Platelet associated immunoglobulins (PAIgG and PAIgM) in autoimmune thrombocytopenia

An enzyme linked assay system was used to quantitate platelet associated IgM (PAIgM) in addition to platelet associated IgG (PAIgG) in normal subjects and in 145 patients with autoimmune thrombocytopenia (AITP). The mean PAIgM level in normals was 1.17 ng/10(6) platelets with a range of 0.01-2.45 ng (mean +/- 2 SD). The corresponding PAIgG values as follows: mean 6.0 ng, range 2.0-10 ng/10(6) platelets. Elevated PAIgG was seen in 67.6% and abnormally raised PAIgM in 79.3% of patients. Both values were raised together in 57.2% and either elevated PAIgG or PAIgM in 89.7%. All patients with PAIgG values greater than 4 times upper limit of normality were found to have abnormal PAIgM. The relevance of elevated PAIgM, the possible interaction between PAIgG and PAIgM and the implication of our results in patients with autoimmune thrombocytopenia are discussed.     

Relationships between platelet counts, platelet volumes and reticulated platelets in patients with ITP: evidence for significant platelet count inaccuracies with conventional instrument methods

The platelet count has a primary role in the diagnosis and treatment of idiopathic thrombocytopenic purpura (ITP). This study analysed the accuracy of ITP patient platelet counts determined by Abbott CD-Sapphire (impedance/optical) and Bayer Advia 120 (optical) analyses, compared with a reference immunoplatelet method. Instrument platelet estimates showed broad equivalence in the higher range of observed values, but significant discrepancies against the immunoplatelet count were seen when platelet counts were <10 x 10(9)/l. CD-Sapphire mean platelet volume (MPV) results revealed increased (>12 fl) platelet volumes in eight of eight ITP patients with counts of <20 x 10(9)/l compared with 6/6 and 5/13 patients with platelet counts of 20-50 and >50 x 10(9)/l. In contrast, Bayer Advia MPV values showed no relationship with the platelet count. Increased reticulated platelets were associated with an increasing CD-Sapphire MPV (R(2) = 0.61) and a decreasing platelet count. High (>40%) reticulated platelet values were seen in 9/9 patients with immunoplatelet counts of <20 x 10(9)/l compared with 0/19 patients with platelet counts above 20 x 10(9)/l. There may be a need for caution in the interpretation of platelet counts in ITP patients obtained with conventional instrument methods, and therapeutic decisions should ideally be validated by reference immunoplatelet procedures.     

Platelet-associated immunoglobulins IgG, IgM, IgA and complement C3c in chronic idiopathic autoimmune thrombocytopenia: relation to the sequestration pattern of 111indium labelled platelets

Levels of platelet-associated immunoglobulins (PAIg) IgG, IgM, IgA and complement C3c were related to parameters of 111Indium-labelled platelet kinetics in 17 patients with chronic idiopathic autoimmune thrombocytopenia (cAITP). Elevated levels of PAIg/C3c were found in 14 patients (82%) (PAIgG n = 13, PAIgM n = 11, PAIgA n = 1, PAC3c n = 5). Only PAIgG correlated with platelet counts (RS = -0.71, p less than 0.01). Mean platelet life span (MLS) was shortened in all patients (median 12.0 h, range 0.3-45.6 h) and correlated with the platelet counts (RS = 0.49, p less than 0.05). MLS was correlated with PAIgG (RS = -0.52, p less than 0.05), but not with PAIgM, PAIgA, or PAC3c. The site of sequestration was splenic in 10 patients and splenic-hepatic in 7 patients. Although no significant correlation between either site of platelet sequestration and any of the investigated PAIg/C3c was demonstrable, platelets coated with higher PAIgG levels were more readily sequestrated in the spleen, while elevations of PAC3c were found in 4 out of 7 patients with hepatic involvement.     

