Serological testing for SARS-CoV-2 antibodies in clinical practice: A comparative diagnostic accuracy study.

BACKGROUND: Serological tests are a powerful tool in the monitoring of infectious diseases and the detection of host immunity. However, manufacturers often provide diagnostic accuracy data generated through biased studies, and the performance in clinical practice is essentially unclear. OBJECTIVES: We aimed to determine the diagnostic accuracy of various serological testing strategies for (a) identification of patients with previous coronavirus disease-2019 (COVID-19) and (b) prediction of neutralizing antibodies against SARS-CoV-2 in real-life clinical settings. METHODS: We prospectively included 2573 consecutive health-care workers and 1085 inpatients with suspected or possible previous COVID-19 at a Swiss University Hospital. Various serological immunoassays based on different analytical techniques (enzyme-linked immunosorbent assays, ELISA; chemiluminescence immunoassay, CLIA; electrochemiluminescence immunoassay, ECLIA; and lateral flow immunoassay, LFI), epitopes of SARS-CoV-2 (nucleocapsid, N; receptor-binding domain, RBD; extended RBD, RBD+; S1 or S2 domain of the spike [S] protein, S1/S2), and antibody subtypes (IgG, pan-Ig) were conducted. A positive real-time PCR test from a nasopharyngeal swab was defined as previous COVID-19. Neutralization assays with live SARS-CoV-2 were performed in a subgroup of patients to assess neutralization activity (n = 201). RESULTS: The sensitivity to detect patients with previous COVID-19 was ≥85% in anti-N ECLIA (86.8%) and anti-S1 ELISA (86.2%). Sensitivity was 84.7% in anti-S1/S2 CLIA, 84.0% in anti-RBD+LFI, 81.0% in anti-N CLIA, 79.2% in anti-RBD ELISA, and 65.6% in anti-N ELISA. The specificity was 98.4% in anti-N ECLIA, 98.3% in anti-N CLIA, 98.2% in anti-S1 ELISA, 97.7% in anti-N ELISA, 97.6% in anti-S1/S2 CLIA, 97.2% in anti-RBD ELISA, and 96.1% in anti-RBD+LFI. The sensitivity to detect neutralizing antibodies was ≥85% in anti-S1 ELISA (92.7%), anti-N ECLIA (91.7%), anti-S1/S2 CLIA (90.3%), anti-RBD+LFI (87.9%), and anti-RBD ELISA (85.8%). Sensitivity was 84.1% in anti-N CLIA and 66.2% in anti-N ELISA. The specificity was ≥97% in anti-N CLIA (100%), anti-S1/S2 CLIA (97.7%), and anti-RBD+LFI (97.9%). Specificity was 95.9% in anti-RBD ELISA, 93.0% in anti-N ECLIA, 92% in anti-S1 ELISA, and 65.3% in anti-N ELISA. Diagnostic accuracy measures were consistent among subgroups. CONCLUSIONS: The diagnostic accuracy of serological tests for SARS-CoV-2 antibodies varied remarkably in clinical practice, and the sensitivity to identify patients with previous COVID-19 deviated substantially from the manufacturer's specifications. The data presented here should be considered when using such tests to estimate the infection burden within a specific population and determine the likelihood of protection against re-infection.

Accuracy of serological testing for SARS-CoV-2 antibodies: First results of a large mixed-method evaluation study.

