The Use of Platelet Count and Indices as Prognostic Factors for Mortality in Children with Sepsis.

Background: Sepsis is still one of the leading causes of mortality and morbidity in children worldwide. Consumptive coagulopathy and suppression of thrombopoiesis in the bone marrow resulting from immune dysregulation are pathological mechanisms that cause thrombocytopenia in sepsis. Platelet count (PLT) and indices, such as mean platelet volume (MPV), platelet distribution width (PDW), and plateletcrit (PCT) are markers of platelet activation and are strongly influenced by platelet morphology and proliferation kinetics. We aimed to study the use of platelet count and indices as predictors of mortality in children with sepsis. Methods: This is a cross-sectional study of 45 children diagnosed with sepsis on admission at Haji Adam Malik Hospital, Medan, North Sumatra, Indonesia, between October and November 2022. Blood samples were drawn upon admission, and platelet count and indices were then determined for all children. Subjects were followed up till discharge from hospital or death. Receiver Operating Characteristic (ROC) curve analysis of platelet parameters was done to determine the area under the curve (AUC), optimal cut-off value, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) in predicting mortality in children with sepsis. Using the cut-off values from ROC curve analysis, the odds ratio with 95% confidence interval was calculated using multiple logistic regression analyses. A P value less than 0.05 was considered statistically significant. Results: MPV, PDW, and PDW/PLT were significantly higher in non-survivors than survivors (P=0.04, P=0.02, and P=0.04, respectively). ROC curve analysis showed that PDW had the largest AUC (0.708 [95% CI=0.549-0.866]) with a cut-off value of 14.1%, sensitivity of 63.6%, and specificity of 82.6%. PDW was also the only parameter that significantly affected the outcome of children with sepsis. PDW≥14.1% at admission increases the risk of mortality by 5.7 times. Conclusion: Admission PDW is a fast and specific tool to predict the outcome of children with sepsis.

Appraising non-linear association between pre-diagnostic platelet counts and cancer survival outcomes: observational and genetic analysis.

Previous studies have reported inconsistent associations between platelet count (PLT) and cancer survival. However, whether there is linear causal effect merits in-depth investigations. We conducted a cohort study using the UK Biobank and a two-sample Mendelian randomization (MR) analysis. PLT levels were measured prior to cancer diagnosis. We adopted overall survival (OS) as the primary outcome. Cox models were utilized to estimate the effects of PLTs on survival outcomes at multiple lag times for cancer diagnosis. We employed 34 genetic variants as PLT proxies for MR analysis. Linear and non-linear effects were modeled. Prognostic effects of gene expression harboring the instrumental variants were also investigated. A total of 65 471 cancer patients were included. We identified a significant association between elevated PLTs (per 100 × 109/L) and inferior OS (HR: 1.07; 95% CI: 1.04-1.10; p < .001). Similar significant associations were observed for several cancer types. We further observed a U-shaped relationship between PLTs and cancer survival (p < .001). Our MR analysis found null evidence to support a causal association between PLTs and overall cancer survival (HR: 1.000; 95% CI: 0.998-1.001; p = .678), although non-linear MR analysis unveiled a potential greater detrimental effect at lower PLT range. Expression of eleven PLT-related genes were associated with cancer survival. Early detection of escalated PLTs indicated possible occult cancer development and inferior subsequent survival outcomes. The observed associations could potentially be non-linear. However, PLT is less likely to be a promising therapeutic target.

What is the context? Previous studies have reported inconsistent associations between platelet counts (PLTs) and cancer survival. However, it is unclear whether there is a linear causal effect, as most studies measured PLTs at the time of cancer diagnosis, which could be influenced by the cancer itself.This study aimed to investigate the association and potential causality between pre-diagnostic PLTs and cancer survival outcomes using a large prospective cohort and genetic analysis.What is new? The observational cohort study found a significant association between elevated pre-diagnostic PLTs and poorer overall and cancer-specific survival. We also identified a U-shaped relationship between PLTs and cancer survival, suggesting that both high and low PLTs may be detrimental.The Mendelian randomization analysis did not support a causal effect of PLTs on overall cancer survival, although it hinted at potential non-linear effects at lower PLT ranges.The study also identified several genes (TPM4, PDIA5, PSMD13, TMCC2, ZFPM2, BAZ2A, CDKN2A, GP1BA, TAOK1, CABLES1, and THPO) related to PLTs that were associated with cancer survival.What is the impact? The findings suggest that early detection of elevated PLTs may indicate occult cancer development and poorer subsequent survival outcomes. However, PLTs are less likely to be a promising therapeutic target for improving cancer survival, as the observed associations could be influenced by confounding factors.The study highlights the need for further research into the complex relationship between PLTs and cancer prognosis, as well as the exploration of other platelet-related traits as potential drug targets.

