Background
Prostaglandin E1 (PGE1) and Iloprost inhibit platelet aggregation and should prevent or minimize preanalytic error with feline platelet enumeration.
Objectives
The objective was to compare ...the relative effectiveness in reducing errors in platelet enumeration by adding Iloprost to feline EDTA blood specimens in comparison to adding PGE1 or EDTA alone. In addition, a grading system for platelet aggregation in blood smears was evaluated for effectiveness in predicting prominent errors and compared to ADVIA's PLT‐CLM flag. Finally, the use of plateletcrit in feline blood with platelet aggregation was evaluated.
Methods
Blood specimens from 35 cats were included. Blood was collected into EDTA tubes with or without Iloprost or PGE1, and was rapidly mixed. Platelet count (PLT), plateletcrit (PCT), mean platelet volume (MPV), and platelet flags were determined with an ADVIA 2120. Manual PLT was performed with a Leucoplate stain. PLT was determined by an IDEXX VetAutoread hematology analyzer (QBC).
Results
Neither addition of Iloprost nor PGE1 to EDTA blood specimens completely prevented platelet aggregation. Iloprost‐treated specimens had the least severe aggregation. PGE1 was better than EDTA alone. Significant errors in PLT results were consistently identified by the grading system. ADVIA's PLT‐CL flag usually predicted significant errors in PLT. QBC PLT results showed high imprecision. Manual PLT error was smaller than ADVIA PLT in EDTA specimens with aggregation.
Conclusions
Adding Iloprost to feline blood specimens improved platelet enumeration accuracy. A grading system for severity of platelet aggregation and usually the ADVIA's PLT‐CL alarm predicted specimens with significant errors in platelet enumeration.
Background: For differential leukocyte counts, automated blood smear evaluation systems have been too slow or inaccurate to replace or supplement the manual differential count. The CellaVision ...DM96Vision (DM96V), a new instrument, is an automated image analysis system that is rapid and accurate enough to be used for enumerating human leukocytes and may be useful for analysis of canine blood.
Objectives: The aims of this study were to evaluate the performance of the DM96V in differential counting of canine leukocytes, to compare its performance with that of other methods, and to analyze interoperator variability.
Methods: Four methods of determining the leukocyte differential count of 108 canine blood samples were compared based on agreement, precision, and errors as well as relative performance. Differential counts were obtained using the DM96V, the manual method, and automated methods performed by the Advia 2120 and Sysmex XT‐2000iV.
Results: All leukocyte types were detected by the DM96V and the manual method, and all 4 methods had similar mean and median results in most cases. The automated methods were more precise than either the DM96V or manual method when comparing identification of a single type of leukocyte, especially neutrophils and lymphocytes. However, precision of the automated methods was only fair for monocytes, and the Advia and Sysmex failed to identify basophils. The Advia reported fewer monocytes and eosinophils than did the other methods. Significantly fewer lymphocytes were identified by the manual method than by the Sysmex, Advia, and DM96V. The DM96V occasionally presented duplicate images of the same neutrophils.
Conclusions: The CellaVision DM96V is a satisfactory system for facilitating canine differential leukocyte counting. The DM96V differential count was more similar to the manual count than to automated counts, which were more precise but had errors and omissions in detecting some types of leukocytes.
A manual method (Thrombo-TIC; Bioanalytic GmbH, Umkirch/Freiburg, Germany) was advertised to disaggregate platelet clumps and to make human platelets spherical to improve platelet enumeration. The ...current study’s hypothesis was that this method would perform better than current methods for feline blood anticoagulated with ethylenediamine tetra-acetic acid (EDTA), which often contains platelet aggregates. Platelet concentrations (PLTs) were determined in 21 feline blood samples by 3 methods. Thrombo-TIC was compared to the manual method (Leucoplate; Sobioda, Montbonnot-Saint-Martin, France) currently used in the authors’ laboratory along with an ADVIA 2120 (Siemens AG, Eschborn, Germany) optical platelet concentration. Feline blood samples often contained platelet aggregates. ADVIA flagged for platelet aggregates in 11 of the 21 feline blood samples, and examination of blood smear revealed platelet aggregates in 14 of the 21 samples. The hemocytometers displayed more platelet aggregates with the Thrombo-TIC method than with Leucoplate. The method giving the greatest PLT was considered most accurate. The Leucoplate median PLT (238 × 109/1) was greater than Thrombo-TIC (202 × 109/1) or ADVIA (157 × 109/1). Intra-assay precision was determined for the 3 methods using the 21 feline blood samples. Median Thrombo-TIC and Leucoplate precision (7.4% and 7.3% coefficient of variation CV, respectively) were similar and not much worse than ADVIA (5.9% CV). The Thrombo-TIC method did not appear to perform better than the current manual method (Leucoplate). Leucoplate appeared least affected by platelet aggregation in feline blood. The ADVIA automated PLT appeared to be most negatively affected by platelet aggregation. The Thrombo-TIC method did not appear to prevent platelet aggregation in feline EDTA blood samples and, thus, is not recommended for such use.