BACKGROUND: Serological immunoassays that can identify protective immunity against SARS-CoV-2 are needed to adapt quarantine measures, assess vaccination responses, and evaluate donor plasma. To date, however, the utility of such immunoassays remains unclear. In a mixed-design evaluation study, we compared the diagnostic accuracy of serological immunoassays that are based on various SARS-CoV-2 proteins and assessed the neutralizing activity of antibodies in patient sera. METHODS: Consecutive patients admitted with confirmed SARS-CoV-2 infection were prospectively followed alongside medical staff and biobank samples from winter 2018/2019. An in-house enzyme-linked immunosorbent assay utilizing recombinant receptor-binding domain (RBD) of the SARS-CoV-2 spike protein was developed and compared to three commercially available enzyme-linked immunosorbent assays (ELISAs) targeting the nucleoprotein (N), the S1 domain of the spike protein (S1), and a lateral flow immunoassay (LFI) based on full-length spike protein. Neutralization assays with live SARS-CoV-2 were performed. RESULTS: One thousand four hundred and seventy-seven individuals were included comprising 112 SARS-CoV-2 positives (defined as a positive real-time PCR result; prevalence 7.6%). IgG seroconversion occurred between day 0 and day 21. While the ELISAs showed sensitivities of 88.4% for RBD, 89.3% for S1, and 72.9% for N protein, the specificity was above 94% for all tests. Out of 54 SARS-CoV-2 positive individuals, 96.3% showed full neutralization of live SARS-CoV-2 at serum dilutions ≥ 1:16, while none of the 6 SARS-CoV-2-negative sera revealed neutralizing activity. CONCLUSIONS: ELISAs targeting RBD and S1 protein of SARS-CoV-2 are promising immunoassays which shall be further evaluated in studies verifying diagnostic accuracy and protective immunity against SARS-CoV-2.

Changepoint analysis of gestational age and birth weight: proposing a refinement of Diagnosis Related Groups.

BACKGROUND: Although the complexity and length of treatment is connected to the newborn's maturity and birth weight, most case-mix grouping schemes classify newborns by birth weight alone. The objective of this study was to determine whether the definition of thresholds based on a changepoint analysis of variability of birth weight and gestational age contributes to a more homogenous classification. METHODS: This retrospective observational study was conducted at a Tertiary Care Center with Level III Neonatal Intensive Care and included neonate cases from 2016 through 2018. The institutional database of routinely collected health data was used. The design of this cohort study was explorative. The cases were categorized according to WHO gestational age classes and SwissDRG birth weight classes. A changepoint analysis was conducted. Cut-off values were determined. RESULTS: When grouping the cases according to the calculated changepoints, the variability within the groups with regard to case related costs could be reduced. A refined grouping was achieved especially with cases of >2500 g birth weight. An adjusted Grouping Grid for practical purposes was developed. CONCLUSIONS: A novel method of classification of newborn cases by changepoint analysis was developed, providing the possibility to assign costs or outcome indicators to grouping mechanisms by gestational age and birth weight combined.

The links of hepcidin and erythropoietin in the interplay of inflammation and iron deficiency in a large observational study of rheumatoid arthritis.

Anaemia affects quality of life and radiographic outcome in rheumatoid arthritis (RA). In a cross-sectional study with 779 patients, we assessed the prognostic potential of the major haematopoietic regulators, hepcidin and erythropoietin, comparing their serum concentrations with respect to different anaemia types, inflammatory activity, anti-cytokine-specific treatment effects and iron deficiency (ID) indices. The results showed that clinical disease activity was more closely associated with haemoglobin levels than with anti-tumour necrosis factor-alpha or interleukin 6 receptor effects. In ID, hepcidin was suppressed, independently of inflammation. Erythropoietin levels were inappropriately low in relation to the degree of anaemia, but, in contrast to low haemoglobin, not directly associated with joint damage progression. Hepcidin and erythropoietin levels are intimately connected with inflammation and ID. Interventional studies on these important targets are already in progress.

Targeted and global pharmacometabolomics in everolimus-based immunosuppression: association of co-medication and lysophosphatidylcholines with dose requirement.

INTRODUCTION: The immunosuppressive therapy with everolimus (ERL) after heart transplantation is characterized by a narrow therapeutic window and a substantial variability in dose requirement. Factors explaining this variability are largely unknown. OBJECTIVES: Our aim was to evaluate factors affecting ERL metabolism and to identify novel metabolites associated with the individual ERL dose requirement to elucidate mechanisms underlying ERL dose response variability. METHOD: We used liquid chromatography coupled with mass spectrometry for quantification of ERL metabolites in 41 heart transplant patients and evaluated the effect of clinical and genetic factors on ERL pharmacokinetics. Non-targeted plasma metabolic profiling by ultra-performance liquid chromatography and high resolution quadrupole-time-of-flight mass spectrometry was used to identify novel metabolites associated with ERL dose requirement. RESULTS: The determination of ERL metabolites revealed differences in metabolite patterns that were independent from clinical or genetic factors. Whereas higher ERL dose requirement was associated with co-administration of sodium-mycophenolic acid and the CYP3A5 expressor genotype, lower dose was required for patients receiving vitamin K antagonists. Global metabolic profiling revealed several novel metabolites associated with ERL dose requirement. One of them was identified as lysophosphatidylcholine (lysoPC) (16:0/0:0). Subsequent targeted analysis revealed that high levels of several lysoPCs were significantly associated with higher ERL dose requirement. CONCLUSION: For the first time, this study describes distinct ERL metabolite patterns in heart transplant patients and detected potentially new drug-drug interactions. The global metabolic profiling facilitated the discovery of novel metabolites associated with ERL dose requirement that might represent new clinically valuable biomarkers to guide ERL therapy.

