Spurious counts and spurious results on haematology analysers: a review. Part I: platelets

Performance evaluation of Rayto RT-7600Vet hematology analyzer in side-by-side comparison with manual hematological methods for apparently healthy Cholistani cattle blood

The present study is the first from Pakistan being reported with an objective to assess performance of Rayto RT-7600Vet hematology analyzer (HA) for Cholistani cattle blood (n = 134), in comparison to the manual hematological methods. The four hematological attributes viz. total erythrocyte count (TEC), hemoglobin (Hb), packed cell volume (PCV) and platelet count (PLT) were deduced through HA (A) and manual (M) methods. Various statistical tests were implied to ascertain level of interrelationship, accuracy and level of agreement between the two methods. All attributes attained through manual methods had high positive, leptokurtic distribution (having many outliers) except for PLT-M and PCV-M. The coefficient of variation for attributes attained through HA and manual methods ranged from 16-24% and from 16-59%, respectively. Comparison between the overall results revealed that all the studied attributes, except TEC, were significantly (P≤0.05) different for both methods. A weak relationship was noticed between the attributes attained through two methods as indicated by weak r-values and adjusted r-square values. The reliability level of estimating Hb and PCV had highest intraclass correlation coefficient value of 0.722 and 0.555 for average measures, respectively. However, accuracy level, as determined through Lin's concordance correlation coefficient was highest for TEC (0.9504) for both analytical methods. Poor level of agreement, in general, was shown for the two methods of analysis regarding all four hematological attributes through Bland and Altman test. In conclusion, the Rayto RT-7600Vet) may present data having higher skewness, kurtosis, and CV%, however, they are valid for multi-species hematological analysis. Caution must however, be taken in interpreting their results with corrected reference intervals and CV% for each machine and for each tested attribute.

Cryoglobulinemia concurrent with Leishmania infantum infection in a dog and its interference with two automated hematology analyzers

A 6-year-old, intact male English Bulldog presented for evaluation of weakness. Physical examination revealed mildly pale mucous membranes and ophthalmologic alterations. A complete blood cell count was performed on the Urit Smart V5 and the Sysmex XN-1000V, and showed several hematologic discrepancies between the analyzers. The Urit reported marked leukocytosis and thrombocytosis, and the Sysmex reported marked thrombocytosis on the impedance and optical RET channel but mild thrombocytopenia on the optical PLT-F channel. On the blood smear examination, there was an abundant proteinaceous material compatible with cryoglobulins. The red blood cell exhibited a notable degree of poikilocytosis. The number of leukocytes was found to be correlated with the Sysmex total white blood cell count, while the platelet count demonstrated a better correlation with the optical PLT-F channel from the Sysmex. Centrifugation of the blood in a capillary tube (at room temperature) identified a cryoglobulin precipitate. Additionally, the blood was reanalyzed soon after warming it to 37°C, which partially corrected most of the interferences. The serum protein electrophoresis demonstrated a marked hyperproteinemia with mild hypoalbuminemia and a marked hypergammaglobulinemia. On diagnostic imaging, a mild splenomegaly was noted. Cytology of the spleen showed Leishmania infantum infection, plasma cell hyperplasia, and extramedullary hematopoiesis. This is the first description of a dog infected with Leishmania. infantum with concurrent monoclonal hypergammaglobulinemia and cryoglobulinemia. We present a detailed description of the interference of cryoglobulin with the Urit Smart V5 and the Sysmex XN-1000V, along with the usefulness of Sysmex PLT-F in this condition.

Hematological reference intervals for Danish crossbred Landrace Yorkshire Duroc (LYD) pigs used in biomedical research

BACKGROUND

The health and welfare of pigs used in biomedical research is essential to research quality and compliance with the 3Rs (replacement, reduction, and refinement). Hematological variables are objective markers to quantitatively determine health issues and evaluate physiological differences before and after experimental procedures. There are no recent validated hematologic reference intervals (RIs) published for Danish crossbred Landrace Yorkshire Duroc (LYD) pigs to aid researchers and veterinarians in their decision-making. The objective of this study was to establish hematologic RIs for LYD pigs used for biomedical research. Blood samples were collected from healthy female LYD pigs (35-65 kg) and analyzed using the in-house ProCyte Dx Hematology Analyzer. Means with 90% confidence intervals for lower and upper limits were calculated according to guidelines by the American Society of Veterinary Clinical Pathology.

RESULTS

Inspection of 141 pigs led to 133 blood samples available for analyses after exclusions due to clinical signs of disease, inadequate tube filling or presence of macroscopic clots. Thirty-two samples reported platelet abnormalities and upon further investigation these samples were excluded when calculating RIs for platelets and platelet indices. Other measurements were not affected. The RI for red blood cells, hemoglobin, hematocrit and white blood cells were 5.10-7.00 × 106/µL, 9.36-12.29 g/dL, 30.46-40.47%, and 11.73-25.00 × 103/µL, respectively.

CONCLUSIONS

Our study provides RIs for hematological variables in LYD pigs, revealing significant differences from published RIs of other breeds. These findings highlight the influence of factors like age, breed and health status on measurements, emphasizing the importance of using breed-specific RIs. This research supports the 3Rs, guiding better animal care and enhancing overall research quality.

Influence of Anticoagulants on Platelet Counts: A Study and Recommendations From the French Speaking Cellular Hematology Group (GFHC)

INTRODUCTION

For complete blood count, ethylenediaminetetraacetic acid (EDTA) is universally used and has been recognized as the most robust anticoagulant. However, it may lead to pseudothrombocytopenia (PTCT), due to the formation of platelet clumps, which is currently followed by resampling on sodium citrate. Other possible anticoagulants are citrate theophylline adenosine dipyridamole (CTAD) and MgSO4. These anticoagulants were compared here for resolution of PTCT and platelet count values and stability.

METHODS

Paired blood samples were used to compare the four anticoagulants. First, samples containing clumps on EDTA were compared to samples collected on sodium citrate (335), CTAD (31), or MgSO4 (160). For platelet counts, compared series were of respectively, 168, 191, and 87, paired to PTCT-free EDTA samples. Finally, platelet count stability was evaluated over 2-24 h.

RESULTS

MgSO4, followed by CTAD, was the most efficient to avoid platelet clump formation, while sodium citrate performed poorly. Regarding platelet count, significantly lower values were obtained with sodium citrate (p < 0.0001), with more samples (35% vs. 6.5%) below the 150 × 109/L threshold. Conversely, CTAD yielded similar values as EDTA, while higher counts were observed with MgSO4 (p = 0.008). Finally, platelet count stability began to decrease at 4 h for sodium citrate, while the other anticoagulants were stable for at least 8 h, up to 12 h for MgSO4 and 24 h for EDTA.

CONCLUSIONS

This real-life study confirms that sodium citrate should no longer be used to improve platelet counts in patients with platelet clumps, CTAD, if available, and MgSO4 being much better alternatives.

Establishing reflex test rules for platelet fluorescent counting method using machine learning models on Sysmex XN-series hematology analyzer

INTRODUCTION

The platelet fluorescent counting (PLT-F) method is utilized as a reflex test method following the initial test of the platelet impedance counting (PLT-I) method in clinical practice on the Sysmex XN-series automated hematology analyzer. Our aim is to establish reflex test rules for the PLT-F method by combining multiple parameters provided by the "CBC + DIFF" mode of the Sysmex XN-series automated hematology analyzer.

METHODS

We tested 120 samples to evaluate the baseline bias between the PLT-F and PLT-I methods. Then, we selected 1256 samples to establish and test reflex test rules using seven machine learning models (decision Tree, random forest, neural network, logistic regression, k-nearest neighbor, support vector machine, and Naive Bayes). The training set and test set were divided at a ratio of 7:3. We evaluated the performance of machine learning models on the test set using various metrics to select the most valuable model.