The effects of continuous positive airway pressure therapy on mean platelet volume in patients with obstructive sleep apnea

Previous studies have reported increased platelet activation and aggregation in patients with obstructive sleep apnea (OSA). Continuous positive airway pressure (CPAP) treatment has been shown to decrease platelet activation. We aimed to study the effects of nasal CPAP therapy has on MPV values in patients with severe OSA. Thirty-one patients (21 men; mean age 53.8?±?9.2 years) with severe OSA (AHI?>?30 events/hour) constituted the study group. An age, gender and body mass index (BMI) matched control group was composed 25 subjects (14 men; mean age 49.6?±?8.5 years) without OSA (AHI?相似文献   

Study of platelet-associated immunoglobulins of IgG,IgM, IgA,and IgE classes and platelet kinetics in 33 patients with idiopathic thrombocytopenic purpura

Summary The role of platelet-associated immunoglobulins (PAIg) of four different immunoglobulin classes -IgM, IgG, IgA, and IgE- and their relation to platelet count and platelet kinetics was studied in 33 patients with idiopathic thrombocytopenic purpura (ITP). During the course of 1 year, repeated determinations of PAIg were made. The results indicate that PAIgG, PAIgM, and PAIgA are present in all ITP patients, and that autoantibodies of all three Ig classes show highly significant correlations to the platelet counts (p< 0.0001). Double logarithmic negative correlations have been found between PAIgG and platelet count (r=–0.71), PAIgM and platelet count (r=–0.84), and PAIgA and platelet count (r=–0.79). Statistical analyses using partial correlation and multiple regression methods showed that PAIgM is predominantly related to the platelet count, whereas PAIgG and PAIgA are only of secondary importance. Accordingly, a relation of PAIgM (and PAIgA) to increased liver destruction of platelets was found in kinetic studies using¹¹¹indium-labeled platelets. Taken together, these results suggest a predominant role of PAIgM in the pathogenesis of ITP.     

Platelet count, mean platelet volume and smoking status in stable chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD), an increasing global health problem, may be complicated by acute atherothrombotic events. Although systemic inflammation plays the leading role in atherothrombotic processes, platelet activation and increased coagulation together with oxidative stress can significantly exacerbate atherosclerosis in COPD patients. In this study we determined platelet count, mean platelet volume (MPV) and classical markers of systemic inflammation - serum C-reactive protein (CRP), white blood cell (WBC) count and the relative proportion of segmented neutrophils in COPD patients, and compared them to those from the healthy controls. The most important and novel finding of this study was that patients with COPD had a significantly increased platelet count, along with a reduced MPV when compared to healthy controls (286 vs. 260 ×?10(9)/l; 9.6 vs. 8.7?fL, respectively). Cigarette smoking had no influence on these results. The presence of systemic inflammation was clearly proved by the increase in classical inflammatory markers (CRP, WBC and segmented neutrophil count).     

The effects of continuous positive airway pressure therapy on mean platelet volume in patients with obstructive sleep apnea

Previous studies have reported increased platelet activation and aggregation in patients with obstructive sleep apnea (OSA). Continuous positive airway pressure (CPAP) treatment has been shown to decrease platelet activation. We aimed to study the effects of nasal CPAP therapy has on MPV values in patients with severe OSA. Thirty-one patients (21 men; mean age 53.8?±?9.2 years) with severe OSA (AHI?>?30 events/hour) constituted the study group. An age, gender and body mass index (BMI) matched control group was composed 25 subjects (14 men; mean age 49.6?±?8.5 years) without OSA (AHI?<?5 events/hour). We measured MPV values in patients with severe OSA and control subjects and we measured MPV values after 6 months of CPAP therapy in severe OS patients. The median (IQR) MPV values were significantly higher in patients with severe OSA than in control group (8.5 [8.3–9.1] vs. 8.3 [7.5–8.8] fL; p?=?0.03). The platelet counts were significantly lower in patients with severe OSA than in control group (217.8?±?45.9 vs. 265.4?±?64.0?×?10⁹/L; p?=?0.002). The six months of CPAP therapy caused significant reductions in median (IQR) MPV values in patients with severe OSA (8.5 [8.3–9.1] to 7.9 [7.4–8.2] fL; p?<?0.001). Six months of CPAP therapy caused significant increase in platelet counts when compared with baseline values (217.8?±?45.9 to 233.7?±?60.6?×?10⁹/L; p?<?0.001). We have found that the MPV values of patients with severe OSA were significantly higher than those of the control subjects and 6 months CPAP therapy caused significant reductions in the MPV values in patients with severe OSA.     

