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Mean Platelet Volume (mean + platelet_volume)

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Medical Sciences	92%

Selected Abstracts

The effects of maximal treadmill graded exercise testing on haemorheological, haemodynamic and flow cytometry platelet markers in patients with systolic or diastolic heart failure

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 3 2008
I. Chung
ABSTRACT Background, Acute exercise has been associated with activation of thrombosis, and this risk may be accentuated in patients with heart failure. Given the relation of platelets to atherothrombosis, we tested the hypothesis that acute exercise would adversely affect platelet indices and platelet activation markers in patients with systolic and diastolic heart failure. Materials and methods, We studied 20 patients with systolic heart failure (17 men, 3 women; mean age 64 ± 10 years, all with ejection fraction (EF) , 40%) and 20 patients with diastolic heart failure (14 men, 6 women; mean age 64 ± 8 years, mean EF = 66%) who were exercised to maximal intensity, who were compared to 13 healthy controls (6 men, 7 women; mean age 60 ± 4 years, mean EF = 73%). We measured platelet indices (platelet volume, mass and component) and platelet activation markers (platelet-bound CD62P%G, CD63%G and CD40L%G using flow cytometry, as well as plasma sCD40L and soluble P-selectin (sP-sel) levels). Results, Baseline Mean Platelet Volume (MPV), sP-sel, CD40L%G and CD63%G levels were significantly higher in patients with systolic and diastolic heart failure, when compared with controls. The mean exercise duration and VO2 peak in patients with systolic and diastolic heart failure were not significantly different, but lower than that seen in healthy controls. Following exercise, mean haematocrit, CD62P%G, and CD63%G significantly increased in all three subject groups (all P < 0·05). The proportional change in CD62P%G and CD63%G were not significantly different between healthy controls and heart failure patients (P > 0·05). Conclusion, Acute maximal graded exercise increases platelet activation markers, with no disproportionate differences between heart failure patients and healthy controls, despite the former group having a lower exercise tolerance and VO2 peak. [source]

Mean platelet volume in neonatal respiratory distress syndrome

PEDIATRICS INTERNATIONAL, Issue 2 2009
Fuat Emre Canpolat
Abstract The aim of this study was to investigate the differences in mean platelet volume (MPV) between neonates with and without neonatal respiratory distress syndrome (RDS). Eighty-three premature infants who were admitted to the neonatal intensive care unit were included in the study. Forty-four of these infants were diagnosed as having RDS and the other 39 infants were non-RDS patients. Infants born to mothers with pre-eclampsia, or a drug history that had negative effects on platelet count, perinatal hypoxia, sepsis and necrotizing enterocolitis were excluded. Blood collection was done on the first and third days of life. There were no demographic, gestational or platelet count differences between groups, but MPV was higher in RDS patients and this difference was statistically significant (P= 0.011). High platelet volumes in RDS patients is probably related to young platelet production and may be a result of increased platelet consumption in pulmonary damage due to RDS. [source]

The use of platelet density and volume measurements to estimate the severity of pre-eclampsia