RESULTS

The PLT-F method exhibited a high degree of correlation with the PLT-I method (r = 0.998). The random forest model emerged as the most valuable, boasting an accuracy of 0.893, an area under the curve of 0.954, an F1 score of 0.771, a recall of 0.719, a precision of 0.831, and a specificity of 0.950. The most important variable in the random forest model was mean cell volume, weighted at 15.09%.

CONCLUSION

The random forest model, which demonstrated high efficiency in our study, can be used to establish PLT reflex test rules based on the PLT-F method for the Sysmex XN-series automated hematology analyzer.

Integration of an MC-80 Digital Image Analyzer With an Automated BC-6800Plus Hematology Analyzer Enables Accurate Platelet Counting in Samples With EDTA-Induced Pseudothrombocytopenia

Background

EDTA-induced pseudothrombocytopenia (PTCP) during whole blood collection requires significant laboratory resources to obtain accurate results. We evaluated platelet-deaggregation function in EDTA-induced PTCP and platelet-clump flagging by the BC-6800Plus hematology analyzer using integrated digital image analysis.

Methods

We prospectively collected 132 whole blood samples suspected of platelet clumping (102 in EDTA and 30 in sodium citrate) from 88 individuals. We compared platelet counts determined using the platelet count by impedance (PLT-I) function of the DxH 900 hematology analyzer and the PLT-I or optical platelet count (PLT-O) function of the BC-6800Plus. Platelet clumping was verified through manual inspection and the MC-80 digital image analyzer.

Results

Among the 132 whole blood samples, 43 EDTA samples showed platelet clumping. The DxH 900 PLT-I and BC-6800Plus PLT-I results demonstrated a strong correlation (r=0.711) for the EDTA samples but only a moderate correlation with the BC-6800Plus PLT-O results (r=0.506 and 0.545, respectively). The BC-6800Plus PLT-O results were consistent with the sodium citrate platelet counts, with a median dissociation rate of 102.5% (range, 74.9%-123.1%). The DxH 900 and BC-6800Plus analyzers had sensitivity values of 0.79 and 0.72, respectively, for platelet-clump flagging. When integrating the MC-80 digital image analysis results, the sensitivity of BC-6800Plus improved to 0.89 (standard mode) or 1.0 (PLT-Pro mode).

Conclusions

BC-6800Plus PLT-O measurement results are close to the actual values obtained by platelet deaggregation with PTCP samples. Integrating the BC-6800Plus with a digital imaging analyzer effectively improved the diagnosis of PTCP and reduced the requirement for additional laboratory procedures.

Construction of platelet count-optical method reflex test rules using Micro-RBC#, Macro-RBC%, "PLT clumps?" flag, and "PLT abnormal histogram" flag on the Mindray BC-6800plus hematology analyzer in clinical practice

OBJECTIVES

Utilizing RBC or PLT-related parameters to establish rules for the PLT-O reflex test can assist laboratories in quickly identifying specimens with interfered PLT-I that require PLT-O retesting.

METHODS

Prospective PLT-I and PLT-O testing was performed on 6857 EDTA-anticoagulated whole blood samples, split randomly into training and validation cohorts at a 2:3 ratio. Reflex and non-reflex groups were distinguished based on the differences between PLT-I and PLT-O results. By comparing RBC and PLT parameter differences and flags in the training set, we pinpointed factors linked to PLT-O reflex testing. Utilizing Lasso regression, then refining through univariate and multivariate logistic regression, candidate parameters were selected. A predictive nomogram was constructed from these parameters and subsequently validated using the validation set. ROC curves were also plotted.

RESULTS

Significant differences were observed between the reflex and non-reflex groups for 19 parameters including RBC, MCV, MCH, MCHC, RDW-CV, RDW-SD, Micro-RBC#, Micro-RBC%, Macro-RBC#, Macro-RBC%, MPV, PCT, P-LCC, P-LCR, PLR,"PLT clumps?" flag, "PLT abnormal histogram" flag, "IDA Anemia?" flag, and "RBC abnormal histogram" flag. After further analysis, Micro-RBC#, Macro-RBC%,"PLT clumps?", and "PLT abnormal histogram" flag were identified as candidate parameters to develop a nomogram with an AUC of 0.636 (95 %CI: 0.622-0.650), sensitivity of 42.9 % (95 %CI: 37.8-48.1 %), and specificity of 90.5 % (95 %C1: 89.6-91.3 %).

CONCLUSIONS

The established rules may help laboratories improve efficiency and increase accuracy in determining platelet counts as a supplement to ICSH41 guidelines.

Vortexing specimens to disaggregate platelet clumps in EDTA specimens

OBJECTIVE

To compare platelet count results of specimens that yield platelet clump flags to platelet count results on these specimens after vortexing.

METHOD

Specimens that generated platelet count flags on Sysmex XN 3000 instruments were vortexed and rerun. Only data from specimens demonstrating elimination of platelet clump flags were used in this study. Pearson r analysis was performed on data.

RESULTS

Comparison of complete blood count results (white blood cell count, red blood cell count, hemoglobin, hematocrit, and platelet count) all yielded Pearson r scores >0.9.

CONCLUSION

Additional patient comfort and safety concerns, as well as concerns over additional specimen collection and processing costs, may be avoided by vortexing and rerunning specimens flagged for platelet clumps when the platelet count is normal.

Are monocyte-to-HDL and C-reactive protein-to-albumin ratios useful for the diagnosis and follow-up of Takayasu arteritis?

OBJECTIVE

In this study, we aimed to investigate the role of erythrocyte sedimentation rate, C-reactive protein, neutrophil/lymphocyte ratio, platelet/lymphocyte ratio, monocyte/lymphocyte ratio, red blood cell distribution width, mean platelet volume, monocyte/HDL ratio, and C-reactive protein/albumin ratio in the diagnosis and treatment follow-up of active and remission Takayasu arteritis patients compared with healthy control group.

METHODS

This is a retrospective case-control study in which 56 Takayasu arteritis patients and 40 age- and sex-matched healthy control were included. The blood values of Takayasu arteritis patients were analyzed during their active period and post-treatment remission periods, after comparing them with the healthy control. Furthermore, all parameters were evaluated by receiver operating characteristic analysis.

RESULTS

Erythrocyte sedimentation rate, C-reactive protein, neutrophil/lymphocyte ratio, platelet/lymphocyte ratio, monocyte/lymphocyte ratio, monocyte/HDL ratio, and C-reactive protein/albumin ratio values were significantly higher in active Takayasu arteritis patients compared with healthy control and remission Takayasu arteritis groups. In the receiver operating characteristic analysis performed in active Takayasu arteritis and Takayasu arteritis patients in remission, C-reactive protein had the highest power to indicate disease activity, followed by C-reactive protein/albumin ratio, erythrocyte sedimentation rate, and monocyte/HDL ratio. When Takayasu arteritis in remission was compared with the healthy control, a significant difference was found between erythrocyte sedimentation rate, C-reactive protein, red blood cell distribution width, and C-reactive protein/albumin ratio, while no significant difference was found between monocyte/HDL ratio values.

CONCLUSION

C-reactive protein/albumin ratio and red blood cell distribution width can be used in the diagnosis of Takayasu arteritis, and C-reactive protein/albumin ratio, red blood cell distribution width, and monocyte/HDL ratio measurements can be used in the follow-up. As C-reactive protein/albumin ratio is more powerful than C-reactive protein in differentiating the Takayasu arteritis group from the healthy control group, evaluation of C-reactive protein/albumin ratio together with albumin instead of evaluation of C-reactive protein alone when diagnosing the disease may help us to obtain more accurate results in daily practice.

