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Platelets Jun 2003It has been suggested that thromboelastography TEG) can help in limiting or directing the appropriate use of blood products during surgery. However, the contribution of...
It has been suggested that thromboelastography TEG) can help in limiting or directing the appropriate use of blood products during surgery. However, the contribution of platelets to the TEG profile has not been studied in detail. Blood was taken from eight healthy subjects and eight patients with peripheral arterial disease (PAD). Immunomagnetic separation was achieved by the addition of Dynabeads labeled with a CD41 murine antibody (to the GPIIb/IIIa receptor) to achieve 90-100% depletion of platelets from blood. This was then titrated with whole blood to achieve platelet counts of approximately 0, 25 and 50% of the original count to compare with whole blood using TEG. Platelet function was also assessed by spontaneous platelet aggregometry (SPA) at baseline and at the 50% dilution. SPA, maximum amplitude (MA) and K time were significantly different in PAD patients compared to controls (P < 0.05). In both controls and PAD patients there was a strong linear correlation between Log10 [platelet count] and MA (r = 0.97 for controls, r = 0.89 for PAD) and K time (r = -0.86 for controls, r = -0.68 for PAD). Correlation between Log10 [platelet count] and R time was poor in both groups. The MA and K TEG parameters may be most useful for assessing platelet transfusion requirements.
Topics: Aged; Aged, 80 and over; Blood Platelets; Case-Control Studies; Humans; Immunomagnetic Separation; Middle Aged; Peripheral Vascular Diseases; Platelet Count; Platelet Function Tests; Thrombelastography
PubMed: 12850830
DOI: 10.1080/0953710031000118849 -
Laboratory Medicine Jan 2023Although small red blood cells are a well-known analytical pitfall that could cause artifactual increase of the platelet count, limited information is available on the...
OBJECTIVE
Although small red blood cells are a well-known analytical pitfall that could cause artifactual increase of the platelet count, limited information is available on the accuracy of impedance platelet counting in cases with microcytosis. The aim of this study is to assess the accuracy of impedance platelet counting in the presence of small red blood cells, and to establish the optimal mean corpuscular volume (MCV) cutoff to endorse fluorescence platelet counting.
METHODS
In this study, platelet counts estimated by the impedance method on the Sysmex XN9000 analyzer (Sysmex, Kobe, Japan) were compared with those provided by the fluorescence method. The accuracy of impedance platelet counting was assessed. Receiver operating characteristic curve was used to evaluate the performance of MCV in predicting falsely increased platelet counts.
RESULTS
There was a tendency for the impedance method to overestimate the platelet count in samples with 70 fL < MCV ≤ 80 fL, 60 fL < MCV ≤ 70 fL, MCV ≤ 60 fL. Receiver operating characteristic curve analysis showed that a 73.5fL cutoff of MCV was highly sensitive in predicting falsely increased platelet counts.
CONCLUSION
In cases with MCV < 73.5 fL, we strongly suggest that the platelet counts obtained by the impedance method on the Sysmex XN9000 analyzer should be checked and corrected by fluorescence counting.
Topics: Humans; Platelet Count; Hematology; Erythrocytes; Erythrocyte Indices; Reproducibility of Results
PubMed: 35713611
DOI: 10.1093/labmed/lmac063 -
Laboratory Medicine May 2022To indicate the ability to disaggregate platelet clumps by vortex mixing and kanamycin supplementation in EDTA-dependent pseudothrombocytopenia (EDTA-PTCP) specimens.
OBJECTIVE
To indicate the ability to disaggregate platelet clumps by vortex mixing and kanamycin supplementation in EDTA-dependent pseudothrombocytopenia (EDTA-PTCP) specimens.
MATERIALS AND METHODS
For patients with EDTA-PTCP, citrate-anticoagulated, primary EDTA-anticoagulated, vortex-mixed, and kanamycin-treated specimens were tested for complete blood count and platelet-related parameters.
RESULTS
Forty-eight specimens were included. Nineteen (39.6%) of the vortex-mixed specimens and 42 (87.5%) of the kanamycin-treated specimens revealed platelet counts more than those of the primary EDTA specimens, with levels exceeding 100 × 109/L. The platelet count and platelet recovery of the kanamycin-treated specimens were higher than those of the vortex-mixed specimens.
CONCLUSION
Kanamycin supplementation to EDTA-PTCP blood may be considered as an alternative approach when the recollection of specimens is impractical. Only platelet-related parameters from kanamycin treatment were suitable for guiding patient management. Further studies about the impact of these methods in patients with various conditions, such as in patients with advanced kidney disease, should be conducted.
