Delivering trials in the NHS: more than worth it

Randomised trials are the best method to determine the efficacy and safety of health technologies. A recent report by Lord O'Shaughnessy highlighted many of the current challenges to delivering trials in the UK and proposed potential solutions. Among these, making trials the business of all NHS institutions and a valued part of all doctors' work, while leveraging the potential of the data that the NHS collects routinely, offers an opportunity to improve NHS efficiency, doctors' job satisfaction and population health simultaneously.

Transfusion 2024: A 5-year plan for clinical and laboratory transfusion in England

The Transfusion 2024 plan outlines key priorities for clinical and laboratory transfusion practice for safe patient care across the NHS for the next 5 years. It is based on the outcomes of a multi-professional symposium held in March 2019, organised by the National Blood Transfusion Committee (NBTC) and NHS Blood and Transplant (NHSBT), attended and supported by Professor Keith Willet and Dame Sue Hill on behalf of NHS England and Improvement. This best practice guidance contained within this publication will facilitate the necessary change in pathway design to meet the transfusion challenges and pressures for the restoration of a cohesive, and functional, healthcare system across the NHS following the COVID-19 pandemic.

MRS as an Aid to Diagnose Malignant Transformation in Low-Grade Gliomas with Increasing Contrast Enhancement

BACKGROUND AND PURPOSE

Increased contrast enhancement has been used as a marker of malignant transformation in low-grade gliomas. This marker has been found to have limited accuracy because many low-grade gliomas with increased contrast enhancement remain grade II. We aimed to investigate whether MR spectroscopy can contribute to the diagnosis of malignant transformation in low-grade gliomas with increased contrast enhancement.

MATERIALS AND METHODS

Patients with low-grade gliomas who had contemporaneous MR spectroscopy and histopathology for tumor regions with increased contrast enhancement between 2004 and 2015 were retrospectively reviewed. Clinical data collected were sex and age, Karnofsky Performance Scale, histologic subtypes, isocitrate dehydrogenase 1 mutation status, disease duration, adjuvant therapy, and post-radiation therapy duration. Imaging data collected were contrast-enhancement size, whole-tumor size, MR spectroscopy metabolite ratios, and tumor grades of regions with increased contrast enhancement. Diagnostic values of these factors on malignant transformation of low-grade gliomas were statistically analyzed.

RESULTS

A total of 86 patients with 96 MR spectroscopy studies were included. Tumor grades associated with increased contrast enhancement were grade II (n = 42), grade III (n = 27), and grade IV (n = 27). On multivariate analysis, the NAA/Cho ratio was the only significant factor (P < .001; OR, 7.1; 95% CI, 3.2-16.1) diagnostic of malignant transformation. With 0.222 as the cutoff value, the sensitivity, specificity, and accuracy of NAA/Cho for diagnosing malignant transformation were 94.4%, 83.3%, and 89.6%, respectively.

CONCLUSIONS

MR spectroscopy complements conventional MR imaging in the diagnosis of malignant transformation in a subgroup of low-grade gliomas with increased contrast enhancement.

Activation of Protein C and Its Distribution between Its Inhibitors, Protein C Inhibitor, α1-Antitrypsin and α2-Macroglobulin, in Patients with Disseminated intravascular Coagulation

Activation and inactivation of protein C during the clinical course of disseminated intravascular coagulation (DIC) was studied in three patients by qualitative (Western blotting) and quantitative (ELISA) analysis and the intensity of procoagulant activity monitored by the measurement of thrombin and factor Xa antithrombin III complexes. In one patient, inhibitor complexes of APC with protein C inhibitor (PCI) and α1-antitrypsin (α1-AT) were observed and the latter predominated at presentation. Both disappeared during the development of remission but the loss of α1-AT complexes preceded PCI complexes which on Western blotting appeared to increase in intensity prior to disappearance. The two other patients bled to death from uncontrollable haemorrhage. In both cases, APC/inhibitor complexes with α2-macroglobulin (α2-M) in addition to PCI and αr-AT were detected and persisted until death. Although PCI appeared to be the primary inhibitor in all three cases, α1-antitrypsin and particularly α2-macroglobulin appeared to assume greater roles in the two fatal cases. These data are similar to previous findings in an experimental animal model of DIC that suggested that α2-macroglobulin and α1-antitrypsin become more important inhibitors of APC as the primary inhibitor PCI is consumed in the face of a sustained procoagulant challenge.

APTT Revisited: Detecting Dysfunction in the Hemostatic System Through Waveform Analysis

Despite extensive investigations in both experimental and clinical disseminated intravascular coagulation (DIC), much remains to be learned about this condition of hemostatic dysfunction. Although the technological armory available to the clinical investigator has expanded enormously since the early 1980s, particularly with regard to immunologically-based testing, the sobering fact is that prognosis has remained dismally unchanged.1 Although some of the new laboratory approaches can identify DIC at an early enough stage to allow for useful clinical intervention, most require a level of stringency in performance that is not attainable in the routine clinical setting.2 The pace of acute DIC precludes many of these specific tests, and reliance is still based on traditional screening assays, such as the prothrombin time (PT), activated partial thromboplastin time (APTT) and platelet count (Plt). These tests lack specificity on an individual basis and are only useful in DIC if there is further determination of fibrinogen (Fgn) and fibrin breakdown products (fdp)/D-Dimers.3 However, changes in these battery of tests seldom occur together. As a result, the realization of DIC is often only made after serial testing, with the inevitable delay and consequent jeopardization of patient critical care.4 The numerous failures of new therapies in sepsis and DIC testifies to this problem of a lack of early definition in the disease process to forewarn the clinician of more timely intervention.5 The gold standard must, therefore, be a single, rather than multiple, assay system that is both sensitive and specific for early DIC and simple and rapid to perform. It is therefore, not too surprising that such a test has remained elusive for such a considerable length of time.

