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PubMedDate not supplied

The correlation between thrombopoietin and platelet count in adult dengue viral infection patients.

AIM: To investigate alteration in humoral regulation during the course of dengue viral infection. METHODS: A prospective analytic study had been conducted involving 40 subjects with dengue viral infection. Subjects were recruited according to consecutive non-probability sampling. Subjects were categorized according to days of illness, platelet counts and serum thrombopoietin (TPO) levels. The plasma TPO levels examinations were done once daily until the platelet counts reached more than 100,000/mm(3). RESULTS: Statistical analysis showed the mean serum TPO levels were increased during thrombocytopenia phase of the disease, and differ significantly from the convalescent phase (mean value 428 pg/ml vs 220.1 pg/ml, p= 0.00). There was also a statistically significant inverse correlation between serum TPO levels and platelet counts (p= 0.00). CONCLUSION: TPO levels were significantly increased in adult patients with dengue infection in which platelets in circulation were markedly reduced, and the TPO levels were inversely related to the platelet counts.

Adolescent↗

PubMed1977

[Electronic platelet counting with particular reference to thrombocytopenias (author's transl)].

Platelet counts in platelet-rich plasma without hematocrit dependent correction were performed by following rapid and simple steps: 1. pre-dilution of 20 microliter of whole blood by an isotonic solution 1:25; 2. stabilized low-speed centrifugation with 55 g for 5 minutes; 3. final dilution 1 : 5000; 4. enumeration by use of a TOA platelet counter PL-100 which has been technically improved in comparison to similar machines. Erroneously high results were obtained after a too short or too low centrifugation. As reason for this artifical small pulses due to disturbances of the flow patterns around the aperture (so-called vortex-effect) can be assumed having been caused by large-volumed erythrocytes and leukocytes in the suspension. The routinely used procedure was reliable for all platelet ranges, especially in thrombocytopenias between 100 X 10(9)/l and 25 X 10(9)l. In lower ranges comparisons with visual counts are essential.

Blood Cell Count↗

PubMed1997

[Analysis of mechanism of increased platelet counts during preoperative autologous blood donation].

Autologous blood transfusion is advantageous in that it eliminates the risk of transfusion-transmitted infection or complications caused by the immune reaction. Increased platelet counts after repeated phlebotomy are commonly observed. This study was carried out to clarify the mechanism of increased platelets during preoperative autologous blood donation. Eleven patients of elective surgery in which is in good preoperative condition and there is no emergency were selected for this study. Blood cell counts, platelet size distribution(PDW, MPV, P-LCR) and serum concentration of erythropoietin(EPO), interleukin-3(IL-3) and interleukin-6(IL-6)were measured. A transient increase in platelet was seen in almost patients during preoperative autologous blood donation. No marked changes in platelet size distribution and serum concentration of EPO, IL-3 and IL-6. These results suggest that increased platelet counts during preoperative autologous blood donation might be caused by some specific cytokines related to megakaryocyte differentiation such as c-MPL ligand.

Adult↗

PubMed2004

The importance of platelet counts in dengue infection: 35 cases and literature review.

Dengue infection is a major vector-borne disease. The classical form of this infection has an incubation period of 5 to 8 days followed by fever, violent headache, and chills, with rash developing after 3 to 4 days. A summative report on the platelet count and its clinical correlation to duration of fever in 35 Thai children is presented. Most of the subjects visited to the physician with a complaint for fever. Most patients went to see the physician between the 3rd and the 5th day from the onset of fever. There is no significant correlation between platelet count and duration of fever (ANOVA test, p = 0.28). However, there is a trend of increase platelet count in the later days. In addition, an overview on the previous literatures on platelet count and dengue infection is presented.

Dengue↗

PubMed1989

Improvement of Durie & Salmon staging for multiple myeloma by adding platelet count as a stratifying variable: a multivariate regression analysis of 163 untreated patients.

