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PubMed2006

Hyaluronic acid levels can predict severe fibrosis and platelet counts can predict cirrhosis in patients with nonalcoholic fatty liver disease.

BACKGROUND AND AIM: Nonalcoholic fatty liver disease (NAFLD) represents a spectrum of liver disease from simple steatosis to cirrhosis. Therefore, markers for predicting NAFLD with advanced fibrosis are needed. The aim of this study was to establish non-invasive predictive markers of liver fibrosis in NAFLD. METHODS: One hundred and forty-eight patients were diagnosed as having biopsy-proven NAFLD. In order to separately identify severe fibrosis (bridging fibrosis plus cirrhosis) and cirrhosis, the patients were analyzed twice: first, as mild fibrosis versus severe fibrosis; and second, as non-cirrhosis versus cirrhosis. Univariate and multivariate analyses were conducted. The diagnostic ability to detect severe fibrosis and cirrhosis was assessed by the area under the receiver operating characteristic curve. The cut-off values of serum markers to detect severe fibrosis and cirrhosis were determined. RESULTS: Hyaluronic acid was selected as a predictive marker for severe fibrosis. A cut-off value of 42 ng/mL of hyaluronic acid had a 100% predictive value for patients free of severe fibrosis and was associated with an optimal combination of sensitivity (100%, 95% confidence interval [CI] 90-100%) and specificity (89%, 95%CI 80-94%). The platelet count was found to be an independent predictor of cirrhosis. A cut-off value of 16 x 10(4)/microL for the platelet count was associated with an optimal combination of sensitivity (100%, 95%CI 82-100%) and specificity (95%, 95%CI 90-98%). CONCLUSIONS: Hyaluronic acid levels can accurately identify NAFLD patients with severe fibrosis, and the platelet count can identify NAFLD patients with cirrhosis. Thus, these markers offer a good guideline for the assessment of hepatic fibrosis in the many patients with NAFLD.

Adolescent↗

PubMed1992

Effect of platelet count on the DDAVP-induced shortening of the bleeding time in thrombocytopenic Gaucher's patients.

As part of an investigative protocol requiring serial liver biopsies in patients with Type I Gaucher's disease who were receiving enzyme replacement therapy, we gave 11 patients a total of 15 infusions of DDAVP (0.3 micrograms/kg IV) and measured the Simplate bleeding time pre- and postin-fusion. All patients were thrombocytopenic (one patient 100-150,000; seven 66-99,000; and three 50-65,000/microliters). Nine of 15 infusions resulted in at least a 2-min shortening of the bleeding time; in 6/11 infusions in which the platelet count was greater than 65,000, the bleeding time shortened to less than or equal to 10 min, in 1/11 it shortened greater than or equal to 2 min but not to less than or equal to 10 min. In only 2/4 infusions given to patients with platelet counts less than 65,000 did the bleeding time demonstrate any significant shortening. None of the six liver biopsies performed in the patients whose bleeding time shortened to less than or equal to 10 min resulted in any significant bleeding; blood products were not transfused either pre- or postprocedure. These limited data demonstrate that a high percentage of patients with platelet counts of 65-100,000/microliters can manifest a significant shortening of bleeding time following a standard infusion of DDAVP, and that in approximately half of these patients the bleeding time will shorten enough to safely allow the performance of a liver biopsy without the need for prophylactic transfusion of blood products.

Adolescent↗

PubMed1994

Macroaggregation of platelets in plasma, as distinct from microaggregation in whole blood (and plasma), as determined using optical aggregometry and platelet counting respectively, is specifically impaired following cardiopulmonary bypass in man.