In the context of complex scenarios, the simplest of approaches can often be the most rewarding. Such an axiom could fit with the description of APTT transmittance waveform analysis as a useful test in DIC that could also potentially lead to an improved understanding of the condition.

Early Identification and Prognostic Implications in Disseminated Intravascular Coagulation through Transmittance Waveform Analysis

Efforts to improve the prognosis in disseminated intravascular coagulation (DIC) have been hampered by the lack of an early, useful and rapidly available diagnostic marker. More recently, a characteristic bi-phasic change in the light transmittance waveform profile of the APTT assay has been associated with DIC. In this prospective study, we have assessed the utility of this assay in the routine clinical setting. 1,470 samples were analysed from 747 patients and 41 patients had DIC. The sensitivity and specificity of the bi-phasic waveform pattern for DIC was 97.6% and 98% respectively. The appearance of a biphasic waveform preceded the development of abnormalities in the standard laboratory tests for DIC and waveform changes correlated closely with clinical events. In conclusion, transmittance waveform analysis is not only useful as an early diagnostic and single monitoring marker of DIC but the quantifiable and standardisable changes also allow for prognostic applicability in clinical management.

Prothrombinase enhancement through quantitative and qualitative changes affecting very low density lipoprotein in complex with C-reactive protein

The biphasic waveform that can predict for disseminated intravascular coagulation (DIC) is due to the formation of a calcium-dependent complex between C reactive protein (CRP) and very low density lipoprotein (VLDL). As thrombin generation is pivotal to DIC, this aspect has been specifically investigated and the VLDL component has been found to increase prothrombinase activity via both quantitative and qualitative changes. The specific prothrombinase activity of VLDL from patients manifesting the biphasic waveform was 2.5 times that of normal individuals or critically ill patients without the biphasic waveform. This activity was due to an increase in anionic phospholipid surfaces that could be inhibited with excess annexin V and which was dependent on structurally intact apolipoprotein B.The qualitative change appeared to be due to a deficiency of phosphatidylethanolamine inVLDL from patients with the biphasic waveform.The functional consequence of this enhanced prothrombinase activity was an increased procoagulant effect in plasma. Using a modified activated partial thromboplastin time assay, the mean normal clot time decreased significantly when VLDL from patients with biphasic waveforms was substituted.These results indicate that VLDL derived from patients with the biphasic waveform can enhance thrombin procoagulant activity. As the CRP-VLDL complex exists in vivo, it could have a pathogenic role in disseminating the process of intravascular coagulation.

Accuracy of circulating histones in predicting persistent organ failure and mortality in patients with acute pancreatitis

BACKGROUND

Early prediction of acute pancreatitis severity remains a challenge. Circulating levels of histones are raised early in mouse models and correlate with disease severity. It was hypothesized that circulating histones predict persistent organ failure in patients with acute pancreatitis.

METHODS

Consecutive patients with acute pancreatitis fulfilling inclusion criteria admitted to Royal Liverpool University Hospital were enrolled prospectively between June 2010 and March 2014. Blood samples were obtained within 48 h of abdominal pain onset and relevant clinical data during the hospital stay were collected. Healthy volunteers were enrolled as controls. The primary endpoint was occurrence of persistent organ failure. The predictive values of circulating histones, clinical scores and other biomarkers were determined.

RESULTS

Among 236 patients with acute pancreatitis, there were 156 (66·1 per cent), 57 (24·2 per cent) and 23 (9·7 per cent) with mild, moderate and severe disease respectively, according to the revised Atlanta classification. Forty-seven healthy volunteers were included. The area under the receiver operating characteristic (ROC) curve (AUC) for circulating histones in predicting persistent organ failure and mortality was 0·92 (95 per cent c.i. 0·85 to 0·99) and 0·96 (0·92 to 1·00) respectively; histones were at least as accurate as clinical scores or biochemical markers. For infected pancreatic necrosis and/or sepsis, the AUC was 0·78 (0·62 to 0·94). Histones did not predict or correlate with local pancreatic complications, but correlated negatively with leucocyte cell viability (r = -0·511, P = 0·001).

CONCLUSION

Quantitative assessment of circulating histones in plasma within 48 h of abdominal pain onset can predict persistent organ failure and mortality in patients with acute pancreatitis. Early death of immune cells may contribute to raised circulating histone levels in acute pancreatitis.

Current Pathological and Laboratory Considerations in the Diagnosis of Disseminated Intravascular Coagulation

Systemically sustained thrombin generation in vivo is the hallmark of disseminated intravascular coagulation (DIC). Typically, this is in response to a progressing disease state that is associated with significant cellular injury. The etiology could be infectious or noninfectious, with the main pathophysiological mechanisms involving cross-activation among coagulation, innate immunity, and inflammatory responses. This leads to consumption of both pro- and anticoagulant factors as well as endothelial dysfunction and disrupted homeostasis at the blood vessel wall interface. In addition to the release of tissue plasminogen activator (tPA) and soluble thrombomodulin (sTM) following cellular activation and damage, respectively, there is the release of damage-associated molecular patterns (DAMPs) such as extracellular histones and cell-free DNA. Extracellular histones are increasingly recognized as significantly pathogenic in critical illnesses through direct cell toxicity, the promotion of thrombin generation, and the induction of neutrophil extracellular trap (NET) formation. Clinically, high circulating levels of histones and histone–DNA complexes are associated with multiorgan failure, DIC, and adverse patient outcomes. Their measurements as well as that of other DAMPs and molecular markers of thrombin generation are not yet applicable in the routine diagnostic laboratory. To provide a practical diagnostic tool for acute DIC, a composite scoring system using rapidly available coagulation tests is recommended by the International Society on Thrombosis and Haemostasis. Its usefulness and limitations are discussed alongside the advances and unanswered questions in DIC pathogenesis.