Background
Determination of the plateletcrit (PCT) is the most effective way to evaluate platelet mass in dogs, such as Cavalier King Charles spaniel (CKCS) dogs, with macrothrombocytopenia. The ...IDEXX VetAutoread hematology analyzer, which performs quantitative buffy coat (QBC) analysis, has been validated to determine platelet mass in CKCS dogs. The Advia 2120 reports a PCT, but the validity of this value has not been evaluated for dogs with macrothrombocytopenia.
Objectives
The goal of this study was to validate MPV and PCT determined by the Advia 2120 in dogs, including CKCS dogs, comparing values with those obtained from QBC analysis.
Methods
Advia PCT was compared with QBC results from 43 CKCS dogs and 15 dogs of other breeds in one study. Advia PCT, platelet count, and MPV were evaluated to identify biologic patterns in 31 clinically healthy CKCS dogs and 66 dogs of 3 other breeds and to generate values used for comparisons.
Results
Advia PCT agreed well with QBC results in general, but had a negative bias and appeared to underestimate PCT in CKCS dogs with the lowest PCTs. Advia PCT and MPV results followed expected biologic patterns in CKCS dogs and dogs of other breeds with MPVs being highest in dogs with the lowest platelet counts.
Conclusions
Advia 2120 PCT and MPV satisfactorily identified changes in platelet mass and size in CKCS dogs, but PCTs were lower than expected, especially in CKCS dogs with the lowest PCTs, when compared with QBC results.
Background
Determination of the plateletcrit (
PCT
) is the most effective way to evaluate platelet mass in dogs, such as Cavalier King Charles spaniel (
CKCS
) dogs, with macrothrombocytopenia. The
...IDEXX
VetAutoread hematology analyzer, which performs quantitative buffy coat (
QBC
) analysis, has been validated to determine platelet mass in
CKCS
dogs. The Advia 2120 reports a
PCT
, but the validity of this value has not been evaluated for dogs with macrothrombocytopenia.
Objectives
The goal of this study was to validate
MPV
and
PCT
determined by the Advia 2120 in dogs, including
CKCS
dogs, comparing values with those obtained from
QBC
analysis.
Methods
Advia
PCT
was compared with
QBC
results from 43
CKCS
dogs and 15 dogs of other breeds in one study. Advia
PCT
, platelet count, and
MPV
were evaluated to identify biologic patterns in 31 clinically healthy
CKCS
dogs and 66 dogs of 3 other breeds and to generate values used for comparisons.
Results
Advia
PCT
agreed well with
QBC
results in general, but had a negative bias and appeared to underestimate
PCT
in
CKCS
dogs with the lowest
PCT
s. Advia
PCT
and
MPV
results followed expected biologic patterns in
CKCS
dogs and dogs of other breeds with
MPV
s being highest in dogs with the lowest platelet counts.
Conclusions
Advia 2120
PCT
and
MPV
satisfactorily identified changes in platelet mass and size in
CKCS
dogs, but
PCT
s were lower than expected, especially in
CKCS
dogs with the lowest
PCT
s, when compared with
QBC
results.
Background
Erroneous neutrophil and lymphocyte counts from analysis of feline blood samples were transferred directly into the hospital information system from the ProCyte Dx hematology instrument in ...our after‐hours laboratory. Errors usually were not detected by the users.
Hypothesis/Objectives
To quantify the frequency and severity of errors associated with the ProCyte Dx analyzer and to identify methods to avoid the errors.
Animals
One‐hundred six EDTA blood samples routinely submitted from feline hospital patients were analyzed.
Methods
ProCyte differential leukocyte counts were compared to 2 reference methods: Advia 2120 hematology instrument and manual enumeration. Limits for unacceptable deviation from the reference methods were defined as 18 for % lymphocytes and 23 for % neutrophils.
Results
Fourteen of 106 samples had unacceptable errors for both lymphocytes and neutrophils compared to both reference methods. Median % lymphocytes in those 14 samples were 11.2, 15.0, and 53.0% for Advia, manual, and ProCyte, respectively. Median % neutrophils were 85.4, 81.5, and 34.2% for Advia, manual, and ProCyte, respectively. All errors were avoided by rejecting automated ProCyte differential leukocyte results whenever the dot plot appeared clearly incorrect, but only 9 of these 14 samples had a ProCyte WBC distribution error flag.
Conclusions and Clinical Importance
Results reported by ProCyte had markedly falsely increased lymphocyte and decreased neutrophil counts in 13% of feline patient samples. Users must reject automated differential leukocyte count results when the WBC dot plot appears overtly incorrect. Rejection based only on ProCyte WBC error flag was insufficient.
Objectives
A common and severe error in identifying neutrophils in feline blood samples by the IDEXX ProCyte Dx haematology analyser (ProCyte) has been reported. The hypothesis was that the same or ...similar error would be identified during analysis of canine blood samples and that white blood cell dot plot evaluation would be critical to detect and avoid erroneous results.
Materials and Methods
Eighty‐six canine blood samples collected for clinical diagnosis of hospital patients were evaluated. Differential leukocyte counts were determined by the ProCyte Dx, ADVIA 2120 and manual methods. ProCyte neutrophil percentage results were considered unacceptable if the result was 15% different than percentage results from both ADVIA 2120 and manual counts. ProCyte WBC dot plots and instrument flags were evaluated for correctness.
