Antithrombin and hypercoagulability in sepsis: insights from thrombelastography?

Antithrombin (AT) has been used for over 25 years to successfully treat disseminated intravascular coagulation (DIC). A four-day AT therapy in patients with DIC in the KyberSept trial has been related to a clear survival benefit in patients not receiving concomitant heparin. Gonano and coworkers performed thrombelastography (TEG) measurements in patients with severe sepsis and clearly showed hypercoagulability, as defined by five TEG parameters, compared to healthy controls. In the AT group they found a trend towards normalization of TEG parameters after treatment, although this did not reach statistical significance. This first clinical evaluation of hypercoagulability during AT treatment could not provide evidence for an attenuation of coagulopathy, an effect that might be due to high inter-individual variability

Prothrombin complex concentrate in surgical patients: retrospective evaluation of vitamin K antagonist reversal and treatment of severe bleeding

Introduction Prothrombin complex concentrates are recommended for rapid reversal of vitamin K anticoagulants. As they normalize levels of vitamin K dependent clotting factors and re-establish hemostasis, they may also be used as adjunctive therapy in patients with major bleeding. The aim of this study was to retrospectively evaluate the efficacy of prothrombin complex concentrates in the surgical setting. Methods The case notes of 50 patients requiring urgent oral anticoagulation reversal (n = 12) or with severe perioperative coagulopathic bleeding (n = 38) who received an infusion of prothrombin complex concentrate (Beriplex P/N(R) 500) at the surgical department of the University of Munich Hospital, Germany were retrospectively reviewed. Efficacy of prothrombin complex concentrate application was evaluated using the Quick test, reported as an international normalized ratio, hemodynamic measurements and requirement for blood products. Safety assessments included whole blood hemoglobin levels and specific parameters of organ dysfunction. Results Baseline characteristics were comparable, except that mean baseline international normalized ratio and hemoglobin levels were significantly higher (P < 0.01) in anticoagulation reversal than in bleeding patients. In anticoagulation reversal, the international normalized ratio was significantly reduced (from 2.8 +/- 0.2 at baseline to 1.5 +/- 0.1, P < 0.001) after one prothrombin complex concentrate infusion (median dose 1500 IU; lower quartile 1,000, upper quartile 2,000). No major bleeding was observed during surgery after prothrombin complex concentrate administration. Only one patient received platelets and red blood cell transfusion after prothrombin complex concentrate administration. In bleeding patients, infusion of prothrombin complex concentrate (median dose 2,000 IU; lower quartile 2,000, upper quartile 3,000) significantly reduced the INR from 1.7 +/- 0.1 at baseline to 1.4 +/- 0.1 (P < 0.001). This decrease was unrelated to fresh frozen plasma or vitamin K administration. Bleeding stopped after prothrombin complex concentrate administration in 4/11 (36%) patients with surgical bleeding and 26/ 27 (96%) patients with diffuse bleeding. Hemoglobin levels increased significantly from baseline in bleeding patients (P < 0.05) and mean arterial pressure stabilized (P < 0.05). No thrombotic events or changes in organ function were reported in any patient. Conclusions Prothrombin complex concentrate application effectively reduced international normalized ratios in anticoagulation reversal, allowing surgical procedures and interventions without major bleeding. In bleeding patients, the improvement in coagulation after prothrombin complex concentrate administration was judged to be clinically significant

Antithrombin Reduces Inflammation and Microcirculatory Perfusion Failure in Closed Soft-Tissue Injury and Endotoxemia

