Low Dose Aspirin in high-risk pregnancies: The volatile effect of acetylsalicylic acid on the inhibition of platelets uncovered by G. Born's light transmission aggregometry.

Preeclampsia still represents a life-threatening pregnancy complication, associated with severe maternal and neonatal morbidity and mortality. Low-dose Aspirin is advised to avoid preeclampsia in high-risk pregnancies worldwide. As Aspirin does not cover all women at risk, the prescription raises questions concerning optimal target population, dosage, and onset of therapy. The aim of this study was to test platelet responsiveness on Aspirin by optical aggegrometry, to gain robust biochemically assessment data of Aspirin in an obstetric cohort. 248 women at high risk for development of preeclampsia were included in the study. Aspirin-prophylaxis was administered either in 100 mg (n = 229) or 150 mg (n = 90) daily. Dosing of 100 mg Aspirin was maintained if testing revealed a sufficient platelet inhibition. If platelet inhibition was insufficient, dosage was increased to 150 mg Aspirin and re-testing was advised. 91 patients (91/229 = 39.7%) presented a sufficient inhibitory Aspirin effect at a dosage of 100 mg, but in 138 patients LTA showed an inadequate Aspirin response (138/229 = 60.3%). In 19 women 150 mg Aspirin was administered as starting dose due to new recommendations. Of all women at 150 mg Aspirin 64 did not properly respond (35.4%). The overall rate of sufficient responding women regardless the Aspirin dose was 64.6%. This study demonstrates still an insufficient inhibition of platelet aggregation in about 1/3 of women even with a dosage of 150 mg Aspirin daily, who might potentially benefit from further increase. These data show, that there is a need for further research to allow a personalized approach for individualized Aspirin therapy, maximizing the preventive benefit for mother and child.

False positive serum levels of (1-3)-ß-D-Glucan after infusion of intravenous immunoglobulins and time to normalisation.

OBJECTIVES: (1-3)-ß-D-Glucan (BDG) is a marker for invasive fungal diseases (IFD). Administration of intravenous immunoglobulin preparations (IVIG) has been reported to lead to false positive BDG serum levels >80 pg/ml. The aim of the study was to determine the time interval between IVIG infusion and normalisation of BDG serum levels. METHODS: In 22 paediatric haemato-/oncologic patients, we analysed 92 BDG serum levels obtained within 4 weeks after IVIG administration (0.5 to 1 g/kg body weight), correlated them to 54 IVIG episodes and compared them to 76 BDG levels obtained in 29 patients without IVIG administration in the 4 weeks prior to BDG analyses (control group). RESULTS: BDG peak levels within 3 days after IVIG ranged from 21.47 to 660.38 (median 201.4) pg/ml. BDG serum levels at 7, 14 and 21 days (+/-1 day each) after IVIG infusion were significantly higher than BDG serum levels in the control group (p < 0.001 each). By days 7, 14, and 21 (+/-1 day each) after IVIG infusion, BDG serum levels have normalized (<80 pg/ml) in 64.0%, 76.5% and 100%, respectively. CONCLUSIONS: IVIG administration leads to false positive BDG levels in the vast majority of patients. Elevated BDG levels may be detectable for more than two weeks after IVIG administration, while BDG levels normalized within 3 weeks in all patients. Therefore, BDG should not be used to diagnose IFD within three weeks after IVIG administration.

Implementation of buffy-coat-derived pooled platelet concentrates for internal quality control of light transmission aggregometry: a proof of concept study.

Essentials In platelet function testing, standardized internal controls (IQC) are not commercially provided. Platelet function testing was performed daily on aliquoted pooled platelet concentrates. Pooled platelet concentrates showed stability for control purposes from Monday to Friday. Pooled platelet concentrates provide the necessary steadiness to serve as IQC material. SUMMARY: Background Standardized commercially available control material for internal quality control (IQC) of light transmission aggregometry (LTA) is still lacking. Moreover, the availability of normal blood donors to provide fresh platelets is difficult in small laboratories, where 'volunteers' may be in short supply. Objectives To evaluate the implementation of buffy-coat-derived pooled platelet concentrates (PCs) for IQC material for LTA. Methods We used buffy-coat-derived pooled PCs from the blood bank as IQC material for LTA. On each weekend one PC was prepared (> 200 mL) and aliquoted from the original storage bag on a daily basis in four baby bags (40-50 mL), which were delivered from Monday to Friday to our laboratory. The IQC measurements of at least 85 work-weeks (from Monday to Friday) were evaluated with this new IQC material. LTA was performed on a four-channel Chronolog 700 Aggregometer (Chronolog Corporation, Havertown, PA, USA) (agonists: collagen, adenosine diphosphate [ADP], arachidonic acid [AA] and thrombin receptor activator peptide-6 [TRAP-6]). Results The medians of platelet aggregation from IQC measurements with collagen, ADP and AA from Monday to Friday were 68.0-59.5, 3.0-2.0 and 51.0-50.0%, respectively, and the mean of platelet aggregation with TRAP-6 was 71.2-66.4%. Conclusions Buffy-coat-derived pooled PCs serve as a reliable and robust IQC material for LTA measurements and would be beneficial for the whole laboratory procedure and employees' safety.

