Immunoplatelet counting: platelet transfusions.
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Humans↗
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Results for “Platelet Count”
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Platelet counts in pools of platelet-rich plasma-derived platelet concentrates.
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Blood Banking↗
[Artificial increase in leukocyte and platelet counts disclosing type II cryoglobulinemia].
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Aged↗
[Counting platelets by flow cytometry with platelet-specific antibody CD42a].
OBJECTIVE: To investigate a reference method for platelet (PLT) count. METHODS: 76 samples of daily whole blood of high, normal and low values in patients were collected and analyzed by flow cytometry (FCM) with CD42a monoclonal antibody that could combine specifically with the platelet membrane glycoprotein Ib-Ix (GPIb-Ix). PLT counts were analyzed by multiplying PLT/RBC ratio from FCM with the RBC that was counted by a calibrated blood analyzer. Meanwhile, the results of PLT from FCM were compared with that from blood analyzers SE-9500, NE-1500, CD-1600 or manual count. RESULTS: The within-replicate coefficient of variance(CV) of FCM was less than 4% for a high count(501 x 10(9)/L) and middle count(184 x 10(9)/L), the CV of low count(23 x 10(9)/L) was 11.432%, the between-replicate CV was 10.792%, and the overall reproducibility was less than 5%. Linearity was demonstrated well(r = 0.9975 P < 0.001) when the PLT counts were 20 x 10(9)/L-700 x 10(9)/L. PLT count was stable at room temperature within 6 hr. The carry-over was 0.87%. The results between FCM and SE-9500, NE-1500, CD-1600 or manual count was comparable (r > 0.975, P < 0.001). CONCLUSION: These findings confirm that FCM for PLT count is specific, accurate and precise and could be considered as a candidate of reference method for PLT count.
Antibodies, Monoclonal↗
Assessment of a therapeutic strategy for adults with severe autoimmune thrombocytopenic purpura based on a bleeding score rather than platelet count.
BACKGROUND AND OBJECTIVES: The optimal treatment for patients with autoimmune thrombocytopenic purpura (AITP) and a platelet count < or =20x10(9)/L is intravenous immunoglobulin (IVIg) but this treatment is expensive and steroids are a good alternative in less severe cases. Since the occurrence of life-threatening hemorrhage in adult AITP is a rare event, the aim of our study was to validate a therapeutic strategy based on a bleeding score for the short-term management of adults with AITP and a platelet count < or =20x10(9)/L. DESIGN AND METHODS: We developed a method to quantify hemorrhage in adults with AITP. Bleeding severity was graded on a numerical scale based on physical examination. When the bleeding score was < or =8, the patients were treated with steroids alone. For scores >8, patients received IVIg (1 to 2 g/kg) in combination with oral steroids. A good response was defined as the lowering of the initial bleeding score within 2 days after treatment initiation regardless of the platelet count. RESULTS: We applied this strategy for the management of 60 consecutive adults (mean age 48+/-23 years) with AITP and a platelet count < or =20x10(9)/L/L (mean platelet count 6+/-5x10(9)/L/L). Based on this strategy, IVIg was required in only 50% of the patients and no life-threatening bleeding occurred in patients treated with steroids alone. INTERPRETATION AND CONCLUSIONS: A therapeutic strategy based on a bleeding score rather than the platelet count appears to be relevant and safe and is a good IVIg-sparing strategy.
Adolescent↗
A prenatal study of fetal platelet count and size with application to fetus at risk for Wiskott-Aldrich syndrome.
Platelet counts and platelet size were determined in midtrimester fetuses to obtain reference values to be used in prenatal diagnosis of inheritable platelet disorders. In 17- to 21-week fetuses, platelet counts ranged between 135 and 283 x 10(9)/L, and thus did not differ from those of newborn infants and adults. Mean platelet volume fell between 6.0 and 7.0 fl, which is in the range for adults. The data were used to exclude Wiskott-Aldrich syndrome in an 18-week fetus at 50% risk of being affected.