Hemoglobin, albumin, lymphocytes and platelets (HALP) score as a predictor of survival in patients with glioblastoma (GBM).

BACKGROUND: We aimed to investigate whether the HALP score was a predictor of survival in patients with Glioblastoma (GBM). METHODS: A total of 84 Glioblastoma (GBM) patients followed in our clinic were included in the study. HALP scores were calculated using the preoperative hemoglobin, albumin, lymphocyte and platelet results of the patients. For the HALP score, a cut-off value was found by examining the area below the receiver operating characteristic (ROC) curve. Patients were divided into two groups as low and high according to this cut-off value. The relationships among the clinical, dermographic and laboratory parameters of the patients were examined using these two groups. RESULTS: Median OS, PFS, HALP score, NLR, PLR were 15 months (1.0-78.0), 8 months (1.0-66.0), 37.39 ± 23.84 (min 6.00-max 132.31), 4.14, 145.07 respectively. A statistically significant correlation was found between HALP score and OS, PFS, NLR, PLR, ECOG-PS status using Spearman's rho test (p = 0.001, p < 0.001, p < 0.001, p < 0.001, p = 0.026 respectively). For the HALP score, a cut-off value of = 37.39 (AUC = 0.698, 95% CI, p < 0.002) was found using ROC analysis. Median OS was 12 (6.99-17.01) months in the low HALP group and 21 (11.37-30.63) months in the high HALP group (p = 0.117). NLR and PLR were significantly lower in the HALP high group (p < 0.001, p < 0.001 respectively). The ratio of receiving treatment was significantly higher in the high HALP group (p < 0.05). In Multivariate analysis, significant results were found for treatment status and ECOG-PS status (p < 0.001, p = 0.038 respectively). CONCLUSIONS: The HALP score measured at the beginning of treatment seems to have predictive importance in the prognosis of GBM patients. A HALP score of > 37.39 was associated with prolonged survival in high-grade brain tumors.

Prognostic Significance of Thrombocytopenia and Mean Platelet Volume in COPD Patients with Acute Exacerbations in ICU Settings.

BACKGROUND Platelets have important modulatory effects on inflammatory and immune-mediated pathways. Thrombocytopenia is a critical condition that is frequently encountered in the intensive care unit (ICU) and increases mortality. This retrospective study of 472 patients admitted to the ICU with acute exacerbation of chronic obstructive pulmonary disease (COPD) aimed to evaluate thrombocytopenia and mean platelet volume (MPV) with prognosis and patient mortality. MATERIAL AND METHODS A total of 472 patients diagnosed with COPD according to GOLD criteria and hospitalized in the tertiary ICU between 1 April 2018 and 11 May 2021 were included in the study. Platelets were calculated by the impetance method and MPV was simultaneously calculated based on the platelet histogram. Patients with platelet count ≤100×109/L and >100×109/L and patients with MPV values <7 fl, 7-11 fl, and >11fl were compared in terms of mortality and prognosis. RESULTS The mortality rate in COPD patients with thrombocytopenia was high, at 61.5%. Thrombocytopenia (P=.002), high MPV (P=.006) Acute Physiology and Chronic Health Evaluation-2 (APACHE-II) score (P=.025), length of stay (LOS) in the ICU (P=.009), mechanical ventilation duration (P<.001), leukocytosis (P<.001), high Sequential Organ Failure Assessment (SOFA) score (P<.001), LOS in the hospital (P=.035), and hypoalbuminemia (P<.001) were significantly associated with mortality. CONCLUSIONS Thrombocytopenia, high MPV, high APACHE-II and SOFA scores, LOS in the ICU and hospital, duration of mechanical ventilation, leukocytosis, and hypoalbuminemia predict mortality in COPD patients. Since infection-sepsis, hypoalbuminemia, and hypoxia can worsen this situation, ensuring early infection control, providing albumin support, and preventing hypoxia contribute significantly to reducing thrombocytopenia and mortality.

