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.     

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.     

Influence of aspirin on platelet count and volume in humans.

Platelet volume and total platelet mass are parameters of platelet activity and have become a prognostic factor in coronary heart disease. We have studied the influence of aspirin on platelet count, volume and total platelet mass in vitro and in a randomized double-blind, placebo-controlled study in 20 healthy young male volunteers in vivo. Aspirin had no influence in vitro on either platelet count, volume or mass. Repeated blood sampling during a 7-day treatment with 250 mg aspirin daily showed an increased platelet count (7.3% on day 1, 3.0% on day 2, 6.8% on day 4 and 9.3% on day 7; p < 0.01) and total platelet mass (7.2, 5.0, 8.6 and 11.5% on days 1, 2, 4 and 7, respectively, p < 0.01). Aspirin treatment without repeated blood withdrawal had no effect. These data indicate that aspirin may affect the circulating platelet mass under certain conditions.     

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.     

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.     

Correlation between serum gamma-glutamyl transferase activity and the platelet count

The serum gamma-glutamyl transferase (GGT) activity correlated significantly (P < 0.008) with the platelet count in 55 patients with thrombocytosis. All patients were selected so as to have normal liver function tests(including serum GGT). This correlation was present in both genders and there was no significant correlation with the other liver function tests. These findings are additional evidence that platelets may contribute to the total serum GGT activity.     

The effect of pre-eclampsia on complete blood count, platelet count and mean platelet volume

Pre-eclampsia is a condition observed during pregnancy and threatens the life of both mother and foetus. There are studies, which suggest platelets play a major role in the pathogenesis of pre-eclampsia. The aim of this study is to compare the complete blood count (CBC) parameters, especially platelet count and mean platelet volume (MPV), in pre-eclamptic and normal pregnant women and to evaluate whether these parameters have a prognostic significance in determining the severity of eclampsia. The study and control groups consist of 56 pre-eclamptic and 43 normal pregnant women, respectively. There was no statistically significant difference according to CBC, platelet count and MPV when pre-eclamptic and severely pre-eclamptic patients were compared with controls. As a result, we observed no prognostic significance of CBC, platelet count and MPV on the presence and/or severity of pre-eclamptic condition. There are conflicting results especially on the significance of MPV in the literature, and possibly this confliction is due to the difference between methods and/or equipments used for automated blood count.     

辐照与去白细胞过滤单采血小板对血小板诸参数与部分细胞因子含量影响

目的：了解应用去白细胞过滤器制备去白细胞单采血小板以及经γ射线辐照单采血小板血小板参数与血浆部分细胞因子含量变化情况。方法：应用SysmexF-800血液分析仪检测血小板参数与应用ELISA法检测血浆IL-2、IL-6、INF-γ与TNF-α细胞因子。结果：去白细胞单采血小板与经γ射线辐照单采血小板悬液血小板包括：血小板数、血小板平均体积、血小板平均宽度、血小板压积以及血浆IL-2、IL-6、INF-γ与TNF-α含量与对照组相互比较差异均无统计学意义（P〉0．05）。结论：单采血小板经去白细胞或经γ射线辐照后,不会影响血小板参数与血浆部分细胞因子含量。     

Influence of the needle bore size on platelet count and routine coagulation testing.

The phlebotomy technique, particularly the use of small-bore needles, may influence the reliability of coagulation testing and platelet count. Routine coagulation tests were assayed in blood specimens collected from 22 consecutive patients in three separate, sequential phlebotomies, using butterfly devices with different needle sizes. Test results of samples collected with 23 and 25 G needles were compared with those obtained with the currently recommended 21 G needle. Although both the prothrombin time and activated partial thromboplastin time displayed a trend towards lower values employing the smaller 23 and 25 G needles, results did not differ significantly from the reference 21 G needle specimen, with the exceptions of D-dimer (25 G versus 21 G needle, 186 +/- 70 versus 178 +/- 66/ml, P < 0.01) and platelet count (23 G versus 21 G needle, 246 +/- 55 versus 254 +/- 56 x 10(-3)/l, P < 0.01; 25 G versus 21 G needle, 240 +/- 55 versus 254 +/- 56 x 10(-3)/l, P < 0.01). None of the mean biases recorded for the parameters was clinically meaningful, nor did they exceed the current desirable analytical quality specifications for desirable bias. Results of the present investigation suggest that, when a proper technique is used and within certain limitations, butterfly devices with small-bore needles may be a reliable alternative to draw venous blood for platelet count and coagulation testing.     