Early-Stage Glioblastomas: MR Imaging-Based Classification and Imaging Evidence of Progressive Growth

BACKGROUND AND PURPOSE

The serial imaging changes describing the growth of glioblastomas from small to large tumors are seldom reported. Our aim was to classify the imaging patterns of early-stage glioblastomas and to define the order of appearance of different imaging patterns that occur during the growth of small glioblastomas.

MATERIALS AND METHODS

Medical records and preoperative MR imaging studies of patients diagnosed with glioblastoma between 2006 and 2013 were reviewed. Patients were included if their MR imaging studies showed early-stage glioblastomas, defined as small MR imaging lesions detected early in the course of the disease, demonstrating abnormal signal intensity but the absence of classic imaging findings of glioblastoma. Each lesion was reviewed by 2 neuroradiologists independently for location, signal intensity, involvement of GM and/or WM, and contrast-enhancement pattern on MR imaging.

RESULTS

Twenty-six patients with 31 preoperative MR imaging studies met the inclusion criteria. Early-stage glioblastomas were classified into 3 types and were all hyperintense on FLAIR/T2-weighted images. Type I lesions predominantly involved cortical GM (n = 3). Type II (n = 12) and III (n = 16) lesions involved both cortical GM and subcortical WM. Focal contrast enhancement was present only in type III lesions at the gray-white junction. Interobserver agreement was excellent (κ = 0.95; P < .001) for lesion-type classification. Transformations of lesions from type I to type II and type II to type III were observed on follow-up MR imaging studies. The early-stage glioblastomas of 16 patients were pathologically confirmed after imaging progression to classic glioblastoma.

CONCLUSIONS

Cortical lesions may be the earliest MR imaging-detectable abnormality in some human glioblastomas. These cortical tumors may progress to involve WM.

A multi-factorial analysis of response to warfarin in a UK prospective cohort

Background

Warfarin is the most widely used oral anticoagulant worldwide, but it has a narrow therapeutic index which necessitates constant monitoring of anticoagulation response. Previous genome-wide studies have focused on identifying factors explaining variance in stable dose, but have not explored the initial patient response to warfarin, and a wider range of clinical and biochemical factors affecting both initial and stable dosing with warfarin.

Methods

A prospective cohort of 711 patients starting warfarin was followed up for 6 months with analyses focusing on both non-genetic and genetic factors. The outcome measures used were mean weekly warfarin dose (MWD), stable mean weekly dose (SMWD) and international normalised ratio (INR) > 4 during the first week. Samples were genotyped on the Illumina Human610-Quad chip. Statistical analyses were performed using Plink and R.

Results

VKORC1 and CYP2C9 were the major genetic determinants of warfarin MWD and SMWD, with CYP4F2 having a smaller effect. Age, height, weight, cigarette smoking and interacting medications accounted for less than 20 % of the variance. Our multifactorial analysis explained 57.89 % and 56.97 % of the variation for MWD and SMWD, respectively. Genotypes for VKORC1 and CYP2C9*3, age, height and weight, as well as other clinical factors such as alcohol consumption, loading dose and concomitant drugs were important for the initial INR response to warfarin. In a small subset of patients for whom data were available, levels of the coagulation factors VII and IX (highly correlated) also played a role.

Conclusion

Our multifactorial analysis in a prospectively recruited cohort has shown that multiple factors, genetic and clinical, are important in determining the response to warfarin. VKORC1 and CYP2C9 genetic polymorphisms are the most important determinants of warfarin dosing, and it is highly unlikely that other common variants of clinical importance influencing warfarin dosage will be found. Both VKORC1 and CYP2C9*3 are important determinants of the initial INR response to warfarin. Other novel variants, which did not reach genome-wide significance, were identified for the different outcome measures, but need replication.

Electronic supplementary material

The online version of this article (doi:10.1186/s13073-015-0255-y) contains supplementary material, which is available to authorized users.

A randomized trial of genotype-guided dosing of warfarin

BACKGROUND

The level of anticoagulation in response to a fixed-dose regimen of warfarin is difficult to predict during the initiation of therapy. We prospectively compared the effect of genotype-guided dosing with that of standard dosing on anticoagulation control in patients starting warfarin therapy.

METHODS

We conducted a multicenter, randomized, controlled trial involving patients with atrial fibrillation or venous thromboembolism. Genotyping for CYP2C9*2, CYP2C9*3, and VKORC1 (-1639G→A) was performed with the use of a point-of-care test. For patients assigned to the genotype-guided group, warfarin doses were prescribed according to pharmacogenetic-based algorithms for the first 5 days. Patients in the control (standard dosing) group received a 3-day loading-dose regimen. After the initiation period, the treatment of all patients was managed according to routine clinical practice. The primary outcome measure was the percentage of time in the therapeutic range of 2.0 to 3.0 for the international normalized ratio (INR) during the first 12 weeks after warfarin initiation.

RESULTS

A total of 455 patients were recruited, with 227 randomly assigned to the genotype-guided group and 228 assigned to the control group. The mean percentage of time in the therapeutic range was 67.4% in the genotype-guided group as compared with 60.3% in the control group (adjusted difference, 7.0 percentage points; 95% confidence interval, 3.3 to 10.6; P<0.001). There were significantly fewer incidences of excessive anticoagulation (INR ≥4.0) in the genotype-guided group. The median time to reach a therapeutic INR was 21 days in the genotype-guided group as compared with 29 days in the control group (P<0.001).

