SEARCH · Search PubMed

Results for “Platelet Count”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

PubMed1987

Platelet count is positively correlated with white cell count and red cell count.

Platelet count is positively correlated with the white cell count in healthy males aged 20-68 years (p less than 0.002) and in healthy medical students of both sexes aged 18-22 years (p less than 0.0001). Platelet count is also positively correlated with red cell count in healthy males (p less than 0.02). Red cell count is positively correlated with white cell count in the older healthy males (p less than 0.02) and in the male medical students (p less than 0.003). These findings provide support for the concept of a single hormone-dependent pluripotent stem cell whose effect is seen concomitantly in all circulating blood cells. The white cell count and platelet count correlation is less significant in the males aged 35 or above which may represent the development of pathological mechanisms.

Adolescent↗

PubMed1995

Platelet count and platelet indices at various stages of normal pregnancy in smoking and non-smoking women.

UNLABELLED: Our objective was to compare the platelet count and platelet indices of smoking and non-smoking women at different stages of normal pregnancy. STUDY DESIGN: In 247 non-smoking and 123 smoking healthy pregnant women the platelet count, the mean platelet volume, the platelet distribution width and the plateletcrit were compared at 0-10, 11-20, 21-30 and 31-40 weeks of pregnancy. Exclusion criteria were a diastolic pressure > or = 90 mmHg, an endocrine disease, a coagulation disorder, acetylsalicylic acid or phenprocoumon use. A women was considered a smoker if she smoked more than 4 cigarettes a day. Non-smokers were defined as women reporting no smoking at all. Blood samples were run on the Sysmex NE-8000. RESULTS: There was no significant difference between the platelet count in the two groups. In the non-smoking group, the platelet count showed a significant decrease with gestational age (287 x 10(9)/l to 258 x 10(9)/l). This was not the case in the smokers group. The mean platelet volume of the smokers was significantly lower than that of the non-smokers in the last ten weeks of pregnancy (10.4 fl versus 10.7 fl). The platelet distribution width and the plateletcrit did not change under the influence of cigarette smoking. CONCLUSION: Smoking during pregnancy does not significantly affect platelet count or platelet indices.

Adult↗

PubMed1996

Ethnic and sex differences in the total and differential white cell count and platelet count.

AIM/BACKGROUND: Previous studies have suggested that healthy subjects of African ancestry have lower total white cell counts, neutrophil counts and platelet counts than Caucasian subjects and that, at least among Caucasians, women have higher neutrophil and platelet counts than men. The primary aim of this study was to confirm and quantify the ethnic differences, confirm the sex difference in Caucasians and determine whether there was a similar sex difference in non-Caucasians. A secondary aim was to establish reference ranges for white cell and platelet counts for the different ethnic and sex groups. METHODS: The study population comprised 417 healthy volunteers (201 women and 216 men), of whom 200 were Caucasian, 102 were Afrocaribbean and 115 were African. Full blood counts, including a differential white cell count, were measured using a H.2 automated differential counter. White cell and platelet counts were compared between the three different ethnic groups and between men and women. Reference ranges were determined for each ethnic and sex group. RESULTS: Africans and Afrocaribbeans had lower total white cell, neutrophil and platelet counts than Caucasians and counts were lower in Africans than in Afrocaribbeans. Women had higher neutrophil and platelet counts than men in all ethnic groups. CONCLUSIONS: Sex and ethnic origin should be taken into consideration when assessing white cell and platelet counts.

Adult↗

PubMed2005

Producing accurate platelet counts for platelet rich plasma: validation of a hematology analyzer and preparation techniques for counting.