The presenting clinical features of 163 previously untreated patients with multiple myeloma were correlated with survival duration using univariate and multivariate regression analyses. The univariate proportional hazard analysis ranked the parameters in the following order of importance: platelet count, haemoglobin level (Hb), tumour cell mass stage, lytic bone lesions, creatinine and age. When the individual contribution of each variable was assessed by multivariate regression analysis, platelet count was confirmed to be the dominant feature for prognosis, while clinical stage provided additional information. The introduction of platelet count could then be used to improve the discriminating power of Durie & Salmon staging, by allowing separation of the high-risk group (stages II and III) into a smaller subgroup (22%) of thrombocytopenic patients (less than 150 x 10(9) platelets/l) whose risk of death was actually very high (median survival: 9 months) and a larger subgroup (46%) of patients with normal platelet count and intermediate or standard risk (median survival: 48 months).

Humans↗

PubMed1997

Spontaneous rise of fetal platelet counts despite increasing anti-HPA-5b antibodies.

BACKGROUND AND OBJECTIVES: Maternal anti-HPA alloantibodies are a rare cause of severe fetal thrombocytopenia. So far there have been no reports on the dynamics of maternal anti-HPA-5 during gestation and its effect on the fetus. MATERIALS AND METHODS: We monitored maternal anti-HPA-5b antibody titers and fetal platelet counts during gestation in a woman with known anti-HPA-5b alloimmunization. The patient was a 32-year-old woman in her third pregnancy. The 1st pregnancy and delivery of a healthy child had been uneventful. At delivery, anti-HPA-5b was detectable in the maternal serum. A 2nd pregnancy ended in early miscarriage. RESULTS: A steady rise in the alloantibody titer was recorded throughout the 3rd pregnancy. Therefore, cordocentesis was performed at 28 weeks of gestation (platelet count 76 x 10(9)/l). Serial platelet transfusions were administered to the fetus at 28, 32, and 37 weeks of gestation. The platelet counts rose spontaneously thereafter and were 220 x 10(9)/l at delivery, despite an increase in the anti-HPA-5b antibody titer. The child developed normally during the first year of life. CONCLUSIONS: This case illustrates the spontaneous recovery of fetal platelet counts in late pregnancy despite a rise in maternal alloantibody titer.

Adult↗

PubMed2002

Effect of cigarette smoking and 3.2% ethanol alone or together on RBC and platelet counts in rats.

The present study was conducted on 32 rats divided into four groups. Group C served as control, Group S rats were exposed to cigarette smoke alone, Group SE to cigarette smoke and ethanol (3.2%) and Group E to ethanol alone for twelve weeks. The basal RBC and platelet count were determined and compared with the values obtained at the end of 12 weeks. A significant increase in RBC and platelet counts was seen in Groups S (P < 0.001 and P < 0.01 respectively) and SE (P < 0.01 for both counts). The increase in group SE is less than that seen in Group S. Ethanol consumption alone has shown a significant decrease (P < 0.01) in RBC count and apparent decrease in platelet count as compared to control. This study indicates that cigarette smoke is damaging to health alone or when combined with ethanol.

Alcohol Drinking↗

PubMed1998

Platelet activation in the Dutch haemocytometry quality assessment programme: correlation between P-selectin expression and variation in platelet count.

Since 1990, our laboratory has prepared a set of 8 fresh whole blood samples for use in a countrywide quality assessment (QA) programme. The samples are intended as external controls for haemocytometry analysers. These samples are of 8 different haematocrit levels and each one is prepared from a single donor. About 210 laboratories participate in this QA programme. From the start of this programme large interlaboratory variations in platelet counts were encountered in some of the samples. This variability was much higher than would be expected and was independent of the platelet count of the samples. The main cause was thought to be formation of platelet aggregates. The aim of the present study was to find a parameter that can predict a high interlaboratory variation in the QA programme. Therefore we investigated the initial platelet activation status in the donors and the activation status of platelets in the prepared QA blood. As a marker for platelet activation P-selectin expression on the platelets was measured using flow cytometry. During 5 rounds of the QA programme we found a good correlation of r = 0.53 (p < 0.001) between P-selectin expression on platelets in the reconstituted QA blood and the interlaboratory platelet count variability. We conclude that P-selectin expression in the prepared QA blood is an important parameter to exclude samples that lead to high CVs of platelet counts in the QA programme.

Blood Specimen Collection↗

PubMed1997

Effects of maternally administered immunoglobulin on platelet counts of neonates born to mothers with autoimmune thrombocytopenia: re-evaluation.