Association between Pan-Immune-Inflammation Value and Contrast-Induced Nephropathy with Coronary Angiography.

Background: Contrast-induced nephropathy (CIN) is one of the most important complications after invasive cardiovascular procedures. Considering the pivotal role of inflammation in CIN development, the use of peripheral blood-based indexes may be an easily available biomarker to predict CIN risk. Therefore, in the present study, we evaluated the association between the pan-immune-inflammation value (PIV) and the risk of CIN. Patients and Methods: A total of 1343 patients undergoing coronary angiography (CAG) were included. The PIV was calculated with the following equation: (neutrophil count × platelet count × monocyte count)/lymphocyte count. Multivariable regression analyses were used to determine the association between clinical and laboratory parameters and CIN development. Results: The median age of the cohort was 58 (IQR 50-67), and 48.2% of the patients were female. CIN developed in 202 patients (15%) in follow-up. In multivariate analyses, older age (OR: 1.015, 95% CI: 1.002-1.028, p = 0.020) and higher PIV levels (OR: 1.016, 95% CI: 1.004-1.028, p = 0.008) were associated with a higher CIN risk, while the use of antiplatelet agents was associated with a lower risk of CIN (OR: 0.670, 95% CI: 0.475-0.945, p = 0.022). Conclusions: We demonstrated that the risk of CIN was significantly higher in patients with higher PIV and older patients in a large cohort of patients undergoing CAG for stable ischemic heart disease. If supported with prospective evidence, PIV levels could be used as a minimally invasive reflector of CIN.

Concordance between platelet counts by impedance and optical technique during microcytic anemia: towards a threshold value of the mean corpuscular volume.

INTRODUCTION: Platelet count is crucial for clinical decision. In cases of microcytosis, platelet count based on impedance technique (PLT-I) may overestimate platelet count. AIM: To compare PLT-I with platelet count using the optical technique (PLT-O) and establish a Mean Corpuscular Volume (MCV) threshold for considering PLT-O. METHODS: A prospective analytical study conducted over two months involved blood samples collected in standard K2 EDTA tubes for complete blood count analysis, revealing microcytosis (MCV<80 fL). PLT-O analysis in channel-Ret mode was performed using the Sysmex-XN1000 (Sysmex Corporation, Kobe, Japan). Percentage of fragmented red cells (FRC%) and percentage of microcytic red cells (Micro-R%) were recorded. Blood smears stained with May-Grünwald-Giemsa were examined for potential interfering particles. RESULTS: A strong correlation was observed between the two techniques for all platelet values as well as for PLT <150 x 109/L (correlation coefficient r = 0.971, 95% CI: [0.956-0.982]; P<10-3 and r = 0.90, 95% CI: [0.79-0.95]; P< 10-3). The Bland-Altman plot revealed a bias of 16.53 x 109/L between the two methods, with agreement limits between -55.8 and 88.8 x 109/L. A threshold MCV value indicating the use of the optical method, with a cut-off at 72.9fL, demonstrated promising performance consistent with literature findings. However, less favorable performance was observed with Micro-R%. CONCLUSION: Impedance could be employed in routine practice. However, for MCV<72.9 fL or in the presence of schizocytes, the hemogram validation procedure may incorporate the use of PLT-O.

Relationship between thrombocytopenia and prognosis in children with septic shock: a retrospective cohort study.