Influence of splenectomy and the functional hyposplenism of coeliac disease on platelet count and volume

Platelet count and volume were measured in 84 splenectomised subjects, 142 patients with coeliac disease and 77 healthy subjects. An inverse, non-linear correlation between platelet count and volume was found in healthy subjects and coeliac patients, but was not present in splenectomised subjects who had higher platelet counts (P = 0.0001) and mean platelet volumes (P = 0.0001) than healthy subjects. Platelet counts correlated with splenic function in patients with coeliac disease and were higher in patients with severe hyposplenism than in normosplenic coeliacs (P = 0.0001). Splenic function did not influence the mean platelet volume (MPV) in coeliac disease but normosplenic coeliacs had higher MPV than normal subjects (P = 0.05). Serum iron and red cell folate were not correlated to MPV in coeliac disease. We conclude that splenic function effects platelet count and volume in non-coeliac subjects and platelet count in coeliac disease. However, other unidentified factor(s) influence the MPV in coeliac disease.     

关于采供血机构预测采后血小板数方法的探讨

目的:对采供血机构单采血小板后血小板预测数的方法进行探讨。方法:通过对30例单采血小板献血者进行采前公式计算预测采后血小板数和采后血小板计数的方法来验证采前预测是否相对准确。结果:通过采后检测和用公式计算比较,两者差异无统计学意义。结论:预测采后血小板数是保护献血者安全的一项重要措施,通过采前一定方法的计算,可以预测采后血小板数,从而保护献血者。     

Effect of recombinant human erythropoietin on platelets in patients with anemia of renal failure: correlation of platelet count with erythropoietic activity and iron parameters

Abstract: We examined the effect of treatment with rHuEpo on platelet counts in 61 hemodialysis patients and correlated them with changes in erythropoietic activity, iron status and inflammation. Platelets (10⁹/l) increased from 220 ±80 to 245 ±102 after 14 days and stabilized at that level up to day 90 (p<0.0001). The increment was similar in complete or partial responders but was not observed in failures. Serum transferrin receptor (sTfR, a measure of total erythropoiesis) and Hct rose much more progressively, but relative platelet increments correlated with relative increases in sTfR and Hct. Relative platelet increments correlated inversely with relative changes of SeFe or transferrin saturation, but not with their absolute values, nor with baseline ferritin or its progressive decrease. Although baseline platelet count was 12% higher in patients with inflammation and correlated with serum haptoglobin, relative increases were similar in patients with or without inflammation. In conclusion, rHuEpo produced a clinically minor but consistent elevation of platelet counts. These modifications were not related primarily to modifications in iron stores, functional iron deficiency, or inflammation, but paralleled the expansion of erythropoietic activity. The results suggest that rHuEpo has a small positive effect on platelet production, but it cannot be ruled out that this could be partially mediated through functional iron deficiency.     

光学法计数在低值血小板检测中的研究应用

目的：评价光学法计数在低值血小板检测中的研究应用。方法：200例低值血小板患者血标本,在血液分析仪上分别进行电阻抗法和光学法血小板计数,同时进行镜检法计数。结果：以镜检法为参考方法,光学法的相关系数为0．994。电阻抗法的相关系数0．921。在小红细胞组、红细胞碎片组和大血小板组,电阻抗法和镜检法计数结果差异有统计学意义（P〈0．05）,光学法和镜检法计数结果差异无统计学意义（P〉0．05）。结论：光学法计数可以满足低值血小板检测准确性的要求,值得临床实验室推广应用。     

Metoprolol and the peripheral platelet count.

An acute oral administration of 50 mg metoprolol (a selective beta-1-receptor antagonist) to 18 healthy volunteers induced a significant increase in the peripheral platelet concentration lasting more than 4 h. It is suggested that this increment in the platelet count originates from the exchangeable splenic platelet pool. The mechanism by which metoprolol exerts its effect remains to be established.