Regulation of platelet heterogeneity: effects of thrombocytopenia on platelet volume and density

We have examined the effects of variable degrees of acute thrombocytopenia on platelet levels, mean platelet volume (MPV), and buoyant density after induction of thrombocytopenia by platelet antiserum (PAS) in mice with or without spleens. Mice were studied serially 10-16, 36, 48, 60-64, 84, 108, 144, 180, 228, 276, 348-360, 372, and 516 h after PAS treatment. MPV and platelet count (PC) x 10(6)/microliters for normal intact mice (n = 136) were 4.7 +/- 0.3 fl (SD) and 1.69 +/- 0.52 (SD), respectively. Twelve hours after PAS-induced severe thrombocytopenia (PC less than 0.05 x 10(6)/microliters), MPV increased significantly (p less than 0.01) to 6.4 fl, was maximal at 36 h (8.2 fl), remained elevated until 144 h following PAS treatment, and then returned to normal. Platelet density decreased significantly (p less than 0.05) 64 h after PAS treatment and returned to normal at 144 h. Hematocrits of repeatedly bled intact control mice decreased from 45% to 30%, accompanied by thrombocytosis (maximal PC 2.24 x 10(6)/microliters) without significant changes in either MPV or platelet density. Moderate thrombocytopenia (PC 0.1-0.2 x 10(6)/microliters) in intact mice produced significantly (p less than 0.05) increased MPV, at 5.7 fl 12 h after PAS treatment, with a peak MPV of 7.6 fl (p less than 0.001) at 36 h; MPV returned to normal at 84 h. Platelet density decreased (p less than 0.001) 12 h after PAS treatment and returned to baseline at 228 h. Control splenectomized mice (n = 185) had an MPV of 5.0 fl +/- 0.7 fl and a PC of 2.14 +/- 0.6 x 10(6)/microliters. Comparably severe and moderate thrombocytopenia in splenectomized mice produced alterations in platelet count, MPV, and density similar to those in intact mice, although maximal MPV and the degree of rebound thrombocytosis after severe thrombocytopenia were more marked in splenectomized mice. In response to reduction of the platelet mass in both intact and splenectomized mice, MPV increased in proportion to the severity of thrombocytopenia, occurred as early as 4 h after induction, and persisted during early rebound thrombocytosis. Previous observations that megakaryocyte ploidy did not shift until 48 h after onset of thrombocytopenia confirm that both initial and maximal changes in MPV in response to this stimulus are regulated by processes other than alterations of megakaryocyte DNA levels.(ABSTRACT TRUNCATED AT 400 WORDS)     

An overlooked indicator of disease activity in ulcerative colitis: Mean platelet volume

Many non-invasive tests have been studied for diagnosis and determining the activation degree of inflammatory bowel disease (IBD). Nevertheless, an ideal test has not been found yet. Mean platelet volume (MPV) is influenced by the inflammation. In a few study, decreased platelet volume have been reported in IBD. The aim of this study is to determine whether platelet volume would be useful in ulcerative colitis (UC) activity. Additionally we have analyzed overall accuracy of MPV in disease activity and compared with other inflammatory markers. A total of 61 UC patients (male/female : 41/20), and 27 healthy subjects (male/female : 18/9) were enrolled into the study. For all subjects following tests were performed; ESR, CRP, white blood cell count and mean platelet volume. A statistically significant decrease in MPV was noted in patients with UC (8.29 ± 1.02fL) compared with healthy controls (8.65 ± 0.79 fL). MPV of active UC (8.06 ± 1.19 fL) patients were significantly lower than that of inactive UC (8.45 ± 0.87 fL). Overall accuracy of MPV in determination of active UC was 71% (with sensitivity 67%, specificity 73%). A negative correlation was found between MPV and endoscopic activity index (r : -0.358 p : 0.005). In UC, MPV did not correlate with ESR, CRP and white blood cell. Our study showed that MPV reduced in UC, particularly in patients with active UC. Decreased MPV may be an indicator for increased disease activity in patients with UC.     