Septic shock is a life-threatening disease worldwide often associated with thrombocytopenia. Platelets play a crucial role in bridging the gap between immunity, coagulation, and endothelial cell activation, potentially influencing the course of the disease. However, there are few studies specifically evaluating the impact of thrombocytopenia on the prognosis of pediatric patients. Therefore, the study investigates effects of early thrombocytopenia in the prognosis of children with septic shock. Pediatric patients with septic shock from 2015 to 2022 were included monocentrically. Thrombocytopenia was defined as a platelet count of <100 × 109/L during the first 24 hours of septic shock onset. The primary outcome was the 28-day mortality. Propensity score matching was used to pair patients with different platelet counts on admission but comparable disease severity. A total of 419 pediatric patients were included in the analysis. Patients with thrombocytopenia had higher 28-day mortality (55.5% vs. 38.7%, p = .005) compared to patients with no thrombocytopenia. Thrombocytopenia was associated with reduced 28-PICU free days (median value, 0 vs. 13 days, p = .003) and 28-ventilator-free (median value, 0 vs. 19 days, p = .001) days. Among thrombocytopenia patients, those with platelet count ≤50 × 109/L had a higher 28-day mortality rate (63.6% vs. 45%, p = .02). Multiple logistic regression showed that elevated lactate (adjusted odds ratio (OR) = 1.11; 95% confidence interval (CI): 1.04-1.17; P <0.001) and white blood cell (WBC) count (OR = 0.97; 95% CI: 0.95-0.99; p = .003) were independent risk factors for the development of thrombocytopenia. Thrombocytopenia group had increased bleeding events, blood product transfusions, and development of organ failure. In Kaplan-Meier survival estimates, survival probabilities at 28 days were greater in patients without thrombocytopenia (p value from the log-rank test, p = .004). There were no significant differences in the type of pathogenic microorganisms and the site of infection between patients with and without thrombocytopenia. In conclusion, thrombocytopenia within 24 hours of shock onset is associated with an increased risk of 28-day mortality in pediatric patients with septic shock.

What is the context? Septic shock is a life-threatening disease worldwide, leading to higher mortality.Platelets play a crucial role in bridging the gap between immunity, coagulation, and endothelial cell activation.Although it is known that platelets are associated with prognosis, most studies have focused on adult populations. Limited data are available on the incidence of thrombocytopenia and its correlation with clinical outcomes , specifically, in pediatric patients with sepsis and septic shock. What is new? The present study suggests that thrombocytopenia within 24 hours of septic shock onset reflects a reliable tool for predicting the prognosis of septic shock in pediatric patients.Furthermore, elevated lactate and reduced white-blood-cell count were independent risk factors for the development of thrombocytopenia in pediatric patients with septic shock. What is the impact? This study suggests that thrombocytopenia within 24 hours of septic shock onset is associated with an increased risk of 28-day mortality and decreased ventilation-free, PICU-free days in pediatric patients with septic shock. In septic shock, thrombocytopenia is also associated with increased bleeding events, blood product transfusions, and organ dysfunction.

A Case of Pseudothrombocytopenia due to Pre-Analytical Issues Revealed by the Presence of Fibrin in a Blood Film.

BACKGROUND: Pseudothrombocytopenia (PTCP) can be caused by anticoagulants or pre-analytical issues. The authors present a case of PTCP attributed to pre-analytical issues in a 68-year-old male patient. METHODS: The platelet count results were obtained using both the impedance and fluorescence channels of Sysmex XN-10. The blood film was scanned using both Cellavision DM96 and a microscope. RESULTS: The flag for PLT-Clumps and the scattergram from the PLT-F channel indicated the presence of platelet aggregation. Fibrin could be observed at the feathered end of the blood film. A diagnosis of PTCP resulting from pre-analytical issues was made. CONCLUSIONS: The presence of fibrin in a blood film is a critical indicator for diagnosing PTCP due to pre-analytical issues.

In vitro evaluation of a new viscoelastometry-based point-of-care analyzer.

INTRODUCTION: The VCM is a point-of-care analyzer using a new viscoelastometry technique for rapid assessment of hemostasis on fresh whole blood. Its characteristics would make it suitable for use in austere environments. The purpose of this study was to evaluate the VCM in terms of repeatability, reproducibility and interanalyzer correlation, reference values in our population, correlation with standard coagulation assays and platelet count, correlation with the TEG5000 analyzer and resistance to stress conditions mimicking an austere environment. METHODS: Repeatability, reproducibility, and interanalyzer correlation were performed on quality control samples (n = 10). Reference values were determined from blood donor samples (n = 60). Correlations with standard biological assays were assessed from ICU patients (n = 30) and blood donors (n = 60) samples. Correlation with the TEG5000 was assessed from blood donor samples. Evaluation of vibration resistance was performed on blood donor (n = 5) and quality control (n = 5) samples. RESULTS: The CVs for repeatability and reproducibility ranged from 0% to 11%. Interanalyzer correlation found correlation coefficients (r2) ranging from 0.927 to 0.997. Our reference values were consistent with those provided by the manufacturer. No robust correlation was found with conventional coagulation tests. The correlation with the TEG5000 was excellent with r2 ranging from 0.75 to 0.92. Resistance to stress conditions was excellent. CONCLUSION: The VCM analyzer is a reliable, easy-to-use instrument that correlates well with the TEG5000. Despite some logistical constraints, the results suggest that it can be used in austere environments. Further studies are required before its implementation.

