SEARCH · PubMed Health

Results for “Platelet Count”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 289 records · Page 16Linked to original sources

PubMed1985

Spurious elevated platelet counts associated with bacteremia.

Spuriously elevated automated platelet counts secondary to in vivo bacteremia have not been reported previously. Two patients are described with blood cultures positive for Escherichia coli and Klebsiella pneumoniae, respectively, and bacteria present on peripheral blood smear. Those bacteria caused falsely elevated platelet counts to be generated by the Ortho ELT-8. These cases illustrate an unusual artifact and demonstrate that spurious counts can be generated by laser optical blood cell counters.

Adult↗

PubMed1980

Platelet count on acute induction to high altitude.

Platelet counts in 50 normal healthy volunteers were performed at sea level and then serially on rapid induction to 3658 m by air. Subjects were divided into "symptomatic# and "asymptomatic# groups depending on their score on the symptoms score chart. All were brought back to sea level and study repeated. Platelet count in the symptomatic group showed a falling trend while in the asymptomatics a gradual rise was noted.

Adult↗

PubMed1999

Course of platelet counts in cirrhotic patients after implantation of a transjugular intrahepatic portosystemic shunt--a prospective, controlled study.

BACKGROUND/AIMS: The pathogenesis of thrombocytopenia associated with advanced liver disease is still controversial. To study the impact of portal decompression on this hematologic complication, we conducted a prospective, controlled study to compare the course of platelet counts in patients after implantation of a transjugular intrahepatic portosystemic shunt (TIPS) with matched controls without shunts. METHODS: Fifty-five TIPS patients and 110 controls matched for age, sex, Child-Pugh class, etiology of liver disease and baseline platelet count were included, and followed for 1 year. Follow-up visits were scheduled after 1 month, after 3 months, and at 3-month intervals thereafter. RESULTS: Nonparametric Mann-Whitney U-tests revealed significantly higher platelet counts for TIPS patients as compared to controls from the 1st through the 12th month (p<0.01). During the study period, the median platelet count of TIPS patients increased by 19.7%, from 104.0/nl (IR: 68.0) to 124.5/nl (IR: 41.0). In contrast, during the same period the median platelet count of controls decreased by 17.1%, from 102.5/nl (IR: 66.0) to 85.0/nl (IR: 67.5). In the group of cases with baseline platelet counts < or =100/nl, platelet counts had increased by at least 25% at month 12 in 65% of TIPS patients, but in only 5% of controls (p<0.001). However, normalization of platelet counts, i.e. > or =150/nl, was not achieved in any case. Neither the portosystemic pressure gradient after TIPS implantation, nor the percentage of portosystemic pressure gradient reduction during the procedure was predictive of platelet response. CONCLUSIONS: TIPS implantation increases platelet counts significantly. However, portal hypertension is clearly not the only mechanism contributing to thrombocytopenia in advanced liver disease.

Adult↗

PubMed2003

Platelet-mediated microvascular inflammation and thrombosis in thrombocythemia vera: a distinct aspirin-responsive arterial thrombophilia, which transforms into a bleeding diathesis at increasing platelet counts.

