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Transfusion and Apheresis Science :... Jun 2024While 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... (Review)
Review
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.
Topics: Humans; Platelet Function Tests; Platelet Count; Blood Platelets
PubMed: 38644062
DOI: 10.1016/j.transci.2024.103930 -
International Journal of Laboratory... Feb 2023The aim of this study performed on Sysmex XN is to compare platelet values on citrate and MgSO (TBX) in patients with K2EDTA-induced platelet clusters and to identify...
INTRODUCTION
The aim of this study performed on Sysmex XN is to compare platelet values on citrate and MgSO (TBX) in patients with K2EDTA-induced platelet clusters and to identify platelet biases of these matrices compared to K2EDTA.
METHODS
Sixty patients with K2EDTA-induced platelet clusters were re-sampled with K2EDTA, citrate and TBX. Platelet results were then compared, and smears were analysed for clumping. Platelet results from 120 patients without K2EDTA-induced platelet clusters were compared between K2 EDTA, citrate, and MgSO with impedance and fluorescence modes. Biases from regressions were analysed.
RESULTS
Out of the 60 patients with K2EDTA-induced platelet clusters, none showed platelet clusters with MgSO whereas 50% still showed clusters with citrate. Among those without platelet clusters on citrate, the mean relative difference between (citrate- MgSO )/MgSO was -12.7% in impedance and -9.8% in fluorescence. Among the 120 patients without K2EDTA-induced platelet clusters, in fluorescence the mean relative bias with respect to K2EDTA was -2.06% for MgSO and -10.3% for Citrate. For the MgSO versus K2 EDTA regressions, the maximum absolute values of the 95% CI of the relative biases at 150 × 10 /L (5.45%) and 450 × 10 /L (3.56%) were below the desirable analytical objectives of the EFLM.
CONCLUSION
In patients with K2EDTA-induced platelet clusters, MgSO is preferable to citrate. MgSO provides a bias with XN in fluorescence when compared to EDTA which is within analytical tolerance.
Topics: Humans; Platelet Count; Anticoagulants; Edetic Acid; Citric Acid; Blood Platelets
PubMed: 36093831
DOI: 10.1111/ijlh.13966 -
Chest Mar 2021ARDS is a devastating syndrome with heterogeneous subtypes, but few causal biomarkers have been identified.
BACKGROUND
ARDS is a devastating syndrome with heterogeneous subtypes, but few causal biomarkers have been identified.
RESEARCH QUESTION
Would multistage Mendelian randomization identify new causal protein biomarkers for ARDS 28-day mortality?
STUDY DESIGN AND METHODS
Three hundred moderate to severe ARDS patients were selected randomly from the Molecular Epidemiology of ARDS cohort for proteomics analysis. Orthogonal projections to latent structures discriminant analysis was applied to detect the association between proteins and ARDS 28-day mortality. Candidate proteins were analyzed using generalized summary data-based Mendelian randomization (GSMR). Protein quantitative trait summary statistics were retrieved from the Efficiency and safety of varying the frequency of whole blood donation (INTERVAL) study (n = 2,504), and a genome-wide association study for ARDS was conducted from the Identification of SNPs Predisposing to Altered Acute Lung Injury Risk (iSPAAR) consortium study (n = 534). Causal mediation analysis detected the role of platelet count in mediating the effect of protein on ARDS prognosis.
RESULTS
Plasma insulin-like growth factor binding protein 7 (IGFBP7) moderately increased ARDS 28-day mortality (OR, 1.11; 95% CI, 1.04-1.19; P = .002) per log2 increase. GSMR analysis coupled with four other Mendelian randomization methods revealed IGFBP7 as a causal biomarker for ARDS 28-day mortality (OR, 2.61; 95% CI, 1.33-5.13; P = .005). Causal mediation analysis indicated that the association between IGFBP7 and ARDS 28-day mortality is mediated by platelet count (OR, 1.03; 95% CI, 1.02-1.04; P = .01).
INTERPRETATION
We identified plasma IGFBP7 as a novel causal protein involved in the pathogenesis of ARDS 28-day mortality and platelet function in ARDS, a topic for further experimental and clinical investigation.
Topics: Biomarkers; Female; Genome-Wide Association Study; Humans; Insulin-Like Growth Factor Binding Proteins; Male; Mediation Analysis; Mendelian Randomization Analysis; Middle Aged; Mortality; Platelet Count; Platelet Function Tests; Polymorphism, Single Nucleotide; Prognosis; Proteomics; Respiratory Distress Syndrome; Risk Assessment
PubMed: 33189655
DOI: 10.1016/j.chest.2020.10.074 -
Annals of Epidemiology Apr 2017We used data from the Women's Health Initiative to examine the association of platelet count with total mortality, coronary heart disease (CHD) mortality, cancer...