Background: Closed soft-tissue trauma leads to activation of the coagulation cascade and is often complicated by systemic inflammation and infection. Previous investigations have shown potent anti-inflammatory properties of antithrombin. We herein report on the action of antithrombin on skeletal muscle injury in experimental endotoxemia. Materials and Methods: By using a pneumatically driven computer-controlled impact device, closed soft-tissue trauma was applied on the left hind limb of pentobarbital-anesthetized rats. Six hours later, endotoxemia was induced by intraperitoneal injection of Escherichia coli]ipopolysaccharide. An equivalent volume of physiological saline was given in controls. At the same time point, treatment of animals was started by intravenous injection of antithrombin (250 IU/kg body weight) or vehicle solution. Twenty-four hours after trauma, the extensor digitorum longus muscle was microsurgically exposed and analyzed by means of high-resolution multifluorescence microscopy. Results: Traumatic soft-tissue injury with additional endotoxemia was characterized by nutritive perfusion failure (functional capillary density: 379 +/- 20 cm/cm(2)), tissue hypoxia (nicotinamide adenine dinucleotide autofluorescence: 77 +/- 4 aU), and enhanced leukocyte-endothelial cell interaction (773 +/- 35 cells/mm(2)). Therapeutic intervention with antithrombin 6 hrs after trauma restored nutritive perfusion and tissue oxygenation (functional capillary density: 469 +/- 22 cm/cm(2); nicotinamide adenine dinucleotide autofluorescence: 61 +/- 5 aU p < 0.05]) and reduced inflammatory leukocyte adherence (237 +/- 20 cells/mm(2) p < 0.05]) toward values found in nontraumatized controls (functional capillary density: 573 +/- 13 cm/cm(2); nicotinamide adenine dinucleotide autofluorescence: 56 +/- 2 aU; leukocyte adherence: 204 +/- 20 cells/mm(2)). Conclusion: Antithrombin ameliorates microcirculatory dysfunction and tissue injury in traumatized animals during endotoxemia. Furthermore, a reduced inflammatory cell response helps to prevent leukocyte-dependent secondary tissue injury. (Crit Care Med 2013; 41:867-873

Microcirculatory alterations in ischemia–reperfusion injury and sepsis: effects of activated protein C and thrombin inhibition

Experimental studies in ischemia–reperfusion and sepsis indicate that activated protein C (APC) has direct anti-inflammatory effects at a cellular level. In vivo, however, the mechanisms of action have not been characterized thus far. Intravital multifluorescence microscopy represents an elegant way of studying the effect of APC on endotoxin-induced leukocyte–endothelial-cell interaction and nutritive capillary perfusion failure. These studies have clarified that APC effectively reduces leukocyte rolling and leukocyte firm adhesion in systemic endotoxemia. Protection from leukocytic inflammation is probably mediated by a modulation of adhesion molecule expression on the surface of leukocytes and endothelial cells. Of interest, the action of APC and antithrombin in endotoxin-induced leukocyte–endothelial-cell interaction differs in that APC inhibits both rolling and subsequent firm adhesion, whereas antithrombin exclusively reduces the firm adhesion step. The biological significance of this differential regulation of inflammation remains unclear, since both proteins are capable of reducing sepsis-induced capillary perfusion failure. To elucidate whether the action of APC and antithrombin is mediated by inhibition of thrombin, the specific thrombin inhibitor hirudin has been examined in a sepsis microcirculation model. Strikingly, hirudin was not capable of protecting from sepsis-induced microcirculatory dysfunction, but induced a further increase of leukocyte–endothelial-cell interactions and aggravated capillary perfusion failure when compared with nontreated controls. Thus, the action of APC on the microcirculatory level in systemic endotoxemia is unlikely to be caused by a thrombin inhibition-associated anticoagulatory action

Age-related changes in T lymphocytes of patients with head and neck squamous cell carcinoma

