs with primary immune-mediated haemolytic anaemia (IMHA) and 99 healthy controls. The DNI RI was set from 0 to 9.2%. The DNI was significantly higher in dogs with sepsis compared to dogs with IMHA and healthy dogs (P<0.001), and significantly higher in dogs with septic shock compared to septic dogs without circulatory failure (P<0.03). No differences were detected between survivors (78/118) and non-survivors (40/118). Septic dogs with a DNI above the RI had significantly higher frequencies of IG and toxic neutrophil changes on manual blood smear evaluation (P=0.03 and P<0.001, respectively). The DNI had a fair performance in identifying dogs with sepsis in this population and predicted septic shock. Larger prospective studies are needed to validate DNI measurement in dogs and to test its clinical utility.

Evaluation of mouse red blood cell and platelet counting with an automated hematology analyzer.

An evaluation of mouse red blood cell (RBC) and platelet (PLT) counting with an automated hematology analyzer was performed with three strains of mice, C57BL/6 (B6), BALB/c (BALB) and DBA/2 (D2). There were no significant differences in RBC and PLT counts between manual and automated optical methods in any of the samples, except for D2 mice. For D2, RBC counts obtained using the manual method were significantly lower than those obtained using the automated optical method (P<0.05), and PLT counts obtained using the manual method were higher than those obtained using the automated optical method (P<0.05). An automated hematology analyzer can be used for RBC and PLT counting; however, an appropriate method should be selected when D2 mice samples are used.

Evaluating Atlantic bottlenose dolphin (Tursiops truncatus) leukocyte differential counts comparing the CellaVision DM96 and the manual method.

BACKGROUND: The leukocyte differential count is an excellent diagnostic tool; however, the manual differential count has several drawbacks, especially for nontraditional species. Automated cell analyzers commonly used in veterinary practices require species-specific validation for use in nondomestic species other than dogs and cats. OBJECTIVES: The purpose of this study was to examine the potential of the CellaVision DM96 (DM96), an automated image analysis system, as a rapid and accurate method for providing a WBC differential count in comparison to the manual WBC differential count in bottlenose dolphins. METHODS: Ten fresh, EDTA anticoagulated blood samples were collected, blood smears were made and stained, and the differential WBC counts were performed on the DM96 and compared with manual differential WBC counts. Agreement, means, and errors were compared between the methods. RESULTS: There was good agreement between the DM96 and manual differential WBC counts for neutrophils; however, there was significant variation when comparing lymphocyte, monocyte, and eosinophil counts. No basophils were seen by any method. CONCLUSIONS: Despite a small sample size, the DM96 appeared to provide a viable alternative for automated neutrophil counting in blood of bottlenose dolphins. Whether the counts are comparable in animals with highly pathologic differential counts must be addressed in follow-up studies, preferably with more study animals.

Detecting endotoxin activity in bovine serum using an automated testing system.

The aim of the present study was to compare the ability of the commercially available portable test system (PTS(TM)) to detect endotoxin activity in bovine serum, with that of the traditional LAL-kinetic turbidimetric (KT) and chromogenic (KC) assays. Prior to testing, serum samples, which were obtained from endotoxin-challenged cattle, were diluted 1:20 in endotoxin-free water and heated to 80°C for 10 min. The performance of the PTS(TM) was not significantly different from that of the traditional LAL-based assays. The results using PTS(TM) correlated with those using KT (r(2)=0.963, P<0.001) or KC assays (r(2)=0.982, P<0.001). Based on these findings, the PTS(TM) could be applied as a simplified system to assess endotoxin activity in bovine serum.

Validation of a commercially available automated canine-specific immunoturbidimetric method for measuring canine C-reactive protein.