Erythromelalgia is the main, pathognomonic and presenting symptom in patients with essential thrombocythemia and thrombocythemia associated with polycythemia vera. Complete relief from erythromelalgic and acrocyanotic pain is obtained with the cyclooxygenase inhibitors aspirin and indomethacin, but not with sodiumsalicylate, dipyridamol, sulfinpyrozone and ticlopedine. Thus, cyclooxygenase metabolites are necessary for erythromelalgia to develop. Local platelet consumption in erythromelalgic areas became evident by the demonstration of arteriolar fibromuscular intimal proliferation and occlusions by platelet-rich thrombi in skin biopsies, by the findings of shortened platelet survival times, significant higher levels of platelet activation markers beta-thromboglobulin, thrombomoduline and increased urinary thromboxane B2 excretion in thrombocythemia patients suffering from erythromelalgia. Aspirin treatment of erythromelalgia in thrombocythemia patients resulted in the disappearance of the erythromelalgic, thrombotic signs and symptoms, correction of the shortened platelet survival times, and a significant reduction of the increased levels of beta-TG, PF4, TM and urinary TxB2 excretion to normal. Erythromelalgia is frequently preceded or followed by atypical transient neurologic, ocular or coronary ischemic symptoms, which specifically respond to low-dose aspirin or reduction of platelet counts to normal. The broad spectrum of acropareshesias, erythromelalgia and acrocyanotic ischemia together with the episodic and transient atypical TIAs and ocular or coronary ischemic symptoms are caused by spontaneous activation and aggregation of hypersensitive platelets in the end-arterial microvasculature involving the peripheral, cerebral and coronary circulation of thrombocythemia patients. These microvascular circulation ischemic disturbances in thrombocythemia vera already occur at platelet counts in excess of 400 x 10(9) l(-1). Low-dose aspirin is highly effective and safe in the cure and prevention of thrombotic and ischemic events and does not elicit bleedings at platelet counts below 1000 x 10(9) l(-1). Spontaneous hemorrhages usually occur at very high platelet counts far in excess of 1000 x 10(9) l(-1) (HT) due to an acquired von Willebrand factor deficiency at increasing platelet counts. At platelet counts between 1000 and 2000 x 10(9) l(-1), thrombosis and bleeding (ETT and HT) frequently occur in sequence or paradoxically and low-dose aspirin does prevent thrombotic complications but aggravates or may elicit bleeding symptoms. Reduction of the platelet count to below 1000 x 10(9) l(-1) by platelet lowering agents usually results in the disappearance of the bleeding tendency and improvement of the von Willebrand syndrome, but the thrombotic tendency persists as long as platelet counts are above the upper limit of normal.

Aspirin↗

PubMed1997

Platelet transfusion requirements during autologous peripheral blood progenitor cell transplantation correlate with the pretransplant platelet count.

The use of primed peripheral blood progenitor cells (PBPC) has improved platelet engraftment following autologous bone marrow/PBPC transplantation (ABMT). The thrombocytopenia associated with ABMT generally lasts 14-18 days, and is associated with variable platelet transfusion requirements. Little, if any, data exist examining prognostic parameters for platelet transfusion requirements during autologous transplantation. We retrospectively examined 286 consecutive patients undergoing autologous transplantation from 1 January 1994 to 1 June 1996 with respect to platelet engraftment and platelet transfusion requirements. One hundred and fifty four patients were transplanted for breast cancer (54%), 72 for non-Hodgkin's lymphoma (25%), 35 for Hodgkin's disease (12%), 13 for acute leukemia (5%), eight for myeloma (3%), and four for other malignancy (1%). The median age was 44. All patients received cytokine priming, usually with G-CSF, for the procurement of PBPC. The median number of CD34+ cells collected was 4.3 x 10(6)/kg. All patients received a chemotherapeutic preparative regimen and all received an autologous transplant using PBPC alone. The median time to a platelet count of 20 x 10(9)/l was 13 days. Patients beginning the transplant with a less than normal platelet count (less than 150 x 10(9)/l) engrafted in 17 days, and received a median number of seven platelet transfusions, as compared with platelet engraftment of 12 days, and four platelet transfusions, for patients beginning the transplant with a normal platelet count (P = 0.001). Both groups of patients received an equivalent dose of CD34+ cells. We conclude that thrombocytopenia at the initiation of autologous transplantation is associated with increased platelet transfusion requirements, independent of the dose of CD34+ cells infused.

Adult↗

PubMed2003

Platelet counts and interleukin-6 (IL-6) promoter polymorphism in patients with Gaucher disease.