CONCLUSIONS

Pharmacogenetic-based dosing was associated with a higher percentage of time in the therapeutic INR range than was standard dosing during the initiation of warfarin therapy. (Funded by the European Commission Seventh Framework Programme and others; ClinicalTrials.gov number, NCT01119300.).

Assessment of angiographic vascularity of meningiomas with dynamic susceptibility contrast-enhanced perfusion-weighted imaging and diffusion tensor imaging

BACKGROUND AND PURPOSE

The roles of DTI and dynamic susceptibility contrast-enhanced-PWI in predicting the angiographic vascularity of meningiomas have not been studied. We aimed to investigate if these 2 techniques could reflect the angiographic vascularity of meningiomas.

MATERIALS AND METHODS

Thirty-two consecutive patients with meningiomas who had preoperative dynamic susceptibility contrast-enhanced-PWI, DTI, and conventional angiography were retrospectively included. The correlations between angiographic vascularity of meningiomas, classified with a 4-point grading scale, and the clinical or imaging variables-age and sex of patient, as well as size, CBV, fractional anisotropy, and ADC of meningiomas-were analyzed. The meningiomas were dichotomized into high-vascularity and low-vascularity groups. The differences in clinical and imaging variables between the 2 groups were compared. Receiver operating characteristic curve analysis was used to determine the diagnostic performance of these variables.

RESULTS

In meningiomas, angiographic vascularity correlated positively with CBV but negatively with fractional anisotropy. High-vascularity meningiomas demonstrated significantly higher CBV but lower fractional anisotropy as compared with low-vascularity meningiomas. In differentiating between the 2 groups, the area under the curve values were 0.991 for CBV and 0.934 for fractional anisotropy on receiver operating characteristic curve analysis.

CONCLUSIONS

CBV and fractional anisotropy correlate well with angiographic vascularity of meningiomas. They may differentiate between low-vascularity and high-vascularity meningiomas.

Adherence and variability in warfarin dose requirements: assessment in a prospective cohort

AIM

Although several genetic and nongenetic factors are associated with warfarin dose, approximately 40% of variability remains unexplained. An as yet unexplored factor is medication adherence. Here, we investigate the influence of adherence on response to warfarin and on pharmacogenetic analyses of association.

PATIENTS & METHODS

A total of 311 patients starting warfarin were followed-up prospectively, and adherence was measured at 1, 8 and 26 weeks. The association between adherence and warfarin response was tested, and the additional proportion of variability in response explained by adherence was assessed.

RESULTS

Significant associations were found between adherence and achievement of stable dose and time taken to achieve it, with nonadherers taking longer. Adjusting for adherence increased the proportion of explained variability in treatment response by up to 8%.

CONCLUSION

Given the significant contribution of adherence to drug response, we recommend that consideration is given to the value of assessing adherence when designing future pharmacogenetic studies of warfarin and other drugs.

Differentiation of primary central nervous system lymphomas and glioblastomas: comparisons of diagnostic performance of dynamic susceptibility contrast-enhanced perfusion MR imaging without and with contrast-leakage correction

BACKGROUND AND PURPOSE

Contrast leakage results in underestimation of the CBV of brain tumors. Our aim was to compare the diagnostic performance of DSC perfusion MR imaging without and with mathematic contrast-leakage correction in differentiating PCNSLs and glioblastomas.

MATERIALS AND METHODS

Perfusion parameters-CBV, corrected CBV, and leakage coefficient-were measured in enhancing tumor portions and contralateral NAWM of 15 PCNSLs and 20 glioblastomas, respectively. The ratios of CBV and corrected CBV were calculated by dividing the tumor values by those obtained from contralateral NAWM. A paired t test was used to compare tumor K2 and NAWM K2, as well as tumor CBV ratios without and with leakage correction. Comparisons of CBV, corrected CBV, and K2 between PCNSLs and glioblastomas were done by using a 2-sample t test. The diagnostic performance of DSC perfusion MR imaging without and with contrast-leakage correction was assessed with receiver operating characteristic curve analysis.

RESULTS

PCNSLs and glioblastomas demonstrated higher K2 than those in their contralateral NAWM. Corrected CBV ratios were significantly higher than the uncorrected ones for both tumors. PCNSLs had lower CBV ratios (P < .001), lower corrected CBV ratios (P < .001), and higher K2 (P = .001) compared with glioblastomas. In differentiating between PCNSLs and glioblastomas, the area under the curve of the CBV ratio, corrected CBV ratio, and K2 were 0.984, 0.940, and 0.788, respectively.

CONCLUSIONS

PCNSL can be differentiated from glioblastoma with CBV ratios, corrected CBV ratios, and K2. CBV without contrast-leakage correction seems to have the best diagnostic performance in differentiating the 2 tumors.

Current consideration and management of disseminated intravascular coagulation

Disseminated intravascular coagulation (DIC) is a devastating clinical condition that is characterized by the loss of normal hemostatic control in response to sustained and systemic cell injury. The inciting injury may be from infection, trauma, or malignancy, but the consequent pathophysiology is multifactorial involving intertwined feedback loops between the coagulant, immune, and inflammatory pathways. Central to this is thrombin generation, but the ubiquitous nature of its in vivo functional consequences can make it difficult to dissect away the separate but overlapping components to the clinical problem. Therefore, early recognition and resolution of the precipitating events leading to DIC remains the central tenet to clinical care. This article refreshes our conceptual understanding of DIC pathogenesis and draws in recent advances in the cycle of cell death caused by extracellular nuclear proteins. It also aims to delineate recognition of response pathways that can be predominantly procoagulant or profibrinolytic to enable a more personalized and evidence-based approach to be delivered to the patient with DIC.