Efficacy of Helicobacter pylori eradication in raising platelet count in adult patients with idiopathic thrombocytopenic purpura

BACKGROUND AND OBJECTIVES: There are data consistent with an association between idiopathic thrombocytopenic purpura (ITP) and Helicobacter pylori (HP) infection. In addition, a significant increase of platelet count following HP eradication has been reported in a proportion of ITP patients. We describe here our experience on the efficacy of anti-HP treatment in ITP patients. DESIGN AND METHODS: Between December 1998 and May 2001 sixteen adult patients with ITP and documented HP infection were treated with standard antibiotic therapy for HP eradication (amoxicillin and clarithromycin plus pantoprazole combination). Of these patients, 7 had untreated ITP with mild/moderate thrombocytopenia (median platelet count 70x10(9)/L, range 41-91), 5 had relapsed following a previous steroid treatment (median platelet count 39x10(9)/L, range 30-90) and 4 were refractory to steroids (median platelet count 18.5x10(9)/L, range 9-30). RESULTS: An improvement of platelet count was observed in 11/15 patients (73.3%) who achieved HP eradication. The difference between the mean platelet count SD before and after HP eradication was statistically significant (51.6 28.2x10(9)/L vs. 143.3 131.1x10(9)/L; p=0.01). Complete or partial responses were obtained in 11/16 treated patients (68.7%). This result still persisted after a median follow-up of 11.7 months. INTERPRETATION AND CONCLUSIONS: Our data confirm the efficacy of Helicobacter pylori eradication in increasing platelet count in adult ITP patients.     

The relationship between mean platelet volume, stroke subtype and clinical outcome

Platelets play a crucial role in the pathophysiology of atherothrombotic disease and are involved in the early thromboembolic phase of ischaemic stroke. Large platelets are known to be more active. We hypothesized that thrombomegaly would be limited to patients with cortical infarction as compared with patients with lacunar infarcts, and that it would be associated with functional outcome. Mean platelet volume (MPV) and platelet count (PC) were studied in 167 hospitalized patients with stroke within 48 h of symptom onset, and 65 age, gender and race matched controls. Stroke was clinically and radiologically sub-typed. MPV was significantly higher in patients with ischaemic stroke than the control group: mean (SD) 7.35 (1.05) vs 7.09 (0.74) fl, 2 P = 0.04; this difference could be explained by MPV being higher in patients with cortical stroke: 7.46 (1.00) fl, 2 P = 0.039, but not lacunar infarction: 7.14 (1.16) fl, 2 P = 1.0. No difference was seen in PC between ischaemic patients and controls: 231 (82) 10(9)/l vs 236 (54) 10(9)/l, 2 P = 0.63. MPV did not change at 3 months post-stroke in surviving patients with ischaemic stroke: 7.39 (1.03) fl vs 7.34 (0.97) fl, 2 P = 0.53. Patients who were dead or dependent at 3 months had a significantly higher baseline MPV and a tendency to a lower PC than those who returned to independence. MPV and PC were not altered in patients with primary intracerebral haemorrhage. No differences in red cell volume was observed. Platelet volume is elevated in acute ischaemic stroke, a finding that persists at 3 months post-stroke and is limited to patients with cortical infarction. Thrombomegaly is a risk factor for a poor outcome after ischaemic stroke.     

血液光量子疗法对急性白血病患者血小板输注效果的影响

目的　探讨血液光量子疗法对急性白血病患者血小板输注效果的影响。方法　将 5 4例血小板减少的急性白血病患者随机分为两组 ,治疗组采用血液光量子疗法行血小板输注 ,对照组单纯行血小板输注。两组均采用酶联免疫吸附法 ,在血小板输注前后定量测定血小板表面相关抗体 (PAIg G和 PAIg M) ;计数血小板 ,计算1、2 4小时血小板增值 (CCI) ;观察其临床效果和非溶血性输血反应 (NHFTR)。结果　血小板输注前两组 PAIg M及 PAIg G值无显著性差异 ,输注后两组 PAIg M无显著性差异 ,而治疗组 PAIg G值明显低于对照组 (P<0 .0 5 )。两组 1小时 CCI无显著性差异 ,治疗组 2 4小时 CCI和临床效果明显优于对照组 (P<0 .0 5 ) ;治疗组的 NHFTR低于对照组 (P<0 .0 5 ) ,其临床效果优于对照组 (P<0 .0 5 )。结论　血液光量子疗法可减少血小板输注无效     

