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PubMed1978

Rapid reduction of platelet count in essential hemorrhagic thrombocythemia by discontinuous flow plateletpheresis.

Dramatic reduction of the platelet count by discontinuous flow plateletpheresis was achieved safely and swiftly in a patient with essential hemorrhagic thrombocythemia. The patient had a history of thrombo-occlusive arterial disease and on admission had gastrointestinal bleeding. This technic is recommended as an effective means of rapidly controlling marked increase in the platelet count and its consequences in the interval before chemotherapy becomes effective.

Aged↗
PubMed1997

[Platelet count in the cat].

The technique of collecting blood samples is primarily responsible for the appearance of platelet-agglomeration in cats. Blood obtained by the conventional way ("one syringe technology", drips of blood) caused in 52% of the cases an activation of the large and therefore active thrombocytes however. Rejection of the first 2-5 ml blood for the platelet count ("two syringe technology") reduced the rate of platelet-agglomeration significantly. No big differences in platelet-agglomeration were found with regard to the place used for collecting blood (V. cephalica antebrachii/V. jugularis). Platelet-agglutination was observed with Li-Heparin, K-EDTA, Na-Citrat or ACD anticoagulated blood samples. Citrat (Na-Citrat, ACD) seemed to have a stabilizing effect on feline thrombocytes as has been described for human thrombocytes. The platelet count in cats should be performed within 30 minutes.

Animals↗
PubMed1998

Acute immune thrombocytopenia in childhood. Are we treating the platelet count?

Acute immune thrombocytopenia (ITP) in children is a benign disease, presenting mostly with skin purpura and minor bleeds. It has a high rate of spontaneous remission. Intracranial hemorrhage (ICH) is extremely rare; the risk is higher during the chronic phase and in children with additional risk factors. The threshold platelet count in ITP is not known because of problems with platelet counting in thrombocytopenia and the lack of clinical data. The threshold is probably lower than in leukemia, because primary hemostasis is better in ITP. So far, there is no proof for the clinical efficacy of treatment or prophylaxis with intravenous immunoglobulin (IVIg) and glucocorticoids (GC), medications that have several adverse effects. The question remains open whether or not we are treating the platelet count in children with acute ITP.

Acute Disease↗
PubMed2004

Correlation between low platelet count and multicentricity of hepatocellular carcinoma in patients with chronic hepatitis C.

We investigated correlations between laboratory test results and multicentric development of hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) in 202 patients who underwent liver resection. Two types of HCC were considered to meet multicentricity criteria: in one, at least one tumor was well-differentiated, with at least one other being less differentiated; in the other, all tumors included well-differentiated HCC with or without less differentiated components. Forty-five patients had multicentric HCC. Platelet counts were lower in patients with multicentric HCC than in others. Serum concentrations of type IV collagen 7s domain and alpha-fetoprotein, histologic hepatitis activity score, and histologic hepatic fibrosis score were higher in patients with multicentric HCC. By multiple logistic regression analysis, low platelet count was an independent risk factor for multicentric HCC. The proportion of patients with multicentric HCC was significantly higher among patients with low platelet counts (below 10(5)/mm(3)) than in patients with a higher count. Thus, HCC patients with a platelet count below 10(5)/mm(3) may require particularly careful examination for multicentricity.

Journal Article↗
PubMed2000

Strong inverse correlation between serum TPO level and platelet count in essential thrombocythemia.

Serum thrombopoietin (TPO) levels in 50 essential thrombocythemia (ET) patients were measured using a highly sensitive sandwich ELISA. In nine cases, TPO levels were measured at two points with different platelet counts. ET patients showed significantly higher serum TPO levels (n = 59, 2.70 +/- 2.74 fmol/mL, P < 0.0001) than those of normal individuals (n = 29, 0.83 +/- 0.36 fmol/mL). Twenty-three previously untreated ET patients also showed significantly higher serum TPO levels (1.33 +/- 0.75 fmol/mL, P = 0.0066) than normal individuals. Extremely high serum TPO levels (5.46 +/- 3.68 fmol/mL) were observed in ET patients with normal platelet counts. Furthermore, a strong inverse correlation was found between serum TPO levels and platelet counts in ET patients (R = -0.729, P < 0. 0001). This inverse correlation also held for each of nine cases with two-point TPO measurements. In the clinical course of ET, megakaryocyte mass may parallel the platelet mass before and after chemotherapy. Although it is unknown whether overproduction of TPO exists or not in ET, total platelet and megakaryocyte mass, i.e., the total number of c-Mpl, may play a role to regulate serum TPO levels.