Platelet function testing: Update on determinant variables and permissive windows using a platelet-count-based device.

While there are various aspects of platelet biology that can be studied in the lab (i.e. adhesion, degranulation, integrin activation), the master test for platelet function is that which gives a measure of the platelet aggregation capacity upon stimulation with an agonist. Platelet function testing is necessary for the diagnosis of platelet disorders and the monitoring of patients receiving anti-platelet treatments. Furthermore, it becomes relevant in the quality control of platelet concentrates for transfusion purposes, especially considering the global concern about long term storage, other forms of storage (i.e. cryopreservation, lyophilization), and the impact of Pathogen Reduction Treatments (PRTs) on platelet performance upon transfusion. However, it has been acknowledged as technically difficult and demanding, since a fine platelet function test must be carried out under specific conditions. Still, there might be occasions that preclude the platelet function testing abiding to the gold standard requirements, thus, leaving us with the necessity to redefine which variables may condition or limit the analysis of platelet function testing. In the present manuscript, we test different variables (such as the anticoagulant used or the time elapsed since extraction) and the possibility to reconstitute blood prior to platelet function analysis. This study aims to provide windows of action at the diagnostics lab, especially when not all of the recommended procedures and conditions can be followed: for example, when a sample is sent from a long distance, when there is a limitation on blood extraction volume or when certain parameters (platelet count) preclude reliable test results.

Spurious High Platelet Count without PLT Flag(S) in a Patient with Severe Aplastic Anaemia.

BACKGROUND: Platelet (PLT) count is one of the most important parameters of automated hematology, as spurious PLT reports could affect medical judgement and bring significant risks. In most cases, spurious PLT will not be reported for review criteria, which will be triggered by abnormal PLT histograms and PLT flag(s). Here, we present a case of severe aplastic anemia after hematopoietic stem cell transplantation with spurious high platelet count with normal histogram and no PLT flag(s). METHODS: The electrical impedance channel (PLT-I) and the fluorescence channel (PLT-F) of Sysmex XN-series hematology analyzer was used to obtain PLT results. Then, the sample was retested by another hematology analyzer MINDRAY BC-7500 [NR] CRP, and incubation was performed to rule out cryoglobulin interference. Furthermore, a microscope was used to estimate the PLT count by the ratio of platelets to red blood cells and observe the morphology of cells. RESULTS: Both PLT-I and PLT-F test results were spuriously high, and microscopically assessed platelet counts were relatively reliable. The observed spiny cells and ghost cells caused by hemolysis may have contributed to the inaccuracy of instrumental counting in this case. CONCLUSIONS: For special hematologic patients, PLT-I with flags may not be sufficient for screening purposes and PLT-F is not always accurate. Multiple testing methods including manual microscopy are needed.

An Introduction to the Complete Blood Count for Clinical Chemists: Platelets.

BACKGROUND: The most ordered laboratory test worldwide is the complete blood count (CBC). CONTENT: In this primer, an introduction to platelet testing in the context of the CBC is provided with a discussion of the laboratory evaluation of platelet abnormalities including thrombocytopenia and thrombocytosis. SUMMARY: As clinical chemists continue to be tasked to direct laboratories outside of the traditional clinical chemistry sections such as hematology, expertise must be developed. This primer is dedicated to that effort.

Can platelet activation markers predict preeclampsia and/or its severity?

OBJECTIVE: This study aimed to evaluate the value of platelet activation markers in predicting preeclampsia and its severity. Preeclampsia is a serious pregnancy complication that affects 3-5% of pregnancies and can lead to significant morbidity and mortality for both the mother and the fetus. METHODS: The study included 99 patients diagnosed with preeclampsia and 60 healthy pregnant women as a control group. Platelet activation markers such as mean platelet volume (MPV), platelet distribution width (PDW), platelet count, and plateletcrit were evaluated along with other clinical parameters. RESULTS: The results of the study showed that platelet activation markers, particularly PDW and MPV, are valuable in the diagnosis and follow-up of preeclampsia. However, they are not sufficient to predict the severity of the disease. CONCLUSION: The study suggests that platelet activation markers could aid in predicting, diagnosing, and managing preeclampsia. However, further research is needed to determine the role of these markers in predicting the severity of the disease. The findings of this study could contribute to the development of more effective strategies for the prevention and management of preeclampsia, which could ultimately improve maternal and fetal outcomes.