Prophylactic platelet transfusions from healthy apheresis platelet donors undergoing treatment with thrombopoietin

Many patients receiving dose-intensive chemotherapy acquire thrombocytopenia and need platelet transfusions. A study was conducted to determine whether platelets harvested from healthy donors treated with thrombopoietin could provide larger increases in platelet counts and thereby delay time to next platelet transfusion compared to routinely available platelets given to thrombocytopenic patients. Community platelet donors received either 1 or 3 microg/kg pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) or placebo and then donated platelets 10 to 15 days later. One hundred sixty-six of these platelet concentrates were then transfused to 120 patients with platelets counts 25 x 10(9)/L or lower. Pretransfusion platelet counts (11 x 10(9)/L) were similar for recipients of placebo-derived and PEG-rHuMGDF-derived platelets. Early after transfusion, the median platelet count increment was higher in patients receiving PEG-rHuMGDF-derived platelets: 19 (range, -12-66) x 10(9)/L, 41 (range, 5-133) x 10(9)/L, and 82 (range, -4-188) x 10(9)/L for placebo-, 1-microg/kg-, and 3-micro/kg-derived platelets, respectively. This difference was maintained 18 to 24 hours after transfusion. Transfusion-free intervals were 1.72, 2.64, and 3.80 days for the recipients of the placebo-, 1-microg/kg-, and 3-micro/kg-derived platelets, respectively. The rate of transfusion-related adverse events was not different in recipients of placebo-derived and PEG-rHuMGDF-derived platelets. Therefore, when transfused into patients with thrombocytopenia, platelets collected from healthy donors undergoing thrombopoietin therapy were safe and resulted in significantly greater platelet count increments and longer transfusion-free intervals than platelets obtained from donors treated with placebo.     

营养支持联合美他多辛治疗酒精性肝病患者肝功能和外周血细胞参数的变化

目的 探讨营养支持联合美他多辛治疗酒精性肝病患者对肝功能、红细胞和血小板参数的影响。方法 2015年5月~2017年10月我院诊治的酒精性肝病患者90例,被分为两组,每组45例,分别给予美他多辛片或美他多辛联合营养支持治疗4周,后者为给予35~40 kcat·kg^-1·d^-1的热量。结果 治疗前,两组肝功能指标差异无统计学意义（P>0.05）,治疗结束时,两组血清ALT、GGT和TBIL水平明显降低,ALB明显升高;治疗前,两组凝血功能指标差异无统计学意义（P>0.05）,治疗后两组PT、APTT和TT均明显缩短,FIB显著升高;治疗前,两组红细胞参数和血红蛋白水平差异无统计学意义（P>0.05）,治疗后两组RBC、HGB和HCT均显著上升,RDW和MCV显著下降;治疗前,两组血小板计数（PLT）、血小板平均体积（MPV）和血小板分布宽度（PDW）相比无统计学差异（P>0.05）,治疗后PLT显著上升,MPV和PDW明显降低（P<0.05）,联合组以上变化均显著优于对照组（P<0.05）。结论 营养支持联合美他多辛治疗酒精性肝病患者能够显著改善肝功能、凝血功能、红细胞和血小板参数,提示营养支持治疗可能更重要,需要高度重视。     

Stroke prediction using mean platelet volume in patients with atrial fibrillation