ATG12 deficiency leads to tumor cell oncosis owing to diminished mitochondrial biogenesis and reduced cellular bioenergetics.

In contrast to the "Warburg effect" or aerobic glycolysis earlier generalized as a phenomenon in cancer cells, more and more recent evidence indicates that functional mitochondria are pivotal for ensuring the energy supply of cancer cells. Here, we report that cancer cells with reduced autophagy-related protein 12 (ATG12) expression undergo an oncotic cell death, a phenotype distinct from that seen in ATG5-deficient cells described before. In addition, using untargeted metabolomics with ATG12-deficient cancer cells, we observed a global reduction in cellular bioenergetic pathways, such as ß-oxidation (FAO), glycolysis, and tricarboxylic acid cycle activity, as well as a decrease in mitochondrial respiration as monitored with Seahorse experiments. Analyzing the biogenesis of mitochondria by quantifying mitochondrial DNA content together with several mitochondrion-localizing proteins indicated a reduction in mitochondrial biogenesis in ATG12-deficient cancer cells, which also showed reduced hexokinase II expression and the upregulation of uncoupling protein 2. ATG12, which we observed in normal cells to be partially localized in mitochondria, is upregulated in multiple types of solid tumors in comparison with normal tissues. Strikingly, mouse xenografts of ATG12-deficient cells grew significantly slower as compared with vector control cells. Collectively, our work has revealed a previously unreported role for ATG12 in regulating mitochondrial biogenesis and cellular energy metabolism and points up an essential role for mitochondria as a failsafe mechanism in the growth and survival of glycolysis-dependent cancer cells. Inducing oncosis by imposing an ATG12 deficiency in solid tumors might represent an anticancer therapy preferable to conventional caspase-dependent apoptosis that often leads to undesirable consequences, such as incomplete cancer cell killing and a silencing of the host immune system.

Development of a stable closed femoral fracture model in mice.

BACKGROUND: Mice have become of increasing interest as experimental model for fracture studies. Due to their small size, most studies use simple pins for fracture stabilization, although insufficient rigidity of fixation critically affects fracture healing. Herein, we studied whether longitudinal fracture compression by an intramedullary screw represents a standardized, stable osteosynthesis technique in mice, and whether it may accelerate fracture healing. MATERIALS AND METHODS: A micro-screw (MouseScrew) was constructed, allowing closed fracture stabilization without traumatizing surgery. Fracture stabilization was achieved by longitudinal compression, which was confirmed by biomechanical testing of osteotomized cadaver femora. Bone repair was analyzed histomorphometrically at 2 and 5 wk after surgery. RESULTS: Ex vivo analyses showed a significantly increased rotational and axial stiffness after screw stabilization (n = 8 each) compared with stabilization techniques using a conventional pin (n = 8 each) or a locking nail (n = 8 each). In the in vivo setting, 2 wk of screw stabilization (n = 8) demonstrated a significantly decreased fibrous tissue formation and an increased cartilage production compared with fractures stabilized by the locking nail (n = 8). After 5 wk callus consisted exclusively of bone in all animals studied without differences between the two stabilization techniques (n = 8 each). CONCLUSIONS: Because prolonged fibrous tissue formation indicates delayed fracture healing, we conclude that the increased stability of the fracture by the use of our newly developed MouseScrew accelerates initial bone repair. Further, this fracture model may represent an ideal tool to study bone repair in mice under conditions of stable fixation.

Rapid Centrifugation in the Routine Hemostasis Laboratory.