PURPOSE
We used data from the Women's Health Initiative to examine the association of platelet count with total mortality, coronary heart disease (CHD) mortality, cancer mortality, and non-CHD/noncancer mortality.
METHODS
Platelet count was measured at baseline in 159,746 postmenopausal women and again in year 3 in 75,339 participants. Participants were followed for a median of 15.9 years. Cox proportional hazards models were used to estimate the relative mortality hazards associated with deciles of baseline platelet count and of the mean of baseline + year 3 platelet count.
RESULTS
Low and high deciles of both baseline and mean platelet count were positively associated with total mortality, CHD mortality, cancer mortality, and non-CHD/noncancer mortality. The association was robust and was not affected by adjustment for a number of potential confounding factors, exclusion of women with comorbidity, or allowance for reverse causality. Low- and high-platelet counts were associated with all four outcomes in never smokers, former smokers, and current smokers.
CONCLUSIONS
In this large study of postmenopausal women, both low- and high-platelet counts were associated with total and cause-specific mortality.
Topics: Aged; Cause of Death; Coronary Disease; Female; Humans; Middle Aged; Mortality; Neoplasms; Platelet Count; Proportional Hazards Models; Women's Health
PubMed: 28320576
DOI: 10.1016/j.annepidem.2017.02.001 -
Neonatology 2015Five percent of newborn infants admitted to UK neonatal units during a recent study developed a platelet count <60 × 10(9)/l, and 60% of these were transfused... (Review)
Review
Five percent of newborn infants admitted to UK neonatal units during a recent study developed a platelet count <60 × 10(9)/l, and 60% of these were transfused platelets. This review summarises the common causes and mechanisms of thrombocytopenia in the newborn. Relevant evidence relating the platelet count to the risk of haemorrhage is reviewed, and current UK guidance on transfusion thresholds outlined. The UK policy for the provision of platelets for transfusion to neonates is described, including the particular requirements for neonatal allo-immune thrombocytopenia. Finally, we look towards the future and prospects for reducing the need to expose newborns to donor-derived platelets.
Topics: Hemorrhage; Humans; Infant, Newborn; Needs Assessment; Platelet Count; Platelet Transfusion; Practice Guidelines as Topic; Thrombocytopenia, Neonatal Alloimmune; United Kingdom
PubMed: 25301082
DOI: 10.1159/000365163 -
Platelets Nov 2020Despite the fact that elderly patients represent a prevalent and challenging population in the current practice, few data exist on the impact of platelet parameters on...
Despite the fact that elderly patients represent a prevalent and challenging population in the current practice, few data exist on the impact of platelet parameters on cardiovascular risk in these patients. Therefore, the aim of the present study was to evaluate the impact of age on the immature platelet count (IPC) and their relationship with CAD. We included a total of 2236 consecutive patients undergoing coronary angiography in a single center. Elderly patients (age ≥ 75 years) were 756 (33.7%). IPC was measured at admission. Elderly patients were more often females ( < .001), with lower BMI and prevalence of smokers ( < .001), and a more complex cardiovascular risk profile and coronary disease ( = .02). Platelet count decreased with aging ( = .05), whereas no difference in the mean IPC was found between patients < or ≥75 years. In fact, advanced age did not emerge as an independent predictor of IPC above III tertile (≥8.6*10^6/ml), (adjusted OR[95%CI] = 0.97[0.78-1.21], = .79). When considering elderly patients according to tertiles values of IPC (<5.1,5.1-8.59; ≥8.6*10^6/ml), we found no impact of IPC on the prevalence of CAD (81.1% vs 84.5% vs 81.5%, = .92; adjusted OR[95%CI] = 1.08[0.67-1.72], = .75) and its extent (37.7% vs 34.5% vs 40.2%, = .57; adjusted OR[95%CI] = 1.22[0.85-1.73], = .28). However, we observed a higher rate of calcified and type C lesions in elderly patients with higher IPC ( = .03 and < .001, respectively). Therefore, advanced age is not associated with higher immature platelet count and the prevalence and severity of CAD. Moreover, IPC does not contribute to explain the higher prevalence and extent of coronary artery disease observed in elderly patients.
Topics: Aged; Aging; Coronary Artery Disease; Female; Humans; Male; Platelet Count
PubMed: 31973643
DOI: 10.1080/09537104.2020.1714572 -
Diabetes Research and Clinical Practice Sep 2018The aim of this study is to investigate the effect of platelet count on the incidence of type 2 diabetes mellitus (DM) in the overall Korean adults and in participants...
AIMS
The aim of this study is to investigate the effect of platelet count on the incidence of type 2 diabetes mellitus (DM) in the overall Korean adults and in participants with impaired glucose tolerance (IGT) at baseline.
METHODS
A total of 7502 participants (3528 men and 3974 women) aged 40-69 years were enrolled in this study. The study population was divided into tertiles (T) of serum platelet counts. We used Cox regression to analyse the relationship between baseline platelet count and new-onset type 2 DM.