Platelet rich plasma (PRP) has been shown to clinically accelerate healing of both soft and hard tissues. As a result, it has gained increasing popularity. However, the clinical effectiveness of each type of PRP preparation method can vary in technique and efficiency, and current methods to evaluate the platelet concentration efficiency of PRP systems have several limitations. Therefore, the purpose of this study was to validate an automated hematology analyzer, the Cell-Dyn 3700, to accurately count platelets in concentration ranges of approximately 2,000,000-4,800,000 platelets/microL. PRP platelets were counted by way of a manual counting method and on the Cell-Dyn 3700, and the statistical evaluation indicated no difference between the groups (P > 0.05). Dilution of the PRP was not required, and accurate platelet counts could be achieved up to platelet concentrations of 4,800,000 platelets/microL. PRPs must be resuspended on a rocker for at least 5 minutes before platelet counts, and the entire PRP sample must be resuspended to allow for equal distribution of platelets before counting. With use of the validated Cell-Dyn 3700, a platelet concentrate system was used to prepare 153 PRPs. The baseline whole blood platelet concentration (328,000 platelets/microL +/- 69,000 platelets/microL) and the average PRP samples (2,645,000 platelets/microL +/- 680,000 platelets/microL) were compared, resulting in an eightfold increase in concentration and an average platelet percent recovery of approximately 76%. Automated hematology analyzers can be used to accurately count platelets in PRP given the system has been validated appropriately and the PRP samples are prepared properly to provide adequate platelet suspension.

Animals↗

PubMed1999

Economic impact of donor platelet count and platelet yield in apheresis products: relevance for emerging issues in platelet transfusion therapy.

INTRODUCTION: We analyzed donor platelet counts and platelet product yields in 708 consecutive platelet aphereses in our program in order to define the importance of this relationship for emerging issues in platelet transfusion therapy. METHODS: Aphereses performed on the Spectra 3.6 (COBE, Lakewood. Colo.) the CS-3000 Plus (Fenwall-Baxter, Deerfield, Ill.) were analyzed. RESULTS: Mean platelet count was 237+/-49x10(3)/mm3 (mean +/- SD), and mean yield was 4.24+/-1. 09x10(11) platelets. Eigthy-five (12%) procedures generated less that 3x10(11) platelets. Only thirty-eight (5.4%) procedures yielded >/=6x10(11) platelets, so that 'split products' could be obtained. Platelet yields were primarily related to the biologic contribution (baseline platelet count) of the donor. Procedure parameters selected for harvest, and the efficiency of the device also had a significant, but less important role in determining the final platelet yield. An increase in mean donor platelet count achieved with Mpl ligand therapy from 240,000 to 320,000/mm3 would reduce the cost from USD 378 to 267 for each apheresis product, since the fraction of split products would exceed 50% of apheresis procedures. CONCLUSION: Increasing the donor platelet count would have a significant economic impact on platelet apheresis programs, as well as important clinical consequences for the role of platelet apheresis products in future transfusion strategies.

Adult↗

PubMed2006

The influence of bromelain on platelet count and platelet activity in vitro.

Bromelain is a general name for a family of sulfhydryl-containing, proteolytic enzymes from the pineapple plant. The aim of the present study was to investigate the influence of bromelain on platelet count, platelet aggregation and platelet activity in vitro. Blood samples were taken from the antecubital vein of 10 healthy male non-smokers. Platelet count decreased after incubation with 2.5 and 5 mg bromelain/ml from 277 +/- 17 platelets/nl before to 256 +/- 21 and 247 +/- 19 platelets/nl after the treatment. The ADP and TRAP-6 induced platelet aggregation led to a significant decrease after the incubation with 2.5 mg (ADP: 48.6 +/- 25.7%; TRAP-6: 49.6 +/- 28.9%) or 5 mg (ADP: 5.0 +/- 4.6%; TRAP-6: 9.0 +/- 4.9%) bromelain/ml in comparison to control (ADP: 81.4 +/- 5.0%; TRAP-6: 77.4 +/- 10.4%). The percentage of unstimulated CD62P positive platelets which were investigated by flow cytometry was minimally higher after incubation with 5 mg bromelain/ml (0.57 +/- 0.48% PC) in comparison to control (0.22 +/- 0.11% PC), but after TRAP-6 stimulation the incubation with 5 mg bromelain/ml led to a remarkable decrease in comparison to the untreated control (50.4 +/- 20.2 to 0.9 +/- 0.8% PC). The changes of CD62P (TRAP-stimulated) and the results of platelet aggregation after incubation with bromelain in vitro may demonstrate the potential of bromelain as a substance for platelet inhibition.

Adenosine Diphosphate↗

PubMed2005

Platelet count, mean platelet volume and thrombocytopoietic indices in healthy women and men.