OBJECTIVE: Since immunoglobulin is transported across the placenta, maternal administration of it theoretically seems attractive as an antenatal treatment for a fetus. However, the effects of antenatally administered intravenous immunoglobulin (IVIG) on fetal platelet counts have been controversial. Our series of 11 cases of idiopathic thrombocytopenic purpura (ITP) and a review of previous reports are presented. A combined retrospective analysis to know whether maternal response to IVIG is associated with improvement of fetal thrombocytopenia was conducted. METHODS: IVIG was given to 11 steroid refractory pregnancies with ITP. Good maternal response to the therapy was defined as an increase in the platelet count to greater than 50 x 10(9)/L after completion of the IVIG infusion. Neonatal platelet counts of the umbilical cord were performed just after birth and followed-up for at least the first week of life. RESULTS: Seven of the 11 neonates had thrombocytopenia of less than 100 x 10(9)/L, and two of them had severe thrombocytopenia of less than 50 x 10(9)/L. Two out of two neonates born to mothers with a good response to IVIG were thrombocytopenic; whereas five out of nine neonates born to mothers with a poor response were thrombocytopenic. The combined retrospective analysis of our results and published reports have shown that fetal thrombocytopenia was not associated with the maternal response to IVIG but with the level of immunoglobulin G of neonates at birth. Passive thrombocytopenia was more frequently observed in neonates with normal levels of immunoglobulin G than those with elevated levels. CONCLUSION: This combined analysis confirmed the proposed hypothesis that the lack of effect of maternally administered IVIG on fetal platelet counts may mainly be attributed to the insufficient therapeutic level of transferred immunoglobulin G in the cord blood.

Female↗

PubMed2003

Effect of fibrinogen concentration and platelet count on the inhibitory effect of abciximab and tirofiban.

Glycoprotein (Gp) IIb/IIIa blockers are powerful antithrombotic agents, but display a wide variability of their effect using weight adjusted dosing. We investigated whether some hemostatic variables affected in vitro platelet inhibition exerted by the antibody abciximab and the peptidomimetic tirofiban. High fibrinogen concentrations reduced platelet inhibition by tirofiban, assessed in whole blood (r = -0.85, n = 10, p <0.01) and in platelet rich plasma (r = -0.89, n = 10, p <0.01) through PFA 100 and Born's aggregometry assay, respectively. Both drugs were unaffected by von Willebrand factor levels, while platelet count was inversely related to their inhibitory effect (tirofiban: r = -0.9, n = 7, p <0.01; abciximab: r = -0.81, n = 9, p <0.01). Analysis of GpIIb-IIIa blockade showed that receptor occupancy at a fixed abciximab dose was inversely related to platelet counts. These experimental data were in agreement with the classical model of receptor saturation by a tight binding inhibitor. A role for fibrinogen and/or platelet count in influencing the antithrombotic properties of platelet GpIIb-IIIa antagonists can be hypothesized.

Abciximab↗

PubMed1999

Effect of Trillium Biopassive Surface coating of the oxygenator on platelet count drop during cardiopulmonary bypass.

The new Trillium Biopassive Surface is a coating designed to minimize the adsorption of protein and the attachment of cells. In previous studies, we were able to demonstrate that, by coating the bypass circuit with small amounts of albumin, the drop in circulating platelet count seen with the newer low-prime hollow-fiber membrane oxygenators is eliminated. A study was undertaken to compare the Avecor Affinity oxygenator with albumin in the prime with the Trillium-coated Affinity. Fifty-six patients undergoing nonemergency open-heart surgery were randomly divided into two groups. One group (Albumin) received the Affinity oxygenator with 10 ml of 25% albumin added to the pump prime. The other group (Trillium) received the Trillium-coated Affinity oxygenator. To normalize the data for the effects of hemodilution, the mean net platelet count drop on bypass was calculated for each group. The Albumin group had a net platelet count drop of 0.81+/-9.78%, while the Trillium group had a drop of 1.58+/-13.0%. There was no significant statistical difference between the two groups. From our investigation, we concluded that Trillium Biopassive Surface coating affords the Affinity oxygenator the same protective effects on circulating platelet counts as adding albumin to the prime.

Aged↗

PubMed1990

Platelet counts in maternal and umbilical venous blood at the time of delivery.