OBJETIVO: El estudio tuvo como objetivo determinar el valor de los marcadores de activación plaquetaria en la predicción de la preeclampsia y su gravedad. MÉTODO: Se incluyeron 99 pacientes diagnosticadas con preeclampsia, incluyendo 36 casos graves, y un grupo control de 60 mujeres embarazadas sanas. Se evaluaron diversas variables, como el volumen plaquetario medio, el recuento de plaquetas, el hematocrito plaquetario y la amplitud de distribución plaquetaria. RESULTADOS: Los resultados mostraron que el volumen plaquetario medio y la amplitud de distribución plaquetaria son parámetros valiosos en el diagnóstico y seguimiento de la preeclampsia, aunque no son suficientes para predecir su gravedad. El análisis estadístico reveló que la edad, el volumen plaquetario medio, la amplitud de distribución plaquetaria, la semana de gestación y los puntajes de Apgar al primer y quinto minuto fueron significativamente diferentes en el grupo de preeclampsia en comparación con el grupo control. CONCLUSIONES: En conclusión, estos resultados sugieren que los marcadores de activación plaquetaria pueden ser útiles para el diagnóstico y seguimiento de la preeclampsia, y que el volumen plaquetario medio y la amplitud de distribución plaquetaria, por ser parámetros económicos y accesibles, podrían ayudar a predecir, diagnosticar y manejar esta complicación durante el embarazo.

Marked Underestimation of Platelet Count and a Characteristic Platelet Histogram as Clues to MYH9-Related Disorders.

BACKGROUND: The rapid development of automatic blood cell analyzers has greatly optimized complete blood count results. However, erroneous results relevant to automatic blood cell analyzers still exist. Pseudothrombocytopenia can be observed in both cases of anticoagulant-induced platelet aggregation, and the presence of large and giant platelets. METHODS: A rare case of a MYH9-related disorder, in which marked underestimation of platelet count was led by large and giant platelets using the impedance count by an automated hematology analyzer. Moreover, lancet-shaped and Dohle body-like cytoplasmic inclusions were detected in almost all white blood cells of the patient. RESULTS: The platelet count was done by an optical platelet counter or a fluorescence platelet counter, and peripheral blood smear was evaluated. In addition, the diagnosis of MYH9-related disorder was established by the molecular findings. CONCLUSIONS: Identification of the peripheral blood smear and familial history will eliminate the need for further laboratory testing and bone marrow examination.

Reproducibility and stability of the immature platelet fraction using Sysmex XN-10.

BACKGROUND: The Immature Platelet Fraction (IPF) is an indicator of thrombopoiesis which is a useful parameter in thrombocytopenia. It demonstrates compensatory mechanisms in production of platelets, but currently not implemented in routine clinical practice. The aim of this study was to establish the reproducibility and stability of IPF, for both percentage (%-IPF) and absolute (A-IPF) measurements.Material/methods: A total of 71 samples, of which 45 for reproducibility and 26 for stability analysis, were assayed for full blood count using the Sysmex XN-10 analyser at room temperature (RT:19-25 °C). For reproducibility analysis, IPF measurements were analysed 11 times by different appraisers using the same sample, while for stability analysis, IPF was measured over fourteen hourly-intervals up to 24 h (n = 21) and then separately extended beyond the point of stability to 72 h (n = 5). RESULTS: Reproducibility analysis of %-IPF and A-IPF (n = 45) showed very reliable results, with the range of mean CV% values between 1.25-8.90% and 1.70-9.96%, respectively. On the other hand, overall, stability analysis of %-IPF and A-IPF (n = 21) at RT over 24 h showed reliable results, with pooled mean CV% values of 1.32% and 1.43%, respectively, with no significant difference between %-IPF and A-IPF (p = 0.767 and p = 0.821). All %-IPF and A-IPF values had exceeded the set acceptance criterion of stability (CV% ≥ 10.0%) before 72 h. CONCLUSIONS: Overall, %-IPF and A-IPF reproducibility and storage at RT for 24 h predominantly demonstrates the suitability of their usage for testing on the Sysmex XN-series analysers.