Differentiation of pyogenic brain abscesses from necrotic glioblastomas with use of susceptibility-weighted imaging

BACKGROUND AND PURPOSE

A common imaging finding in brain abscess and necrotic glioblastoma is a T2 hypointense margin. The features of this hypointense rim on SWI have not been previously described, to our knowledge. We aimed to differentiate abscesses from glioblastomas by assessing the morphology of their lesion margin by using SWI.

MATERIALS AND METHODS

T2WI and SWI were performed in 12 abscesses and 20 rim-enhancing glioblastomas. On T2WI and SWI, the prevalence and the border types (complete versus incomplete) of hypointense rims were qualitatively assessed. On SWI, the contour (smooth versus irregular) and the location of hypointense rims relative to the contrast-enhancing rims as well as the prevalence of the "dual rim sign," defined as 2 concentric rims at lesion margins with the outer one being hypointense and the inner one hyperintense relative to cavity contents, were also analyzed.

RESULTS

Prevalence and the border types of the hypointense rims on T2WI were not different between abscesses and glioblastomas. On SWI, there were significantly more hypointense rims that were complete (P < .001) and smooth (P < .001), having the same location as the contrast-enhancing rims (P < .001) for abscesses. A dual rim sign was present in 9 of 12 abscesses but absent in all glioblastomas (P < .001).

CONCLUSIONS

SWI may be helpful in differentiating pyogenic abscesses from necrotic glioblastomas. The dual rim sign is the most specific imaging feature distinguishing the 2.

Differentiation of tumefactive demyelinating lesions from high-grade gliomas with the use of diffusion tensor imaging

BACKGROUND AND PURPOSE

TDLs may be indistinguishable from high-grade gliomas on conventional MR imaging. The role of DTI in differentiating TDLs from high-grade gliomas is not clear, and quantitative comparison between the 2 has not been reported. Here we aimed to differentiate TDLs from high-grade gliomas by using DTI.

MATERIALS AND METHODS

DTI was performed in 8 TDLs and 13 high-grade gliomas. The presence of 3 findings (ie, intralesional hyperintensities on the FA map, restricted diffusion in the lesion periphery, and a perilesional hyperintense FA rim) was assessed by visual inspection. The FA and MD values were measured in the central nonenhancing portion, peripheral enhancing portion, and perilesional edema for each lesion and compared between the 2 groups respectively.

RESULTS

TDLs had a significantly higher incidence of intralesional hyperintensities on FA maps (P = .049) but a lower incidence of a perilesional hyperintense FA rim (P < .001), compared with those of high-grade gliomas on visual inspection. TDLs had significantly higher FA (P = .004) and lower MD (P = .001) values in the peripheral enhancing portions of the lesions compared with those of high-grade gliomas. In perilesional edema, FA values were significantly higher in high-grade gliomas (P = .001).

CONCLUSIONS

DTI is helpful in differentiating TDLs from high-grade gliomas by using visual inspection and quantitative analysis.

The clinical and functional relevance of microparticles induced by activated protein C treatment in sepsis

INTRODUCTION

Activated protein C (APC) induces release of microparticles (MP) from primary physiological cells, which are found in patients undergoing treatment with recombinant human APC (rhAPC) for severe sepsis. We hypothesised that APC on these circulating MPs activate endothelial protease-activated receptor 1 (PAR1) to induce anti-apoptotic and anti-inflammatory properties that can improve patient outcome.

METHODS

This was an experimental study on clinical samples in an intensive care setting, and included patients with severe sepsis who fulfilled criteria for treatment with rhAPC. The number of CD13+ MPs from the patients were analysed to determine their origin. They were also quantified for endothelial protein C receptor (EPCR) and APC expression. Clinical relevance of these MPs were ascertained by comparing survival between the group receiving rhAPC (n = 25) and a control group of untreated patients (n = 25). MPs were also incubated with endothelial cells to analyse apoptotic gene expression, cytoprotection and anti-inflammatory effects.

RESULTS

rhAPC treatment induced a significant increase in circulating MP-associated EPCR by flow cytometry (P < 0.05) and by quantitative ELISA (P < 0.005). APC expression also showed significant increases (P < 0.05). Numerically, CD13+ MPs were higher in rhAPC-treated survivors versus non-survivors. However, the number of non-survivors was low and this was not significantly different. APC on MPs was demonstrated to induce anti-apoptotic and endothelial barrier effects through the activation of endothelial PAR1.

CONCLUSIONS

rhAPC treatment in patients with sepsis significantly increases circulating EPCR + MPs. These MPs were noted to express APC, which has specific anti-apoptotic and anti-inflammatory effects, with a non-significant correlative trend towards survival. This suggests that MPs could disseminate APC function and activate endothelial PAR1 at distal vascular sites.

Differentiation of brain abscesses from necrotic glioblastomas and cystic metastatic brain tumors with diffusion tensor imaging

BACKGROUND AND PURPOSE

The differentiation of abscesses from glioblastomas and metastases may not always be possible on the basis of DWI. Our hypothesis was that differences in diffusion properties as detected by DTI allow differentiation of abscess from glioblastomas and metastasis. Furthermore, diagnostic performance of tensor metrics quantifying anisotropy or tensor shapes is better than that of ADC in measuring mean diffusivity for this purpose.