BACKGROUND: The use of short and uniform centrifugation schemes contributes significantly to the successful automation of laboratory procedures. It is however unclear if this is applicable to the hemostasis laboratory. OBJECTIVES: This article assesses the accuracy of measurements obtained with a rapid, high-speed centrifugation scheme in a large set of hemostasis tests, covering the full spectrum of values obtained in clinical practice, and using meaningful statistical measures. METHODS: Two citrated plasma samples were obtained from consecutive patients of a tertiary hospital with suspected abnormal hemostasis tests and processed with two centrifugation schemes in parallel: 1,500 × g for 10 minutes and 3,137 × g for 7 minutes. The following tests were conducted: prothrombin time (n = 125), international normalized ratio (n = 146), activated partial thromboplastin time (n = 119), thrombin time (n = 105), fibrinogen (n = 125), factor (F)II (n = 69), FV (n = 64), FVII (n = 64), FX (n = 67), FVIII (n = 55), FIX (n = 37), FXI (n = 35), and FXIII (n = 20), D-dimer (n = 34), antithrombin (n = 31), anti-Xa activity (n = 30), von Willebrand antigen (n = 25), and von Willebrand activity (VWF:GPIbM; n = 27). RESULTS: A wide range of results were obtained in all tests. Spearman's rank correlation coefficient was at least 0.95 for all tests except FV, FIX, and FXI. The coverage probability π at a given deviation index κ of 15% was above 0.9 for all tests except FV, FVII, FX, FVIII, FIX, FXI, and VWF:GPIbM, suggesting a lack of agreement. CONCLUSION: Our results suggest that high-speed centrifugation is applicable to the majority of routine hemostasis parameters. The coverage probability was more sensitive than Spearman's rank correlation to detect disagreement among centrifugation schemes.

Genetic alterations crossing the borders of distinct hematopoetic lineages and solid tumors: Diagnostic challenges in the era of high-throughput sequencing in hemato-oncology.

Owing to the introduction of next-generation sequencing (NGS) new challenges for diagnostic algorithms and the interpretation of the results for therapeutic decision making in hemato-oncology have arisen. Recurrent somatic mutations crossing the borders between different hematological entities and solid neoplasms have been detected. In analogy to mutant TP53, the same mutation type may occur in myeloid, B- or T-lymphatic malignancies or solid neoplasms. At the same time, a certain mutation can show different prognostic outcomes in different entities and co-existence of certain mutations may change the prognostic relevance. These insights may spark the investigation of targeted therapies with the same substances across different disease entities. This review article summarizes mutations that can emerge in different hematologic and solid malignancies and summarizes other obstacles in the era of modern molecular diagnostics, such as the phenomenon of "clonal hematopoiesis of indeterminate potential" being difficult to interpret in the individual patient.

Current status and trends in the diagnostics of AML and MDS.

Diagnostics of acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) have recently been experiencing extensive modifications regarding the incorporation of next-generation sequencing (NGS) strategies into established diagnostic algorithms, classification and risk stratification systems, and minimal residual disease (MRD) detection. Considering the increasing arsenal of targeted therapies (e.g. FLT3 or IDH1/IDH2 inhibitors) for AML, timely and comprehensive molecular mutation screening has arrived in daily practice. Next-generation flow strategies allow for immunophenotypic minimal residual disease (MRD) monitoring with very high sensitivity. At the same time, standard diagnostic tools such as cytomorphology or conventional cytogenetics remain cornerstones for the diagnostic workup of myeloid malignancies. Herein, we summarize the most recent advances and new trends for the diagnostics of AML and MDS, discuss the difficulties, which accompany the integration of these new methods and their results into daily routine, and aim to define the role hemato-oncologists may play in this new diagnostic era.

Challenges in the introduction of next-generation sequencing (NGS) for diagnostics of myeloid malignancies into clinical routine use.

Given the vast phenotypic and genetic heterogeneity of acute and chronic myeloid malignancies, hematologists have eagerly awaited the introduction of next-generation sequencing (NGS) into the routine diagnostic armamentarium to enable a more differentiated disease classification, risk stratification, and improved therapeutic decisions. At present, an increasing number of hematologic laboratories are in the process of integrating NGS procedures into the diagnostic algorithms of patients with acute myeloid leukemia (AML), myelodysplastic syndromes (MDS), and myeloproliferative neoplasms (MPNs). Inevitably accompanying such developments, physicians and molecular biologists are facing unexpected challenges regarding the interpretation and implementation of molecular genetic results derived from NGS in myeloid malignancies. This article summarizes typical challenges that may arise in the context of NGS-based analyses at diagnosis and during follow-up of myeloid malignancies.