Oxidative stress: Determination of 4-hydroxy-2-nonenal by gas chromatography/mass spectrometry in human and rat plasma.

The lipid peroxidation product 4-hydroxynonenal (HNE) is a biomarker of oxidative stress which is essentially involved in the pathophysiology of many diseases. The analysis of HNE is challenging because this aldehyde is extremely reactive and thus unstable. Hence, we adopted a gas chromatography-mass spectrometry (GC-MS) method based on derivatization of HNE with pentafluorobenzyl-hydroxylamine-HCl followed by trimethylsilylation to trimethylsilyl ethers. Ions representative for a negative ion chemical ionization mode were recorded at m/z = 152 for HNE and at m/z = 162 for the deuterated analogon (HNE-d11) as internal standard. This excellent stable and precise GC-MS method was carefully validated for HNE, and showed good linearity (r(2) = 0.998), and high specificity and sensitivity. Within-day precisions were 4.4-6.1% and between-day precisions were 5.2-10.2%. Accuracies were between 99% and 104% for the whole calibration range (2.5-250 nmol/L) of HNE. To examine the versatility of this modified GC-MS method, we analyzed HNE in ethylenediaminetetraacetic acid (EDTA) plasma in a well-defined collective of migraine patients; recently published. The results underline our former observations that women with migraine are afflicted with increased levels of HNE. Patients with thyroidal dysfunction showed no significant HNE alterations. This was confirmed by normal HNE EDTA plasma levels in hyper- und hypothyroid Sprague-Dawley rats. Taken together, the GC-MS method presented herein is of excellent quality to record oxidative stress-related bioactive HNE levels. This is important for a reorientation of oxidative stress analytics in other human diseases first of atherosclerosis and cancer.

Patatin-like phospholipase 3 (rs738409) gene polymorphism is associated with increased liver enzymes in obese adolescents and metabolic syndrome in all ages.

BACKGROUND: Obesity is associated with non-alcoholic fatty liver disease (NAFLD), and the patatin-like phospholipase 3 (PNPLA3) rs738409 (Ile148Met, C>G) gene polymorphism is one of the most important genetic determinants of NAFLD. Carriers have been reported to better respond to lifestyle modification. AIM: To investigate the effect of rs738409 on overweight/obese adolescents and adults with and without metabolic syndrome (MetS). METHODS: Two hundred and eighty-eight overweight/obese and 209 normal weight participants of the STYJOBS/EDECTA cohort (NCT00482924) were analysed for PNPLA3 genotypes. RESULTS: Compared to overweight/obese without MetS, in overweight/obese study participants with MetS, the presence of the G allele (148Met) was significantly higher (CC: 5.0% vs. 9.2%, Spearman's correlation, 0.12; P = 0.038). Persons with CG (heterozygote for the risk allele) and with GG (homozygote for the risk allele) genotypes showed significantly higher ALT levels than those with CC genotypes. Even young individuals aged below 20 years had significantly increased ALT levels if they were homozygote with the G allele. CONCLUSIONS: The PNPLA3 rs738409 polymorphism is associated already in youths with increased ALT, and is more frequent in obese with MetS of all ages. Hence, overweight/obese rs738409 carriers should be identified early in life and treated with a rigorous life style intervention.

Ultra-endurance exercise induces stress and inflammation and affects circulating hematopoietic progenitor cell function.

Although amateur sports have become increasingly competitive within recent decades, there are as yet few studies on the possible health risks for athletes. This study aims to determine the impact of ultra-endurance exercise-induced stress on the number and function of circulating hematopoietic progenitor cells (CPCs) and hematological, inflammatory, clinical, metabolic, and stress parameters in moderately trained amateur athletes. Following ultra-endurance exercise, there were significant increases in leukocytes, platelets, interleukin-6, fibrinogen, tissue enzymes, blood lactate, serum cortisol, and matrix metalloproteinase-9. Ultra-endurance exercise did not influence the number of CPCs but resulted in a highly significant decline of CPC functionality after the competition. Furthermore, Epstein-Barr virus was seen to be reactivated in one of seven athletes. The link between exercise-induced stress and decline of CPC functionality is supported by a negative correlation between cortisol and CPC function. We conclude that ultra-endurance exercise induces metabolic stress and an inflammatory response that affects not only mature hematopoietic cells but also the function of the immature hematopoietic stem and progenitor cell fraction, which make up the immune system and provide for regeneration.

Soluble urokinase plasminogen activator receptor predicts mortality in patients with systemic inflammatory response syndrome.