Performance evaluation of a novel platelet count parameter, hybrid platelet count, on the BC-780 automated hematology analyzer

OBJECTIVES

Automated hematology analysis is expected to improve the performance of platelet counting. We evaluated the performance of a new platelet counting, hybrid (PLT-H) and also impedance (PLT-I) and optical (PLT-O) on the BC-780 automated hematology analyzer compared to the international reference method (IRM) in blood samples with thrombocytopenic and platelet interference.

METHODS

The basic platelet count performance of the BC-780 automated hematology analyzer was evaluated according to the requirements of the Clinical Laboratory and Standards Institute (CLSI) Document H26-A2. Additionally, the thrombocytopenic (low PLT count) blood samples and the platelet interference blood samples including fragmented red blood cells (RBCs), microcytes or small RBCs, and giant platelets were determined with the BC-780 hematology analyzer compared to the IRM.

RESULTS

Blank counting and the carry-over contamination rate of platelet count using the BC-780 both met the manufacturers' claim. For both 123 thrombocytopenic and 232 platelet interference blood samples (72 fragmented RBCs, 91 microcytes and 51 giant platelets), all three platelet counting methods exhibited high comparability with the IRM (the lowest correlation (r)=0.916). Interestingly, the comparability of PLT-H (r=0.928-0.986) with the IRM was better than that of PLT-I (r=0.916-0.979).

CONCLUSIONS

The performance of PLT-H in the BC-780 met the manufacturer's specifications. PLT-H exhibits better reproducibility than did PLT-I, correlates well with the PLT-O for thrombocytopenic samples and demonstrates good anti-interference ability. PLT-H counting is therefore recommended as a zero-cost alternative platelet counting method for platelet interference samples in clinical settings.

Performance evaluation of PLT-H (hybrid-channel platelet) under various interferences and application studies for platelet transfusion decisions

The hybrid-channel platelet counting method (PLT-H) is a new platelet counting technique proposed by Mindray of China. In this study, we aimed to evaluate the accuracy of this technique in various situations and its reliability in platelet transfusion decision-making. A total of 378 venous blood samples were tested. Using the immunological PLT counting method recommended by the International Council for Standardization in Hematology as the reference method (PLT-IRM), Passing-Bablok regression and Bland-Altman analysis were performed on the PLT-H results. The anti-interference performance of PLT-H under different interference levels was explored using intergroup comparisons, and confusion matrices were analyzed at various transfusion cutoff values. In the absence of interference, there was a strong correlation between PLT-H and PLT-IRM (r = 0.993, 95% CI: 0.990-0.996). Under various interference conditions, the correlation between PLT-H and PLT-IRM was between 0.963 and 0.992, with an average deviation of -14.56 to -2.02. The performance of PLT-H against interference did not change significantly with increasing levels of small RBCs, large PLTs, and RBC fragments (P = .5704, 0.0832, 0.9893). In low-value samples (PLT <100 × 109/L), the coefficient of variation (CV) for PLT-H was less than 7.6%, regardless of the presence or absence of interfering substances. In addition, there was a high agreement between PLT-H and PLT-IRM (ICC = 0.972). Confusion matrice analysis at each medical decision level showed similarity to methods using the fluorescence channel (PLT-O) and superiority to the impedance channel (PLT-I). Compared with PLT-I, PLT-H has higher accuracy in PLT counting, stronger anti-interference ability, better performance in low-value samples at no extra economic cost and can be more useful for platelet transfusion decision-making. PLT-H is a novel method for platelet counting that offers higher accuracy, providing physicians with the ability to make better medical decisions, particularly in cases where values are low, or interference is present. As it does not require additional reagents, it is highly likely to replace PLT-I and become the mainstream method for platelet counting in the future.

Frequency and Outcome of Pregnant Females Presenting With Thrombocytopenia at a Tertiary Care Hospital

BACKGROUND

Platelet-related problems are more frequently discovered in women during pregnancy because screening is carried out as part of the initial clinic examination using automated blood counts. This study was done to find out the frequency and outcomes of pregnant females presenting with thrombocytopenia at a tertiary care hospital.

METHODOLOGY

This cross-sectional study was conducted at the Department of Obstetrics and Gynecology, Jinnah Hospital, Lahore, Pakistan, from April 2023 to September 2023. This study involved 280 pregnant women presenting in the third trimester. Blood examination was acquired, and a platelet count less than 150x109/L was labeled as thrombocytopenia. Outcome variables were frequency of thrombocytopenia, while post-delivery, frequency of placental abruption, preterm delivery, stillbirth, need for blood transfusion, and poor Apgar score were noted and compared among women with and without thrombocytopenia.

RESULTS

In a total of 280 pregnant females, the mean age and gestational age at the time of presentation were 29.34±4.38 years and 31.30±2.87 weeks, respectively. The mean BMI of the females was 27.97±4.72 kg/m2. Thrombocytopenia was noted in 34 females (12.1%). Placental abruption, preterm delivery, need for blood transfusion, stillbirth, and poor Apgar score were observed in 1.4%, 4.3%, 8.2%, 1.1%, and 2.1% cases, respectively. Placental abruption (11.8% vs. 0.0%; p<0.001), preterm delivery (29.4% vs. 0.8%; p<0.001), need of blood transfusion (35.3% vs. 4.5%; p<0.001), stillbirth (8.8% vs. 0.0%; p<0.001), and poor Apgar score (17.6% vs. 0.0%; p<0.001) were all significantly higher among pregnant women with thrombocytopenia as compared to those with a normal platelet count.

CONCLUSION

The frequency of thrombocytopenia was 12.1% among pregnant females. The frequency of placental abruption, preterm delivery, need for blood transfusion, stillbirth, and poor Apgar score were all significantly higher among pregnant women with thrombocytopenia as compared to those with a normal platelet count, irrespective of the patient's age, parity, and BMI.

Can Pseudothrombocytopenia be recognised at first look?

Our aim was to determine the laboratory parameters that distinguish pseudothrombocytopenia from true thrombocytopenia. A total of 107 patients who were referred to the adult hematology outpatient clinic with thrombocytopenia and subsequently diagnosed with acute myeloid leukaemia, immune thrombocytopenia and pseudothrombocytopenia were included in our study. Hemogram parameters on admission, platelet value in the control hemogram and peripheral smear findings were recorded. Forty three (40.2%) males and 64 (59.8%) females, were included in our study. There were 25 patients in the leukaemia group, 39 in the immune thrombocytopenia group and 43 in the pseudothrombocytopenia group. Control platelet value and red cell distribution width/platelet ratio were found to be statistically significantly different between the 3 groups. Receiver operating characteristic analysis based on platelet values showed that platelet value ≤ 38,000/µL (86% sensitivity, 78.1% specificity, P < .001), difference between 2 consecutively measured platelet levels ≤ 11. 000/µL (79.1% sensitivity, 79.7% specificity, P < .001), red cell distribution width/platelet ratio ≥ 0.413 (90.7% sensitivity, 78.1% specificity, P < .001) were found to be in favor of true thrombocytopenia. In the differentiation of pseudothrombocytopenia and true thrombocytopenia, the difference between the hemogram parameters at the time of admission and the platelet count in the control blood count may be guiding. This result may reduce patient and physician anxiety and prevent patient referral.