Platelet size, measured as mean platelet volume (MPV), is associated with platelet reactivity. MPV has been identified as an independent risk factor for future stroke and myocardial infarction. The aim of this study was to determine the association of MPV with the development of stoke in patients with atrial fibrillation (AF). MPV, N-terminal pro B-type natriuretic peptide (NT-proBNP), and high-sensitivity C-reactive protein (hsCRP) were analysed in 200 patients with AF (mean age 69 years; 56% male). The primary endpoint was ischaemic stroke event. The mean MPV was 8.5?±?1.0?fL and the median NT-proBNP was 1916.5 (IQR 810-4427) pg/mL. The median hsCRP was 0.47 (IQR 0.32-2.46)?mg/dL. There were 14 stroke events during a mean of 15.1 months of follow up. Kaplan-Meier analysis revealed that the higher tertile MPV group (≥8.9 fL) had a significantly higher stroke rate compared to the lower tertile MPV group (<8.0 fL) (14.7% vs. 3.1%, log-rank: P?=?0.01). A higher MPV was an independent predictor of stroke risk after adjusting for age, gender, and other CHADS(2) (congestive heart failure, hypertension, diabetes, and previous stroke or transient ischemic attack (TIA) history) score components (hazard ratio: 5.03, 95% CI 1.05-24.05, P?=?0.043) in Cox proportional hazard analysis. When the MPV cut-off level was set to 8.85 fL using the receiver operating characteristic curve, the sensitivity was 71% and the specificity was 69% for differentiating between the group with stroke and the group without stroke. This value was more useful in patients with a low to intermediate traditional thromboembolic risk (CHADS(2) score <2). Furthermore, AF patients with an MPV over 8.85 fL had high stroke risk without anticoagulation, especially in the low thromboembolic risk group (Log-Rank <0.0001). The results of this study show that MPV was a predictive marker for stroke; its predictive power for stroke was independent of age, gender, and other CHADS(2) score components in patients with AF. These findings suggest that anticoagulation may be needed in patients with a high MPV, even if they have low to intermediate traditional thromboembolic risk (CHADS(2) score <2).     

Mean platelet volume/platelet count ratio in hepatocellular carcinoma

Mean platelet volume (MPV) has been actively investigated in liver disease such as steatosis, cirrhosis and hepatitis. Recently, MPV/platelet count (PC) ratio has been proposed as a predictor of long-term mortality after myocardial infarction. As PC is known to be decreased in various liver diseases such as cirrhosis, hepatosplenomegaly and malignancy, we planned to evaluate MPV/PC ratio in patients with hepatocellular carcinoma (HCC) in this study. Mean of MPV levels showed significant difference, which were 8.69?fl (range 6.7–12.2?fl) in patients group and 8.02?fl in control group (range 6.7–11.0?fl). In receiver operating characteristic (ROC) curve analysis, the MPV/PC ratio (fl/(10⁹/l)) presented 74.5% of sensitivity and 96.5% of specificity at the criterion?>?0.0491 (area under the curve (AUC)?=?0.884), while MPV alone showed 57.4% of sensitivity and 81.4% of specificity at the criterion?>?8.4?fl. Further studies should evaluate underlying pathogenic mechanisms of MPV/PC ratio difference and various possibilities of this ratio as an indicator of presence of a tumor in HCC.     

Pattern of platelet-associated immunoglobulin (classes and IgG subclasses) in childhood immune thrombocytopenic purpura

Platelet-associated Ig classes and IgG subclasses were studied by a semiquantitative platelet ELISA test in 17 children with immune thrombocytopenic purpura (ITP). An elevation of PAIg was found in 94% of the children. In nearly all cases increased amounts of PAIgG of subclass G1 was seen, and in half of the cases increased amounts of PAIgM were also seen. No statistical difference in the composition of PAIg classes and PAIgG subclasses in acute and in chronic ITP was found. However, a correlation of increased amount of PAIgG3 and very low platelet count (20 x 10(9)/l) was observed.     