We determined changes in platelet aggregability following cardiopulmonary bypass, using optical aggregometry to assess macroaggregation in platelet-rich plasma (PRP), and platelet counting to assess microaggregation both in whole blood and PRP. Hirudin was used as the anticoagulant to maintain normocalcaemia. Microaggregation (%, median and interquartile range) in blood stirred with collagen (0.6 micrograms/ml) was only marginally impaired following bypass (91 [88, 93] at 10 min postbypass v 95 (92, 96] prebypass; n = 22), whereas macroaggregation (amplitude of response; cm) in PRP stirred with collagen (1.0 micrograms/ml) was markedly impaired (9.5 [8.0, 10.8], n = 41 v 13.4 [12.7, 14.3], n = 10; p < 0.0001). However, in PRP, despite impairment of macroaggregation (9.1 [8.5, 10.1], n = 12), microaggregation was near-maximal (93 [91, 94]), as in whole blood stirred with collagen. In contrast, in aspirin-treated patients (n = 14), both collagen-induced microaggregation in whole blood (49 [47, 52]) and macroaggregation in PRP (5.1 [3.8, 6.6]) were more markedly impaired, compared with control (both p < 0.001). Similarly, in PRP, macroaggregation with ristocetin (1.5 mg/ml) was also impaired following bypass (9.4 [7.2, 10.7], n = 38 v 12.4 [10.0, 13.4]; p < 0.0002, n = 20), but as found with collagen, despite impairment of macroaggregation (7.2 [3.5, 10.9], n = 12), microaggregation was again near-maximal (96 [93, 97]). The response to ristocetin was more markedly impared after bypass in succinylated gelatin (Gelofusine) treated patients (5.6 [2.8, 8.6], n = 17; p < 0.005 v control), whereas the response to collagen was little different (9.3 v 9.5).(ABSTRACT TRUNCATED AT 250 WORDS)

Aprotinin↗

PubMed2004

Blood platelet count and reactivity are associated with restenosis 6 months after coronary angioplasty.

OBJECTIVES: Restenosis occurs in 40-50% of patients treated with percutaneous transluminal coronary angioplasty (PTCA). Some data indicate that platelet derived growth factor (PDGF) plays a pathogenetic role. The aims of the present study were to measure the plasma levels of PDGF across the coronary circulation during PTCA and relate them to the development of restenosis. DESIGN AND RESULTS: Blood samples from the aortic root and coronary sinus were drawn simultaneously before, and after completed PTCA in 26 patients. Plasma levels of PDGF and beta-thromboglobulin (BTG), as well as platelet counts were measured. Restenosis was evaluated by quantitative coronary angiography after 6 months. Significant increases both in PDGF and BTG were encountered in the aortic root after PTCA in patients who developed restenosis as compared to patients without restenosis. Patients who developed restenosis also had significantly higher platelet counts compared to those without. CONCLUSION: Increases in plasma PDGF and BTG in the aortic root after PTCA seem to be markers for restenosis 6 months after PTCA. This finding may strengthen the hypothesis that platelets contribute to the process of restenosis.

Age Distribution↗

PubMed1980

A review of platelet counting performance in the United States.

An interlaboratory comparison of platelet counting in clinical hematology laboratories in the United States is presented. Comparison of performance during the 1979 CAP platelet survey with performance in 1976 indicates a significant improvement in accuracy and interlaboratory precision. The calibration of instruments by clinical laboratories remains as a source of bias. Recommendations for calibration are presented.

Decision Making↗

PubMed1990

Acute leukemia with normal platelet count at diagnosis.

Thirty-six (17.8%) of 202 children with acute lymphoblastic leukemia (ALL) and 2 (3.7%) of 54 children with acute nonlymphoblastic leukemia (ANLL) had a platelet count over 150 x 10(9)/l at diagnosis. Children with ALL and a platelet count over 150 x 10(9)/l were analysed in detail. The ALL patients without thrombocytopenia tended to be male predominant and had less frequent bleeding manifestations (p less than 0.01). These patients without thrombocytopenia had also significantly less marked leukocytosis (p less than 0.01), less severe anemia (p less than 0.05) and lower percentages of bone marrow blasts (p less than 0.05) than those with thrombocytopenia. In addition, ALL patients without thrombocytopenia had a significantly higher probability of continuous complete remission than those with thrombocytopenia (p less than 0.01).

Child↗

PubMed1974

Electronic platelet counting after isopycnic differential centrifugation a simple rapid and accurate method.

