No abstract

BackgroundNon-invasive prenatal testing (NIPT) is a relatively new technology for diagnosis of fetal aneuploidies. NIPT is more accurate than conventional maternal serum screening (MSS) but is also more costly. Contingent NIPT may provide a cost-effective alternative to universal NIPT screening. Contingent screening used a two-stage process in which risk is assessed by MSS in the first stage and, based on a risk cutoff, high-risk pregnancies are referred for NIPT. The objective of this study was to (1) determine the optimum MSS risk cutoff for contingent NIPT and (2) compare the cost effectiveness of optimized contingent NIPT to universal NIPT and conventional MSS.Study DesignDecision-analytic model using micro-simulation and probabilistic sensitivity analysis. We evaluated cost effectiveness from three perspectives: societal, governmental, and payer.ResultsFrom a societal perspective, universal NIPT dominated both contingent NIPT and MSS. From a government and payer perspective, contingent NIPT dominated MSS. Compared to contingent NIPT, adopting a universal NIPT would cost $203,088 for each additional case detected from a government perspective and $263,922 for each additional case detected from a payer perspective.ConclusionsFrom a societal perspective, universal NIPT is a cost-effective alternative to MSS and contingent NIPT. When viewed from narrower perspectives, contingent NIPT is less costly than universal NIPT and provides a cost-effective alternative to MSS.

Objectives COVID-19 has brought about tests from many manufacturers. While molecular and rapid antigen tests are targeted for early diagnosis, immunoassays have a larger role in epidemiological studies, understanding longitudinal immunity, and in vaccine development and response. Methods The performance of the LIAISON® SARS-CoV-2 TrimericS IgG assay was evaluated against the Beckman ACCESS SARS-CoV-2 IgG assay in New Mexico, and against the Siemens ADVIA Centaur COV2G assay in New York. Discordant samples were parsed using a microneutralization assay. Results A SARS-CoV-2 antibody positivity rate of 23.8% was observed in the samples tested in New York (September 2020), while in the same month the positivity rate was 1.5% in New Mexico. Positive and negative agreement were 67.6% (95% CI 49.5–82.6%) and 99.8% (95% CI 99.5–99.9%), respectively, with the Beckman test, and 98.0% (95% CI 95.7–99.3%) and 94.8% (95% CI 93.4–96.0%), respectively, with the Siemens test. Receiver operating characteristic analysis for the detection of SARS-CoV-2 antibodies discloses an AUC, area under the curve, of 0.996 (95% CI 0.992–0.999) for the LIAISON® SARS-CoV-2 TrimericS IgG assay. The criterion associated to the Youden Index was determined to be >12.9 kAU/L with a sensitivity of 99.44% and a specificity of 99.82%. Conclusions The LIAISON® SARS-CoV-2 TrimericS IgG assay is highly sensitive and specific. The balance of these parameters, without emphasis on high specificity alone, is particularly important when applied to high prevalence populations, where a highly sensitive assay will result in reporting a lower number of false negative subjects.

No abstract

The ␣ 2 ␤ 1 integrin serves as a receptor for collagens, laminin, and several other nonmatrix ligands. Many studies have suggested that the ␣ 2 ␤ 1 integrin is a critical mediator of platelet adhesion to collagen within the vessel wall after vascular injury and that the interactions of the platelet ␣ 2 ␤ 1 integrin with subendothelial collagen after vascular injury are required for proper hemostasis. We have used the ␣ 2 ␤ 1 integrin-deficient mouse to evaluate the contributions of the ␣ 2 ␤ 1 integrin in 2 in vivo models of thrombosis. Studies using a model of endothelial injury to the carotid artery reveal that the ␣ 2 ␤ 1 integrin plays a critical role in vascular thrombosis at the blood-vessel wall interface under flow conditions. In contrast, the ␣ 2 ␤ 1 integrin is not required for the formation of thrombi and pulmonary emboli follow- IntroductionThe ␣ 2 ␤ 1 integrin serves as a receptor for collagens, laminin, and several other nonmatrix ligands. [1][2][3] The integrin has been extensively studied as a collagen receptor on platelets. [4][5][6][7] Many studies have suggested that the ␣ 2 ␤ 1 integrin is a critical mediator of platelet adhesion to collagen within the vessel wall after vascular injury and that the interactions of the platelet ␣ 2 ␤ 1 integrin with subendothelial collagen after vascular injury are required for proper hemostasis. Collagen not only serves as an adhesive substrate, but in its fibrillar form also activates platelets leading to secretion of granule contents and platelet aggregation. 4 The relative roles of the ␣ 2 ␤ 1 integrin and the glycoprotein VI (GPVI)/F c receptor ␥ (F c ␥R) chain complex, another platelet collagen receptor, in platelet adhesion, platelet activation, and platelet aggregation have been intensely debated. [8][9][10][11][12][13][14][15][16][17][18][19] Experimental evidence documenting a role for the platelet ␣ 2 ␤ 1 integrin in thrombus formation in vivo has been lacking.The extent of ␣ 2 ␤ 1 expression varies greatly among individuals and is determined by several linked polymorphisms within the ␣ 2 -integrin subunit gene. [20][21][22] A potentially important role for the ␣ 2 ␤ 1 integrin is suggested by recent epidemiologic data. Some data reveal a direct correlation between the genetically determined surface density of platelet ␣ 2 ␤ 1 -integrin expression and the risk of thrombotic events. High-level expression of ␣ 2 ␤ 1 integrin on platelets is an independent risk factor for nonfatal myocardial infarction in individuals younger than 62 years of age, for the development of diabetic retinopathy in patients with type 2 diabetes mellitus, and for stroke in the young. [23][24][25][26][27][28] However, other studies failed to find a correlation between the level of expression of ␣ 2 ␤ 1 integrin and the risk of thrombotic events. The mechanistic relationship inferred between the level of expression of ␣ 2 ␤ 1 integrin and the development of vascular disease requires experimental evaluation in vivo using animal models.To better define the role of the ␣ 2 ␤ 1 in...