MATERIALS AND METHODS

DTI was performed in 15 abscesses, 15 necrotic glioblastomas, and 26 cystic metastases. In each lesion, manually segmented into 4 regions of interest (ie, cystic cavity, enhancing rim, and immediate [edema most adjacent to the enhancing rim] and distant zones of edema), FA, ADC, C(l), C(p), and C(s) values were measured and statistically compared among groups and evaluated with ROC curve analysis. The presence of a hyperintense FA rim (a rim of edematous tissue that was hyperintense on the FA map) was assessed visually.

RESULTS

Abscess was significantly different from glioblastoma for all tensor metrics measured in the cystic cavity and immediate zone of edema and for all except C(l) in the enhancing rim. Abscess was significantly different from metastasis for all tensor metrics measured in the cystic cavity and enhancing rim and for FA, ADC, and C(l) in immediate zone of edema. The incidence of a hyperintense FA rim was significantly higher in glioblastoma and metastasis compared with abscess. The 3 tensor metrics with the highest performance in differentiating abscess from glioblastoma and metastasis were FA, C(l), and C(s) of the cystic cavity.

CONCLUSIONS

DTI is able to differentiate abscess from glioblastoma and metastasis. FA, C(l), and C(s) outperformed ADC in diagnostic performance comparisons.

Accuracy of platelet counting by automated hematologic analyzers in acute leukemia and disseminated intravascular coagulation: potential effects of platelet activation

Platelet counting in patients with acute leukemia or disseminated intravascular coagulation (DIC) may have a risk for erroneous counts owing to the presence of nonplatelet particles or platelet activation. We evaluated automated platelet counting methods using the Abbott Cell-Dyn Sapphire (Abbott Diagnostics, Santa Clara, CA), Sysmex XE-2100 (Sysmex, Kobe, Japan), ADVIA 2120 (Siemens Diagnostics, Tarrytown, NY), and Beckman Coulter LH 750 (Beckman Coulter, Miami, FL) compared with the international reference method (IRM). Automated platelet counting methods were inaccurate compared with the IRM, without evidence of interfering nonplatelet particles. It is interesting that platelet activation markers were associated with DIC severity and erroneous platelet counting, suggesting that platelet activation is a potential source of inaccuracy. Furthermore, the artifactual in vitro platelet activation induced a high degree of intermethod variation in platelet counts. The inaccuracy of automated platelet counts increased the risk for misdiagnosis of DIC. More attention needs to be given to the accuracy of platelet counts, especially in clinical conditions with florid platelet activation.

Modified non-overt DIC diagnostic criteria predict the early phase of overt-DIC

Diagnostic criteria for non-overt disseminated intravascular coagulation (DIC) have been proposed by the International Society of Thrombosis and Hemostasis, but are not useful for the diagnosis of early phase of overt-DIC (pre-DIC). Therefore, in the current study the non-overt DIC diagnostic criteria were modified using the global coagulation tests, the change rate in the global coagulation tests and molecular hemostatic markers to detect the pre-DIC state and were prospectively evaluated in 613 patients with underlying DIC disease. The frequencies of patients with DIC (DIC positive), late onset DIC, and without DIC (DIC absent) were 29.5%, 7.2%, and 63.3%, respectively. The modified non-overt-DIC criteria can correctly predict 43/44 patients (97.7%) who were DIC absent at admission and became DIC positive, within a week (late onset DIC state). The mortality rate was higher in DIC positive compared with pre-DIC (37.6% vs. 22.7%, P < 0.05) or DIC negative (37.6 vs. 13.7%, P < 0.01). It was also significantly higher in pre-DIC compared with DIC negative (P < 0.05). Thus, these modified non-overt DIC diagnostic criteria might therefore be useful for the diagnosis of early-phase DIC.

Appropriate use of D-dimer in hospital patients

D-dimer, the final product of plasmin-mediated degradation of fibrin-rich thrombi, has emerged as a simple blood test that can be used in diagnostic algorithms for the exclusion of venous thromboembolism. D-dimer also is used as a part of the diagnostic tests for disseminated intravascular coagulation, where excessive thrombin generation is the key pathophysiological factor. However, there are no robust data available at present on the use of this test to exclude venous thromboembolism in a hospital inpatient. Considerable confusion also exists among physicians about its appropriate use and interpretation in disseminated intravascular coagulation. This article focuses on the available evidence to guide the appropriate use of D-dimer in patients admitted to a hospital.

Microparticle-associated endothelial protein C receptor and the induction of cytoprotective and anti-inflammatory effects

BACKGROUND

The endothelial protein C receptor plays an important role within the protein C pathway in regulating coagulation and inflammation. Recently, we described that endothelial protein C receptor can be released in vitro in microparticulate form from primary endothelial cells by exogenous activated protein C. Activated protein C bound to this endothelial protein C receptor retains anticoagulant activity and we hypothesize that this microparticulate endothelial protein C receptor-activated protein C complex can also cleave endothelial protease-activated receptor 1 to modulate inflammation and increase cell survival. Our main objective was, therefore, to study the effect that microparticle-associated endothelial protein C receptor-activated protein C has on endothelial function.

DESIGN AND METHODS

Mini-arrays were used and probed with cDNA obtained from endothelial cells after treatment with microparticle-associated endothelial protein C receptor-activated protein C and results were confirmed by real time polymerase chain reaction. The functional relevance of changes at gene level were further analyzed by endothelial apoptosis and permeability assays, in the presence and absence of specific blockade of endothelial protein C receptor, protein C and protease-activated receptor 1.