Blood Coagulation Disorders↗
The impact of platelet count on mortality in unstable angina/non-ST-segment elevation myocardial infarction.
BACKGROUND: Expanding the knowledge of pathogenesis of arteriosclerosis points at a central role of platelets in the development of acute coronary syndromes. Therefore, we sought to determine the impact of platelet count on long-term outcome in unstable angina/non-ST-segment elevation myocardial infarction (UA/NSTEMI) receiving contemporary treatment. METHODS: This prospective cohort study included 1616 consecutive patients with UA/NSTEMI. All patients underwent coronary angiography and, if appropriate, subsequent catheter-based revascularization within 24 hours of admission. Patients were divided in quintiles according to platelet count. The primary end point was all-cause mortality during long-term follow-up of up to 60 months. RESULTS: During follow-up (median 17 months, interquartile range 6-31 months), 89 deaths and 74 nonfatal myocardial infarctions occurred. Patients with higher platelet counts were younger, more often female, and had lower height and weight as compared with patients with lower platelet counts. Mortality was significantly lower among patients in the second quintile of platelet count (181-210 x 10(9)/L) as compared with the other quintiles (hazard ratio 0.39, 95% CI 0.19 to 0.81, P = .011). Kaplan-Meier survival analysis showed cumulative 4-year mortality rates of 12.5%, 3.8%, 10.4%, 9.8%, and 11.4% for patients in the first, second, third, fourth, and fifth quintiles. This association persisted after multivariate adjustment. No association of platelet count and nonfatal myocardial infarctions was observed. CONCLUSIONS: We found a nonlinear association between platelet count and long-term mortality. The lowest mortality was observed in patients with a platelet count between 181 and 210 x 10(9)/L.
Aged↗
Elevated platelet counts and thrombocytosis in erythema nodosum leprosum.
Changes in peripheral blood platelet counts associated with the onset of symptomatic erythema nodosum leprosum (ENL) were studied by comparing, in each patient, the value obtained on the day thalidomide therapy commenced with the average of the three preceding values. In the 11 patients studied, the mean platelet count rose from 235 to 322 x 10(3)/mm3, p < 0.001. In 3, the platelet count was above the normal limit, qualifying as thrombocytosis, in 7 the rise was appreciable, and in 2 it was negligible. In the 3 patients studied 1-2 weeks after beginning thalidomide, the mean count was 414 x 10(3)/mm3. Counts obtained after 3 or more weeks of thalidomide therapy were within normal limits. This study provided no direct evidence as to the mechanism responsible for the elevated platelet count, but mediation by interleukin-6 (IL-6) was concluded to be an attractive hypothesis, consistent with prior studies of IL-6 in reactive thrombocytosis and of IL-6 in ENL.
Adult↗
Increased preoperative platelet count is associated with decreased survival after resection for adenocarcinoma of the pancreas.
BACKGROUND: Platelets are thought to participate in tumor metastasis. However, the relationship between platelet count and prognosis in pancreatic cancer remains unresolved. METHODS: A chart review of patients undergoing resection for pancreatic adenocarcinoma was undertaken. Demographic, perioperative, and outcome data were collected. Kaplan-Meier survival and Cox regression analyses were used to determine the impact of preoperative platelet count on survival. RESULTS: Between June 1995 and March 2003, 109 patients (63% male) with a median age of 68 years (range 42 to 85 years) underwent resection for pancreatic cancer. Univariate analysis demonstrated that platelet count, lymph node or margin status, and histology were associated with survival. In multivariate analysis, the association between increased platelet count and poor survival maintained significance. CONCLUSIONS: Increased preoperative platelet count is associated with adverse survival outcome in patients undergoing resection for pancreatic cancer. Antiplatelet medications warrant further study in an attempt to improve survival in these patients.
Adenocarcinoma↗
Neonatal platelet counts in fetal brain injury.