BACKGROUND: Measurement of C-reactive protein (CRP) is used for diagnosing and monitoring systemic inflammatory disease in canine patients. An automated human immunoturbidimetric assay has been validated for measuring canine CRP, but cross-reactivity with canine CRP is unpredictable. OBJECTIVE: The purpose of the study was to validate a new automated canine-specific immunoturbidimetric CRP method (Gentian cCRP). METHODS: Studies of imprecision, accuracy, prozone effect, interference, limit of quantification, and stability under different storage conditions were performed. The new method was compared with a human CRP assay previously validated for canine CRP determination. Samples from 40 healthy dogs were analyzed to establish a reference interval. RESULTS: Total imprecision was < 2.4% for 4 tested serum pools analyzed twice daily over 10 days. The method was linear under dilution, and no prozone effect was detected at a concentration of 1200 mg/L. Recovery after spiking serum with purified canine CRP at 2 different concentrations was 123% and 116%, respectively. No interference from hemoglobin or triglycerides (10 g/L) was detected. CRP was stable for 14 days at 4°C and 22°C. In the method comparison study, there was good agreement between the validated human CRP assay and the new canine-specific assay. Healthy dogs had CRP concentrations that were less than the limit of quantification of the Gentian cCRP method (6.8 mg/L). CONCLUSIONS: The new canine-specific immunoturbidimetric CRP assay is a reliable and rapid method for measuring canine CRP, suitable for clinical use due to the option for an automated assay.

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

BACKGROUND: 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. OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

An automated turbidimetric method for fibrinogen determination in dogs.

BACKGROUND: Several methods have been used for fibrinogen determination in dogs, but to the authors' knowledge, methods based on ammonium sulfate precipitation have not yet been reported in this species. OBJECTIVES: The aim of this study was to develop and validate an automated method based on ammonium sulfate precipitation for canine fibrinogen determination. METHODS: A reagent containing ammonium sulfate, sodium chloride, and K2 EDTA was used to precipitate fibrinogen at a final ammonium sulfate concentration of 0.57 M and final turbidity was measured on a Cobas Mira Plus autoanalyzer. Analytic validation included imprecision, accuracy, comparison with reference method (Clauss), limits of detection and quantification, and the evaluation of the influence of different anticoagulants. For diagnostic validation, fibrinogen was determined in a group of Beagle dogs before and after neutering, and in dogs affected by diseases known to produce low fibrinogen plasma concentration, such as liver insufficiency, disseminated intravascular coagulation, and protein-losing enteropathy. RESULTS: Low imprecison (<4%), excellent recovery (>90%), and low bias (0.092 g/L) with respect to Clauss method indicated a high reproducibility and accuracy. Limits of detection and quantification were 0.01 and 0.22 g/L, respectively. The method was applicable in plasma samples anticoagulated with EDTA, heparin, or sodium citrate. The fibrinogen concentration in Beagle dogs after neutering was increased, and decreased in animals with disseminated intravascular coagulation, liver insufficiency, or gastrointestinal protein loss. CONCLUSIONS: The automated method validated in this study represents a rapid, cheap, and easy protocol to quantify canine fibrinogen in routine practice.

Measurement of thyroxine and cortisol in canine and feline blood samples using two immunoassay analysers.

OBJECTIVES: The AIA-360 (Tosoh Corporation) is an automated immunoassay analyser. The aims of this study were to estimate the precision of thyroxine and cortisol AIA-360 immunoassays in canine and feline samples and to compare the results produced with those obtained by a chemiluminescence analyser (Immulite® 1000, Siemens). METHODS: Blood samples from 240 clinical cases (60 dogs and 60 cats for both thyroxine and cortisol) were analysed using both instruments. RESULTS: Deming regression calculations showed excellent correlation (thyroxine, canine rs = 0 · 94, feline rs = 0 · 97; cortisol, canine rs = 0 · 97, feline rs = 0 · 97). Agreement between the two instruments was examined by Bland-Altman difference plots, which identified wide confidence intervals and outliers for thyroxine (canine n = 6, feline n = 4) and cortisol (canine n = 3, feline n = 4) results. Inter/intra-run precision of the AIA-360 was excellent for both cortisol and thyroxine (coefficients of variation <7%). CLINICAL SIGNIFICANCE: The instrument showed excellent correlation for cortisol and thyroxine in canine and feline samples demonstrating that the AIA-360 can be used in clinical practice. The agreement studies suggest that the results from the AIA-360 cannot be used interchangeably with those generated by the Immulite 1000 and should be interpreted using reference intervals that have been established specific to the AIA-360.