A semi-automatized platelet counting procedure with the use of a Coulter Counter is described. Its originality consists in providing an electronic method of counting of the platelets after a differential centrifugation of the blood sample previously diluted with a hypertonic NaCl solution (density 1.053) which is isopycnic to platelet density. This procedure allows elimination of red and white cells without loss of platelets in the supernatant. The final platelet number can be calculated without further corrections. The method is quick and does not require specially skilled technicians. A single technician can perform 40 counts in one hour. The reproductibility of the method is excellent and the coefficient of variation 2,4%. The accuracy and feasibility of the method is also sustained by two years' experience in an haematological routine laboratory.

Blood Cell Count↗

PubMed1977

Factor-VIII activity and antigen, platelet count and biochemical changes after adrenoceptor stimulation.

Adrenaline, isoprenaline and salbutamol were administered by intravenous infusion to human subjects. Isoprenaline was covered with practolol in an attempt to reduce the unpleasantness of the circulatory effects. Changes were recorded in pulse rate and blood pressure, and in blood levels of factors V, VIII, X, XI, and XII, platelet count, lactate, pyruvate, potassium and free fatty acids. Factor VIII was studied by clotting assays, by reactions with two rabbit antisera and two human antibodies, and by desulphated agarose chromatography. At the rate at which they were adiminstered, all three drugs increased the pulse rate by 20-40 beats/min. Factor VIII rose c. 2.5 X with adrenaline but only c. 1.5 X with isoprenaline and salbutamol; but other clotting factors did not alter. Chromatography provided no evidence of a change in the size of the molecule carrying factor-VIII clotting activity. The rate of clearance of the heightened plasma activity could not be shown to differ from that of "ordinary" factor VIII infused into haemophiliacs. The platelet count rose after adrenaline, fell after salbutamol and did not change significantly after isoprenaline. Among the biochemical responses, the only significant difference between the drugs was that lactate rose after adrenaline and salbutamol but did not change after isoprenaline. The rise in factor-VIII clotting activity after adrenaline is considered to represent a real increase in blood concentration, presumably by release of additional factor VIII from stores. The evidence suggests that this could be classified as a beta2 effect; and that the quantity which can be released is unrelated to the current plasma level. The rise in platelet count produced by adrenaline may be the resultant of an alpha-mediated rise due to contraction of the exchangeable splenic pool and a beta2-mediated fall, the alpha effect predominating.

Adult↗

PubMed1981

Improvement of bleeding time, platelet aggregation and platelet count during CAPD treatment.

Mean bleeding time in 11 uraemic patients improved from 11.2 (range 3.5--20) before the 5.8 (range 2.5--20) minutes during CAPD treatment (p less than 0.025). Bleeding time became normal in six out of seven patients with a prolonged bleeding time prior to CAPD. There was a concomitant improvement in platelet aggregation. Mean platelet count rose from 195 (range 117--414) to 311 (148--522) x 10(9)/L (p less than 0.01). A significant correlation was found between the change in bleeding time and in platelet aggregation induced by ristocetin, but not between the change in bleeding time and the platelet count. Our results suggest that CAPD treatment improves the uraemic bleeding tendency, even in patients on previous haemodialysis treatment.

Adenosine Diphosphate↗

PubMedDate not supplied

Idiopathic thrombocytopenic purpura and pregnancy. Maternal platelet count and antiplatelet antibodies do not predict the risk of neonatal thrombocytopenia.

The aim of this study was to try to better characterize, on the basis of maternal platelet count and antiplatelet antibodies, women with ITP or a history thereof at risk of being delivered of a child affected by neonatal thrombocytopenia. Results show that either clinical classification or maternal platelet count were not effective in predicting the occurrence of neonatal thrombocytopenia. Effects of prednisone on platelet-bound and unbound antibodies were studied prospectively in 12 non-pregnant women with ITP; no increase of these parameters was observed after treatment. Thus, the risk of corticosteroid therapy in the management of pregnant ITP patients remains hypothetical and unproven.

