Gray platelet syndrome: Management of perioperative bleeding in redo cardiac surgery

Gray platelet syndrome (GPS) is a rare (<1/1 000 000) and inherited platelet function disorder characterized by macrothrombocytopenia, α-granule deficiency, and hemorrhages. Bleeding intensity does not correlate with platelet count nor with functional test results. We hereby describe the perioperative bleeding prevention and management of a patient with GPS requiring multiple redo cardiac surgeries.     

Higher melatonin secretion is associated with lower leukocyte and platelet counts in the general elderly population: the HEIJO‐KYO cohort

Circulating white blood cell (WBC) and platelet (PLT) counts are widely available and inexpensive cellular biomarkers of systemic inflammation and have been associated with a risk of cardiovascular disease, cancer, and mortality. Melatonin may reduce systemic inflammation through its direct and indirect antioxidative effect; however, the associations of melatonin secretion with systemic inflammation remain unclear. In this cross‐sectional study on 1088 elderly individuals (mean age, 71.8 years), we measured overnight urinary 6‐sulfatoxymelatonin excretion (UME) and WBC and PLT counts as indices of melatonin secretion and systemic inflammation, respectively. UME was naturally log‐transformed for linear regression models because of skewed distribution (median, 6.8 μg; interquartile range, 4.1–10.6 μg). Univariate models revealed that higher log‐transformed UME levels were significantly associated with lower WBC and PLT counts (P = 0.046 and 0.018). After adjusting for potential confounding factors significantly associated with WBC or PLT counts, higher log‐transformed UME levels were significantly associated with lower WBC and PLT counts (WBC: β, ?0.143; 95% confidence interval, ?0.267 to ?0.020; P = 0.023; PLT: β, ?6.786; 95% confidence interval, ?12.047 to ?1.525; P = 0.012). Furthermore, the adjusted mean differences in WBC and PLT counts between the lowest and highest UME tertile groups were 0.225 × 10⁹/L and 9.480 × 10⁹/L, respectively. In conclusion, melatonin secretion was significantly and inversely associated with WBC and PLT counts in the general elderly population. The associations were independent of several major causes of systemic inflammation, including aging, obesity, smoking, hypertension, diabetes, and physical inactivity.     

How does measurement of platelet P-selectin compare with other methods of measuring platelet function as a means of determining the effectiveness of antiplatelet therapy?

Measurement of P-selectin on activated platelets as a means of measuring platelet function utilizing the technology described here has the advantage of not requiring immediate access to specialist equipment and expertise. Blood samples are activated, fixed, stored, and transported to a central laboratory for flow cytometric analysis. Here we have compared P-selectin with other more traditional approaches to measuring platelet function in blood and/or platelet-rich plasma (PRP) from patients with acute coronary syndromes on treatment for at least 1 month with either aspirin and clopidogrel or aspirin with prasugrel. The comparators were light transmission aggregometry (LTA), VerifyNow and Multiplate aggregometry (for determining the effects of aspirin) and LTA, VerifyNow and Multiplate together with the BioCytex VASP phosphorylation assay (for the P2Y₁₂ antagonists). The P-selectin Aspirin Test revealed substantial inhibition of platelet function in all but three of 96 patients receiving aspirin with clopidogrel and in none of 51 patients receiving aspirin and prasugrel. The results were very similar to those obtained using LTA. There was only one patient with high residual platelet aggregation and low P-selectin expression. The same patients identified as “non-responders” to aspirin also presented with the highest residual platelet activity as measured using the VerifyNow system, although not quite as well separated from the other values. With the Multiplate test only one of these patients clearly stood out from the others. The results obtained using the P-selectin P2Y₁₂ Test in 102 patients taking aspirin and clopidogrel were similar to the more traditional approaches in that a wide scatter of results was obtained. Generally, high values seen with the P-selectin P2Y₁₂ Test were also high with the LTA, VerifyNow, Multiplate, and BioCytex VASP P2Y₁₂ Tests. Similarly, low residual platelet function using the P2Y₁₂ test was seen irrespective of the testing procedure used. However, there were differences in some patients. Prasugrel was always more effective than clopidogrel in inhibiting platelet function with none of 56 patients (P-selectin and VerifyNow), only 2 of 56 patients (Multiplate) and only 3 of 56 patients (Biocytex VASP) demonstrating high on-treatment residual platelet reactivity (HRPR) defined using previously published cut-off values. The exception was LTA where there were 11 of 56 patients with HRPR. It remains to be seen which experimental approach provides the most useful information regarding outcomes after adjusting therapies in treated patients.     

Bernard–Soulier syndrome in pregnancy

Bernard–Soulier syndrome (BSS) is a rare autosomal recessively inherited bleeding disorder. Pregnancy in patients with BSS is characterized by ante‐, intra‐, or postpartum haemorrhage, which may be delayed and severe. There is no consensus in the management of BSS in pregnancy and so far only 16 pregnancies in nine patients have been described. We report a further three pregnancies in two women with the syndrome. We also outline our management of pregnant patients with BSS.     

Preliminary laboratory based diagnostic criteria for immune thrombocytopenic purpura: evaluation by multi-center prospective study

BACKGROUND: We proposed diagnostic criteria for immune thrombocytopenic purpura (ITP) by modifying the existing guidelines for diagnosis of ITP and by incorporating laboratory tests found useful for predicting its diagnosis, for example erythrocyte count, leukocyte count, anti-GPIIb/IIIa antibody-producing B cells, platelet-associated anti-GPIIb/IIIa antibodies, percentage of reticulated platelets, and plasma thrombopoietin. OBJECTIVE AND METHODS: To validate our criteria, we conducted a multi-center prospective study involving 112 patients with thrombocytopenia and a morphologically normal peripheral blood film at the first visit. Each patient underwent a physical examination, routine laboratory tests, and specialized tests for the anti-GPIIb/IIIa antibody response and platelet turnover. RESULTS: Ninety-one patients (81%) satisfied the proposed criteria at first visit. Clinical diagnosis was made by skilled hematologists > 6 months after the first visit; ITP was diagnosed in 88 patients and non-ITP disorders in 24. The proposed criteria had 98% sensitivity, 79% specificity, a 95% positive predictive value, and a 90% negative predictive value. A relatively low specificity appears to be attributed to a few patients who had both ITP and aplastic anemia or myelodysplastic syndrome. CONCLUSIONS: Our preliminary diagnostic criteria based on ITP-associated laboratory findings were useful for the differential diagnosis of ITP, but additional evaluations and modifications will be necessary to develop criteria that can be used routinely.     

血栓的形成及中药抗栓溶栓概况

血栓形成是由于正常的凝血机制的扰乱而促使某些血细胞和蛋白质被激活相互作用而最终导致血小板－纤维蛋白血栓的形成．ＡＴ－Ⅲ、ＰＣ、ＴＭ是体内重要的抗凝物质．白细胞与血小板的相互作用、ＰＧＩ２／ＴＸＡ２值以及许多疾病状态是影响血栓形成的诸因素．许多中药具有抗血小板聚集、抗血栓形成的作用，包括生物碱类，如小檗碱、北豆根碱和钩藤碱；中药蒲黄、花椒、沙棘、大蒜的提取物；一些中药复方等．