Topics: Blood Platelet Disorders; Dietary Supplements; Edetic Acid; Humans; Kanamycin; Platelet Aggregation; Platelet Count; Thrombocytopenia
PubMed: 34668538
DOI: 10.1093/labmed/lmab090 -
Hamostaseologie Apr 2021Aside from their canonical role in hemostasis, it is increasingly recognized that platelets have inflammatory functions and can regulate both adaptive and innate immune... (Review)
Review
Aside from their canonical role in hemostasis, it is increasingly recognized that platelets have inflammatory functions and can regulate both adaptive and innate immune responses. The main topic this review aims to cover is the proinflammatory effects and side effects of platelet transfusion. Platelets prepared for transfusion are subject to stress injury upon collection, preparation, and storage. With these types of stress, they undergo morphologic, metabolic, and functional modulations which are likely to induce platelet activation and the release of biological response modifiers (BRMs). As a consequence, platelet concentrates (PCs) accumulate BRMs during processing and storage, and these BRMs are ultimately transfused alongside platelets. It has been shown that BRMs present in PCs can induce immune responses and posttransfusion reactions in the transfusion recipient. Several recent reports within the transfusion literature have investigated the concept of platelets as immune cells. Nevertheless, current and future investigations will face the challenge of encompassing the immunological role of platelets in the scope of transfusion.
Topics: Humans; Platelet Count; Platelet Transfusion
PubMed: 33711849
DOI: 10.1055/a-1347-6551 -
Platelets Jan 2021The spleen, in addition to its role in immunity, plays key roles in erythrocyte maintenance and platelet sequestration. Loss of the spleen via splenectomy occurs in... (Review)
Review
The spleen, in addition to its role in immunity, plays key roles in erythrocyte maintenance and platelet sequestration. Loss of the spleen via splenectomy occurs in approximately 6.4 to 7.1 per 100 000 people per year globally, commonly as a life-saving emergency procedure in trauma and a therapeutic procedure in hematological and hematological malignant conditions. It is associated with increased risk of life-threatening infection and thromboembolism, presumably via loss of splenic function, but the underlying mechanisms behind post-splenectomy thromboembolism are unclear. The splenectomized individual has a two-fold risk of thromboembolism as compared to non-splenectomized individuals and the risk of thromboembolism is elevated both post-operatively and in the longer term. Although those splenectomized for hematological conditions or hematological malignant conditions are at highest risk for thromboembolism, an increase in thromboembolic outcomes is also observed amongst individuals splenectomized for trauma, suggesting underlying disease state is only a partial factor. Although the physiological role of the splenic platelet pool on platelets is unclear, platelet changes after splenectomy suggest that the spleen may play a role in maintaining platelet quality and function. In hypersplenic conditions, sequestration can increase to sequester up to 72% of the total platelet mass. Following splenectomy, a thrombocytosis is commonly seen secondary to the loss of the ability to sequester platelets. Abnormal platelet quality and function have been observed as a consequence of splenectomy. These platelet defects seen after splenectomy may likely contribute to the increase in post-splenectomy thromboembolism. Here we draw upon the literature to characterize the post-splenectomy platelet and its potential role in post-splenectomy thromboembolism.
Topics: Blood Platelets; Female; Humans; Male; Phenotype; Platelet Count; Spleen; Splenectomy
PubMed: 32106750
DOI: 10.1080/09537104.2020.1732322 -
International Journal of Laboratory... Feb 2015
Topics: Blood Platelets; Hematopoietic Stem Cell Transplantation; Humans; Platelet Count; Reference Values; Thrombopoiesis
PubMed: 24739132
DOI: 10.1111/ijlh.12237 -
Platelets Nov 2016Several hundreds of studies recently investigated mean platelet volume (MPV) as measured by electronic cell counters in a wide variety of acquired diseases, and most of... (Review)
Review
Several hundreds of studies recently investigated mean platelet volume (MPV) as measured by electronic cell counters in a wide variety of acquired diseases, and most of them found that platelet size was significantly increased with respect to healthy subjects. On this basis, it has been suggested that MPV can be used for diagnostic purposes. Moreover, investigation of subjects with arterial thrombosis not only revealed that their platelets were larger than those of controls, but also found that a high MPV predicted poor prognosis. Despite the large amount of available data, the pathogenesis of increased platelet size in these conditions is unclear. In particular, we do not know whether the increased platelet size is the cause or the consequence of thrombosis. Differences in MPV between patients and controls are usually very small and they reach the statistical significance because of the large number of investigated patients and the standardized methodology for MPV measurement. In real life, the wide variability of MPV possibly due to platelet count, sex, age, and ethnicity, as well as the very poor standardization of the methodologies used for MPV measurement, makes it impossible to decide whether an individual patient has normal or instead slightly increased MPV. So, MPV has presently no role in making diagnosis and defining prognosis in any acquired illness.