UNLABELLED: The objective of this study was to determine whether neonatal platelet counts can be used in fetal brain injury. The initial platelet counts, expressed as 1000 per mm3, of singleton term infants with and without permanent asphyxial brain injury were compared. Neonates with encephalopathy were divided into 3 groups: I--nonreactive fetal heart rate (FHR) pattern from admission until delivery; II--reactive FHR pattern on admission followed by nonreactivity, tachycardia, a loss of variability and repetitive FHR decelerations; and III--acute: reactive FHR pattern followed by a sudden prolonged FHR deceleration that lasted until delivery. The neonates and platelet counts for each group were as follows: CONTROL: 104 neonates, mean 281 +/- 56, range 154 to 411; I: 60, mean 185 +/- 80, range 28 to 365; II: 34, mean 251 +/- 66, range 100 to 375; and III: 35, mean 267 +/- 93, range 86 to 569. Platelet counts were significantly lower in neonates with encephalopathy (p <0.001). Group I differed statistically from both Groups II and III (p <0.001). These data suggest an association between the FHR pattern, fetal asphyxial brain injury, and the initial platelet count in singleton term neonates. Further investigation should be pursued to clarify the physiological processes leading to this result.
Brain Diseases↗
Excess soluble fms-like tyrosine kinase 1 and low platelet counts in premature neonates of preeclamptic mothers.
OBJECTIVE: To investigate the relationship of neonatal platelet count and preeclampsia to levels of soluble fms-like tyrosine kinase 1 (sFlt-1), placental growth factor (PlGF), and vascular endothelial growth factor (VEGF) in the cord blood of preterm infants. METHODS: Sixty-nine preterm infants with a gestational age between 26 and 37 weeks at birth were enrolled. sFlt-1, PlGF, and VEGF levels in the cord blood of preterm neonates, with or without maternal preeclampsia, were measured using a standardized sandwich enzyme-linked immunosorbent assay method. RESULTS: Infants with maternal preeclampsia had higher cord blood sFlt-1 but lower PlGF and VEGF levels. There was a significantly positive relationship between neonatal platelet count and birth weight and a significantly negative relationship between neonatal platelet count and cord blood sFlt-1 levels. Multiple regression analysis revealed that only birth weight and cord blood sFlt-1 levels were independently related to neonatal platelet count, whereas maternal preeclampsia, gestational age (GA), and small for GA (SGA) were not related. Neonates with thrombocytopenia had higher cord blood sFlt-1 levels but lower birth weight. A significant correlation was also found between birth weight and cord blood sFlt-1 levels. Multiple regression with birth weight as the dependent variable found that only GA and cord blood sFlt-1 levels were independently related. Furthermore, infants with high cord blood sFlt-1 were more likely to have lower platelet count and maternal preeclampsia, be SGA, and have a trend toward lower birth weight. CONCLUSION: Excess sFlt-1 may play an important role in the development of maternal preeclampsia- induced neonatal thrombocytopenia, and SGA.
Birth Weight↗
Effect of platelet count on serum and plasma potassium: evaluation using database information from two hospitals.
The availability of retrospective data from potassium (K+) analyses from two hospitals, one using serum and the other plasma for electrolyte measurements, offered us the possibility to investigate the effect of blood platelet count on serum and plasma K+ concentrations. A weak correlation between plasma K+ and platelet count was observed. The in vitro increase of serum K+ in proportion to the platelet count has clinical significance in conditions, where it may impede the detection of an underlying true K+ disorder. Nomograms and correction factors, based on the correlation between platelet count and serum K+, have been suggested also in some recent reports. In the present study unselected routine patient data was used as source data. The effect of platelet count on the concentration of K+ in serum was lower than reported in previous studies, as indicated by the regression analysis. An increase of 1000 x 10(9)/l in the blood platelet count would cause an increase of about 0.7 mmol/l in the serum K+ concentration (p < 0.0001, r = 0.155). The weak correlation between platelet count and serum K+ does not support the application of platelet-count-based correction of serum K+ level in thrombocytosis. The laboratory should notify the clinician of the significance of the in vitro increase of K+ caused by increased platelet count. K+ should be measured from plasma in such cases.