RESULTS

Gene profiling of endothelial cells stimulated by 40 nmol/L activated protein C on microparticles showed significant changes in anti-apoptotic and inflammatory pathways. This was accompanied by protease-activated receptor 1-dependent anti-apoptotic and barrier protective effects, the latter of which also involved sphingosine 1-phosphate receptor and vascular endothelial growth factor receptor-2/ kinase insert domain receptor. Protein C blockade reversed these effects showing specificity for activated protein C on microparticles. Furthermore, confocal microscopy and enzyme-linked immunosorbent assay of plasma obtained from septic patients during recombinant activated protein C treatment showed evidence of their presence in vivo.

CONCLUSIONS

Activated protein C on microparticle-associated endothelial protein C receptor release can induce protease-activated receptor 1-dependent endothelial effects. The mechanisms underlying barrier protection involve sphingosine 1-phosphate receptor and kinase insert domain receptor.

New approaches for measuring coagulation

Although specific assays of coagulation factors are essential for diagnostic purposes they only give partial information about an individual's haemostatic state. This can be better assessed by various global tests, and recent developments and evaluations of five such tests are described in this symposium: the PFA-100; waveform analysis; thrombin generation; overall haemostasis potential; thrombelastography. Each test has advantages in various applications, but the thrombin generation test and waveform analysis have been found most useful in haemophilia, whilst the PFA-100 is helpful in von Willebrand's disease.

Autocrine VEGF mediates the antiapoptotic effect of CD154 on CLL cells

CD154 is an important regulator of chronic lymphocytic leukaemia (CLL)-cell survival. In CLL, high serum levels of VEGF are a feature of advanced disease, and we and others have previously shown that CLL cells produce and secrete this growth factor. Since CD154 stimulates VEGF production in other cell types, and VEGF is known to promote cell survival, we examined whether the cytoprotection of CLL cells by CD154 involves VEGF. We report for the first time that treatment of CLL cells with CD154 results in increased VEGF production and demonstrate involvement of NF-kappaB in this process. Moreover, we show that CD154-induced CLL-cell survival is reduced by anti-VEGF-neutralising antibody and by inhibiting VEGF receptor (VEGFR) signalling with SU5416. However, addition of exogenous VEGF alone or blocking secreted autocrine VEGF had little or no effect on CLL-cell survival. We therefore conclude that CLL-cell cytoprotection in the presence of CD154 requires combined signalling by both CD40 and VEGFR. This combined signalling and resulting cytoprotection were shown to involve NF-kappaB activation and increased survivin production. In conclusion, our findings identify autocrine VEGF as an important mediator of the antiapoptotic effect of CD40 ligation, and thus provide new insights into CLL-cell rescue by CD154 in lymphoreticular tissues.

Performance and prognostic importance of a new clinical and laboratory scoring system for identifying non-overt disseminated intravascular coagulation

A template for diagnosing the non-overt phase of disseminated intravascular coagulation (DIC) has recently been proposed. However, validation of its performance and the proposal of a defining score are required. The aim was to assess feasibility of the non-overt DIC scoring template and its potential prognostic significance. Consecutive patients admitted to a university hospital intensive care unit were initially assessed over 2 months. Following this, a 12-month study examined the prognostic performance of the derived scores prospectively. Outcome parameters were overt DIC and 28-day mortality. The 2-month study, involving 66 patients and 919 time points, demonstrated practical feasibility and prognostic associations for mortality with scores of 5 and greater. The 12-month study involving 450 patients showed that the mortality rate was 29% (105 of 360) and 78% (70 of 90) for scores below 5 and scores of 5 or above, respectively. The mortality rate for overt DIC was also 78% (38 of 49). The non-overt DIC scoring template is workable and has prognostic relevance. A score of 5 and greater is recommended as diagnostic of non-overt DIC.

Combined hepatocellular-cholangiocarcinoma: a case report

Combined hepatocellular-cholangiocarcinoma (HCC-CC) is a rare primary liver tumour. We report a carrier of both HBV and HCV presenting with intermittent abdominal pain, fever, chillness and elevated á-fetoprotein (AFP) of 1197 ng/ml. Computed tomography showed an irregular hypodense mass in the left lateral segment of the liver with vague contrast enhancement and multiple regional lymphadenopathy. Hepatic angiogram showed that the mass was hypovascular and the left portal vein was occluded with a tapered end. Percutaneous ultrasound-guided core needle biopsy of the liver yielded HCC-CC. We suggest that HCC-CC should be considered in hypovascular liver tumours with striking elevation of serum AFP and multiple regional lymphadenopathy.

Activated protein C induces the release of microparticle-associated endothelial protein C receptor

Activated protein C (APC) treatment is now used for patients with severe sepsis. We investigated its effect in vitro on primary, physiologically relevant cells and demonstrate a novel mechanism of endothelial protein C receptor (EPCR) release that is not inhibited by metalloproteinase inhibitors. Exposure of human umbilical vein endothelial cells or monocytes to APC (6.25-100 nM) results in the release of EPCR-containing microparticles, as demonstrated by confocal microscopy and characterized through flow cytometry, enzyme-linked immunosorbent assay quantitation of isolated microparticles, and Western blotting. The phenomenon is time- and concentration-dependent and requires the APC active site, EPCR, and protease activated receptor 1 (PAR1) on endothelial cells. Neither protein C nor boiled or D-Phe-Pro-Arg-chloromethylketone-blocked APC can induce microparticle formation and antibody blockade of EPCR or PAR1 cleavage and activation abrogates this APC action. Coincubation with hirudin does not alter the APC effect. The released microparticle bound is full-length EPCR (49 kDa) and APC retains factor V-inactivating activity. Although tumor necrosis factor-alpha (10 ng/mL) can also induce microparticle-associated EPCR release to a similar extent as APC (100 nM), it is only APC-induced microparticles that contain bound APC. This novel observation could provide new insights into the consequences of APC therapy in the septic patient.