The effect of a previous created distal arteriovenous-fistula on radial bone DXA measurements in prevalent renal transplant recipients.

BACKGROUND: Accelerated bone loss occurs rapidly following renal transplantation due to intensive immunosuppression and persistent hyperparathyroidism. In renal transplant recipients (RTRs) due to the hyperparathyroidism the non-dominant forearm is often utilized as a peripheral measurement site for dual-energy x-ray absorptiometry (DXA) measurements. The forearm is also the site of previous created distal arteriovenous fistulas (AVF). Although AVF remain patent long after successful transplantation, there are no data available concerning their impact on radial bone DXA measurements. METHODS: In this cross-sectional study we performed DXA in 40 RTRs with preexisting distal AVF (RTRs-AVF) to assess areal bone mineral density (aBMD) differences between both forearms (three areas) and compared our findings to patients with chronic kidney disease (CKD, n = 40), pre-emptive RTRs (RTRs-pre, n = 15) and healthy volunteers (n = 20). In addition, we assessed relevant demographic, biochemical and clinical aspects. RESULTS: We found a marked radial asymmetry between the forearms in RTRs with preexisting AVF. The radial aBMD at the distal AVF forearm was lower compared to the contralateral forearm, resulting in significant differences for all three areas analyzed: the Rad-1/3: median (interquartile range) in g/cm2, Rad-1/3: 0.760 (0.641-0.804) vs. 0.742 (0.642, 0.794), p = 0.016; ultradistal radius, Rad-UD: 0.433 (0.392-0.507) vs. 0.420 (0.356, 0.475), p = 0.004; and total radius, Rad-total: 0.603 (0.518, 0.655) vs. 0.599 (0.504, 0.642), p = 0.001). No such asymmetries were observed in any other groups. Lower aBMD in AVF forearm subregions resulted in misclassification of osteoporosis. CONCLUSIONS: In renal transplant recipients, a previously created distal fistula may exert a negative impact on the radial bone leading to significant site-to-site aBMD differences, which can result in diagnostic misclassifications.

Attenuation of proinflammatory gene expression and microcirculatory disturbances by endothelin A receptor blockade after orthotopic liver transplantation in pigs.

BACKGROUND: Endothelin-1 (ET-1), a very potent mediator of vasoconstriction, leads to microcirculatory disturbances and release of proinflammatory cytokines under pathophysiologic conditions. Our aim was to evaluate the effect of a selective ET(A)-receptor antagonist (ET(A)-RA) on cold ischemia/reperfusion (I/R) injury in a pig model. METHODS: Twenty pigs revealed orthotopic liver transplantation. The animals were randomized into 2 groups: control pigs received isotonic saline; the treated group received the selective ET(A)-RA BSF 208075 at the beginning of reperfusion. On postoperative days 4 and 7, animals were re-laparotomized to obtain tissue specimens. Liver tissue samples were collected and quantitative mRNA expression for prepro-ET-1, ET(A) receptor, pro-IL-1beta, pro-IL-6, pro-TNF-alpha, and endothelial nitric oxide synthase was analyzed using the TaqMan system. Additionally, immunohistochemical analysis for ET-1 was performed. Hepatic microcirculation was evaluated by laser Doppler flow measurement and partial pressure of oxygen and carbon dioxide measurements with the Paratrend sensor. Postischemic liver damage was monitored by measurement of liver enzymes and by histologic analysis using a semiquantitative scoring classification. RESULTS: Treatment with the ET(A)-RA significantly reduced the severity of I/R injury evidenced by lower serum AST, ALT and GLDH. Analysis of partial pressure of oxygen and blood flow revealed a significant improvement of capillary perfusion and blood flow in the treated group and was associated with a relevant reduction of tissue injury. One hour after reperfusion, quantitative RT-PCR revealed significantly lower expression of prepro-ET-1, ET(A) receptor, endothelial nitric oxide synthase, pro-TNF-alpha, pro-IL-1beta and pro-IL-6 in the therapy group. Immunohistochemical analysis demonstrated significantly reduced ET-1 immunostaining after therapy. Histologic investigation suggested less tissue damage in treated animals. CONCLUSIONS: Treatment with the selective ET(A)-RA BSF 208075 has protective effects on microcirculation after liver transplantation. ET(A)-RA not only affects the expression of vasoactive genes, but also decreases gene expression of proinflammatory cytokines such as TNF-alpha, IL-1beta and IL-6.

