Bowersmcdonald6045

Purpose Although many assays have been developed to detect anti-aquaporin-4 (AQP4) antibodies, most of these assays require sophisticated techniques and are thus only available at specialized laboratories. The aim of this study was to evaluate the analytical and clinical performance of a new commercial enzyme-linked immunosorbent assay (ELISA RSR, AQP4 Ab Version 2) to detect anti-AQP4 antibodies performed on a fully automated system (SkyLAB 752). Methods Serum samples from 64 patients with neuromyelitis optica spectrum disorders (NMOSD) (including NMO, longitudinally extensive myelitis-LETM, optical neuritis and myelitis) and 27 controls were tested for anti-AQP4 antibodies. All sera were previously tested using an indirect immunofluorescence (IIF) method on primate tissue, as the reference method. Commercial control sera were used to determine within-run, between-day and within-laboratory precision (CLSI guidelines). Results At a cut-off value of 2.1 U/mL as determined by ROC curves, sensitivity and specificity for NMO were 83.3% and 100%, respectively. The ELISA assay provided 100% concordant results with the reference IIF method. The median concentration of anti-AQP4 antibodies was statistically higher in patients with NMO than in patients with LETM (p = 0.0006) or with other NMOSD and in controls (p  less then  0.0001). At the concentration of 12.4 and 28.1 U/mL, the within-run, between-day and within-laboratory coefficients of variation (CV) were 3.2% and 3%, 7.6% and 7.4%, and 8.2% and 8.0%, respectively. Conclusions This new ELISA method performed on a fully automated system, showed high sensitivity and absolute specificity, good CV in precision tests, and provided observer-independent quantitative results. © The Author(s) 2019.Background Apart from endoscopic interventions, readily attainable cost-effective biomarkers for ulcerative colitis (UC) assessment are required. For this purpose, we evaluated differential leucocytic ratio, mainly neutrophil-lymphocyte ratio (NLR) and lymphocyte-monocyte ratio (LMR) as simple available indicators of disease activity in patients with ulcerative colitis. Methods Study conducted on 80 UC patients who were classified into two groups of 40 each according to Mayo score and colonoscopic findings. Group 1 (active UC) and group 2 (inactive UC). Another 40 group-matched healthy participants were enrolled. White blood cell count, NLR, LMR, C-reactive protein, and Erythrocyte sedimentation rate were measured and recorded. Results Significant elevation of NLR was observed in active UC group compared to inactive UC and controls (2.63 ± 0.43, 1.64 ± 0.25, 1.44 ± 0.19 respectively; p  1.91, with a sensitivity and a specificity of 90% and 90% respectively. The mean LMRs of active UC was significantly lower compared with inactive UC patients and controls (2.25 ± 0.51, 3.58 ± 0.76, 3.64 ± 0.49 respectively; p  less then  0.0001). The cut-off value of LMR for determining the disease activity was ≤ 2.88 with a sensitivity of 90% and a specificity of 90%. NLR, LMR, and CRP were found to be significant independent markers for discriminating disease activity (p = 0.000). Besides, NLR was significantly higher in patients with pancolitis and positively correlated with endoscopically severe disease. Conclusion NLRs and LMRs are simple non-invasive affordable independent markers of disease activity in UC. © The Author(s) 2019.Purpose The introduction of the anti-phosphatidylserine/prothrombin (aPS/PT) antibodies among the routinely investigated anti-phospholipid (aPL) antibodies led to an improvement in anti-phospholipid syndrome (APS) laboratory diagnostic performance; however, their pathogenic mechanism is still substantially undefined. To support clinical data and future inclusion as possible new criteria antibodies, we designed a head-to-head study to directly compare the procoagulant effects sustained in vitro by aPS/PT to those sustained by anti-β2-glycoprotein I (aβ2GpI) domain 1-specific antibodies. Methods Blood donors-derived monocytes and endothelial cells (HUVEC) were stimulated with lipopolysaccharides (LPS) alone or in combination with the IgG fractions isolated from the serum of six APS patients, positive only for aβ2GpI or for aPS/PT antibodies. As control, cells were incubated with LPS plus the IgG isolated from blood donors. Tissue factor (TF) mRNA expression was measured after four hours incubation by real-time PCR. Nitric oxide (NO) levels were measured in cells supernatant after 16 h incubation by colorimetric assay. Results aPS/PT and aβ2GpI IgG antibodies fractions showed comparable ability to enhance LPS-induced TF mRNA expression, either in monocytes and in HUVEC. Compared to LPS alone, we found that NO levels are strongly overproduced in HUVEC treated with LPS plus aβ2GpI and aPS/PT IgG fractions. Conclusions Our data support the significant and independent role of aPS/PT in the pathogenesis of the thrombotic events in APS patients, possibly adding new light to the therapeutic management of cases characterized by the sole presence of aPS/PT IgG antibodies. © The Author(s) 2019.Proximally located in the membrane, oncogenic Ras dimers (or nanoclusters) can recruit and promote Raf dimerization and MAPK (Raf/MEK/ERK) signaling. Among Ras isoforms, KRas4B is the most frequently mutated. Recent data on the binary KRas4B-Raf-1 complex suggested that Raf-1 CRD not only executes membrane anchorage, but also supports the high-affinity interaction of Raf-1 RBD with KRas4B catalytic domain. For a detailed mechanistic picture of Raf activation at the membrane, we employ explicit MD simulations of the quaternary KRas4B-Raf-1 complex. The complex contains two active GTP-bound KRas4B proteins forming a dimer through the allosteric lobe interface and two tandem RBD-CRD segments of Raf-1 interacting with the effector lobes at both ends of the KRas4B dimer. We show that Raf-1 RBD-CRD supports stable KRas4B dimer at preferred interface and orientation at the membrane, thereby cooperatively enhancing the affinity of the KRas4B-Raf-1 interaction. Afuresertib in vitro We propose that a Ras dimer at the membrane can increase the population of proximal Raf kinase domains, promoting kinase domain dimerization in the cytoplasm.