Platelet count in 38 paired maternal venous and umbilical venous specimens were determined at delivery. Umbilical values were significantly higher than simultaneous maternal values (p = 0.004), and a significant relationship was demonstrated between umbilical values and maternal values (r = 0.54, p = 0.0004). Associations between platelet counts and acid-base variables were found to be insignificant in the mother and the umbilical cord.

Adolescent↗

PubMed1985

[Automated platelet count in thrombocytopenic patients--a comparison of methods].

157 EDTA blood samples from thrombocytopenic patients (platelets less than 100 X 10(9)/1) were measured and the platelet counts compared using the various blood cell counters of the central laboratory, University Clinic, Göttingen. Using the H 6000, Hemalog 8 (both Technicon) and ELT-8 (Ortho Instruments), product-moment correlation coefficients (r) ranging from 0.88 to 0.92 were obtained between the different counters. The correlation coefficients of the thrombocounter (Coulter) to the other instruments were only 0.84 and 0.85. Discrepant platelet counts (difference greater than 40 X 10(9)/1) were reinvestigated using the Neubauer chamber. From a total of 354 platelet measurements, falsely high concentrations were observed only in three cases and falsely low concentrations in seven cases.

Edetic Acid↗

PubMed1981

The specific activity of platelet monoamine oxidase varies with platelet count during severe exercise and noradrenaline infusion.

During severe exercise or noradrenaline infusion in healthy male volunteers, the platelet count first rose and then fell. Platelet monoamine oxidase activity per unit protein rose and fell in parallel and the correlation with the platelet count was highly significant (P less than 0.001). The increase in observed specific monoamine oxidase activity might be due to the release of a population of platelets with higher specific activity, and the decrease to their selective removal.

Adult↗

PubMed2000

Thrombocytosis in temporal arteritis rising platelet counts: a red flag for giant cell arteritis.

OBJECTIVES: To determine whether early recognition and detection of thrombocytosis in patients with giant cell arteritis can help secure an earlier diagnosis, and whether it can help differentiate cases of arteritic optic neuropathy from other forms of optic neuropathy. METHODS: Medical and ophthalmologic records from 1993 to 1998 of the authors' patients with biopsy-proven temporal arteritis versus the authors' patients with nonarteritic anterior ischemic optic neuropathy and idiopathic demyelinating optic neuritis were prospectively collected. Past and present blood analyses were collected, and platelet counts were compared between patients with giant cell arteritis and control populations. This was done to determine whether thrombocytosis could help with the diagnosis and differentiation of these different disease states. RESULTS: There was a significant difference in the frequency of thrombocytosis in patients with giant cell arteritis (13 out of 19 patients), with or without arteritic ischemic optic neuropathy, as compared with those with nonarteritic anterior ischemic optic neuropathy (zero out of 30 patients), idiopathic optic neuritis (zero out of 26 patients), and healthy age-matched controls (one out of 22 control subjects). This difference was especially helpful in patients whose sedimentation rates were within the normal range (adjusting for age). Also noted was the finding that the rise in the platelet counts was not acute, but rather it was a slow gradual increase for approximately 12 months before the onset of significant systemic or visual symptoms. CONCLUSION: Thrombocytosis should be considered an important marker in patients being referred for evaluation of ischemic optic neuropathy, diplopia, amaurosis fugax, headache, or even generalized malaise. Westegren sedimentation rates <50 mm/hr are often erroneously viewed as nondiagnostic or equivocal in the elderly and just followed. An over-the-phone review of patients' sedimentation rates, complete blood counts, and platelet counts can lead to expedited evaluation and treatment of patients who may be at high risk of visual loss from temporal arteritis. Thrombocytosis should lower a physician's threshold to acutely treat patients for possible arteritic ischemic optic neuropathy until the disease is definitely ruled out.

Aged↗

PubMed1980

Effect of long-term low and moderate levels of carbon monoxide exposure on platelet counts of rabbits.