Introduction The number of aging cancer patients has increased continuously and will do so further in the future. The immune system of elderly people experiences critical changes over the time. Therefore, tumor-induced changes in the immune system are believed to differ in young and elderly cancer patients as well. Methods The effect of aging on the immune system was measured in peripheral blood lymphocytes (PBL) of healthy volunteers (n = 48, 21–84 yrs.) divided into three different age groups. Seventy years was set as a cut-off for defining subjects as elderly. Results were compared to two groups of adult cancer patients, which donated PBL and tumor infiltrating lymphocytes (TIL): young cancer patients (40–69 yrs.; blood: n = 13; TIL: n = 17) and elderly cancer patients (70–90 yrs.; blood: n = 20; TIL: n = 15) with head and neck squamous cell carcinoma (HNSCC). Frequencies and phenotypes of CD4+ and CD8+ T cells as well as regulatory T cells (Treg) were assessed by flow cytometry. Results We observed lower frequencies of CD8+ cytotoxic T cells during aging in both groups. Frequencies of tumor infiltrating regulatory T cells were significantly higher than in the peripheral blood but showed a significant decline in older tumor patients. With increasing age, expression of immunosuppressive CD73 and CCR7 was lower and expression of PD1 elevated on peripheral T cells in healthy volunteers and tumor patients. Conclusion Immunosenescence takes place in healthy donors and cancer patients. Our results suggest that in elderly tumor patients, the immune system is impaired and the tumor-induced immune escape is less pronounced. The increased expression of PD1 implies the potential for effective immunotherapies in elderly, as treatment with checkpoint inhibitors could be more beneficial for elderly HNSCC patients

Schleimhautmelanome des Kopf-Hals-Bereichs

Mukosale Melanome des Kopf-Hals-Bereichs stellen sehr seltene, wenig erforschte Malignome dar, welche sich durch ein aggressives Wachstum, eine hohe Rate an lokoregionären Rezidiven und eine schlechte Prognose charakterisieren lassen. Bisher konnten keine Risikofaktoren für deren Entstehung identifiziert werden. Der Tumor tritt klassischerweise erst in fortgeschrittenem Stadium durch Symptome wie Epistaxis nasi oder nasale Obstruktion in Erscheinung und ist per Definition mindestens im T3 Stadium vorliegend. Der Goldstandard besteht in der radikalen Tumorresektion, welche bei knappen oder non in-sano Resektionen durch eine adjuvante Radiotherapie ergänzt wird. Die Anwendung klassischer Chemotherapeutika, Interferon oder zielgerichteter Antikörper konnte bislang zu keiner signifikanten Verbesserung der Prognose beitragen. Bemühungen, den Tumor besser biologisch und genomisch zu charakterisieren werden nach wie vor durch dessen geringe Inzidenz erschwert. Dennoch ist die molekulare Charakterisierung dieser prognostisch und therapeutisch klar vom kutanen Melanom abzugrenzenden Tumorentität dringend erforderlich, um innovative Therapiestrategien zu entwickeln, was wiederum interdisziplinärer und multizentrischer Anstrengungen bedarf

Aerosol Chemistry Resolved by Mass Spectrometry: Linking Field Measurements of Cloud Condensation Nuclei Activity to Organic Aerosol Composition

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Environmental Science & Technology, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/acs.est.6b01675Aerosol hygroscopic properties were linked to its chemical composition by using complementary online mass spectrometric techniques in a comprehensive chemical characterization study at a rural mountaintop station in central Germany in August 2012. In particular, atmospheric pressure chemical ionization mass spectrometry ((−)APCI-MS) provided measurements of organic acids, organosulfates, and nitrooxy-organosulfates in the particle phase at 1 min time resolution. Offline analysis of filter samples enabled us to determine the molecular composition of signals appearing in the online (−)APCI-MS spectra. Aerosol mass spectrometry (AMS) provided quantitative measurements of total submicrometer organics, nitrate, sulfate, and ammonium. Inorganic sulfate measurements were achieved by semionline ion chromatography and were compared to the AMS total sulfate mass. We found that up to 40% of the total sulfate mass fraction can be covalently bonded to organic molecules. This finding is supported by both on- and offline soft ionization techniques, which confirmed the presence of several organosulfates and nitrooxy-organosulfates in the particle phase. The chemical composition analysis was compared to hygroscopicity measurements derived from a cloud condensation nuclei counter. We observed that the hygroscopicity parameter (κ) that is derived from organic mass fractions determined by AMS measurements may overestimate the observed κ up to 0.2 if a high fraction of sulfate is bonded to organic molecules and little photochemical aging is exhibited