Teaching clinical hematology and leukocyte differentiation in veterinary medicine using virtual patients

Due to contact restrictions imposed because of the COVID-19 pandemic, we created a novel digital course on the Moodle learning platform for winter term in 2020. In the clinical pathology course (CPC) with hematological content, third-year students were able to work independently on 10 extra digital cases of internal medicine involving eight different animal species as a compensation for the reduction in traditional microscopy exercises. Each case presented was initiated using an anamnesis, also the participants to generate a differential blood count based on digitized leukocytes, previously been photographed using a microscope camera. The cases were successive and increased in complexity, for example through the increase in the number of different cell types to be differentiated. The participants had the opportunity to evaluate the course through a final module to rate user-friendliness and acceptance. The total results of the participants in 2021 were analyzed descriptively, focusing on success rates, time spent on the tasks, and number of attempts. A total of 237 (= 96%) of 247 students completed all cases, each assessing 1033 photographed blood cells in sum. The mean processing time was 22.48 min for a differentiation and the students spent an average of 1.48 attempts on it. A voluntary feedback form was completed by 192 (= 78%) students, with more than 95% rating the course positively in 12 evaluation questions, and 29 of 33 comments (= 87.88%) providing positive statements in a comment box. Suggestions for improvement primarily included more explanations on erythrocyte morphologies, followed by adjusting the difficulty level and improving the presentational set-up. Slight improvements in results, time spent on processing the tasks, and the number of attempts indicated an achievement of routine and confidence during the course and were associated with an increase of competency. The positive feedback showed a high acceptance of the digital format and students evaluated the course as improving the quality of teaching when combined with practical exercises.

Stability over time of immature platelet fraction and comparison between EDTA and citrated whole blood samples

BACKGROUND

Immature platelets (IP) are the youngest circulating platelets, released from megakaryocytes, and demonstrating increased dimensions, significant RNA content, and enhanced activity. Immature platelet research focuses on a differential diagnostic help in patients with thrombocytopenia. The objectives of this study were to compare the variability of IP in citrate and EDTA samples, and to determine stability over time.

METHODS

Fifty-six patients were included for comparison between EDTA and citrate whole blood sample collection. Among the patients, 28 had thrombocytopenia (platelet count < 150G/L). Platelet measurement impedancemetry and fluorimetry were performed with Sysmex XN-9000. The immature platelet fraction (IPF) and absolute immature platelet count (A-IPC) were determined with a fluorescent method.

RESULTS

The mean value of platelet count with fluorescence was, in EDTA sample, 215 ± 171 and, in citrate sample, 153 ± 118 G/L. No significant difference was observed between IPF between EDTA and citrate (7.74 ± 6.68% vs. 8.45 ± 7.37%, p = 0.69), respectively. With the Bland-Altman analysis, the mean difference in the EDTA sample, between 1 and 24 h, was 8.06 ± 6.96% and 8.73 ± 7.12% for IPF, whereas in the citrate sample, between 1 and 6 h, it was 8.60 ± 7.29% and 7.54 ± 6.97%, for IPF. Comparing 1 h EDTA sample with 6 h citrate sample, the variance ratio was 0.974 (95% CI: 0.864-1.084) in IPF.

CONCLUSIONS

We confirmed the potential to conduct IP measurements up to 24 h in the EDTA sample and IPF measurements in the citrate sample for up to 6 h. These results may be useful for the use of IPF, which is a promising parameter whose interest in clinical practice and standardization is not yet well defined.

Pseudothrombocytopenia, beyond a laboratory phenomenon: study of 192 cases

The platelet antibodies that cause pseudothrombocytopenia (PTCP) act only in vitro and do not produce clinical bleeding. Most studies on PTCP have focused on improving differential diagnosis with true thrombocytopenia but studies on the characteristics of patients with PTCP are limited. In this study, we aimed to evaluate the clinical and biological characteristics of 192 patients with PTCP. In addition to general variables, we evaluated automated and microscopic platelet counts, platelet clumps, platelet diameters, immature platelet fraction (IPF), and platelet antibodies. Adult women accounted for the largest subgroup of patients (n=82; 42.7%) and 67 patients (34.9%) were grouped into families. Forty-four patients (22.9%) had one or more associated autoimmune disorders (ADs); 39 relatives of these patients (19.8%) had ADs and 45 relatives (23.4%) had immune thrombocytopenia (ITP) or unspecified thrombocytopenia. Platelet cryptantibodies and/or autoantibodies were positive in 56 patients (30.1%). Most patients (n=169; 80%) had automated platelet counts >80×10⁹/L. In all patients, microscopic platelet counts were ≥150×10⁹/L. The platelet clump index (% increase in microscopic platelet count compared to automatic count) ranged from 30 to >7000%. Platelet diameters and IPF parameters were significantly greater in the PTCP versus healthy controls (p<0.001). A total of 17 patients (8.8%) had had previous ITP or the PTCP evolved into ITP. Our data suggest that PTCP should be considered a situation of autoimmunity; the assessment of platelet clumps has a high diagnostic value; the close association between ITP and PTCP suggests that these conditions could be different phases of the same process.

Unreliable Automated Complete Blood Count Results: Causes, Recognition, and Resolution

Automated hematology analyzers generate accurate complete blood counts (CBC) results on nearly all specimens. However, every laboratory encounters, at times, some specimens that yield no or inaccurate result(s) for one or more CBC parameters even when the analyzer is functioning properly and the manufacturer’s instructions are followed to the letter. Inaccurate results, which may adversely affect patient care, are clinically unreliable and require the attention of laboratory professionals. Laboratory professionals must recognize unreliable results, determine the possible cause(s), and be acquainted with the ways to obtain reliable results on such specimens. We present a concise overview of the known causes of unreliable automated CBC results, ways to recognize them, and means commonly utilized to obtain reliable results. Some examples of unreliable automated CBC results are also illustrated. Pertinent analyzer-specific information can be found in the manufacturers’ operating manuals.

Alinity hq platelet count is not impacted by severe microcytosis

Background

Impedance technology has been shown to overestimate platelet (PLT) count in samples with microcytes, while the optical‐fluorescence PLT count (PLT‐F) by Sysmex has been suggested to be unaffected by microcytosis. The Abbott Alinity hq analyzer employs multi‐dimensional optical PLT counting. Our goal was to assess the accuracy of this technology in microcytic samples.

Methods

Platelet measurements were performed by Alinity hq and the impedance (PLT‐I) and PLT‐F methods on a Sysmex XN‐3000 analyzer on 464 samples. PLT concentration range was 6.56–947 × 10⁹/L and mean cell volume (MCV) 40.9–123.0 fL. Samples were categorized into normocytic (MCV > 80 fL), microcytic (MCV 65–80 fL), and severely microcytic (MCV < 65 fL) groups.

Results

Alinity hq PLT count showed excellent agreement with PLT‐F (r = 1.00). Sysmex PLT‐I data showed somewhat weaker correlation with both PLT‐F and Alinity hq (r = 0.98). Increasing bias between Sysmex PLT‐I and PLT‐F was seen with decreasing MCV values, with mean bias of 35.2 × 10⁹/L in severe microcytosis. An inverse relationship was demonstrated between the PLT‐I versus PLT‐F bias and MCV (p < 0.0001). Consistent mean bias was observed between Alinity hq and PLT‐F across all MCV ranges.

Mean platelet volume was suppressed or flagged by Sysmex XN in 50% of the samples in the severely microcytic group, and markedly higher red cell distribution width (RDW) was reported compared to Alinity hq (18.1% vs 13.7%, p < 0.0001).

Conclusion

The Sysmex PLT‐I method overestimated the PLT count in samples with severe microcytosis. Alinity hq provided PLT counts and PLT and RBC indices that were not impacted by microcytosis.