Topics: Blood Platelets; Humans; Mean Platelet Volume; Platelet Count; Practice Guidelines as Topic; Prognosis; Reproducibility of Results; Thrombosis
PubMed: 27686008
DOI: 10.1080/09537104.2016.1224828 -
American Journal of Hematology Nov 1987The in vitro effect of heparin on platelet aggregation was studied in three groups: in 26 subjects recently treated with heparin, in 18 subjects on maintenance...
The in vitro effect of heparin on platelet aggregation was studied in three groups: in 26 subjects recently treated with heparin, in 18 subjects on maintenance hemodialysis, and in 20 normal controls. With the aid of Technicon H6000, platelet counts and platelet aggregations were compared in whole blood samples collected in ethylenediaminetetraacetic acid (EDTA) and in heparinized tubes. Although there was no significant difference between platelet count of heparinized and EDTA blood in the control group, the dialysis group and the group recently treated with heparin showed significantly lower platelet counts and more platelet aggregation in heparinized tubes than in EDTA tubes. We speculate that the majority of subjects exposed to heparin develop an antibody or a proaggregator which can aggregate or agglutinate platelets in the presence of heparin and causes destruction of platelets; but only in a small percentage of subjects receiving heparin is this reaction severe enough to cause thrombocytopenia.
Topics: Edetic Acid; Heparin; Humans; In Vitro Techniques; Kinetics; Platelet Aggregation; Platelet Count; Reference Values; Renal Dialysis; Temperature
PubMed: 3118699
DOI: 10.1002/ajh.2830260307 -
Veterinary Clinical Pathology Sep 2008Many Cavalier King Charles Spaniel (CKCS) dogs are affected by an autosomal recessive dysplasia of platelets resulting in fewer but larger platelets. The IDEXX Vet...
BACKGROUND
Many Cavalier King Charles Spaniel (CKCS) dogs are affected by an autosomal recessive dysplasia of platelets resulting in fewer but larger platelets. The IDEXX Vet Autoread (QBC) hematology analyzer directly measures the relative volume of platelets in a blood sample (plateletcrit). We hypothesized that CKCS both with and without hereditary macrothrombocytosis would have a normal plateletcrit and that the QBC results would better identify the total circulating volume of platelets in CKSC than methods directly enumerating platelet numbers.
OBJECTIVES
The major purpose of this study was to compare the QBC platelet results with platelet counts from other automated and manual methods for evaluating platelet status in CKCS dogs.
METHODS
Platelet counts were determined in fresh EDTA blood from 27 adult CKCS dogs using the QBC, Sysmex XT-2000iV (optical and impedance), CELL-DYN 3500, blood smear estimate, and manual methods. Sysmex optical platelet counts were reanalyzed following gating to determine the number and percentage of normal- and large-sized platelets in each blood sample.
RESULTS
None of the 27 CKCS dogs had thrombocytopenia (defined as <164 x 10(9) platelets/L) based on the QBC platelet count. Fourteen (52%) to 18 (66%) of the dogs had thrombocytopenia with other methods. The percentage of large platelets, as determined by regating the Sysmex optical platelet counts, ranged from 1% to 75%, in a gradual continuum.
CONCLUSIONS
The QBC may be the best analyzer for assessing clinically relevant thrombocytopenia in CKCS dogs, because its platelet count is based on the plateletcrit, a measurement of platelet mass.
Topics: Animals; Blood Platelet Disorders; Diagnostic Tests, Routine; Dog Diseases; Dogs; Platelet Count; Predictive Value of Tests
PubMed: 18761517
DOI: 10.1111/j.1939-165X.2008.00054.x -
Clinical Chemistry and Laboratory... Feb 2016
Topics: Area Under Curve; Automation; Blood Platelets; Humans; Platelet Count; ROC Curve
PubMed: 26154195
DOI: 10.1515/cclm-2015-0409