Temporal changes in factors associated with neutrophil elastase and coagulation in intensive care patients with a biphasic waveform and disseminated intravascular coagulation

Summary. The biphasic waveform is an early marker of disseminated intravascular coagulation (DIC). Neutrophil elastase (NE) cleaves coagulation factors; thus, elevated elastase levels or its dysregulation by alpha-1-protease inhibitor (Alpha1PI) may be linked to DIC. Time courses over a period were determined for factors associated with NE and coagulation in 14 Intensive Care Unit patients with a biphasic waveform who developed DIC. The data were analyzed using a random coefficient linear regression model to predict the variables' mean values on day 0 and their mean rates of change over the period in which the biphasic waveform appeared. The biphasic waveform was normal on day 0, maximized on day 1, and approached normal again by day 4. Alpha1PI/NE complex levels were 2.5-fold greater than normal for the entire period. The A1PI activity, antigen, and specific activity levels were normal on day 0 and increased thereafter by 21.0, 10.5, and 8.9% of normal per day, respectively. Factor II, V, VII, IX, and X activity levels were, respectively, 57, 46, 46, 77, and 46% of normal on day 0, whereas factor VIII and fibrinogen levels were normal. All coagulation factor levels trended upward with time but not significantly. The prothrombin time, but not the activated partial thromboplastin time, was prolonged, and the platelet counts and hematocrits were below normal on day 0 and remained so thereafter. We conclude that events associated with neutrophil activation, elastase release, and perturbations of coagulation precede both the appearance of the biphasic waveform and the diagnosis of DIC in these patients.

Characterization of thrombin activatable fibrinolysis inhibitor in normal and acquired haemostatic dysfunction

Thrombin activatable fibrinolysis inhibitor (TAFI) is a carboxypeptidase B-like proenzyme, which is synthesized in the liver and circulates in the blood at a concentration of about 275 nmol/l. Once activated, by thrombin or plasmin, TAFI down regulates fibrinolysis, slowing clot lysis by cleaving the C-terminal lysine and arginine residues from partially degraded fibrin. Thrombomodulin enhances thrombin activation of TAFI by more than 1000-fold, suggesting that the thrombin-thrombomodulin complex is the physiological activator of TAFI. Activated protein C can up-regulate fibrinolysis by limiting the activation of TAFI via the attenuation of thrombin production. While impairment of fibrinolysis may predispose to thrombosis, excessive fibrinolysis may result in a bleeding tendency. In acquired coagulopathies, TAFI antigen levels are reduced in patients with disseminated intravascular coagulation. In focusing on women with major post-partum haemorrhage requiring blood transfusion, a significant reduction in TAFI levels is observed. The precise degree of TAFI activation is currently being characterized using new and more specific assays. The resulting data may provide insight into therapeutic options to treat post-partum haemorrhage, which is associated with significant morbidity.

Disseminated intravascular coagulation: old disease, new hope

Disseminated intravascular coagulation has long been associated with increased mortality in patients with sepsis. An effective treatment is now available, and the authors of this review describe how improved understanding and earlier diagnosis could lead to targeted treatment and improved prognosis

A longitudinal study of maternal dose response to low molecular weight heparin in pregnancy

OBJECTIVE

To assess the maternal response to low molecular weight heparin during pregnancy, by estimation of plasma anti-Xa activity, at three specified gestation points and in the nonpregnant state.

METHODS

A longitudinal, prospective, observational study was set in a tertiary referral recurrent miscarriage clinic. Twenty-four women, attending consecutively, were invited to participate and gave informed consent. Each woman had a history of recurring pregnancy loss and positive preconception screening for antiphospholipid syndrome. After confirmation of a viable pregnancy all subjects began taking 5000 IU of dalteparin once daily subcutaneously. Serial measurement of plasma anti-Xa activity after administration of dalteparin was performed at three standard gestation points (12, 24, and 36 weeks) and in the nonpregnant state (6 weeks postpartum).

RESULTS

Peak anti-Xa levels occurred at 4 hours postbolus in pregnancy, as compared with 2 hours in the nonpregnant state. The mean anti-Xa levels at 12, 24, and 36 weeks' gestation were significantly reduced, at 2 hours postinjection, as compared with the nonpregnant state (P <.001, P <.01, P <.001, respectively). The lowest dose-response curve was at 36 weeks' gestation. A repeated-measures analysis of variance found a significant difference (P <.05) between the 36-week group and the postterm group but not between any of the other groups.

CONCLUSION

During pregnancy, differences in the pharmacokinetics of low molecular weight heparin were observed, with an overall reduction in anti-Xa activity. On the basis of this study it is questionable to extrapolate dosing and lack of dose monitoring, in pregnant women, using data derived from a nonpregnant population.

Current clinical practice. DIC 2002: a review of disseminated intravascular coagulation

The turn of the millennium has seen clear advances in the understanding and management of Disseminated Intravascular Coagulation (DIC). The recognition that its pathogenesis stems from sustained thrombin generation in fuelling the cycle between inflammation and coagulation has seen the first successful treatment in severe sepsis through targeting this activity. An advance in treatment brings heightened relevance to laboratory testing, which now emphasises earlier detection and better monitoring to facilitate improved risk-identification and assessment of therapeutic efficacy. This review article also provides insights into future strategies that might build on the foundation of improving prognosis for the patient with DIC.