Improving the Quality of EDTA-treated Blood Specimens from Mice

Nonterminal blood sampling in laboratory mice is a very common procedure. With the goal of improving animal welfare, different sampling sites and methods have been compared but have not achieved a consensus. Moreover, most of these studies overlooked the quality of blood specimens collected. The main preanalytical concern with EDTA-treated blood specimens for hematology analyses is platelet aggregation, which is known to cause analytical errors. Our objective was to find a nonterminal blood sampling method with minimal adverse effects on mice and few or no platelet aggregates. We tested and compared 2 collection sites, 4 sampling methods, and 3 antithrombotic drugs in 80 C57BL6/j male and female mice by evaluating platelet aggregates on blood smears and platelet, WBC, and RBC counts. In addition, the blood collection process was carefully evaluated, and adverse effects were recorded. Platelet aggregation was lower in specimens collected from the jugular vein than from the facial vein, with no effect of the sampling device or the presence of an antithrombotic additive. Highly aggregated specimens were significantly associated with lower platelet counts, whereas aggregation had no effect on WBC or RBC counts. Adverse events during sampling were significantly associated with more numerous platelet aggregates. The jugular vein is thus a satisfactory sampling site in mice in terms of both animal welfare and low platelet aggregation. Using antithrombotic agents appears to be unnecessary, whereas improving sampling conditions remains a key requirement to ensure the quality of EDTA-treated blood specimens from mice.

Policies and practices in the field of laboratory hematology in Croatia - a current overview and call for improvement

OBJECTIVES

In 2019 The Croatian Working Group for Laboratory Hematology, on behalf of the Croatian Society of Medical Biochemistry and Laboratory Medicine, wanted to explore the background in field of laboratory hematology routine practice among Croatian laboratories in order to develop future strategies for producing national recommendations, if needed.

METHODS

During April and May 2019, a comprehensive survey covering all main parts of the total testing process within the field of laboratory hematology among Croatian medical laboratories was conducted. The survey comprised 49 inquiries. Data was collected using Survey Monkey (Palo Alto, CA, USA). All collected data was anonymized.

RESULTS

The response rate was 72%. There is still a substantial number of laboratories that have only three-part differential hematology analyzers (9%). Furthermore, a very high number of laboratories did not perform analyzer verification prior to implementation into routine work (31%). Out of those who have verified their analyzers, a diversity of guidelines and recommendations were used. Nearly 10% of the laboratories do not have a defined policy regarding specimen rejection. The majority of the participants perform internal quality control daily (83%), however, only 51% of respondents evaluate the agreement between different hematology analyzers on daily basis. Although more than 90% of Croatian laboratories have a defined policy regarding specimen rejection, only 61% of respondents continuously monitor quality indicators in routine practice.

CONCLUSIONS

The survey revealed substantial differences in all aspects of laboratory hematology practices among Croatian medical laboratories, indicating the need for universal recommendations at the national level.

Unusual Morphological and Automated Hematology Analyzer Features in 3 Cases of B-cell Malignancy-associated Type I Cryoglobulinemic Vasculitis

Type I cryoglobulins are monoclonal immunoglobulins produced due to underlying hematological malignancy. Cryoglobulins spontaneously precipitate from serum and plasma at low temperatures and become soluble again on rewarming to 37 °C. Processing of blood at temperature lower than 37 °C in the laboratory may cause precipitation of cryoglobulins resulting in interferences in the automated cell counter analysis. We report three patients with cryoglobulinemic vasculitis wherein each case had different morphology of cryoglobulin precipitates on peripheral blood film, like needle shaped bluish-gray crystals, amorphous weakly basophilic extracellular deposits extraneously indenting red blood cells and basophilic neutrophilic inclusions respectively. The effect of cryoglobulins on two technologically different automated cell counters based on principles of impedance, Volume-Conductivity-Scatter (VCS) and fluorescence flow cytometry was assessed. This case series provides interesting insight into the varying morphological features of cryoglobulins on May-Grunwald-Giemsa stained blood films and interference caused by cryoglobulins in different automated cell counter analysis resulting in pseudo-leucocytosis, pseudo-thrombocytosis, abnormal histograms and scatterplots. Identification of these hematologic abnormalities and artifacts induced by cryoglobulins is necessary since it may be the first clue leading to the timely diagnosis of cryoglobulinemia and hence the underlying hematological malignancy, as in our cases.

EDTA-dependent pseudo thrombocytopenia mimicking dengue fever-associated persistent thrombocytopenia: A case report

No hemorrhagic manifestations, presence of platelet clumps on the peripheral blood smear, normal manual count, and normal autoanalyzer count after collecting blood in citrate vial help confirm the diagnosis of EDTA-dependent thrombocytopenia.

Alinity hq platelet results are equivalent with the international reference method in thrombocytopenic samples

INTRODUCTION

Accurate and precise platelet (PLT) count is critical for the appropriate management of patients with thrombocytopenia. This study evaluated the performance of PLT counting with the Abbott Alinity hq hematology analyzer, which utilizes multi-dimensional optical technology.

METHODS

Imprecision, linearity, and accuracy were assessed per CLSI guidelines. Alinity hq PLT results were compared to the international flow cytometry reference method (IRM) in the concentration range of 6.3 to 103.0 × 10⁹ /L. Additional comparisons were made with Sysmex XN-3000 PLT counts: impedance (PLT-I), optical (PLT-O), and optical fluorescent (PLT-F) methods.

RESULTS

The average within-run %CV was 4.7% on patient samples with PLT concentrations ranging from 13.1 to 41.7 × 10⁹ /L, and the within-laboratory %CV was 3.6% at the level of 68.2 × 10⁹ /L. Linearity evaluation indicated a maximum deviation of 3.1% from the linear fit in the range of 0.1 to 316.8 × 10⁹ /L. Comparison between Alinity hq and the IRM PLT counts yielded a correlation coefficient of 0.99 and predicted bias of 0.0 and -0.5 × 10⁹ /L at 10.0 and 20.0 × 10⁹ /L transfusion thresholds, respectively. Alinity hq PLT counts also correlated well with Sysmex PLT counts, with strongest correlation obtained with PLT-F and PLT-O (r = .99) methods.

CONCLUSION

This study demonstrated excellent analytical performance of Alinity hq PLT counting in thrombocytopenic samples, equivalency with the IRM and strong agreement with Sysmex PLT-F and PLT-O methods. The Alinity hq multi-dimensional optical PLT count is available with every CBC without additional reagents and may help promote efficiency in clinical laboratories.

Performance evaluation of optical platelet counting of BC-6000Plus automated hematology analyzer

Background

The BC-6000Plus (Mindray, Shenzhen, China) is a recently developed hematology analyzer that utilizes fluorescent technology. Based on fluorescent nucleic acid stain and optical detection, the optical platelet counting (PLT-O) on the BC-6000Plus has strong anti-interference potential in platelet (PLT) detection. Its Auto 8×PLT-O Counting Tech can be automatically triggered in low-PLT samples, which enables the PLT-O on the BC-6000Plus to count low PLT more efficiently. Here, we evaluated the performance of the BC-6000Plus automated hematology analyzer in optical PLT counting.

Methods

The basic features (including blank counting, carryover, trueness, and accuracy) of the BC-6000Plus for PLT counting were evaluated according to the Analytical Quality Specifications for Routine Tests in Clinical Hematology (WST 406-2012). Low-PLT samples with a PLT count of below 100×10⁹/L were selected for repeatability tests. Meanwhile, the potential correlations of BC-6000Plus with the XN-L 350 and manual microscopy within different PLT ranges or under interferences of small red blood cells (RBCs) or PLT aggregation were analyzed.

Results

The PLT-O on BC-6000Plus met the technical requirements of PLT counting in terms of blank count, carryover, trueness, and accuracy. The repeatability of the enhanced mode (PLT-O 8×) on the BC-6000Plus was better than that of the XN-L 350 in three low PLT count ranges, including 10–20, 20–60, and 60–100 (×10⁹/L). Under the interference-free conditions, the BC-6000Plus correlated well with the XN-L 350 in different PLT counting ranges. Under the interferences of small RBCs and PLT aggregation, the PLT-O on BC-6000Plus correlated better with microscopy than with the platelet impedance count (PLT-I).