Artifacts↗
Diagnostic significance of platelet count and other blood analyses in patients with lung cancer.
The objective of this study was to evaluate the clinical value of an elevated platelet count and other routine laboratory tests for predicting malignancy in patients with radiologically suspected lung cancer. Platelet count, haemoglobin, total leukocyte count, erythrocyte sedimentation rate (ESR) and serum lactate dehydrogenase (LDH) were analysed in 126 prospectively admitted patients with suspected lung cancer. The patients were divided by pathologic diagnosis into those with benign disorders (n=65) and with malignancies (n=61). Patients with lung cancer were staged (TNM) and the tumours were classified according to histological types (WHO). Thrombocytosis (platelet count >400x10(9)/l) was present in 8% (5/65) of patients with benign disease and in 57% (35/61) of patients with malignant disease (p<0.00001). The prevalence of thrombocytosis in patients with primary lung cancer was 53% (27/51). Elevated platelet count was more common in advanced disease (stage III and IV). No difference was observed between histological types. The sensitivity of thrombocytosis for predicting malignancy was 0.57 and the specificity 0.92. When elevated platelet counts, LDH and ESR were combined, a sensitivity of 0.71 and a specificity of 1.00 was achieved. The positive and negative predictive values were 1.00 and 0.89, respectively. Elevated platelet count is frequently observed in patients with lung cancer. When test results of platelet count and other routine blood analyses are combined, a high sensitivity and specificity for predicting malignancy can be achieved. These tests are clinically useful in the evaluation of patients with radiologically suspected lung cancer.
Blood Sedimentation↗
Serial determinations of platelet counts in mice by flow cytometry.
Elucidation of the pathophysiological basis of platelet disorders in murine models requires a reliable method for the frequent determinations of platelet counts in individual mice. Here, we present a rapid, reproducible and accurate flow cytometric method for enumeration of platelets that involves fluorescent staining of platelets in whole blood with specific antibody and the addition of known numbers of fluorescent beads for standardization of the sample volume. Analysis of platelets obtained by tail bleeding indicated that this sampling procedure did not activate platelets, and that only five microliters of blood were required for platelet counting. Using this method, we followed platelet counts in mice infected with the relapsing fever spirochete Borrelia turicatae for 26 days, and found that this bacterium induces thrombocytopenia, a common manifestation of human relapsing fever. Therefore, this method can be used to follow the number and the activation state of circulating platelets from individual mice over extended periods of time and is applicable to a wide range of murine models of platelet disorders.
Animals↗
Helicobacter pylori infection and platelet counts during pregnancy.
OBJECTIVE: To investigate whether there is any correlation between Helicobacter pylori infection and platelet counts during pregnancy. METHODS: One hundred and twenty pregnant women without any complications were evaluated. Platelet counts were determined during pregnancy and postpartum. H. pylori infection was assessed by the detection of serum antibodies at the 3rd day postpartum. Statistically significant differences of platelet count between H. pylori-positive and -negative patients were determined. RESULTS: H. pylori infection was found in 29 of 120 (24.2%). Platelet counts in the 3rd trimester were 22.7+/-4.7 x 10(3)/microl in H. pylori-positive group and 22.8+/-5.6 x 10(3)/microl in negative group (p=0.98). Platelet count in the 3rd trimester in positive and negative patients were 93+/-17% and 94+/-20%, respectively, of that of the 1st trimester (p=0.92). The incidence of hyperemesis gravidarum in both groups was not significant (p=0.28). CONCLUSION: A correlation between H. pylori infection and thrombocytopenia during pregnancy was not found in this study.
Female↗
Perioperative changes in plasma antithrombin activity and platelet counts in patients undergoing gynecologic surgery.