Adult↗

PubMed1994

A dosing scheme for carboplatin in adult cancer patients based upon pre-infusion renal function and platelet count.

The most important risk factors for the development of carboplatin-induced thrombocytopenia are total dose, glomerular filtration rate (GFR) and pre-infusion platelet count (P0). Pharmacokinetic and toxicity data from 23 patients with ovarian or testicular cancer were combined with published values from four other centers and the relationships between plasma clearance of ultrafilterable platinum and GFR, and between percentage reduction in platelet count and area under the plasma platinum curve were determined. The scatter in the data was estimated and used in a Monte-Carlo computer simulation to derive the following five-level dosing scheme. [table: see text] The scheme is based on 5% of patients incurring grade IV thrombocytopenia. Using this scheme, the majority of patients with ovarian or testicular cancer receiving carboplatin will be given an initial dose of 900 mg.

Adenocarcinoma↗

PubMed2006

Discrepancy between impedance and immunofluorescence platelet counting has implications for clinical decision making in patients with idiopathic thrombocytopenia purpura.

This study investigated whether differences occur between the impedance and immunofluorescence methods for platelet quantification in idiopathic thrombocytopenia purpura (ITP). Immunofluorescence gave a platelet count >50% higher than the impedance test in 9/35 (26%) patients, of which 4/35 (11%) were >100% higher. The clinical severity of thrombocytopenia was changed as a result of the immunofluorescence test in 14/35 (40%) patients. Neither mean platelet volume nor platelet distribution width predicted impedance/immunofluorescence method discrepancy. It is suggested that immunofluorescence platelet counts should be performed on all ITP patients when the implementation of a therapeutic or diagnostic intervention is being considered.

Blood Coagulation↗

PubMed1999

Collection of peripheral blood progenitor cells (PBPC) based on a rising WBC and platelet count significantly increases the number of CD34+ cells.

The kinetics of mobilization and optimal timing of peripheral blood progenitor cell (PBPC) collection were evaluated in 190 patients with multiple myeloma undergoing stem cell harvest after mobilization with cyclophosphamide, prednisone and G-CSF. There was a strong correlation between the WBC count and the number of CD34+ cells circulating in peripheral blood (r = 0.875). Initiating leukapheresis based on rising WBC and platelet counts rather than on a fixed day increased the mean number of CD34+ cells 115% (9.7 to 20.9 x 10(6) CD34+ cells/kg; P = 0.010) for the total of all leukaphereses and 59% for the total of all CD34-selected products (5.1 to 8.1 x 10(6) CD34+ cells/kg; P = 0.011). Although the yield and purity of the CD34-selected product were not significantly affected (P > or = 0.071), the percentage of patients with concentrations of CD34+ cells in the initial leukapheresis of > 1% increased from 47% to 70% (P = 0.004). The mean purity of the selected product was related to the starting percentage: 48.9% if < 1% and 81.5% if > or = 1% (P < 0.001). Collection of stem cells based on rising WBC and platelet counts significantly increased the number of CD34+ cells in leukaphereses and CD34-selected products in comparison with collection on a fixed day.

Adult↗

PubMed1979

Cytoplasmic fragments causing spurious platelet counts in the leukemic phase of poorly differentiated lymphocytic lymphoma.

A patient with a leukemic phase of poorly differentiated lymphocytic lymphoma had a spuriously high automated platelet count because of cytoplasmic fragments. The number and relative percentage of cytoplasmic fragments increased during chemotherapy. The cytoplasmic fragments did not interfere with platelet aggregation using adenosine diphosphate, collagen, and epinephrine even though they were found in platelet-rich plasma. The ultrastructure of the cytoplasmic fragments is discussed. Cytoplasmic fragments as a cause of spuriously high automated platelet counts should be considered in cases of leukemic patients.

Adult↗

PubMed2004

Diagnosis, controversies, and management of the syndrome of hemolysis, elevated liver enzymes, and low platelet count.

Hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome has been recognized as a complication of preeclampsia-eclampsia for decades. Recognition of this syndrome in women with preeclampsia is increasing because of the frequency of blood test results that reveal unexpected thrombocytopenia or elevated liver enzymes. The diagnosis of HELLP syndrome requires the presence of hemolysis based on examination of the peripheral smear, elevated indirect bilirubin levels, or low serum haptoglobin levels in association with significant elevation in liver enzymes and a platelet count below 100,000/mm(3) after ruling out other causes of hemolysis and thrombocytopenia. The presence of this syndrome is associated with increased risk of adverse outcome for both mother and fetus. During the past 15 years, several retrospective and observational studies and a few randomized trials have been published in an attempt to refine the diagnostic criteria, to identify risk factors for adverse pregnancy outcome, and to treat women with this syndrome. Despite the voluminous literature, the diagnosis and management of this syndrome remain controversial. Recent studies suggest that some women with partial HELLP syndrome may be treated with expectant management or corticosteroid therapy. This review will emphasize the controversies surrounding the diagnosis and management of this syndrome. Recommendation for diagnosis, management, and counseling of these women is also provided based on results of recent studies and my own clinical experience.

Adrenal Cortex Hormones↗

PubMed1980

[Platelet counting in whole blood by means of a new counter with hydrodynamic focused aperture (author's transl)].

Platelet counts in whole blood were performed by means of a new particle analyzer with a hydrodynamic focused aperture (Ultra-Flo 100) and its values were compared with the results obtained by an optical counting chamber. The comparison yielded good agreement of the values within the evaluated range of 3-963 G/l thrombocytes. Especially remarkable is the good correlation of the markedly thrombocytopenic values. Equally reliable is the counting of thrombocytes in blood with markedly elevated erythrocytes. The simple procedure of sample preparing combined with the stand-by technic of the analyzer provides advantageous conditions for using it likewisely in routine and emergency laboratories.

Electronic Data Processing↗

PubMed2005

Dual effects of adenovirus-mediated thrombopoietin gene transfer on hepatic oval cell proliferation and platelet counts.

Thrombopoietin (TPO) is the growth factor for megakaryocytes and platelets, however, it also acts as a potent regulator of stem cell proliferation. To examine the significance of TPO expression in proliferation of hepatic oval cells, the effect of adenovirus-mediated TPO gene transfer into livers of the Solt-Farber model, which mimics the condition where liver regeneration is impaired, was examined. Hepatic TPO mRNA peaked its expression at 2 days after gene transduction and then gradually decreased. The peripheral platelet number began to increase at 4 days (P<0.05) and reached its plateau at 9 days (P<0.01). Oval cells expressed c-Mpl, a receptor for TPO as well as immature hematopoietic and hepatocytic surface markers such as CD34 and AFP. The proliferating cell nuclear antigen-positive oval cells in rats into which adenovirus-TPO gene was transferred at 7 and 9 days were significantly greater than those in adenovirus-LacZ gene transferred (P<0.05, each), and the total numbers of oval cells in the adenovirus-TPO gene transferred at 9 and 13 days were also significantly greater than those in adenovirus-LacZ gene transferred (P<0.05, each). Expression of SCF protein was increased at 4, 7, and 9 days by TPO gene administration and that of c-Kit was increased at 4 and 7 days. These data suggest that adenovirus-mediated TPO gene transfer stimulated oval cell proliferation in liver as well as increasing peripheral platelet counts, emphasizing the significance of the TPO/c-Mpl system in proliferation of hepatic oval cells.

Adenoviridae↗

PubMed1993

Increase in platelet count following short course therapy with recombinant alpha-2b-interferon in immune thrombocytopenic purpura in childhood.

Two boys, aged three and seven years with immune thrombocytopenic purpura continued to show platelet counts below 20,000/mm3 inspite of treatment with high dose gammaglobulin and steroids. Alpha-2b-interferon injections were followed by normalisation of platelet counts in both patients. No side effects were seen. Alpha-interferon may be a safe and effective treatment for childhood-ITP.

Child↗