Affects of immunosuppression on circulating dendritic cells: an adjunct to therapeutic drug monitoring after heart transplantation.

OBJECTIVES: Recent evidence emerges dendritic cells (DCs) as pharmacological targets of immunosuppressive drugs. Therefore, in this study we monitored DCs in peripheral blood to compare the effects of calcineurin inhibitors (CNI: cyclosporine, tacrolimus) and mammalian target of rapamycin inhibitors (sirolimus, SRL, everolimus, ERL) basis-immunosuppressive therapies in human heart transplanted (HTx) recipients. METHODS: We compared HTx recipients which were converted from either CNI to ERL (severe renal dysfunction, n=8), or from SRL to ERL (approval of ERL for HTx, n=8) with 20 healthy human controls. Twenty four after the last CNI or SRL dose recipients were treated with ERL/BID on days 1-3. Peripheral blood was collected at trough in the morning before and on day 4 after conversion. Percentages of positive myeloid and plasmacytoid DC (m and pDC) subsets in peripheral blood were analysed by flow cytometry. The status of maturation was further characterised by flow cytometry analysis of % expression of CD83 and % expression of various intracellular cytokines (IL-1beta, TNF-alpha, IL-8, IL-12), respectively. RESULTS: HTx recipients had higher % positive mDCs regardless the immunosuppressive therapy compared to controls (p<0.05). Whereas, % positive pDCs were only significantly lower in recipients converted from CNI to ERL compared to controls (p<0.05). The data consolidate the finding that the subset ratio pDCs/mDCs was lower in recipients compared to controls. But after conversion from CNI or SRL to ERL the ratio increased towards pDCs. Percentages of expression of CD83 on mDCs were not different among the recipient groups and controls. Recipients with CNI and SRL had higher % expression of IL-12 and lower % expression of IL-1beta compared to controls (p<0.05). However, after conversion to ERL % expression of both IL-12 and IL-1beta returned to control values in both groups. CONCLUSIONS: The results showed that analysis of immunosuppression of circulating DCs in peripheral blood may be an adjunct to therapeutic drug monitoring to optimize immunosuppressive therapy after HTx.

Differential effects of selective cyclooxygenase-2 inhibitors on endothelial function in salt-induced hypertension.

BACKGROUND: In view of the ongoing controversy about potential differences in cardiovascular safety of selective cyclooxygenase (COX)-2 inhibitors (coxibs), we compared the effects of 2 different coxibs and a traditional NSAID on endothelial dysfunction, a well-established surrogate of cardiovascular disease, in salt-induced hypertension. METHODS AND RESULTS: Salt-sensitive (DS) and salt-resistant (DR) Dahl rats were fed a high-sodium diet (4% NaCl) for 56 days. From days 35 to 56, diclofenac (6 mg x kg(-1) x d(-1); DS-diclofenac), rofecoxib (2 mg x kg(-1) x d(-1); DS-rofecoxib), celecoxib (25 mg x kg(-1) x d(-1); DS-celecoxib) or placebo (DS-placebo) was added to the chow. Blood pressure increased with sodium diet in the DS groups, which was more pronounced after diclofenac and rofecoxib treatment (P<0.005 versus DS-placebo) but was slightly decreased by celecoxib (P<0.001 versus DS-placebo). Sodium diet markedly reduced NO-mediated endothelium-dependent relaxations to acetylcholine (10-10-10-5 mol/L) in aortic rings of untreated hypertensive rats (P<0.005 versus DR-placebo). Relaxation to acetylcholine improved after celecoxib (P<0.005 versus DS-placebo and DS-rofecoxib) but remained unchanged after rofecoxib and diclofenac treatment. Vasoconstriction after nitric oxide synthase inhibition, indicating basal NO release, with N(omega)-nitro-L-arginine methyl ester (10-4 mol/L) was blunted in DS rats (P<0.05 versus DR-placebo), normalized by celecoxib, but not affected by rofecoxib or diclofenac. Indicators of oxidative stress, 8-isoprostane levels, were elevated in untreated DS rats on 4% NaCl (6.55+/-0.58 versus 3.65+/-1.05 ng/mL, P<0.05) and normalized by celecoxib only (4.29+/-0.58 ng/mL). CONCLUSIONS: These data show that celecoxib but not rofecoxib or diclofenac improves endothelial dysfunction and reduces oxidative stress, thus pointing to differential effects of coxibs in salt-induced hypertension.