Most of the traditional studies of carbon monoxide (CO) toxicology have emphasized the dramatic effects of heavy exposure, therefore, remarkably little information is available about the consequences occurring after exposure to low concentrations similar to those found in the polluted community air. In previous studies hypoxia has been reported to cause a decrease in platelet counts in experimental animals. In an effort to investigate the abnormalities of circulating platelets in rabbits exposed to low and moderate levels of CO, three groups of animals were studied. The first (control) group of rabbits breathed ambient air whereas the second was exposed to low level CO (50 ppm by volume) for 24 hr continuously for 8 weeks. The third group was exposed to 300 ppm for 4 weeks (8 hr/day for 5 days). Per cent oxyhemoglobin (HbO2), per cent hemoglobin (Hb) and per cent carboxyhemoglobin (HbCO) and circulating platelet counts were monitored in all groups. A consistant pattern of change in circulating platelet quantity was found at the observed time intervals in CO exposed animals. No changes were observed in the same tests in rabbits exposed to ambient air. Prolonged low level CO exposure may influence change in circulating platelet counts and/or congenital platelet function disorders in man through this mechanism.

Animals↗

PubMed2003

The maternal benefits of corticosteroids with HELLP (hemolysis, elevated liver enzymes, low platelet count) syndrome.

OBJECTIVES: To determine the more effective regime in improving hematologic abnormalities associated with HELLP (hemolysis, elevated liver enzymes, low platelet count) syndrome, by comparing two different antenatal dosing protocols for dexamethasone (given primarily for fetal lung maturity). STUDY DESIGN: A retrospective cohort study of 30 women between 24 and 34 weeks' gestation, diagnosed with HELLP syndrome prior to delivery, who received 2 doses of dexa-methasone 12 mg intramuscularly, given either 24 hours apart or 12 hours apart. RESULTS: There was a shorter time from the first corticosteroid dose to the beginning of improvement with the 12-hour regime for platelet count (11 hours [9, 25 hours] versus 69 hours [41, 112 hours], median [quartiles], P = 0.003) and for alkaline phosphatase (25 hours [5, 44 hours] versus 59 hours [31, 69 hours], median [quartiles], P = 0.02). Worsening recurred from 11 hours, for alanine aminotransferase (ALT) and aspartate transaminase (AST), to 32 hours, for uric acid, after initial improvement. Hematologic improvement occurred in 37% (for ALT) to 67% (for alkaline phosphatase) of women overall. CONCLUSION: A temporary improvement in the hematologic parameters of HELLP syndrome can occur with antenatal dexa-methasone administration, with the 12-hour regime having quicker onset to improvement in platelet count and alkaline phosphatase.

Adult↗

PubMed2000

A prospective, randomized, sequential crossover trial of large-volume versus normal-volume leukapheresis procedures: effects on serum electrolytes, platelet counts, and other coagulation measures.

BACKGROUND: LVL procedures with the administration of heparin as an additional anticoagulant are increasingly performed because of the potentially higher yield of autologous peripheral blood HPCs. A prospective, randomized crossover trial was performed to evaluate the influence of leukapheresis volume-that is, large versus normal-on serum electrolytes, platelet count, and other coagulation measures in 25 patients with breast cancer and 14 patients with non-Hodgkin's lymphoma. STUDY DESIGN AND METHODS: Patients were randomly assigned to start either with an LVL on Day 1 followed by a normal-volume leukapheresis (NVL) on Day 2 or vice versa. In LVL, heparin was administered in addition to ACD-A. Bleeding complications, transfusion support, whole-blood counts, and several coagulation measures as well as plasma heparin levels were evaluated. RESULTS: Although the duration, the infused amount of ACD-A, the flow rate, the drop in platelet count, and the drop in potassium were significantly greater in LVL, and although LVL patients also received heparin, there was no significant difference in clinical tolerance or bleeding complications. After LVL, patients exhibited a significantly longer activated partial thromboplastin time (APTT), with a median of 70 seconds (range, 44-100 sec), and a median anti-factor Xa activity of 0.69 IU per mL (range, 0.10-1.29 IU/mL). The value of the APTT after LVL correlated with anti-factor Xa activity (r = 0.37, p<0.05), but not with platelet count or heparin infusion rate. Markers for coagulation activation did not increase during NVL or LVL. CONCLUSION: LVL with heparin as an additional anticoagulant seems to be a safe procedure in patients with low preleukapheresis platelet counts. No activation of coagulation occurred after NVL or LVL procedures.

Adult↗