INTRODUCTION: The purpose of this study was to ascertain whether polymorphism of the IL-6 promoter gene affects platelet counts among patients with Gaucher disease since it has been shown that in healthy individuals, the CC genotype is correlated with lower platelet counts. METHODS: Blood samples from all adult patients seen at a referral clinic during a 12 month period were taken for PCR analysis for the IL-6 promoter polymorphism. Platelet counts were culled from the records on date of presentation and prior to advent of enzyme replacement therapy where relevant. RESULTS: Of 138 Ashkenazi Jewish patients, 31 patients had platelet counts <60,000/mm 3 and 37 patients had normal platelet counts (>150,000/mm 3 ). Of the former group, 4/31 (13%) and of the latter group, 3/37 (8%), had the CC genotype. Although all seven patients had relatively mild Gaucher disease (only one required therapy), there was no statistically significant difference in allele frequency of the IL-6 promoter polymorphism in either group relative to healthy Ashkenazi Jews. CONCLUSION: Whether comparing patients with Gaucher disease with normal platelet counts or with thrombocytopenia to healthy Ashkenazi Jews, there was no difference in frequency of the CC state. Thus, the IL-6 promoter polymorphism may not influence Gaucher disease to induce lower platelet counts as shown in other normal Caucasians.

Adolescent↗

PubMed1982

Fresh autologous blood transfusion and platelet counts after cardiopulmonary bypass surgery.

The effect of fresh autologous blood transfusion on platelet count and blood requirement in the early postoperative period is examined in a control group and in patients receiving early and late autologous replacement. Withdrawal of blood in the autologous groups appeared to enhance platelet numbers as the autologous groups had higher mean platelet counts than the control group immediately after bypass, in spite of having lower mean haematocrit. After bypass all groups showed a progressive rise in platelet count with time. A substantial part of the rise was explained by haemoconcentration resulting from fluid shifts but there was also an increase in the total circulating platelet numbers. There was no difference in postoperative blood loss between the three groups. Autologous blood replacement hastens the postoperative rise in platelet count but does not alter the postoperative blood loss.

Blood Transfusion, Autologous↗

PubMedDate not supplied

Thrombopoietin levels and peripheral platelet counts following living related donor liver transplantation.

BACKGROUND/AIMS: Thrombopoietin is the primary hematopoietic growth factor. Thrombopoietin deficiency may cause thrombocytopenia in advanced liver disease. The aim of our study was to investigate the relevance of thrombopoietin levels to peripheral platelet counts in patients with liver disease who underwent LRDLT (living related donor liver transplantation). METHODOLOGY: We divided the six patients who underwent LRDLT into two groups. Group 1 had thrombocytopenia and group 2 had normal platelet counts. We measured serum thrombopoietin and peripheral platelet counts before and after LRDLT. RESULTS: Pre-LRDLT thrombopoietin and peripheral platelet counts were lower in group 1 than in group 2. Thrombopoietin in group 1 significantly increased on the first day after LRDLT and peripheral platelet counts in group 1 increased following the rise in thrombopoietin (p < 0.05). Moreover, a marked increase in thrombopoietin and peripheral platelet counts was found in splenectomized patients during LRDLT. CONCLUSIONS: These findings suggested inadequate thrombopoietin production in advanced stage liver disease which caused thrombocytopenia. Improvement of thrombopoietin production in graft liver function may contribute to increase of peripheral platelet counts.

Adult↗

PubMed1991

Platelet count and venous thromboembolism. A useful test for suspected pulmonary embolism.

We have previously reported that patients with deep vein thrombosis (DVT) and scintigraphic evidence of pulmonary embolism (PE) had a fall in platelet count, as compared with their levels before thrombosis had developed. Otherwise, no changes were found in DVT patients without embolism. We recently conducted a prospective study with a larger series of patients and studied platelet count behavior in 189 consecutive patients with acute venous thromboembolism (VTE) in whom a baseline blood cell count was available (obtained before thromboembolism developed). We found no significant differences in baseline platelet counts between groups. However, at the time of VTE diagnosis the analysis of variance demonstrated that mean platelet count was significantly higher in patients without embolism as compared with PE patients (p less than 0.001). On the other hand, no differences were found between patients with silent PE and those with clinically obvious PE. When patients with postoperative VTE and those with nonpostoperative VTE were analyzed separately, mean platelet count increased only in postoperative DVT patients without embolism (p less than 0.001). In the absence of a previous intervention, DVT did not produce any change in platelet count, while PE significantly reduced platelet number (p less than 0.008). In DVT patients without respiratory symptoms of embolism, we suggest that a lung scan should be performed when platelet count is lower than baseline value. For patients with a higher count, the probability of finding PE is very low, and scintigraphy is not cost-effective.