Automated and visual analysis of commercial urinary dipsticks in dogs, cats and cattle.

Two dipsticks developed for human use were evaluated for routine urinalysis and for detection of proteinuria in dogs (n=101), cats (n=50) and cattle (n=100). The aims were to determine their diagnostic usefulness in dogs, cats and cattle and to compare automated versus visual methods of reading. Results obtained with automated reading correlated better with reference methods than visual reading. Correlation with the reference methods was good to excellent for automated estimation of creatinine (dog: r(s)=0.86, cat: r(s)=0.83, cattle: r(s)=0.87) and pH (dog: r(s)=0.96, cat: r(s)=0.91, cattle: rs=0.94). The correlation was good for protein (dog: r(s)=0.88, cat: r(s)=0.91), glucose (cat: r(s)=0.83) and urine protein:creatinine (UPC) ratio (dog: r(s)=0.75, cat: r(s)=0.89). Estimation of proteinuria in cattle and pyuria in cats lacked specificity and detection of isosthenuria lacked sensitivity in all species. Semiquantitative estimation of UPC ratio was specific (100% and 91.2% at a cut-off of 0.2 in cats and 0.4 in dogs, respectively).

Effects of a urolith prevention diet on urine compositions of glycosaminoglycans, Tamm-Horsfall glycoprotein, and nephrocalcin in cats with calcium oxalate urolithiasis.

OBJECTIVE: To evaluate urine concentrations of glycosaminoglycans, Tamm-Horsfall glycoprotein, and nephrocalcin in cats fed a diet formulated to prevent calcium oxalate uroliths. ANIMALS: 10 cats with calcium oxalate urolithiasis. PROCEDURES: In a previous study conducted in accordance with a balanced crossover design, cats were sequentially fed 2 diets (the diet each cat was consuming prior to urolith detection and a diet formulated to prevent calcium oxalate uroliths). Each diet was fed for 8 weeks. At the end of each 8-week period, a 72-hour urine sample was collected. Concentrations of glycosaminoglycans, Tamm-Horsfall glycoprotein, and the 4 isoforms of nephrocalcin in urine samples collected during that previous study were measured in the study reported here. RESULTS; Diet had no effect on the quantity of Tamm-Horsfall glycoprotein and nephrocalcin in urine. However, the urine concentration of glycosaminoglycans was significantly higher during consumption of the urolith prevention diet. CONCLUSIONS AND CLINICAL RELEVANCE: Feeding a urolith prevention diet increased the urine concentration of glycosaminoglycans, which are glycoprotein inhibitors of growth and aggregation of calcium oxalate crystals.

Evaluation of the automated hematology analyzer Sysmex XT-2000iV ™ compared to the ADVIA ® 2120 for its use in dogs, cats, and horses. Part II: Accuracy of leukocyte differential and reticulocyte count, impact of anticoagulant and sample aging.

The automated laser-based hematology analyzer Sysmex XT-2000iV™ provides a 5-part differential count and specific cytograms that are of great interest for large veterinary laboratories. The aim of the study was to validate the Sysmex XT-2000iV compared to the laser-based hematology analyzer ADVIA® 2120 and manual differential in dogs, cats, and horses as well as the impact of anticoagulant (heparin, ethylenediamine tetra-acetic acid [EDTA], and citrate) and storage at 22°C and 4°C. Consecutive fresh K(3)-EDTA blood samples from 216 cats, 314 dogs, and 174 horses were included. The impact of anticoagulant and sample storage was assessed in specimens obtained from an additional 9 cats, 10 dogs, and 10 horses. Agreement between both analyzers was excellent to good except for monocytes and canine reticulocytes. Spearman rank correlation coefficients (r (s)) between Sysmex XT-2000iV and manual differential were good to fair and ranged from 0.91 (cat lymphocytes) to 0.44 (cat monocytes). Hematocrit value (Hct), mean corpuscular hemoglobin (MCH), MCH concentration (MCHC; all: P < 0.001), and mean corpuscular volume (MCV; P < 0.01) were higher in canine citrated blood compared to heparin and EDTA. In cats, lymphocytes and monocytes were lower in heparinized blood compared to EDTA (P < 0.05), whereas in horses no significant effect was seen. Regarding storage time and temperature, white and red blood cell counts, hemoglobin, and MCH were stable. Hct, MCV, and MCHC were influenced by erythrocyte swelling. Differential count remained stable for 24 hr (22°C) and nearly 72 hr (4°C) except for monocytes. The overall performance of the Sysmex XT-2000iV was excellent and compared favorably with that of the ADVIA 2120. A special strength was the excellent detection of feline eosinophils.