OBJECTIVE: The soluble urokinase plasminogen activator receptor (suPAR) reflects inflammation. However, the prognostic value of suPAR measurements, particularly at the very early onset of systemic inflammatory response syndrome (SIRS), is less well defined. METHODS: The prognostic potential of suPAR levels in patients with SIRS was evaluated. From November 2010 until April 2013, 902 adult patients presenting with SIRS were investigated. Blood samples for laboratory testing of inflammation markers were collected simultaneously with initial blood cultures. suPAR testing was performed using suPARnostic(©) assay. RESULTS: Analyses of receiver operating characteristics curves revealed areas under the curve (AUCs) of 0.818 for predicting overall mortality within 48 h (36/902 patients died), 0.739 for 30-day mortality (117/902 died) and 0.706 for predicting 90-day mortality (151/902 died). AUCs for procalcitonin (0.777, 0.671 and 0.638), interleukin-6 (0.709, 0.593 and 0.569) and C-reactive protein (0.66, 0.594 and 0.586) as well as renal function and age were markedly lower. Using multivariable regression analyses, suPAR levels (P < 0.001) remained significant predictors of 48-h mortality, whereas suPAR levels (P < 0.001) and bacteraemia (P = 0.002 and P = 0.001, respectively) remained significant predictors of 30- and 90-day mortality. Using Kaplan-Meier survival plots, patients with suPAR <9.15 ng mL(-1) at SIRS onset had a clear benefit. CONCLUSION: suPAR plasma level determined at early SIRS is predictive for mortality.

[Platelet function: new drugs, new assays : possible impacts on operative medicine?]. / Thrombozytenfunktion - neue Medikamente, neue Assays : Mögliche Auswirkungen auf die operative Medizin?

Dual antiplatelet therapy with aspirin and a P2Y12 receptor blocker is a well-established strategy to prevent thrombotic complications in patients with acute coronary syndromes (ACS) and after percutaneous coronary interventions (PCI). Current practice guidelines for antiplatelet therapy advocate a 1 to 12-month dual antiplatelet therapy after bare metal stent PCI and an up to 12-month dual antiplatelet therapy after PCI in patients with ACS and drug-eluting stent PCI. Premature withdrawal of dual antiplatelet therapy carries a substantial risk of stent thrombosis but perioperative continuation of dual antiplatelet therapy is associated with an increased risk of bleeding, particularly in patients treated with the new potent drugs prasugrel and ticagrelor. Based on the various available assays, the lack of validated cut-offs and the disappointing results of targeted antiplatelet therapy as demonstrated by the GRAVITAS trial, current guidelines of international societies recommend platelet function testing only for selected high risk patients despite the known association between clopidogrel low responsiveness and ischemic events. However, for individual patients taking clopidogrel, platelet function monitoring may be considered to safely shorten the preoperative waiting period, to assess the risk of bleeding and transfusion and to initiate specific therapy in bleeding patients.

Influence of multicomponent apheresis on donors' haematological and coagulation parameters, iron storage and platelet function.

BACKGROUND AND OBJECTIVES: Multicomponent collection (MCC) enables production and processing of various blood components during one apheresis session. In this prospective crossover study, the effects of donating platelets (PLTs) and packed red blood cells (PRBCs) on donor's blood cell count, coagulation, PLT function and iron state were analysed. MATERIALS AND METHODS: Forty-eight MCCs were performed using two different cell separators (Fenwal Amicus(®), CaridianBCT Trima Accel(®)). Two units of platelet concentrates and one unit of PRBCs were collected during each session. Full blood cell count and iron status were obtained on day 0 before and after apheresis, day 2, day 14 and day 42. PLT function was analysed by aggregometry and rotation thromboelastometry in parallel with coagulation tests before and after MCC and at day 2. RESULTS: Multicomponent collection was well tolerated without adverse side effects. Blood cell count and iron parameters declined and most of them (haemoglobin, haematocrit, transferrin, transferrin saturation and ferritin) were significantly below baseline values until at least day 42 after donation. Absent iron stores were seen in 31·3% of the donors. In contrast, PLTs significantly exceeded pre-donation values after 14 days and remained significantly increased for 42 days. After 2 days, coagulation parameters were only slightly (P > 0·05) altered, whereas PLT function was significantly reduced. CONCLUSION: Multicomponent collection is an obviously safe procedure; however, the significant long-term impact on the donor's blood count and iron store, as well as impaired PLT function, has to be considered in regard to donor safety.

Proximal lower limb vein thrombosis following vipera berus hand bite.

Vipera berus has a wide geographical distribution throughout Central and Northern Europe. The symptoms after a bite usually are mild, life threatening symptoms are mainly described in children. We describe a case of popliteal vein thrombosis of the right leg after systemic envenoming with Vipera berus venom after a bite in the right hand by a female Vipera berus in the alpine region of Styria, Austria. Changes of the plasmatic coagulation system were obvious in our patient. These changes were due to an activation of the coagulation system and might be the reason for the thrombotic event in this usually healthy young male person.