Adult↗
PubMed1998

Thrombopoietin serum levels in patients with aplastic anaemia: correlation with platelet count and persistent elevation in remission.

In an attempt to evaluate the role of thrombopoietin (TPO) in the pathobiology of aplastic anaemia (AA), we have examined TPO levels in sera from 54 AA patients and 119 healthy controls. A total of 92 samples were collected from AA patients: 43 samples were harvested at diagnosis, 23 samples in the cytopenic period after treatment, and 26 samples when patients were in partial (n=10) or complete remission (n=16) following immunosuppressive treatment. TPO serum levels were assessed by a sandwich-antibody ELISA that utilized a polyclonal rabbit antiserum for both capture and signal. Serum samples from normal donors revealed a mean TPO level of 95.3 +/- 54.0 pg/ml (standard deviation). Mean TPO levels in AA sera collected at diagnosis and before onset of treatment were 2728 +/- 1074 pg/ml (P<0.001 compared to normal controls: mean platelet count at that time: 27x10(9)/l). TPO serum levels of AA patients in partial or complete remission after immunosuppressive treatment were significantly lower than TPO levels at diagnosis (P<0.001). However, despite normal platelet counts (mean 167x10(9)/l), TPO levels remained significantly elevated in complete remission (mean TPO 1009 +/- 590 pg/ml, P<0.001 compared to normal controls). There was a significant inverse correlation between serum TPO levels and platelet counts in AA patients who were not transfused for at least 2 weeks prior to sample collection (coefficient of correlation (r) = -0.70, P<0.0001). In summary, TPO levels were highly elevated in sera of patients with AA. Thus there is no evidence to suggest an impaired TPO response contributing to thrombocytopenia in AA. Thrombopoietin did not return to normal levels in remission, indicating a persisting haemopoietic defect in remission of AA. We hypothesize that elevated levels of TPO may be required to maintain normal or near normal platelet counts in remission of AA.

Adolescent↗
PubMedDate not supplied

Homocysteinemia is inversely correlated with platelet count and directly correlated with sE- and sP-selectin levels in females homozygous for C677T methylenetetrahydrofolate reductase.

Plasma homocysteine levels depend in part on the molecular nature of the methylenetetrahydrofolate reductase (MTHFR) and on blood folate intake. Little has been reported on platelet counts in the presence of hyperhomocysteinemia and MTHFR polymorphisms, with the exception of delayed platelet recovery in homozygous MTHFR C677T subjects after treatment with methotrexate for ovarian cancer. The aim of this investigation was to evaluate the possibility of a link between the platelet count and plasma homocysteine levels in different MTHFR variants in 165 female patients. Determinations of plasma homocysteine levels were by ELISA and of MTHFR polymorphisms (A1298C and C677T) were by inverse hybridization. Serum P- and E-selectin concentrations were obtained by ELISA. An inverse correlation (R=-0.88, P<0.001) was observed between blood platelet counts and plasma homocysteine levels in the women homozygous for MTHFR C677T. This correlation did not depend on pregnancy or other variables reported. Serum concentrations of sE- and sP-selectin, markers of endothelial and platelet activation, were significantly and positively correlated with homocysteine levels. These findings suggest that homocysteine affects platelet numbers in women with MTHFR C677T possibly consequent to endothelial and platelet activation.

Adolescent↗
PubMed1990

Idiopathic thrombocytopenic purpura in pregnancy: a randomized trial on the effect of antenatal low dose corticosteroids on neonatal platelet count.

OBJECTIVE: To determine the efficacy of antenatal low dose oral betamethasone in preventing neonatal thrombocytopenia and/or bleeding in infants of mothers with idiopathic thrombocytopenic purpura (ITP). SETTING: Hospital department of obstetrics and gynaecology, referral centre. PATIENTS: 41 pregnancies in 38 women were randomized. The results of 13 pregnancies were considered non-assessable. The final analysis involved 14 in the betamethasone group and 14 in the non-treatment group. All fulfilled the criteria for ITP. INTERVENTIONS: The treated group received 1.5 mg betamethasone orally per day, from day 259 till day 273 and 1 mg from day 273 till delivery. MAIN OUTCOME MEASURES: Effects of treatment were assessed in terms of maternal platelet counts after the first trimester and neonatal platelet counts at birth and the first week of life and neonatal bleeding episodes. RESULTS: There were no significant differences in neonatal platelet counts at birth. Two infants in the betamethasone group and one in the untreated group had a severe thrombocytopenia either at birth or during the first week of life (less than 50 x 10(9)/l). Seven infants in the betamethasone group and six in the non-treatment group had a mild thrombocytopenia. The overall frequency of neonatal thrombocytopenia was similar: 64% in the betamethasone group and 57% in the untreated group (95% CI of the true difference: -43.5% to +29.5%). There was also no significant difference in neonatal bleeding episodes. CONCLUSIONS: Low-dose betamethasone in pregnant women with ITP does not prevent thrombocytopenia or bleeding in their newborn infants.