Conclusions

The PLT-O on BC-6000Plus can meet the technical requirements of PLT counting in terms of blank counting, carryover rate, trueness, and accuracy. The PLT-O 8× has good repeatability, correlates well with the XN-L 350, and demonstrates good anti-interference ability. It can thus meet the needs of blood cell analysis in clinical settings.

Pseudothrombocytopenia-A Review on Causes, Occurrence and Clinical Implications

Pseudothrombocytopenia (PTCP), a relative common finding in clinical laboratories, can lead to diagnostic errors, overtreatment, and further (even invasive) unnecessary testing. Clinical consequences with potential life-threatening events (e.g., unnecessary platelet transfusion, inappropriate treatment including splenectomy or corticosteroids) are still observed when PTCP is not readily detected. The phenomenon is even more complex when occurring with different anticoagulants. In this review we present a case of multi-anticoagulant PTCP, where we studied different parameters including temperature, amikacin supplementation, measurement methods, and type of anticoagulant. Prevalence, clinical risk factors, pre-analytical and analytical factors, along with clinical implications, will be discussed. The detection of an anticoagulant-dependent PTCP does not necessarily imply the presence of specific disorders. Conversely, the incidence of PTCP seems higher in patients receiving low molecular weight heparin, during hospitalization, or in men aged 50 years or older. New analytical technologies, such as fluorescence or optical platelet counting, will be soon overturning traditional algorithms and represent valuable diagnostic aids. A practical laboratory approach, based on current knowledge of PTCP, is finally proposed for overcoming spuriously low platelet counts.

Platelet morphology

Background

The examination of a peripheral blood smear is mandatory in case of unexplained thrombocytopenia or thrombocytosis. First, the number of platelets should be estimated in order to confirm the platelet count determined by the haematology analyser, and to rule out causes of spuriously low or elevated platelet counts. Second, the size and morphological features of the platelets, which may provide information on the underlying cause of the low or enhanced platelet count, have to be assessed.

Content

This review summarizes the physiological and pathological features of platelet size and morphology, circulating megakaryocytes, micromegakaryocytes and megakaryoblasts, and provides an overview of current guidelines on the reporting of platelet morphology.

Summary

In the diagnostic work-up of a patient with thrombocytopenia, the size of the platelets is of diagnostic relevance. Thrombocytopenia with small platelets is suggestive of a defect in platelet production, whereas the presence of large platelets is more likely to be associated with enhanced platelet turnover or hereditary thrombocytopenias. Morphological platelet abnormalities may affect the granulation and the shape and are frequently associated with abnormalities of platelet size. Platelet anomalies can be found in various haematologic disorders, such as myelodysplastic syndromes, myeloproliferative neoplasms, acute megakaryoblastic leukaemia or hereditary thrombocytopenias.

Multicenter evaluation of analytical performances of platelet counts and platelet parameters: Carryover, precision, and stability

INTRODUCTION

The correctness of the results of automated platelet analysis is still highly debated. The aim of this multicenter study, conducted according to international guidelines, was to verify the analytical performance of nine different types of hematology analyzers (HAs) in the automated platelet analysis.

METHODS

Four hundred eighty-six peripheral blood samples (PB), collected in K₃ EDTA tubes, were analyzed by ABX Pentra, ADVIA2120i, BC-6800, BC-6800 Plus, Cell-DYN Sapphire, DxH800, XE-2100, XE-5000, XN-20 with PLT-F App. Within-run imprecision and between-run imprecision were carried out using PB and material control, respectively. The carryover, low limit of quantification (LoQ), and the PB stability were evaluated.

RESULTS

The carryover was absent for all HAs. The LoQ of PLT ranged between 2.0 (Cell-Dyn Sapphire) and 25.0 × 10⁹ /L (ADVIA 2120i), while immature platelet fraction (IPF) ranged between 1.0 (XN-20) and 12.0 × 10⁹ /L (XE-5000). The imprecision (%CV) increases as the platelet count decreases. No HAs showed desirable CV_APS for PLT counts less than 50.0 × 10⁹ /L, with the exception of Cell-DYN Sapphire (CV 3.0% with PLT-O mean value of 26.7 × 10⁹ /L), XN-20 (CV 2.4% with PLT-F mean value of 21.5 × 10⁹ /L), and BC-6800 Plus (CV 1.9% with PLT-O mean value of 26.5 × 10⁹ /L). The sample stability ranged between under two hours for MPV by ADVIA2120i and 8 hours for other PLT parameters and HAs.

CONCLUSION

The findings of this study may provide useful information regarding carryover, precision, and stability of platelet counts and parameters, especially in thrombocytopenic samples. Moreover, the stability of sample for platelet analysis is conditioned by the HA and by temperature and storage time.

Platelet Counting: Ugly Traps and Good Advice. Proposals from the French-Speaking Cellular Hematology Group (GFHC)

Despite the ongoing development of automated hematology analyzers to optimize complete blood count results, platelet count still suffers from pre-analytical or analytical pitfalls, including EDTA-induced pseudothrombocytopenia. Although most of these interferences are widely known, laboratory practices remain highly heterogeneous. In order to harmonize and standardize cellular hematology practices, the French-speaking Cellular Hematology Group (GFHC) wants to focus on interferences that could affect the platelet count and to detail the verification steps with minimal recommendations, taking into account the different technologies employed nowadays. The conclusions of the GFHC presented here met with a "strong professional agreement" and are explained with their rationale to define the course of actions, in case thrombocytopenia or thrombocytosis is detected. They are proposed as minimum recommendations to be used by each specialist in laboratory medicine who remains free to use more restrictive guidelines based on the patient’s condition.

Reticulated platelets – clinical application and future perspectives

Reticulated platelets are immature platelets freshly released from the bone marrow into the circulation and contain vestigial amounts of ribonucleic acid. Thus, they can serve as an indicator for the activity of thrombopoiesis. Despite the current lack of a standardized reference method, two types of hematology analyzers have incorporated a fully automated measurement of reticulated platelets. The “immature platelet fraction” (IPF; Sysmex XE-/XN-series) has some clinical utility in the differential diagnosis of thrombocytopenia. This is less clear for “reticulated platelets” (retPLT; Abbott CELL-DYN Sapphire/Alinity HQ). The usefulness of these parameters in the prediction of platelet recovery after chemotherapy or stem cell transplantation and as a decision aid for platelet transfusions has not been unequivocally confirmed. Recent findings have shown an association of reticulated platelets with an adverse risk in patients with coronary artery disease and stroke as well as resistance to anti-platelet therapy. Furthermore, a role of reticulated platelets for the prediction of sepsis was indicated. However, validation in larger prospective trials is necessary to establish the clinical benefit of reticulated platelets in these conditions. This review gives an overview of the available analytical methods and summarizes the current knowledge regarding the clinical application of reticulated platelets.

Correction of spurious low platelet counts by optical fluorescence platelet counting of BC-6800 hematology analyzer in EDTA-dependent pseudo thrombocytopenia patients

Background

To evaluate the dissociation effect of optical fluorescence platelet counting of BC-6800 hematology analyzer on ethylene diamine tetraacetic acid-dependent pseudo thrombocytopenia (EDTA-PTCP) samples.

Methods

Twenty-three finally identified EDTA-PTCP samples were recruited in this study using criteria as follow: (I) impedance platelet counts lower than 100×10⁹/L with instrument “platelet aggregation” flag; (II) existence of platelet clumps in the blood smear; (III) obviously higher platelet counts without “platelet aggregation” flag and no platelet clumps in blood smear after repeating phlebotomy using citrate anticoagulated tubes. The BC-6800 hematology analyzer and the XE-2100 hematology analyzer were used to test 23 EDTA-PTCP samples and 30 controls on both the impedance channel and the reticulocyte channel. The dissociation rate was defined as optical fluorescence platelet counts in the EDTA tubes/impedance platelet counts in citrate tubes ×100%.