RESULTS
A total of 602 (8.0%) subjects developed type 2 DM during a mean follow-up of 8.4 years. Compared to the lowest tertile, the hazard ratio (95% confidence interval [CI]) for the incidence of type 2 DM was 1.28 (1.04-1.57) for T3 after adjusting for possible confounding factors. In subjects with IGT at baseline, the hazard ratio (95% CI) for the incidence of type 2 DM in T3 compared with T1 was 1.45 (1.05-2.00) after adjusting for the same confounders.
CONCLUSION
This prospective longitudinal study demonstrated that the incidence of type 2 DM increased as the serum platelet count at baseline increased within the normal range. This positive association was more prominent in subjects with IGT.
Topics: Adult; Aged; Diabetes Mellitus, Type 2; Female; Humans; Incidence; Male; Middle Aged; Platelet Count; Prospective Studies; Republic of Korea
PubMed: 30075179
DOI: 10.1016/j.diabres.2018.07.033 -
Platelets Jan 2022This study aimed to assess the association of postoperative platelet counts with early and late outcomes after thoracic endovascular aortic repair (TEVAR) for type B...
This study aimed to assess the association of postoperative platelet counts with early and late outcomes after thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD). We retrospectively evaluated 892 patients with TBAD who underwent TEVAR from a prospectively maintained database. Postoperative nadir platelet counts were evaluated as a continuous variable, and a categorical variable (thrombocytopenia), which was defined as platelet count≤ the lowest 10% percentile (108 × 10/l). Multivariable logistic regression analyses were conducted to assess the impact of postoperative thrombocytopenia on early outcomes, and multivariable cox regression analyses on long-term mortality. Patients with postoperative thrombocytopenia experienced significantly higher rates of postoperative mortality, prolonged intensive care unit stay, death, stroke, limb ischemia, mesenteric ischemia, acute kidney injury (AKI), and puncture-related hematoma (< .05 for each), but similar rates of immediate type I endoleak and spinal cord ischemia. Multivariable logistic analyses showed that postoperative thrombocytopenia was independently associated with postoperative stroke, limb ischemia, and AKI. Similar results were observed when postoperative nadir platelet count was modeled as a continuous predictor (< .05 for each). By multivariable Cox analyses, postoperative thrombocytopenia was an independent predictor for long-term all-cause mortality (hazard ratio 2.72, 95% CI, 1.72-4.29, < .001). For every 30 × 10/L decrease in postoperative platelet count, the risk of long-term all-cause mortality increased by 15% (HR 1.15; 95% CI 1.07-1.25; < .001). Therefore, postoperative thrombocytopenia might be a useful tool for risk stratification after TEVAR.
Topics: Aortic Dissection; Endovascular Procedures; Humans; Morbidity; Platelet Count; Survival Analysis; Treatment Outcome
PubMed: 33213236
DOI: 10.1080/09537104.2020.1847266 -
Journal of Clinical Laboratory Analysis Apr 2022Impedance 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...
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 × 10 /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 × 10 /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.
Topics: Blood Platelets; Erythrocyte Count; Erythrocyte Indices; Humans; Platelet Count; Reproducibility of Results
PubMed: 35274768
DOI: 10.1002/jcla.24218 -
Platelets 2019Cancer is a chronic inflammatory state which is often associated with increased platelet counts. Cancer cells induce thrombopoiesis and activate platelets, which in turn...
Cancer is a chronic inflammatory state which is often associated with increased platelet counts. Cancer cells induce thrombopoiesis and activate platelets, which in turn facilitate cancer invasion and metastasis. In this study, we investigate the correlation between platelet counts with each of stage and overall survival in melanoma. This is a retrospective cohort study of 642 melanoma patients diagnosed or treated at a tertiary medical center between 2000 and 2016. Multivariable analysis adjusted for age, sex, stage, and treatment modality. Using multivariable analysis, patients with thrombocytosis around time of diagnosis were more likely to present with distant metastasis (Prevalence Ratio 3.5, 95% CI 2.35-5.22). In patients with metastatic disease and in all stages combined, thrombocytosis predicted decreased 5-year overall survival in univariate and multivariable analysis, and this was most pronounced during the first year after diagnosis. Finally, we show that mice with thrombocytopenia due to the lack of heat shock protein gp96 in their megakaryocytes are protected from melanoma dissemination to the lungs. These findings are concordant with preclinical studies showing a role for platelets in cancer metastasis and suppression of antitumor immunity, further supporting targeting platelets as an adjuvant to immunotherapy in melanoma.
Topics: Female; Humans; Male; Melanoma; Middle Aged; Neoplasm Staging; Platelet Count; Prognosis; Survival Rate
PubMed: 30759042
DOI: 10.1080/09537104.2019.1572879