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 12 2000
P. Järemo
This study evaluated whether it is possible to estimate the severity of pre-eclampsia through in vitro measurements of platelet and granulocyte parameters. Eighteen pre-eclamptic women in the third-trimester of pregnancy and 11 women in the third-trimester of normal pregnancies were included in the study. Three to 12 months after delivery, 15 patients with pre-eclampsia and all the subjects with normal pregnancies were re-examined. Before delivery, peak platelet density was determined using a specially designed apparatus. Before and 3,12 months after delivery the following were measured: platelet counts, mean platelet volume and neutrophil and monocyte counts. Furthermore, circulating P-selectin, interleukin-6 and myeloperoxidase were determined to estimate platelet, monocyte and granulocyte activities, respectively. Compared to their results after delivery, pre-eclamptic females demonstrated lower platelet counts (P < 0·001) and raised mean platelet volumes (P < 0·01). Both pre-eclamptic women (P < 0·01) and normal pregnancies (P < 0·05) demonstrated elevated soluble P-selectin at pregnancy. Then pre-eclamptic women had advanced neutrophil counts (P < 0·01) but normal pregnancies showed a similar phenomenon (P < 0·001). Interleukin-6 remained normal during pregnancy. Plasma myeloperoxidase levels were lower both in pre-eclampsia (P < 0·05) and in normal pregnancies (P < 0·001). In pre-eclampsia elevated blood pressure was related to higher mean platelet volumes (P < 0·05). Furthermore, a group of pre-eclamptic females whose platelets had disturbed density distribution displayed elevated mean platelet volumes (P < 0·01). The present work demonstrates considerable platelet alterations in pre-eclampsia. We failed to show granulocyte involvement in the pathogenesis of the disease. Severe pre-eclampsia is related to elevated mean platelet volumes. The latter parameter is associated with disturbed density distribution. It appears possible to estimate disease severity from measurements of platelet density and volume. [source]

Haematological reference values in Spanish adolescents: the AVENA study

EUROPEAN JOURNAL OF HAEMATOLOGY, Issue 6 2009
Javier Romeo
Abstract Objectives:, To provide reference values for haematological indices in Spanish adolescents according to age and gender. Methods:, A cross sectional study conducted in five Spanish cities was performed. Blood was drawn from a representative sample of 581 adolescents with age ranging from 13 to 17,18.5 yr. Age- and gender-specific means, standard deviations and percentiles were determined for the following parameters: total red blood cell counts (RBC), haemoglobin concentration (Hb), haematocrit percentage (Hct), mean corpuscular volume (MCV), mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, red cell distribution width and total white blood cell (WBC) counts as well as counts and percentage of neutrophils, lymphocytes, monocytes, eosinophils and basophils; platelet count (PLT), mean platelet volume and plateletcrit percentage. Results:, Younger male subjects presented lower RBC, Hb, Hct and MCV means that their older counterpart. By contrast these differences were not observed in female subjects. As expected, RBC, Hb and Hct mean values in males were found significantly higher than in girls for all studied age groups. No significant differences were observed in WBC by age and gender. PLT values gradually decreased with age, except for females aged 17,18.5 yr. Conclusion:, The present study provides reference data on the distribution of haematological indices of Spanish adolescents. These data can be useful biomarkers of the nutritional status in adolescents. [source]

Quality counts: new parameters in blood cell counting

INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 3 2009
C. BRIGGS
Summary Recently several parameters have been introduced to the complete blood count such as nucleated red blood cells, immature granulocytes; immature reticulocyte fraction, immature platelet fraction and red cell fragments as well as new parameters for detection of functional iron deficiency. Leucocyte positional parameters, which may diagnose specific diseases (e.g. differentiate between abnormal lymphocytes in leukaemia and viral conditions and may also detect malarial infection) are now available. At this time they are only used for research; however, generally such parameters later become reportable. One manufacturer's routine analyser allows measurement of cells by flow cytometry using monoclonal antibodies. Currently, there are no accredited external quality assessment schemes (EQAS) for these parameters. For a number of parameters, on some instruments, there is no internal quality control, which brings into question whether these parameters should be used for clinical decision making. Other more established parameters, such as mean platelet volume, red cell distribution width and the erythrocyte sedimentation rate do not have EQAS available. The UK National EQAS for General Haematology held a workshop earlier this year in 2008 to discuss these parameters. Participants were asked to provide a consensus opinion on which parameters are the most important for inclusion in future haematology EQAS. [source]

Performance evaluation of the PENTRA 60C+ automated hematology analyzer and comparison with the ADVIA 2120

INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 2 2009
K. GUERTI
Summary The PENTRA 60C+ hematology analyzer provides a complete blood cell (CBC) count, including a five-part differential (5-DIFF) count and two leukocyte subpopulations, i.e. large immature cells (LIC's) and atypical lymphocytes (ALY's). We evaluated its analytical performance and assessed agreement with the ADVIA 2120, in order to install the analyzer in a small satellite hematology laboratory. First we assessed repeatability, reproducibility and carry-over to evaluate the analytical performance. Then we used Pearson correlation coefficients, Passing and Bablok regression analysis and a graphical approach (n = 209) to evaluate agreement with the ADVIA 2120. Repeatability and reproducibility were excellent for the majority of CBC and 5-DIFF count parameters. Carry-over was negligible. Our data showed very good correlation for most CBC count parameters. Lower correlation coefficients were observed for red cell distribution width, mean corpuscular volume and mean platelet volume. As compared to the ADVIA 2120, the 5-DIFF count performed very well. Agreement was poorer for low-level eosinophils and basophils. Furthermore, the PENTRA 60C+ was equally able to identify pathological blood samples through the determination of LIC's and ALY's. Therefore, the PENTRA 60C+ is an eligible blood cell counter to be operational in a satellite laboratory setting. [source]

Aging stability of complete blood count and white blood cell differential parameters analyzed by Abbott CELL-DYN Sapphire hematology analyzer

INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 1 2009
P. HEDBERG
Summary This study presents the results of an aging stability study of complete blood count (CBC) and leukocyte differential parameters using the Abbott CELL-DYN Sapphire hematology analyzer. Stability studies showed no substantial change in CBC parameters up to 24,48 h at +23 ± 2 °C (room temperature), except for optical platelet count (PLTo). For specimens aged over 24, the value of impedance platelet count yielded more reliable results than the routine PLTo. White blood cell (WBC) differential parameters, except eosinophils, were stable for up to 48 h at +23 ± 2 °C. CBC parameters were stable for 72 h, except mean platelet volume, which slightly increased between 48 and 72 h, at +4 °C. WBC differentials were stable 48,72 h, with a slight decrease observed in absolute neutrophils and lymphocytes at +4 °C. [source]

Significant differences between capillary and venous complete blood counts in the neonatal period

INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 1 2003
S.M. Kayiran
Summary The normal capillary and venous hematologic values for neonates have not been defined clearly. It is well known that capillary blood has higher hemoglobin (Hb) and hematocrit (Hct) values than venous blood. In a recent study, we reported differences between capillary and venous complete blood counts (CBC) in healthy term neonates on day 1 of life. The aim of this study was to extend our previous investigation. Term neonates (n=141) were stratified into four groups by days of postnatal age: group 2 (day 7, n=38), group 3 (day 14, n=35), group 4 (day 21, n=32) and, group 5 (day 28, n=36). Data from our previous study were included in the statistical analysis as group 1 (day 1, n=95). A CBC and differential count were carried out on each capillary and venous sample drawn simultaneously. Within each group, the mean and standard deviation for each parameter in capillary and venous blood were calculated and then compared using the paired sample t -test. In all groups, the capillary blood samples had higher Hb, Hct, red blood cell (RBC), white blood cell (WBC), and lymphocyte counts. In each group, venous platelet counts were significantly higher than the corresponding capillary values. There was also a trend toward higher venous mean corpuscular volume, higher capillary polymorphonuclear leukocyte (PML) count and mean platelet volume in all groups. In both capillary and venous blood, Hb, Hct, RBC, MCV values and WBC, lymphocyte, PML counts decreased and platelet counts increased steadily during neonatal period. This study reveals that CBC parameters and differential counts may differ depending on the blood sampling used. The findings underline the importance of considering the sample source when using hematologic reference ranges for healthy or septic neonates. When interpreting results, the term ,peripheral blood' should be replaced with ,capillary blood' or ,venous blood' so that an accurate assessment can be made. [source]