Adult↗
PubMed1991

[Mixed type cryoglobulinemia with discrepancy of platelet counts measured with an automated cell counter and by manual counting method].

We experienced an abnormal blood sample which showed larger numbers of white blood cells and platelets counted by the electric resistance system and of platelets in mechanical counting by the flow system, than those in manual counting. Many precipitates were observed in this blood sample at room temperature or 4 degrees C, but were not observed at 37 degrees C. The precipitates were clarified to be caused by the mixed type (IgA, IgG and IgM) cryoglobulin by using an immunofluorescence method and an ouchterlony method. These data indicate that precipitation of cryoglobulin at room temperature induce falsely high value of platelet count in mechanical counting systems.

Chemical Precipitation↗
PubMed2001

Platelet count and interleukin 6 gene polymorphism in healthy subjects.

BACKGROUND: Interleukin 6 (IL-6) is thought to play important roles in the development of reactive thrombocytosis caused by inflammation by its stimulatory effect on megakaryocytopoiesis. A G/C polymorphism of the IL-6 gene at position -174 has been found to be associated to different transcription rates. Specifically, subjects with the CC genotype showed lower plasma IL-6 levels compared with GC or GG subjects. Given this difference in transcription rates of IL-6 we speculated on different platelet count according to this IL-6 polymorphism. METHODS: The G/C polymorphism of the IL-6 gene at position -174, serum IL-6 concentration and platelet count were prospectively analyzed in 59 (25 women) consecutive healthy subjects. RESULTS: Subjects who were homozygotes for the C allele at position -174 of the IL-6 gene (Sfa NI genotype) showed significantly lower platelet count than carriers of the G allele, despite similar age, sex, body mass index and proportion of smokers (205400 +/- 44088 vs 239818 +/- 60194, p = 0.047). This was in parallel to differences in peripheral white blood cell count (5807 +/- 1671 vs 6867 +/- 1192 x 10(9)/ml, p = 0.01). CONCLUSION: This is the first description, to our knowledge, of a genetical influence on basal platelet counts, which appears to be partially dependent on a polymorphism of the IL-6 gene, even in the absence of inflammation.

Journal Article↗
PubMed1982

Spuriously elevated platelet counts due to microspherocytosis.

A patient with an acute burn was noticed to have spuriously elevated platelet counts on an automated system. The major factor accounting for this discrepancy was the presence of numerous microspherocytes which were in the same size range of platelets. It is thus important to add microspherocytosis as an additional cause for a spuriously elevated platelet count. This has special clinical importance when dealing with an acute burn patient.

Aged↗
PubMed1978

Relationship between platelet count and cardiotomy suction return.

A simple, inexpensive, accurate method of measuring the amount of blood returned by the cardiotomy suction system was devised and calibrated. Preoperative and postoperative platelet counts were obtained in 76 patients with congenital heart disease in whom the amount of cardiotomy suction return was measured. The mean percentage of total perfusate returned by the cardiotomy suction system was 8.9%. Both postoperative platelet count and the percentage change between preoperative and postoperative platelet counts correlated with the amount of blood returned by the cardiotomy suction system, time on bypass, and the percentage of total perfusate aspirated by the system.

Adolescent↗
PubMed2000

Hydroxyurea-induced marked oscillations of platelet counts in patients with polycythemia vera.

Two prospectively studied patients with polycythemia vera (PV) whose platelet counts showed marked periodic fluctuation during treatment with hydroxyurea (HU) are reported. Cycle lengths in both were approximately 28 to 30 days. In one patient, the cyclic process was no longer evident when treatment with HU was withheld, and it reappeared on treatment rechallenge. Circulating thrombopoietin (TPO) levels fluctuated out of phase with the platelet count despite markedly reduced TPO-receptor (c-Mpl) expression in bone marrow megakaryocytes. These observations suggest that the cyclic phenomenon may be related to both a transient state of HU-induced depletion of megakaryocytes and a concentration-dependent mitigation by TPO of the HU effect on megakaryocytes and their precursors. It is conceivable that the affected patients harbor a megakaryocyte progenitor pool whose apoptotic activity is differently modulated by either HU or high concentrations of TPO. (Blood. 2000;96:1582-1584)

Antisickling Agents↗
PubMed1997

Transfusions of granulocyte-colony-stimulating factor-mobilized granulocyte components to allogeneic transplant recipients: analysis of kinetics and factors determining posttransfusion neutrophil and platelet counts.