Pseudothrombocytosis Associated with Heatstroke.

BACKGROUND: In several situations, spurious results are observed in the use of hematology analyzers including pseudothrombocytosis caused by part of the cytoplasm of abnormal cells which was reported in leukemic blasts, monoblasts, or lymphoblasts. METHODS AND RESULTS: Here, we report a rare case of pseudothrombocytosis caused by mature leukocyte fragments associated with heatstroke. It was identified by the peripheral blood smear and obvious difference between the PLT-F (fluorescence) and I (impedance) channel. CONCLUSIONS: Observation of peripheral blood smears and determination on the PLT-F channel can identify this interference caused by leukocyte fragments in heatstroke.

Micro-Red Blood Cell, Fragmented Red Blood Cell, Platelet Distribution Width, Mean Platelet Volume, and Platelet-Large Cell Ratio on Sysmex XN Series Hematology Analyzers Can Be Used for the Reflex Test of Impedance Platelet Count in Clinical Practice.

CONTEXT.­: Platelet (PLT) counting with impedance (PLT-I) is widely used but has low specificity. PLT counting with fluorescence (PLT-F), tested by the Sysmex XN series with high specificity, can be a complementary method to PLT-I. OBJECTIVE.­: To identify red blood cell (RBC)- and PLT-related parameters as potential influencing factors for PLT-I and establish PLT reflex test rules with PLT-F. DESIGN.­: We prospectively tested both PLT-I and PLT-F in all 3480 samples. In a development data set of 3000 samples, differences between the reflex and nonreflex groups were compared and influencing factors for PLT-I were identified by logistic regression. The area under the receiver operating characteristic (ROC) curve and cutoff values were obtained by ROC curve analysis. Validation was conducted in the remaining 480 samples (validation data set). RESULTS.­: PLT-F showed comparable results with immunoplatelet counting. In logistic regression, increased micro-RBC absolute count (micro-RBC#), fragmented RBC absolute count (FRC#), PLT distribution width (PDW), mean PLT volume (MPV), PLT-large cell ratio (P-LCR), and immature PLT fraction absolute count (IPF#) were influencing factors for PLT-I. In ROC curve analysis, the cutoff values of micro-RBC#, FRC#, PDW, MPV, and P-LCR were 0.64 × 106/µL, 0.082 × 106/µL, 15.40 fL, 11.15 fL, and 33.95%, respectively. The areas under the ROC curve of micro-RBC# and FRC# were 0.77 and 0.79, respectively. CONCLUSIONS.­: Micro-RBC#, FRC#, PDW, MPV, P-LCR, and IPF# were factors affecting PLT-I. Among them, micro-RBC# and FRC# were the most impactful factors. From our study results, micro-RBC#, FRC#, MPV, PDW, and P-LCR can be used to establish reflex test rules for PLT counting in clinical work.

Performance evaluation the new automated Atellica Hema 580 hematology analyzer.

INTRODUCTION: The Atellica Hema (Siemens Healthineers, Tarrytown, NY, USA) is a new generation multi-parameter analyzer for full blood count, 6-part differential and reticulocyte testing by impedance variation and fluorescence flow cytometry. In this study, we verified the whole blood and limited body fluid modes of the Atellica Hema 580. METHODS: We evaluated precision, linearity, carry-over, throughput and performed a method comparison to assess the performance of the Atellica Hema 580. For comparison of the Atellica Hema 580 with the Sysmex XN-1000 (Sysmex, Kobe, Japan), 140 samples from adult and pediatric patients including both normal and abnormal hematology profiles were analyzed in parallel. RESULTS: The Atellica Hema 580 demonstrated acceptable imprecision within the manufacturer's specifications for whole blood and body fluid modes, good linearity for high and low ranges and no significant carryover. The full blood count, differential and reticulocyte correlated well with the Sysmex XN-1000, except for mean cell hemoglobin concentration, basophil and large immature cells. The optical platelet count, reflexed in 34 samples with a platelet count <150 × 109 /l, showed a strong correlation with the fluorescent platelet count on the Sysmex XN-1000. The morphology flagging efficiency was 92% for white blood cells, 95% for red blood cells and 87% for platelets. CONCLUSION: The Atellica Hema 580 showed good analytical performance and workflow efficiency for a wide range of patient samples.

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.

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.