Results

BC-6800 analyzer’s optical fluorescence platelet counts of EDTA-PTCP samples were significantly higher than impedance platelet counts (t=4.33, P=0.00) and comparable with the platelet counts of re-collected samples in tubes containing citrate anticoagulant. On BC-6800 hematology analyzer, 22 of 23 EDTA-PTCP samples showed a dissociation rate greater than 80%, and the average dissociation rate was 93%. On the XE-2100 hematology analyzer, 1 of the 17 EDTA-PTCP samples showed a dissociation rate greater than 80%, and the average dissociation rate was 56%.

Conclusions

Optical fluorescence platelet counting of BC-6800 Hematology Analyzer is effective for the correction of spurious low platelet counts in EDTA-PTCP patients, and its dissociation effect on EDTA-PTCP samples was independent of fluorescent dye staining.

Comparison between optical microscopy and the Sysmex XN-3000 for schistocyte determination in patients suspected of having schistocytosis

Background and aims

Diagnosis of thrombotic microangiopathy (TMA) relies on microscopic schistocyte determination by an experienced microscopist. In addition, schistocytes can be found in non‐TMA–related disorders such as thalassaemia. We aimed to compare the accuracy of the automated haematology analyser Sysmex XN‐3000 for schistocyte detection, to that of the microscopy approach, in patients suspected of having schistocytosis.

Methods

Consecutive blood samples were collected between April 2016 and March 2017 at Siriraj Hospital, Mahidol University, Bangkok, Thailand. Specimens were collected from adults with suspected TMA or with thalassaemia trait and/or disease. All blood samples were examined by both microscopy and the analyser. Samples were considered to be positive for schistocytes (ie, schistocytosis) if they had a schistocyte count ≥1% by microscopy. The analyser's ability to determine schistocytosis was assessed by receiver operating characteristic (ROC) curve. Sensitivity, specificity, positive (PPV), and negative predictive value (NPV) of an appropriate cut‐off point were calculated, with manual microscopy as the standard. Quantitative agreement in schistocyte counts between the two approaches was assessed using 95% limits of agreement, Bland‐Altman plots, intraclass correlation coefficient, and concordance correlation coefficient.

Results

Ninety‐seven blood samples (62 suspected TMA and 35 thalassaemia) were collected. ROC curve analysis of the analyser for determining schistocytosis showed an area under the curve of 0.803 (95% confidence interval, 0.689‐0.917, P < 0.001). A cut‐off point of 0.6% yielded 86.1% sensitivity, 77.8% specificity, 94.4% PPV, and 56.0% NPV. The automated schistocyte count did not quantitatively agree with schistocyte counts by microscopy, neither in all blood specimens (mean of difference: −1.09; 95% limits of agreement, −11.9 to 9.7) nor in the subgroups (TMA, −0.88; 95% limits of agreement, −6.60 to 4.84; thalassaemia, −2.4; 95% limits of agreement, −14.10 to 9.30). The differences in the estimation of fragmented red blood cells between the methods tended to increase at higher schistocyte counts.

Conclusion

Sysmex XN‐3000 can be used for qualitative measurement of schistocytosis, but should not be used as a quantitative tool for schistocyte counting. Improvements are needed before this analyser's schistocyte detection feature can be recommended for use in clinical practice.

Heinz body-related interference with leukocyte and erythrocyte variables obtained by an automated hematology analyzer in cats

Heinz bodies (HBs) are known to interfere with automated hematology in cats, particularly with the white blood cell (WBC) count. We evaluated the influence of feline HBs on the complete blood count (CBC) results obtained using a flow cytometry-based analyzer. We retrospectively selected cats with circulating HBs and reviewed the results of their CBCs, including red blood cell (RBC) indices, basophil/lobularity (Baso) WBC count (WBCB), peroxidase (Perox) WBC count (WBCP), and cytograms. Based on the presence or absence of HB-related artifacts in their Baso cytogram, cats were grouped into Baso-HBs and HBs groups, respectively, for comparison. The WBCB and WBCP were compared to manual counts of WBCs carried out on blood smears at 400× (MC-WBC). We included 32 cats in our study: 9 of 32 were in the Baso-HBs group, and 23 of 32 were in the HBs group. Baso-HBs cats had a significantly increased HB percentage (p < 0.001), WBCB (p < 0.001), difference between WBCB and WBCP (p < 0.001), lymphocyte count (p < 0.001), mean corpuscular hemoglobin concentration (p < 0.001), and difference between calculated and measured erythrocyte hemoglobin concentrations (p < 0.001) compared to HBs cats. In Baso-HBs cats, the WBCB was significantly higher than the WBCP (p = 0.02); no significant difference was detected between the WBCP and the MC-WBC (p = 0.88). Evaluation of automated CBC results raised the suspicion of HB-related interference when using a hematology analyzer in cats; hence, blood smear examination remains essential in routine practice.

Modulation of micro-rheological and hematological parameters in the presence of artificial carotid-jugular fistula in rats

BACKGROUND

Arteriovenous fistula (AVF) may affect erythrocytes through many pathways (e.g., mechanical, inflammatory). However, these effects haven't been elucidated completely yet.

OBJECTIVE

To follow-up the hemorheological and the hematological changes in the presence of artificial carotid-jugular fistula in rats.

METHODS

Female Wistar rats were subjected to sham-operated group (SG, n = 6) and to fistula group (FG, n = 10). Under general anesthesia, the right carotid artery and jugular vein were isolated via a neck incision, and in the FG carotid-jugular fistula was performed by microsurgical techniques. Hematological variables, red blood cell (RBC) deformability and membrane (mechanical) stability parameters were determined before operation and on the 1st and 6th postoperative weeks. Density separated samples ('young' and 'old' RBCs) were also tested.

RESULTS

In FG group hematocrit, RBC and platelet counts increased gradually to reach highly significant level of increment on the 6th postoperative week. RBC deformability significantly was impaired. The membrane stability test showed lower deformability values after applying mechanical shearing. No significant differences were observed between density separated RBC subpopulations.

CONCLUSIONS

The presence of arteriovenous fistula may lead to an increment of RBC mass and impairment of RBC deformability. These changes could be one of the pathways through which the fistula influences the microcirculation.

Analytical performance of automated platelet counts and impact on platelet transfusion guidance in patients with acute leukemia

The aim of this study was to evaluate the performance of automated impedance platelet counts by Beckman Coulter LH780 (PLT-LH), Sysmex XN-3000 (PLT-XNi) and fluorescence method by Sysmex XN-3000 (PLT-F) in patients with acute leukemia. Blood specimens were subjected to platelet measurements by evaluated methods and then compared against the international reference method (IRM). Eighty-two blood specimens were included. Bland-Altman plots of the differences between the evaluated methods and IRM demonstrated mean biases of PLT-LH, PLT-XNi and PLT-F of 9 × 10⁹/L, 11 × 10⁹/L and 2 × 10⁹/L, respectively. For platelet transfusion guidance, all evaluated methods had acceptable accuracy. For platelet transfusion guidance, the sensitivities of PLT-LH, PLT-XNi and PLT-F were 33.3, 25.0 and 83.3%, respectively, at a transfusion threshold of 10 × 10⁹/L, and 73.1, 61.5 and 84.6%, respectively, at transfusion threshold of 20 × 10⁹/L. High blast count was associated with inaccurate PLT-LH and PLT-XNi. In conclusion, the PLT-F demonstrated excellent performance for diagnosis of thrombocytopenia and for platelet transfusion guidance in the evaluated specimens from acute leukemia patients. With respect to clinical relevance, careful blood smear review is necessary in case of high blast counts.