BACKGROUND: Granulocyte-colony-stimulating factor (G-CSF) is a safe and effective agent for mobilization of neutrophils in normal donors, consistently resulting in cell yields per leukapheresis (LA) procedure that are superior to those with other agents. LA components also contain platelets, whose clinical relevance is unknown. STUDY DESIGN AND METHODS: This study describes the kinetics of and analyzes the factors determining the ANC and platelet count increments seen with each of three transfusions of granulocytes collected from HLA-matched sibling donors receiving G-CSF (n = 10; maximum of 3 LA procedures/donor). The transfusions were given to recipients (n = 10) on alternate days beginning. Day 1 after allogeneic bone marrow transplant (BMT). RESULTS: Significant, sustained increments in the recipient ANCs were observed after the transfusion of G-CSF-mobilized LA components. The mean peak posttransfusion increments in the ANCs were 1195, 729, and 631 per microL with transfusion of donor LA components on Days 1, 3, and 5, respectively. The length of time that the mean posttransfusion ANC was at or above the baseline (pretransfusion) value was 25 to 37 hours, depending on the post-BMT day when the component was administered. No consistent relationship was observed between LA component granulocyte dose, baseline recipient ANC, or temperature elevation and post-transfusion ANC increments. Large numbers of platelets (mean, 2.55 x 10(11)) were present in LA components, and this resulted in significant increments from baseline in the mean platelet count 1 hour after LA component transfusions. Between Days 1 and 7, the duration of severe neutropenia was shorter and the percentage of patients requiring nondonor platelet transfusions was less in study patients who received LA component transfusions than in a similar historical control group who did not. CONCLUSION: The transfusion of G-CSF-mobilized, HLA-matched LA components to allogeneic BMT recipients resulted in significant and sustained increments in the ANC and the platelet count. Within the range examined, a relationship between neutrophil dose and an increment in the ANC was not demonstrated.

Bone Marrow Transplantation↗
PubMed2006

Single dose of anti-D immune globulin at 75 microg/kg is as effective as intravenous immune globulin at rapidly raising the platelet count in newly diagnosed immune thrombocytopenic purpura in children.

OBJECTIVE: To conduct a randomized prospective trial of immune globulin treatment for 105 Rh+ children with newly-diagnosed immune thrombocytopenic purpura and a platelet count<20,000/microL, to determine whether anti-D immune globulin (anti-D) is as effective as intravenous immune globulin (IVIg). STUDY DESIGN: Eligible patients received either a single intravenous dose of 50 microg/kg anti-D (anti-D50), 75 microg/kg anti-D, (anti-D75), or 0.8 g/kg IVIg, (IVIg). Patients were monitored for response to treatment and adverse events. RESULTS: By 24 hours after treatment 50%, 72%, and 77% of patients in the anti-D50, anti-D75, and IVIg groups, respectively, had achieved a platelet count>20,000/microL (P=.03). By day 7, hemoglobin concentrations decreased by 1.6 g/dL, 2 g/dL, and 0.3 g/dL in the anti-D50, anti-D75, and IVIg groups, respectively. Headache, fever, or chills occurred least often in the anti-D50 group. CONCLUSIONS: A single 75 microg/kg dose of Anti-D raised the platelet count in children with newly diagnosed immune thrombocytopenic purpura more rapidly than standard-dose anti-D and as effectively as IVIg, with an acceptable safety profile.

Adolescent↗
PubMedDate not supplied

Differences in platelet count and size between marrow and peripheral blood.

Automatized platelet parameters were evaluated in 23 unselected patients undergoing a bone marrow examination for diagnostic purposes, both in medullary and in peripheral blood, with the aim of investigating the biological significance of platelet volume heterogeneity. In the marrow blood the platelet count was 10.07 +/- 21.25% (p < 0.05) lower and the platelet volume 7.93 +/- 6.88% (p < 0.001) higher compared to peripheral venous blood: 275,173 +/- 108,079 versus 296,652 +/- 104,814/mm3 (p < 0.05) and 8.93 +/- 1.46 versus 8.23 +/- 1.57 fl (p < 0.001), respectively. The same behavior was observed between the marrow and the arterial blood collected from 12 out of the 23 patients, while no significant difference was observed between arterial and venous blood. The differences observed might be attributable to a platelet population replacement under homeostatical regulation and seem to support the concept that the large platelets are younger elements.

Aged↗