UNLABELLED: Gender-dependent differences in platelet count have been demonstrated in few studies. In women platelet count is higher than in men, which seems to reflect different hormonal profiles or a compensatory mechanism associated with menstrual blood loss. The aim of the study was to assess platelet count, mean platelet volume and thrombocytopoietic indices in women and men. The study was conducted on healthy blood donors divided into groups: F - 60 women and M - 65 men. Platelet count and mean platelet volume were determined on a haematological analyser Advia 120, Bayer. The following thrombocytopoietic indices were measured: thrombopoietin concentration (ELISA), percentage of reticulated platelets (flow cytometry, COULTER EPICS XL) and absolute reticulated platelet count. RESULTS: Higher platelet count was noted in the group of women 252.35 +/- 41.25 x 10(9)/l as compared to men 221.87 +/- 37.63 x 10(9)/l (p = 0.0002). At the same time women had lower thrombopoietin concentration 156.50 +/- 57.18 pg/ml compared to men 180.46 +/- 60.98 pg/ml, (p = 0.03). No statistically significant differences were found in the mean platelet volume, percentage of reticulated platelets or absolute reticulated platelet count between group F and M. CONCLUSIONS: Platelet count is gender-dependent, being higher in women than in men. Thrombopoietin concentration is gender-dependent and is lower in women than in men. In physiological conditions, there is no correlation between platelet count and thrombopoietin concentration in women (r = -0.155) and men (r = -0.2586).

Adult↗

PubMed2004

Platelet count and platelet parameters in hemoglobin E carriers.

Hemoglobinopathies are an important inherited disorder with a high prevalence in Thailand. Of several hemoglobinopathies, hemoglobin E (Hb) disorder (beta 26, GAG-AAG, Glu-Lys) is the most common. Coagulation disorders in these patients have also been proposed. Even though thrombotic risks in the patients with hemoglobin disorders from standpoints of platelet dysfunction and coagulation factors are controversial, they are in favor of thrombosis due to thrombocytosis. A study was performed in 57 healthy subjects to evaluate platelet count and platelet parameters in hemoglobin E carriers compared to values in healthy subjects. Classified by standard hemoglobin electrophoresis, there were 46 healthy subjects and 11 hemoglobin E carriers. There are no significant differences in platelet count and platelet parameters between the two groups (p > 0.05). Although there are reports that indicate the change in the quality of platelet in hemoglobin E disorders, no quantitative disorder was detected. There was no trend toward increased platelet count in the HbE carriers.

Adult↗

PubMed1999

[Preeclampsia not (yet) predictable from the blood platelet count].

Platelet activation plays an important role in the pathogenesis of pre-eclampsia as demonstrated by reduced platelet count, increased mean platelet volume and elevated plasma concentrations of beta-thromboglobulin and platelet factor 4 in pre-eclamptic patients. Thrombocytopenia precedes the onset of clinical symptoms of pre-eclampsia. Possibly an enhanced activation state of the platelets in the circulation is present some time before the onset of pre-eclampsia: platelet activation might then be used to predict pre-eclampsia. Flow cytometry is considered the most sensitive technique at this moment to measure the activation of platelets. Fluorescent-labelled antibodies are used to detect antigens that appear on the platelet surface or change their conformation upon activation. During the first and second trimester of pregnancy pre-eclamptic patients have an increased expression of some antigens on the surface of their platelets, such as CD63. There is no reliable platelet test yet to predict the onset of pre-eclampsia.

Adult↗

PubMed2005

Use of native or platelet count adjusted platelet rich plasma for platelet aggregation measurements.

BACKGROUND: It is still not clear whether native or platelet count adjusted platelet rich plasma (PRP) should be used for platelet aggregation measurements. AIM: To evaluate the necessity of using adjusted PRP in platelet function testing. METHODS: Platelet aggregation with native PRP and adjusted PRP (platelet count: 250/nl, obtained by diluting native PRP with platelet poor plasma) was performed on the Behring Coagulation Timer (BCT(R)) using ADP, collagen, and arachidonic acid as agonists. Healthy subjects, patients on antiplatelet treatment, and patients with thrombocytosis (platelet counts in PRP > 1250/nl) were investigated. RESULTS: No significant differences in the maximum aggregation response were seen when using either native or adjusted PRP from healthy subjects and patients on antiplatelet treatment. Nevertheless, some patients taking aspirin or clopidogrel showed reduced inhibition of ADP and arachidonic acid induced aggregation in adjusted PRP but not in native PRP. The maximum velocity of healthy subjects and patients on antiplatelet treatment varied significantly as a result of the degree of dilution of the adjusted PRP. Surprisingly, the BCT provided good results when measuring platelet aggregation of native PRP from patients with thrombocytosis, whereas commonly used aggregometers could not analyse platelet aggregation of native PRP in these patients. CONCLUSION: The time consuming process of PRP adjustment may not be necessary for platelet aggregation measurements. Moreover, using adjusted PRP for monitoring aspirin or clopidogrel treatment may falsify results. Therefore, it may be better to use native PRP for platelet aggregation measurements, even in patients with thrombocytosis.