Results
The ProCyte neutrophil counts were unacceptably lower than the ADVIA 2120 and manual neutrophil counts in 13 samples (15% of 86 samples). Neutrophils misclassified by the instrument were erroneously classified as monocytes and/or lymphocytes. All these samples were from patients with systemic inflammation. The error could be eliminated by rejecting results from samples with incorrect separation of cell clusters in the ProCyte WBC dot plots.
Clinical Significance
The ProCyte neutrophil count error with canine blood samples is common, severe and might affect clinical decisions. Operators of the instrument must evaluate white blood cell dot plots for correctness to avoid the error.
AIMS: To compare the performance of five refractometers for determination of urine specific gravity in cats and dogs, with reference to weight of total solids and pycnometer analysis. METHODS: Urine ...samples from 27 cats and 31 dogs submitted for routine urinalysis were included. Urine specific gravity was determined with five refractometers. Four were optical, hand-held refractometers with a temperature compensation method and one was a digital model. Urine was dried to determine the precise weight of total solids. The total solids (g/L) were converted to an estimated specific gravity by division with 2.33. Urine specific gravity of four feline and seven canine samples were analysed with a pycnometer. Limits of agreement analysis was used to evaluate the agreement between specific gravity (analysed as specific gravity minus 1) measured by the refractometers and estimated from dried total solids, or pycnometer results. RESULTS: The five refractometers reported clearly different results from each other. Proportional negative bias was noted for refractometer results compared to estimated specific gravity from total solids and a constant negative bias compared to pycnometer results. The two refractometers designed for cat urine reported similar and lowest specific gravity results with a mean negative bias of 0.007 and 0.008 units compared to estimated specific gravity from total solids, and a mean negative bias of 0.006 units compared to pycnometer results. CONCLUSIONS: Refractometer results did not increase consistently with increasing urine specific gravity compared to reference methods or to other refractometers. Two feline refractometers reported consistently lower specific gravity results than reference methods and other refractometers. CLINICAL RELEVANCE: Because of this imprecision, veterinarians should not use precise cut off values such as 1.030 or 1.035 for evaluation of renal concentrating ability in dogs and cats. Veterinarians should consider the variability of refractometric specific gravity results in their clinical assessment. Two feline refractometers appeared to report falsely low specific gravity results.
BACKGROUND: In the dog, the normal estrous cycle includes a prolonged luteal phase. Progesterone stimulates local canine mammary growth hormone (GH) production, which may act systemically and ...contribute to insulin resistance. Swedish Elkhounds are predisposed to progesterone‐related diabetes mellitus, and the relationship among insulin resistance, GH, and insulin‐like growth factor I (IGF‐I) is of particular interest. OBJECTIVE: To study insulin resistance in relation to GH and IGF‐I in nondiabetic Swedish Elkhounds during diestrus. We also assessed whether alterations in these hormones could predict diestrus‐linked diseases and all‐cause mortality. ANIMALS: Eighty‐four privately owned female intact Swedish Elkhounds >4 years of age. METHODS: Blood sampling and clinical examination during luteal phase, with a follow‐up questionnaire after 20 months. Insulin resistance was calculated by homeostasis model assessment (HOMA‐IR). RESULTS: In multivariable regression analysis, GH was positively associated with HOMA‐IR (P = .009). An increase in GH of 1 ng/mL was associated with a 12.7% increase in HOMA‐IR. Moreover, C‐peptide was positively associated with IGF‐I (P = .04), and an increase in C‐peptide of 0.1 ng/mL was associated with a 6.9% increase in IGF‐I. Structural equation modeling supported these results. Twenty‐three animals were found to have previously unrecognized mammary masses and had higher GH (P < .0001) and IGF‐I (P = .007) than dogs without mammary masses (n = 61). There was no association between high GH and IGF‐I concentrations at sampling and future mammary masses. CONCLUSION: We showed that GH was strongly associated with insulin resistance in older Swedish Elkhounds during diestrus.
Dogs can spontaneously develop complex systemic autoimmune disorders, with similarities to human autoimmune disease. Autoantibodies directed at self-antigens are a key feature of these autoimmune ...diseases. Here we report the identification of interleukin enhancer-binding factors 2 and 3 (ILF2 and ILF3) as autoantigens in canine immune-mediated rheumatic disease. The ILF2 autoantibodies were discovered in a small, selected canine cohort through the use of human protein arrays; a method not previously described in dogs. Subsequently, ILF3 autoantibodies were also identified in the same cohort. The results were validated with an independent method in a larger cohort of dogs. ILF2 and ILF3 autoantibodies were found exclusively, and at a high frequency, in dogs that showed a speckled pattern of antinuclear antibodies on immunofluorescence. ILF2 and ILF3 autoantibodies were also found at low frequency in human patients with SLE and Sjögren's syndrome. These autoantibodies have the potential to be used as diagnostic biomarkers for canine, and possibly also human, autoimmune disease.
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