In-Hospital Onset of Pseudothrombocytopenia Days before Surgery

Automated cell counters often produce spuriously low platelet counts due to laboratory artifacts. These in vitro phenomena may lead to erroneous treatments, surgical delays, and unnecessary platelet transfusions. An overlooked case of newly developed anticoagulant-induced platelet aggregation diagnosed in a preoperative visit is discussed and diagnostic clues are presented.

The role of complete blood inflammation markers in the prediction of spontaneous abortion

Objective

To investigate relationships between spontaneous abortion and complete blood count inflammation markers and their role in predicting spontaneous abortion.

Methods

This study was conducted at Department of Obstetrics and Gynecology between January 2012 and January 2017. A total of 570 participants, 325 diagnosed with spontaneous abortion and 245 control patients who underwent timely births were included into our study. The complete blood count inflammation markers included white blood cell (WBC), neutrophil (N), lymphocyte (L), neutrophil-lymphocyte ratio (NLR), mean platelet volume (MPV) and platelet-lymphocyte ratio level (PLR) were recorded.

Results

There was difference between the abortion groups and control groups in terms of complete blood count (CBC) inflammation markers, including WBC, PLT, neutrophil, lymphocyte, NLR, PLR, and MPV. We found decreased MPV, PLR levels and increased N, L and NLR in the first. and second. Abortion groups compared with the control group. WBC, N, L and NLR were positive predictive markers, and albeit with low sensitivity and specificity, MPV, PLR were found to be a negative predictive marker for the evaluation of spontaneous abortion.

Conclusions

Unlike several difficult and invasive tests, a CBC is a simple, inexpensive and easily available test. CBC inflammation markers, including WBC, N, L, NLR, PLR, and MPV, which were evaluated at the sixth gestational week, can be used for the risk assessment of spontaneous abortion in pregnancy.

Interference of in vitro hemolysis complete blood count

BACKGROUND

Hemolysis may occur in vivo, under pathological conditions, or in vitro, related to pre-analytical errors. Hemolyzed samples may produce unreliable results, leading to errors in diagnostic and monitoring evaluations. This study aims to evaluate the interference of in vitro hemolysis on the interpretation of the parameters of the blood cell-counting performed by the impedance method.

METHODS

Peripheral blood samples were collected in anticoagulant K2-EDTA and subsequently divided into three 1.0 mL aliquots. The first aliquot was not subjected to any intervention, and the second and third aliquots were passed 5 and 10 times through a small-gauge needle to produce scalar amounts of hemolysis. Hematological tests were performed by Hemacounter 60-RT 7600® .

RESULTS

Comparison of the samples with different degrees of hemolysis showed a decrease in red blood cells count and hematocrit counts and increase in mean corpuscular hemoglobin concentration and platelet count in samples with a high degree of hemolysis. According to the accepted clinical point of view, the samples with a high degree of hemolysis exceeded the desirable bias, presenting decrease in red blood cells count, hematocrit and mean corpuscular volume, and increase in red cell distribution width, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and platelet counts. However, samples with a mild degree of hemolysis showed only a slight increase in mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and platelet count.

CONCLUSION

This study demonstrated that in vitro hemolysis can decrease the clinical and analytical reliability of the assessment of the blood count.

EDTA-induced pseudothrombocytosis and citrate-induced platelet agglutination in a patient with Waldenstrom macroglobulinemia

Hematology analyzers sometimes generate spurious results. A patient had EDTA‐induced pseudothrombocytosis and platelet agglutination in citrate blood samples. This case verifies that addition of 1% paraformaldehyde to the citrate tubes can prevent platelet clumping. Further, it illustrates the advantages of having access to more than one platelet count method.

[A non-EDTA-dependent pseudothrombocytopenia: about a case]

La pseudothrombopénie est un phénomène rare de laboratoire, expliquée par une agglutination in vitro des plaquettes. L’examen au microscope du frottis du sang périphérique est un examen clé, pour confirmer le diagnostic et pour éviter toute décision clinique et thérapeutique inadaptée voir dangereuse. Sa survenue chez un patient, sous traitement par l’héparine, pose le problème de diagnostic différentiel avec la thrombopénie héparino-induite. Notre objective, à travers cette observation, est d’éviter toute confusion entre ce phénomène purement artéfactuel et la thrombopénie héparino-induite.

Factors Affecting Platelet Concentration in Platelet Concentrates from Canine Blood Donors

BACKGROUND

Physiologic factors in dogs that might contribute to enhanced platelet yield in platelet concentrates (PCs) are largely unknown.

OBJECTIVE

To determine whether individual differences in weight, age, preprocessing blood chemistry, and CBC variables predict the final platelet concentrations in PCs. Our hypotheses were (1) increased lipemic indices would be positively associated with increased platelet concentrations in PCs and (2) increased preprocessing platelet concentrations would be associated with higher platelet concentrations in the PCs.

ANIMALS

All blood donation records of dogs from February 2, 2009 through April 1, 2015 at the University of California-Davis Veterinary Blood Bank were examined with 104 cases included in this study.

METHODS

In this retrospective study, data were collected from medical records of canine blood donors. Records were reviewed for internal consistency and accuracy and subjects were included in the study if donor screening and donation occurred on the same day and a viable PC was obtained. Univariate and multivariable regressions were used to test the impact that each variable had on the final platelet concentration in PCs.

RESULTS

Final platelet concentration in PCs was positively associated with the predonation CBC platelet values (P < .001), lipemic index (P = .01), and phosphorous levels (P = .001). Collectively these 3 variables explained 29% of the variance in platelet concentrations in PCs.

CONCLUSIONS AND CLINICAL IMPORTANCE

Future prospective studies are required to determine if canine blood donations from dogs with lipemia yield PCs with higher platelet concentrations without negatively affecting other blood components.

Effects of hemolysis and lipemia interference on kaolin-activated thromboelastography, and comparison with conventional coagulation tests

The effects of hemolysis and lipemia on thromboelastography (TEG) analysis have been scarcely evaluated in human samples, and neglected in clinical practice. We aimed to investigate the effects of in vitro mechanical hemolysis and lipemia on TEG analysis and conventional coagulation tests. Twenty-four healthy volunteers were enrolled in the study. Besides the controls, three groups with slight, moderate and severe mechanical hemolysis were constituted according to free hemoglobin (Hb) concentrations of 0.5-1.0, 2.0-6.0 and 7.0-13.0 g/L, respectively; and three groups with mild, moderate and high lipemia were established according to triglyceride concentrations of ∼6.0, ∼12.0, and ∼18.0 mmol/L, respectively. Four TEG parameters, reaction time (R), coagulation time (K), angle (α), and maximum amplitude (MA), were measured alongside conventional plasma tests including prothrombin time (PT), activated partial thromboplastin time (APTT) and fibrinogen (FIB) by mechanical method, and platelet count by optical method. Results showed that the median R and MA values at moderate and severe hemolysis and K at severe hemolysis exceeded respective reference intervals, and were considered unacceptable. Median values of TEG parameters in lipemic samples were all within reference intervals. Bias values of conventional plasma tests PT, APTT and FIB in hemolyzed or lipemic samples were all lower than the Clinical Laboratory Improvement Amendments (CLIA) allowable limits. Bias values of platelet count at moderate to severe hemolysis and lipemia exceeded the CLIA allowable limits. In conclusion, the detection of TEG was in general more affected by mechanical hemolysis than plasma coagulation tests. Pre-analytical variables should be taken into account when unexpected TEG results are obtained.