Adult↗

PubMed1987

Effect of heparin on platelet count and platelet aggregation.

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.

Edetic Acid↗

PubMedDate not supplied

Endomitotic index of megakaryocytes measured by flow cytometry helps to diagnose hematological disorders with abnormal platelet counts.

Platelet production is a regulated phenomenon. Indeed, megakaryocyte volume is inversely correlated to the platelet count not only in normal individuals and immune thrombocytopenic purpura patients, but also, and surprisingly, in chronic myeloid leukemia patients. Patients with polycythemia vera and essential thrombocythemia are located outside this regression line. Herein, we describe morphometrical data confirmed by the flow cytometric measurement of the megakaryocyte endomitotic index (EI). The EI is a value which reflects the mean ploidy of megakaryocytes and corresponds to the mean of (¿log2 DNA content expressed in N¿-1). In this study, the megakaryocyte endomitotic index of 14 normal individuals was compared to those of chronic myeloid leukemia (CML) patients (n = 16), immune thrombocytopenic purpura (ITP) patients (n = 11), essential thrombocythemia (ET) patients (n = 10) and polycythemia vera (PV) patients (n = 12). The megakaryocyte EI was significantly lower in CML patients than in normal individuals. In contrast, in ET, PV and ITP patients, megakaryocyte EI was higher than in normal individuals. An inverse relationship between the endomitotic index estimated by flow cytometry and the mean megakaryocyte volume performed by morphometry was observed in normal individuals, CML and ITP patients. In conclusion, the endomitotic index is higher in ITP, ET and PV patients and lower in CML patients when compared to normal individuals and is an interesting tool which can help to diagnose rapidly hematological disorders with abnormal platelet counts.

Adolescent↗

PubMed1996

Poor predictive value of platelet count, mean platelet volume and serum urate in hypertension in pregnancy.

OBJECTIVE: To determine the usefulness of platelet count, mean platelet volume and serum uric acid levels in the prediction of pre-eclampsia in women with mild hypertension in pregnancy, and to see if it is appropriate to base the management of such patients on these tests. SUBJECTS: Three hundred and thirty-six women attending the antenatal day unit with a diagnosis of non-proteinuric hypertension in pregnancy (diastolic blood pressure > or = 90 mmHg on two separate recordings) from whom at least one blood sample was taken. MAIN OUTCOMES MEASURED: The development of proteinuria (1+ or greater on urine Albustix); the need for oral antihypertensive medication, the need for the 'pre-eclampsia regime' intra- or post-partum; the need for induction of labour because of hypertension. RESULTS: No test, at any cut-off level, was found to be of any use in predicting the outcomes studied. Nor was a weekly change in any of the tests found to be of any use. CONCLUSION: Basing the management of patients with mild non-proteinuric hypertension on the results of platelet count, mean platelet volume or urate level is unwise as none of these tests was able to predict outcome in such patients.

Female↗

PubMed2002

Thrombocytopenia in patients with malaria: automated analysis of optical platelet counts and platelet clumps with the Cell Dyn CD4000 analyser.