The relationships among perioperative changes in plasma antithrombin (AT) activity, platelet counts, and clinical risk factors for postoperative thromboembolism has not been studied extensively in gynecologic patients. AT activity and platelet counts were determined preoperatively and on postoperative days 1 and 7 in 74 patients who underwent gynecologic surgery. The relationships between each clinical risk factor for postoperative thromboembolism and the decrease in AT activity and platelet count were analyzed using a univariate logistic regression model. No clinically significant thromboembolism occurred in any patient. AT activity and platelet counts decreased significantly on postoperative day 1 and exceeded preoperative levels on day 7. Postoperative patients with malignancy were more likely to exhibit decreased AT activity. AT activity decreased significantly with increases in operating time and blood loss. Known risk factors for postoperative thromboembolism did not appear to be associated with postoperative decreases in platelet counts. Transient hyperconsumption of AT and platelets occurs immediately after gynecologic surgery. Surgery-induced AT deficiency may contribute to postoperative thromboembolism in patients with long operating times and significant blood loss.
Adult↗
Possibilities and limitations of automated platelet counting procedures in the thrombocytopenic range.
The clinical decision to proceed with prophylactic platelet transfusions is widely based on trigger points for platelet counts being equal to 20, 10, or even 5 x 10(9)/L. But an increasing number of publications show evidence that the conventional automated platelet counting methods are unable to provide consistently accurate results in this lower thrombocytopenic range. These measurement errors are mainly associated with the most commonly used impedance principle; optical methods seem to be more precise. The problems of counting imprecision in the low thrombocytopenic range can be avoided with direct or indirect immunological counting methods using monoclonal antibodies or by time-consuming manual procedures. But how should new counting procedures be evaluated? Which method should be used as the "gold standard" for platelet counting? A way out of this apparent dilemma is the application of a statistical procedure as proposed by Gautschi et al. This mathematical model allows a reference method independent evaluation of new methods by calculation of the limits of detection (LD) and limits of quantification (LQ) based on the imprecision profile of the investigated method. Using this evaluation procedure, it can be shown that immunological automated counting methods can provide reliable, sufficient, and prompt platelet counts, especially in the thrombocytopenic range.
Antibodies, Monoclonal↗
The value of preoperative platelet count in the prediction of cervical involvement and poor prognostic variables in patients with endometrial carcinoma.
OBJECTIVE(S): To evaluate the relationship between preoperative platelet counts and prognostic factors extensively, among endometrial cancer patients, especially with respect to cervical involvement. METHODS: One-hundred fifty-five patients with endometrial carcinoma, who underwent surgery as the initial treatment consisting peritoneal cytology, total abdominal hysterectomy, bilateral salpingo-oophorectomy, systematic pelvic-paraaortic lymphadenectomy, and omentectomy were retrospectively analyzed. RESULTS: There were no differences with respect to age, histological type (endometrioid vs. non-endometrioid), depth of myometrial invasion, peritoneal cytology, LVSI, and lymphatic metastasis. However, advanced stage (stages III and IV), poorly differentiated tumor grade (grade 3), the presence of cervical and adnexal involvements were associated with significantly higher median preoperative platelet counts. Accepting 325.000/microl platelet count as a threshold value, multivariate analysis revealed cervical involvement (P=0.008; OR=1.84, 95% CI:1.17-2.89) and presence of high grade histology (P=0.014; OR=2.23, 95% CI:1.18-4.23, for grade 3 disease) to be significantly associated with higher platelet count. At a cut-off value of 326.000/microl, 42.3% sensitivity and 82.8% specificity for the prediction of cervical involvement was observed under receiver operator characteristic curve method. CONCLUSION(S): Higher preoperative platelet counts, even in conditions with normal range (150.000-400.000/microl), may reflect poor prognostic factors such as cervical involvement and high grade among patients with endometrial carcinoma. Also, the higher platelet count should be taken into consideration for the necessity of radical hysterectomy.
Endometrial Neoplasms↗