Correlation of exercise capacity with high-sensitive C-reactive protein in patients with stable coronary artery disease.

BACKGROUND: There is growing evidence for the association between physical activity and systemic inflammatory markers in healthy individuals and populations with a low prevalence of coronary artery disease (CAD). However, the association between fitness and CRP in patients with stable CAD treated with medications known to influence the inflammatory response, such as statins and aspirin, is not well known. METHODS: We prospectively enrolled 209 patients with angiographically documented CAD (161 men; age 63 +/- 10 years; 1-/2-/3-vessel disease in 42%, 34%, and 24% of patients, respectively; left ventricular ejection fraction 60% +/- 13%). Fitness level was assessed by maximal exercise testing. CRP was measured in all patients using high-sensitivity immunoassay. RESULTS: Fitness level was inversely correlated with natural log-transformed CRP level (r = -0.28, P < .001). After multivariate linear regression adjustment for age, sex, body mass index, waist circumference, smoking status, educational level, diabetes, hypertension, modality of exercise testing, exercise-induced ischemia, extent of CAD, medication use, leukocyte count, hemoglobin, renal function, glucose level, and cholesterol level, exercise capacity remained inversely correlated with CRP level (beta = -.226, P = .001). Other covariates associated with CRP remaining in the final model were leukocyte count (beta = .348), pack-years of smoking (beta = .185), diabetes status (beta = -.201), hemoglobin concentration (beta = -.187), and high-density lipoprotein cholesterol level (beta = -.149). CONCLUSIONS: These results indicate that exercise capacity is inversely correlated with CRP level in patients with known stable CAD irrespective of extent of CAD and standard medication for secondary prevention.

Endothelin A receptor blockade reduces hepatic ischemia/reperfusion injury after warm ischemia in a pig model.

It is well established that endothelin-1 (ET-1) is a very potent mediator of vasoconstriction that leads to microcirculatory disturbances. The aim of the study was to evaluate the effect of a selective endothelin A receptor antagonist on severe ischemia/reperfusion injury in a pig model. Fourteen pigs were subjected to 120 minutes of complete vascular exclusion of the liver with a passive bypass. The animals were randomized into two groups: a control group, which was given isotonic saline solution, and a therapy group, which received the selective endothelin A receptor antagonist BSF 208075 at the beginning of reperfusion. On postoperative days 4 and 7, animals were relaparotomized to obtain tissue specimens. Blood monitoring included aspartate aminotransferase (AST), alanine aminotransferase (ALT), glutamate dehydrogenase (GLDH), alkaline phosphatase, and ET-1. Partial oxygen tension (p(ti)O(2)) was measured by a Clarke-type electrode and blood flow by laser Doppler. A semiquantitative scoring index was used for assessment of histologic injury and for immunohistochemical analysis of ET-1. Treatment with the endothelin A receptor antagonist significantly reduced the severity of the ischemia/reperfusion injury, as evidenced by lower levels of AST, ALT, and GLDH. The dramatic increase in plasma ET-1 in the therapy group is clear evidence of effective receptor blockade. Analysis of p(ti)O(2) and blood flow revealed a significant improvement in capillary perfusion and blood flow in the treated group and was associated with relevant reduction of tissue injury. In summary, in the control group we observed serious microcirculatory disturbances and severe histologic damage in the liver after reperfusion. Treatment with a selective endothelin A receptor antagonist attenuated the ischemia/reperfusion injury in a porcine model of severe ischemia/reperfusion, as demonstrated by improved microcirculation, a reduction in histologic damage, and an decrease in liver enzymes.