Adolescent↗

PubMed1991

False-negative prenatal exclusion of Wiskott-Aldrich syndrome by measurement of fetal platelet count and size.

The study of the fetal platelet count and size can, according to the literature, be used for the prenatal diagnosis of the Wiskott-Aldrich syndrome (WAS). So far, no affected fetuses have been identified by this method. All pregnancies in which this method had been applied to resulted, as correctly predicted, in the birth of normal children. Here we report on a familial case of WAS where the haematological parameters failed to reveal the affected second child. Hence we assume that the platelet count and size of platelets remain normal in fetuses with WAS to the gestational age of 22 weeks and cannot be used for prenatal diagnosis.

Adult↗

PubMed2002

Artefactually-normal automated platelet counts due to malaria-infected RBC.

Protein aggregates, red cell or white cell fragments are known to interfere with platelet counts in automated blood analysers, both by aperture impedance and optical technologies. When a falsely high value is suspected, interference by pseudo-platelet particles can be confirmed by systematic examination of stained blood films. The method that best avoids these sources of interference is the reference, immunological platelet count. We describe a case of treated malaria with a false normal platelet count. The blood smear revealed small red cells, infected by trophozoites of Plasmodium falciparum, that interfered with the platelet count. The Cell Dyn 4000 shows different patterns of interference by infected red cells in its impedance and optical counts, and thrombocytopenia was suspected immediately. This was confirmed by a phase-contrast microscopic platelet count.

Adult↗

PubMed2001

Platelet count may predict abnormal bleeding time among pregnant women with hypertension and preeclampsia.

BACKGROUND: Anesthesiologists often require laboratory data to estimate the bleeding risk among hypertensive pregnant women prior to administering regional anesthesia. Many rely on the bleeding time (BT) in making this determination. We examined whether the platelet count can adequately predict BT among a group of hypertensive parturients. METHODS: This retrospective subgroup analysis, taken from a cohort of 2,051 hypertensive pregnant women, comprises 87 individuals who underwent both a BT and platelet count prior to delivery. We calculated the correlation between the platelet count and BT at three platelet cut-off points with respect to prolonged BT of eight minutes or more. RESULTS: There was a significant negative correlation between platelet count at delivery and BT [r= -0.45, 95% confidence interval (CI) -0.26 to -0.60; P <0.0001]. All three platelet cut-off points had a sensitivity of less than 66% with negative predictive values below 75% for an abnormal BT. A platelet count > or =75 x 109/L [corrected] was specific for the presence of an abnormal BT (specificity 97.8%, 95% CI 91.7-100.0), with a positive predictive value of 95.5% (95% CI 83.1-100.0) and a positive likelihood ratio of 24 (95% CI 3.3-168). CONCLUSIONS: In a group of hypertensive parturients, the platelet count appears to be very specific for predicting a prolonged BT The platelet count may aid the anesthesiologist in determining the risk of bleeding from regional anesthesia. Given the study's potential for bias future research is needed to validate these findings.

Adult↗

PubMed2001

Diagnostic value of serum type IV collagen test in comparison with platelet count for predicting the fibrotic stage in patients with chronic hepatitis C.