Platelet counts and automated detection of platelet clumps were evaluated by optical analysis with the Abbott CD4000 analyser (Abbott Diagnostics, Santa Clara, CA, USA) in this South African study of 828 samples referred for malaria investigations. Based on microscopy (Micro) and rapid tests (RT) for HRP2 protein and parasite-associated LDH, malaria negative samples (n = 417) were defined as Micro-, RT-. Convalescent cases (n = 64) were Micro-, RT+ and had a recent record of positive microscopy. Malaria positive cases were subdivided into Micro+ (n = 315) and Micro-, RT+, PCR+ (polymerase chain reaction) (n = 32) subgroups. The mean platelet count for Micro+ cases (89.7 x 10(9)/l) was significantly lower than both the malaria negative (mean 212.6 x 10(9)/l) and convalescent malaria (mean 152.8 x 10(9)/l) groups; 89% of microscopy positive cases were thrombocytopenic (< 150 x 10(9)/l) and 30% had severe thrombocytopenia (< 50 x 10(9)/l). For comparison, 32% of the 417 malaria negative samples were thrombocytopenic and 6% of these were severe. Two thirds of samples with parasitaemia above 10% had platelet counts of < 50 x 10(9)/l while the counts were largely independent of parasite numbers when the parasitaemia was below 10%. Thirty percent of samples with microscopically detectable parasites had a PltClmp flag compared to 13% of the malaria negative group but, when the actual platelet count was taken into account, it became apparent that appearance of the flag was primarily associated with thrombocytopenia per se rather than malaria status. In most samples with a PltClmp flag, the CD4000 optical platelet clump 'signature' was indicative of small platelet aggregates and giant platelets. Morphological examination confirmed the presence of varying numbers of small platelet aggregates (3-12 individual platelets), often together with increased giant platelets, in many samples with a PltClmp flag. The observations suggest that while patients with malaria may be predisposed to the development of thrombocytopenia, a reduced platelet count in some patients may also be due in part to pseudo-thrombocytopenia.

Artifacts↗

PubMed1995

Platelet count and platelet factor 3 (PF-3) availability in sickle cell disease.

In view of the effect of red blood cell membrane on platelet factor 3 release in sickle cell disease, platelet count and platelet factor 3 (PF-3) availability were measured in 30 sickle cell patients in a stable state and 15 with thrombocytosis, and these were compared with 60 non-sickle cell individuals as controls. There were no significant differences in platelet counts, but there was a slightly higher PF-3 availability in sickle cell patients not in crisis than in the controls (P < 0.025). Sickle cell patients with thrombocytosis made PF-3 available more readily than did the control individuals and sickle cell patients not in crisis (P < 0.001). We conclude that sickle cell patients are capable of making platelet factor 3 readily available for coagulation activation, and this may play a decisive role in vaso-occlusive crisis.

Anemia, Sickle Cell↗

PubMed2004

Effect of smoking on platelet count and platelet parameters: an observation.

Arterial thrombosis occurs with increased frequency in cigarette smokers. It is believed that disturbance of platelet function, especially aggregation, is the essential mechanism responsible for this pathology. However, the effect of smoking on the quantity of platelets might be another contributing factor. The effect of smoking on platelet count is still controversial. We performed a cross section-al study to compare the platelet count and platelet parameters in Thai police who are smokers and non-smokers. A total of 30 Thai police in Bangkok were included in this study. Of the 30 police, there are 5 non-smokers and 25 smokers. The platelet counts and platelet parameters of the subjects were not significantly different between smokers and non-smokers.

Adult↗

PubMed1980

A comparison of the effects of membrane and bubble oxygenators on platelet counts and platelet size in elective cardiac operations.

To compare the effects of membrane and bubble oxygenators on platelet counts and the size of circulating platelets, serial hematocrits, platelet counts, and platelet sizing were measured in 23 patients undergoing elective cardiac operations. In 10 patients a bubble oxygenator was used and in 13, a SciMed membrane oxygenator. The two groups were statistically similar with respect to age, weight, time on bypass, and mean blood flow rates during bypass. It was found that platelet counts, when corrected for hemodilution, did not fall from control levels during or up to 24 hours after cardiopulmonary bypass in either group. In both groups, the relative number of platelets per gram of hemoglobin increased slightly during and after bypass, and this increase was significant in the bubble oxygenator group. The average size of circulating platelets increased only in the bubble oxygenator group, and then only in the one-day postoperative sample. These findings suggest that the membrane oxygenator offers no advantage with respect to preservation of platelets during cardiopulmonary bypass lasting up to 2 to 3 hours.

Adult↗

PubMed1985

Platelet count and platelet size in males and females.

The platelet count of healthy males was compared to that of healthy females. A higher platelet count in women was confirmed. A similar inverse non-linear relationship between the platelet count and the mean platelet volume (MPV) was found in the two sexes. The slightly higher MPV in men was insufficient to compensate for the lower platelet count so that the plateletcrit, which measures total volume of platelets in a given volume of blood, was also significantly higher in women.

Adolescent↗