Evaluation of the Mythic 18 hematology analyzer for use with canine, feline, and equine samples.

The Mythic 18 is a fully automated hematology bench-top analyzer using impedance technology for a complete blood cell count (CBC) and a 3-part white blood cell count (WBC) differential. The purpose of the current study was to evaluate the Mythic for assessment of agreement, precision, linearity, carry-over, stability, and usability under practice conditions. Ethylenediamine tetra-acetic acid-blood samples from 122 dogs, 140 cats, and 123 horses were analyzed with the Mythic and reference methods (Sysmex XT-2000iV, manual hematocrit, and microscopic WBC differentiation). Pearson's coefficient of correlation, Passing-Bablok regression analysis, and Bland-Altman difference plots were performed to determine agreement. For precision, standard deviation and coefficients of variation were calculated. Linearity was determined according to Emancipator-Kroll. Red blood cell parameters showed excellent correlation and small biases, except for red cell distribution width and mean corpuscular hemoglobin concentration. Total WBC correlated excellently in canine and equine and very well in feline samples. In 23 feline specimens with platelet aggregates, the Mythic overestimated WBC. In all 3 species, absolute granulocyte counts correlated excellently. Equine lymphocyte counts showed good correlation whereas canine and feline lymphocyte counts correlated poorly. Feline platelets showed good correlation with a negative bias. The instrument showed good to excellent precision. The whole 3-part differential was found to be accurate in horses. In dogs and cats, absolute granulocyte counts were reliable. As with all impedance-based hematological instruments, evaluation of a blood smear is absolutely indicated to check for the presence of platelet aggregates, to verify WBC differentiation, and to identify possible abnormalities.

Stability of hematologic analytes in monkey, rabbit, rat, and mouse blood stored at 4°C in EDTA using the ADVIA 120 hematology analyzer.

BACKGROUND: The time from sampling to analysis can be delayed when blood samples are shipped to distant reference laboratories or when analysis cannot be readily performed. OBJECTIVE: The objective of this study was to evaluate the stability of hematologic analytes in blood samples from monkeys, rabbits, rats, and mice when samples were stored for up to 72 hours at 4°C. METHODS: Blood samples from 30 monkeys, 15 rabbits, 20 rats, and 30 mice were collected into EDTA-containing tubes and were initially analyzed within 1 hour of collection using the ADVIA 120 analyzer. The samples were then stored at 4°C and reanalyzed at 24, 48, and 72 hours after collection. RESULTS: Significant (P<.0003) changes in hematologic analytes and calculations included increased HCT and MCV and decreased MCHC and cell hemoglobin concentration mean (CHCM) at 72 hours and increased MPV at 24 hours in monkeys; increased MCV at 72 hours and MPV at 48 hours and decreased monocyte count at 24 hours in rabbits; increased MCV and decreased MCHC, CHCM, and monocyte count at 24 hours in rats; increased MCV, red cell distribution width, and MPV and decreased MCHC, CHCM, and monocyte count at 24 hours in mice. CONCLUSIONS: Although most of the changes in the hematologic analytes in blood from monkeys, rabbits, rats, and mice when samples were stored at 4°C were analytically acceptable and clinically negligible, the best practice in measuring hematologic analytes in these animals is timely processing of blood samples, preferably within 1 hour after collection.