Clinical approach to the patient with unexpected bleeding

INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 2000
J. M. Teitel
Bleeding can be considered unexpected if it is disproportionate to the intensity of the haemostatic stress in a patient with no known haemorrhagic disorder or if it occurs in a patient in whom a bleeding disorder has been characterized but is adequately treated. A thorough history usually allows the clinician to predict reasonably accurately whether the patient is likely to have a systemic haemostatic defect (and if so whether it is congenital or acquired), or whether the bleeding likely has a purely anatomical basis. The nature of bleeding is instructive with respect to preliminary categorization. Thus, mucocutaneous bleeding suggests defects of primary haemostasis (disordered platelet,vascular interactions). Bleeding into deeper structures is more suggestive of coagulation defects leading to impaired fibrin clot formation, and delayed bleeding after primary haemostasis is characteristic of hyperfibrinolysis. Localized bleeding suggests an anatomical cause, although an underlying haemostatic defect may coexist. Where bleeding is so acutely threatening as to require urgent intervention, diagnosis and treatment must proceed simultaneously. In the case of minor haemorrhage (not threatening to life or limb) it may be preferable to defer therapy while the nature of the bleeding disorder is methodically investigated. Initial laboratory evaluation is guided by the preliminary clinical impression. The amount of blood loss can be inferred from the haematocrit or haemoglobin concentration, and the platelet count will quickly identify cases in which thrombocytopenia is the likely cause of bleeding. In the latter instance, examination of the red cell morphology, leucocyte differential, and mean platelet volume may allow the aetiological mechanism to be presumptively identified as hypoproliferative or consumptive. With regard to coagulation testing, the activated PTT, prothrombin time, and thrombin time usually constitute an adequate battery of screening tests, unless the clinical picture is sufficiently distinctive to indicate the immediate need for more focused testing. In any event, sufficient blood should be taken to allow more detailed studies to be done based on the results of these screening tests. These results will direct the need for further assays, such as specific clotting factor activity levels, von Willebrand factor assays, tests for coagulation inhibitors, platelet function assays, and markers of primary or secondary fibrinolytic activity. [source]

Mean platelet volume in neonatal respiratory distress syndrome

Quantitative trait loci for porcine white blood cells and platelet-related traits in a White Duroc × Erhualian F2 resource population

ANIMAL GENETICS, Issue 3 2009
S. Yang
Summary White blood cell count and platelets are implicated as risk factors for common complex diseases. Genetic factors substantially affect these traits in humans and mice. However, little is known about the genetic architecture of these traits in pigs. To identify quantitative trait loci (QTL) for leucocyte- and platelet-related traits in pigs, the total leucocyte number and differential leucocyte counts including the fraction of basophils, eosinophils, lymphocytes, monocytes, neutrophils, and a series of platelet parameters including platelet count, mean platelet volume, platelet distribution width and plateletcrit were measured in 1033 F2 animals on 240 days from a White Duroc × Erhualian intercross resource population. A total of 183 informative microsatellites distributed across 19 pig chromosomes (SSC) were genotyped across the entire resource population. Thirty-three QTL were identified for the examined traits, including eight genome-wide significant QTL for white blood cells and differential leucocyte counts on SSC2, 7, 8, 12 and 15 and six significant QTL for platelet-related traits on SSC2, 8, 13 and X. Erhualian or White Duroc alleles were not systematically associated with increased phenotypic values. These results not only confirmed many QTL identified previously in the mouse and swine, but also revealed a number of novel QTL for the traits recorded. Moreover, it is the first time that QTL for platelet-related traits in pigs have been reported. [source]

Platelet mass has prognostic value in patients with myelodysplastic syndromes

BRITISH JOURNAL OF HAEMATOLOGY, Issue 2 2006
Kristian M. Bowles
Summary Platelet mass (mean platelet volume × platelet count) can be derived from data obtained from the routine full blood count and separates patients with myelodysplastic syndromes (MDS) at diagnosis into three distinct prognostic groups: low platelet mass group , median survival 5 months and 5-year survival 0%; intermediate platelet mass group , median survival 30 months and 5-year survival 34%; high platelet mass group median survival , not reached at 82 months follow-up with a 5-year survival of 82%. These data provide a simple rapid prognostic index at the time of diagnosis in MDS. [source]