BACKGROUND AND AIM: The serum type IV collagen test is now used as a diagnostic aid for the detection of liver fibrosis and cirrhosis. Recently, a platelet count has been reported to be a useful marker for assessing the fibrotic stage in chronic hepatitis C. The aim of this study was to compare the usefulness of the serum type IV collagen test and platelet count for diagnosing the fibrotic stage in chronic hepatitis C patients. METHODS: The diagnostic values were assessed by the use of receiver operating characteristic (ROC) analysis in 165 patients with chronic hepatitis C, with the exception of those patients with cirrhosis. RESULTS: The serum type IV collagen level increased, and the platelet count decreased significantly with the progression of fibrosis staging. As judged from ROC curves, the serum type IV collagen test was more useful than the platelet count for differentiating moderate or severe fibrosis from no or mild fibrosis. At a cut-off value of 110 ng/mL, the serum type IV collagen test had an overall diagnostic accuracy of 75%, while at a cut-off value of 16 x 10(4)/mm(3), the platelet count had a diagnostic accuracy of 70%. The serum type IV collagen test and platelet count were similar in differentiating severe fibrosis from no, mild or moderate fibrosis. Both serum type IV collagen (at a cut-off value of 130 ng/mL) and platelet count (at a cut-off value of 14 x 10(4)/mm(3)) had a diagnostic accuracy of 73%. CONCLUSION: The serum type IV collagen test was slightly superior to the platelet count for assessing the fibrotic stage in patients with chronic hepatitis C.

Adult↗

PubMed1977

A sex difference in the platelet count.

A study of the platelet counts of 868 blood donors aged 18-65 showed a higher mean count in women than in men, the difference in the premenopausal age groups being highly significant (P less than 0.001) and of the order of 40-70 x 10(9)/1. The mean counts of women taking a contraceptive pill did not differ significantly from those who were not.

Adolescent↗

PubMedDate not supplied

Preoperative platelet count predicts survival after resection of periampullary adenocarcinoma.

BACKGROUND/AIMS: Thrombocytosis or thrombocytopenia have been shown to act as negative predictors of outcome for various solid tumors. No such effect is known for periampullary cancer. The preoperative peripheral blood platelet count impacts on outcome after resection of pancreatic and other periampullary adenocarcinomas. METHODOLOGY: Clinicopathologic information, treatment aspects, and outcome parameters of patients undergoing pancreatectomy at City of Hope Cancer Center were retrospectively collected and tabulated. The impact of the preoperative platelet count on postoperative recovery, disease-free survival, and overall survival was analyzed. RESULTS: Between 1988 and 1998, 65 patients underwent partial or total pancreatectomy at City of Hope Cancer Center, 49 of whom had a diagnosis of pancreatic or periampullary adenocarcinoma. There were 26 females and 23 males, with a median age of 64 years (range: 24-86). Median preoperative platelet count was 308 (x10(9)/L; range: 104 to 547). Diagnoses were pancreatic (n = 28), duodenal (n = 12), and bile duct/ampullary cancer (n = 9). Procedures included pancreatoduodenectomy (n = 42), distal pancreatectomy (n = 4), and total pancreatectomy (n = 3). Six patients underwent a splenectomy. A lower preoperative platelet count was correlated to a shortened prothrombin time (P = 0.02), and a positive resection margin (P = 0.01), but not operative blood loss or transfusion requirements. Postoperative complications and hospital stay were not affected by the platelet count. Preoperative platelets of < 300 were associated with a decreased median overall survival (13 vs. 33 months, P = 0.02) and disease-free survival (11 vs. 29 months, P = 0.02), at a median follow-up of 14 months (18 for survivors). On multivariate analysis, the platelet count remained a significant predictor of survival in addition to grade, perineural invasion, the primary tumor size, and the surgeon. CONCLUSIONS: Based on these retrospective data, a lower preoperative platelet count correlates with inferior, a higher count with superior survival outcome after resection of periampullary cancer. The mechanism is unclear, but may relate to general factors (bone-marrow suppression or hypersplenism for low platelets, systemic antitumor mediators for high platelets) or platelet-specific effects (platelet influence on tumor angiogenesis or metastatic efficiency). The preoperative thrombocyte count should be considered a parameter with potential clinical significance in prospective clinical studies of periampullary neoplasms.

Adenocarcinoma↗

PubMed2006

Long-term monitoring of platelet count, as a non-invasive marker of hepatic fibrosis progression and/or regression in patients with chronic hepatitis C after interferon therapy.