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

BACKGROUND: Classification of leukemias requires specialized diagnostic techniques. Automated preliminary indicators of neoplastic cells in blood would expedite selection of appropriate tests. OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: Using a novel gating strategy the Sysmex XT-2000iV may be used effectively to screen canine blood for hematopoietic neoplasia.

Technical note: Analysis of total lipid and triacylglycerol content in small liver biopsy samples in cattle.

A procedure is described for analyzing total lipid (TL) and triacylglycerol (TAG) in 2 sequential steps using small amounts (<100 mg) of bovine liver tissue. The TL was measured gravimetrically and TAG was measured enzymatically in the TL extract, using an automated analyzer. For gravimetric TL determination in milligrams per gram of liver fresh weight (FW), TL was extracted from homogenized tissue samples with hexane:isopropanol (at 20 degrees C, 24 h, constant agitation). The routine method was modified by adding a second hexane extraction step to optimize lipid extraction. The dry lipid extract was dissolved in hexane and aliquoted according to TL content for TAG analysis. An extra incubation period of 16 h was included for complete hydrolysis of TAG, using microbial lipase and nonaethylene glycol monododecyl ether detergent, before TAG was measured enzymatically using commercial test kits. Triolein was used as an internal standard. Repeated TL analysis (n = 3) of liver specimens from 10 cows (range, 40 to 314 mg/g of FW) yielded a mean CV of 2.2%, whereas repeated TAG analysis (range, 4 to 260 mg/g of FW) yielded a mean intraday CV of 2.5% (n = 5) and a mean interday CV of 3.4% (n = 4). Intraday (n = 5) and interday (n = 4) CV for repeated TAG analysis in triolein standards were <1 and <3%, respectively. Recovery of TAG in triolein standards varied between 99 and 103%. In part 2 of the experiment, hepatic TL and TAG were measured in 150 German Holstein cows to verify the test method in a large sample size. For repeated hepatic TL (n = 3) and TAG (n = 5) determination, mean CV of <2.8 and <1.5%, respectively, were found. The proportion of TAG relative to TL increased linearly to a breakpoint of approximately 100 mg TL/g of FW, at which point it reached a plateau at approximately 68%, indicating an accumulation of other lipid fractions in hepatic tissue with hepatic TL above the breakpoint. Calculation of hepatic TAG from TL was reasonably accurate when a 2-slope linear broken-line model (r(2) = 0.98) was used. Above a TL of approximately 40 mg/g of FW, calculated TAG values deviated by only +/-15% from measured hepatic TAG.

Feline platelet counting with prostaglandin E1 on the Sysmex XT-2000iV.

BACKGROUND: The large size of many feline platelets and the high frequency of platelet aggregation often results in falsely low platelet counts in this species. A combination of optical platelet counting to detect even large platelets and the use of prostaglandin E1 (PGE1) to inhibit platelet clumping may increase the accuracy of feline platelet counting. OBJECTIVE: The objective of this study was to compare platelet counts in feline whole blood samples with and without the addition of PGE1 and using different analytical methods in a clinical setting. METHODS: Platelet counts were determined in 10 feline patients in a referral veterinary hospital using 2 sample types (EDTA, EDTA with PGE1) and 2 methods of analysis (optical counting [PLT-O] and impedance counting [PLT-I]) on the Sysmex XT 2000 iV analyzer. RESULTS: All PGE1-PLT-O samples had platelet counts of >200 x 10(9)/L. Mean platelet count using PGE1-PLT-O (410,256+/-178 x 10(9)/L) was significantly higher (P<.03) compared with PGE1-PLT-I (256+/-113 x 10(9)/L), EDTA-PLT-O (238+/-107 x 10(9)/L), and EDTA-PLT-I (142+/-84 x 10(9)/L) methods. Depending on the method, platelet counts in 2 to 7 of 10 cats were <200 x 10(9)/L when PGE1-PLT-O was not used. A slightly increased platelet count in response to treatment of a feline patient with thrombocytopenia would have been missed without use of PGE1-PLT-O. CONCLUSIONS: Using PLT-O analysis on EDTA samples containing PGE1 provides higher, and therefore likely more accurate, feline platelet counts in a clinical setting.