Mean platelet volume has a prognostic value in patients with coronary artery ectasia

The aim of this study was to investigate the prognostic role of mean platelet volume (MPV) in patients with coronary artery ectasia (CAE). The baseline MPV values of 258 patients with CAE were screened. The mean time of follow-up was 49 ± 21 months for major adverse cardiac events (MACEs) defined as the combination of cardiac death, nonfatal myocardial infarction (MI), rehospitalization due to cardiac disorders, and readmission due to chest pain. During follow-up period, 63 (24%) MACEs developed. There were 4 (2%) cardiovascular deaths, 0 nonfatal MI, 14 (5%) rehospitalization, and 45 (17%) readmission. Mean platelet volume values were significantly higher in patients with CAE with MACEs than in patients with CAE without MACEs (9.5 ± 1.2 fL vs 8.9 ± 1.1 fL, respectively, P = .002). The rate of MACE was higher in CAE patients with MPV of >9 fL than those with MVP of ≤9 fL (33% vs. 15%, P = .001). Mean platelet volume has a prognostic value for MACEs in patients with CAE.     

A randomized, double-blind study of romiplostim to determine its safety and efficacy in children with immune thrombocytopenia

Romiplostim, a thrombopoietin-mimetic peptibody, increases and maintains platelet counts in adults with immune thrombocytopenia (ITP). In this first study of a thrombopoietic agent in children, patients with ITP of ≥ 6 months' duration were stratified by age 1:2:2 (12 months-< 3 years; 3-< 12 years; 12-< 18 years). Children received subcutaneous injections of romiplostim (n = 17) or placebo (n = 5) weekly for 12 weeks, with dose adjustments to maintain platelet counts between 50 × 10(9)/L and 250 × 10(9)/L. A platelet count ≥ 50 × 10(9)/L for 2 consecutive weeks was achieved by 15/17 (88%) patients in the romiplostim group and no patients in the placebo group (P = .0008). Platelet counts ≥ 50 × 10(9)/L were maintained for a median of 7 (range, 0-11) weeks in romiplostim patients and 0 (0-0) weeks in placebo patients (P = .0019). The median weekly dose of romiplostim at 12 weeks was 5 μg/kg. Fourteen responders received romiplostim for 4 additional weeks for assessment of pharmacokinetics. No patients discontinued the study. There were no treatment-related, serious adverse events. The most commonly reported adverse events in children, as in adults, were headache and epistaxis. In this short-term study, romiplostim increased platelet counts in 88% of children with ITP and was well-tolerated and apparently safe. The trial was registered with http://www.clinicaltrials.gov as NCT00515203.     

Logistic回归联合受试者工作特征曲线评价血小板参数对急性冠脉综合征的诊断价值

目的：探讨平均血小板体积（MPV）和大型血小板比例（P-LCR）在胸痛患者急性冠脉综合征（ACS）中的诊断价值。方法测定83例2013年1月至6月因胸痛就诊于空军总医院的ACS患者和56例非心源性胸痛患者的血小板参数,通过组间均值比较和logistic回归分析筛选出有效指标,并利用受试者工作特征（ROC）曲线评价其在ACS判断中的诊断价值。结果（1）与非心源性胸痛患者相比,ACS患者血小板数量减少[（191.28±67.07）x10^9/L vs（236.75±64.09）x10^9/L], MPV[（11.88±1.24） vs （10.73±1.08）fL]、血小板分布宽度（PDW）[（15.54±1.87） vs（13.40±2.35）fL]和P-LCR[（47.49±9.55）% vs （35.11±10.00）%]等明显升高（P＜0.05）;（2）不同临床类型的ACS患者血小板参数无显著变化（P＞0.05）;（3）logistic分析表明P-LCR和MPV是ACS的辅助诊断指标;（4）ROC曲线显示肌钙蛋白Ⅰ、P-LCR、MPV、肌酸激酶同工酶对应的诊断界值分别是0.15μg/L、38.5%、11.05fL和19.0U/L,曲线下面积分别为0.987,0.817,0.754和0.598,灵敏度为97.3%,92.8%,71.1%和45.8%,特异度为90.3%,64.3%,62.5%和73.2%,诊断符合率100%,80%,72.6%和67.2%。结论 MPV和P-LCR分别有助于ACS的发现,可作为胸痛患者ACS的辅助诊断指标,由于MPV和P-LCR升高对ACS的判断准确性较高,因此可以为ACS的早期判断和鉴别诊断提供参考。