BACKGROUND: Platelet count has been shown to correlate with the hepatic fibrosis stage in chronic hepatitis C (CHC). The aim of the present study was to assess hepatic fibrosis progression or regression of CHC patients by long-term monitoring of the platelet count. METHODS: A total of 429 interferon (IFN)-treated CHC patients were studied. Follow-up data on the platelet count were collected every 6 months after IFN therapy. The IFN response was defined as follows: complete responders (CR, n = 121) demonstrating persistent clearance of serum hepatitis C virus (HCV) RNA; biochemical responders (BR, n = 94) demonstrating alanine aminotransferase (ALT) normalization for >/=6 months without eradication of HCV-RNA; and non-responder (NR, n = 214) demonstrating all other patterns. RESULTS: In comparison with the baseline level, mean platelet count increased in the CR group from 0.5 years after IFN therapy (for each point, P < 0.01), but significantly decreased in the NR group from 1 year after IFN therapy (for each point, P < 0.01). In the BR group, an increase in mean platelet count was observed from 0.5 to 3.5 years following IFN therapy (for each point, P < 0.01), followed by a gradual decrease. CONCLUSION: An increase from baseline values in platelet count was observed, regardless of the presence of HCV-RNA, in both the CR and BR groups, suggesting the importance of ALT normalization in preventing hepatic fibrosis progression in IFN-treated CHC patients.

Antiviral Agents↗

PubMed1994

Accurate intrapartum estimation of fetal platelet count by fetal scalp samples smear.

Fetal scalp sampling has been used to determine fetal platelet count in early labor. Because platelet clumping may lead to falsely low platelet counts, this pilot study was carried out to evaluate an improved method of scanning an intrapartum fetal scalp smear for platelet estimation. We report 5 years' experience with the use of scanning of the smear for platelet aggregates instead of direct measurement of platelets. In 22 cases, intrapartum examination of the scalp blood smear at low power revealed the great majority of high-power, dry microscopic fields devoid of platelets, whereas isolated fields contained aggregates of more than 10 platelets. In one case, an adequate number of platelets were evenly distributed. Intrapartum fetal platelet estimation by scanning of the smear (using these platelet aggregates) correctly identified an adequate neonatal platelet count in 23 cases (mean, 264,600 +/- 15,000; range, 133,000 to 396,000). Cesarean section was avoided in 82.6% of these cases. In this pilot study, platelet estimation on fetal scalp sample were reliably performed by scanning of the smear for platelet aggregates. When aggregates were seen, platelet adequacy was found in all cases.

Blood Specimen Collection↗

PubMed1999

[Clinical reference values for laboratory hematology tests calculated using the iterative truncation method with correction: Part 2, Reference values for white blood cell (WBC) count, WBC differential including segmented neutrophil, band neutrophil, lymphocyte, monocyte, eosinophil, basophil, platelet count and mean platelet volume].

Age and sex dependent differences in the clinical reference values for white blood cell(WBC) count, WBC differential including segmented neutrophils(SEG), band neutrophils(BAND), lymphocytes (LYMPH), monocytes(MONO), eosinophils(EOSINO), basophils(BASO), platelet count(PLT) and mean platelet volume(MPV) were calculated by the iterative truncation method with correction(Usui's method) using the result from tests on 6,300 patient specimens obtained at Kyoto University Hospital. WBC counts exhibited log-normal distribution in all age either in male and female. PLT counts and MPV showed normal or log-normal distribution. WBC differential (SEG, BAND, LYMPH, MONO, EOSINO, BASO) usually showed log-normal distribution. As to the reference value for WBC, high limit values gradually decreased in the age range of 5-14 year old in males and females. After 15 year old, it gradually increased and reached adult's level. Low limit values for WBC gradually decreased with age both in males and females. The reference value for SEG showed similar change to WBC. The reference value for LYMPH gradually decreased age both in males and females. The reference values for BAND, MONO, EOSINO, BASO were generated by the percentile method instead of the iterative truncation method because of the strong deviation in the distribution pattern. BAND, MONO and BASO values were very stable for all ages in males and females. High limit values for EOSINO in the age range of 5-10 year old in males and females remained constant, and gradually decreased in 10-20 year old, and were stable at ages above 20 year old. PLT counts gradually decreased with age, and the MPV remained constant in all age populations both in male and female.

Adolescent↗