Quantification of antibody avidities and accurate detection of SARS-CoV-2 antibodies in serum and saliva on plasmonic substrates.

Accurate assays for the detection of antibodies to SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) are essential for the control of the COVID-19 (coronavirus disease 2019) pandemic. Here, we report antibody and antibody-avidity assays, relying on near-infrared-fluorescence amplification by nanostructured plasmonic gold substrates, for the simultaneous detection of antibodies to the S1 subunit of the spike protein and to the receptor binding domain of SARS-CoV-2 in human serum and saliva, and for quantifying immunoglobulin avidities against coronavirus antigens from SARS-CoV-2, SARS-CoV-1 and the common-cold viruses OC43, HKU1, NL63 and 229E. The antibody assay detected immunoglobulin M in 87% (52 of 60) COVID-19-positive serum samples collected 6 or more days after symptom onset (and the immunoglobulins M and G in all 33 samples collected at least 15 days after symptom onset), and correctly classified 456 out of the 457 COVID-19-negative serum samples tested (424 of them collected before the pandemic, including 73 that were positive for other viruses). We used the antibody-avidity assay to study antibody-maturation patterns, anamnestic responses, and cross-immunity to the common-cold coronaviruses.

Outcomes with the polymer-based paclitaxel-eluting TAXUS stent in patients with diabetes mellitus: the TAXUS-IV trial.

OBJECTIVES: We sought to determine the safety and efficacy of polymer-regulated site-specific delivery of paclitaxel in patients with diabetes mellitus undergoing stent implantation. BACKGROUND: Percutaneous coronary intervention in patients with diabetes is associated with high rates of restenosis and repeat revascularization due to excessive neointimal proliferation, a process that may be blunted with the site-specific delivery of paclitaxel. METHODS: In the TAXUS-IV trial, 1,314 patients were prospectively randomized to the slow rate-release polymer-based paclitaxel-eluting TAXUS stent or the bare-metal EXPRESS stent (Boston Scientific Corp., Natick, Massachusetts). Medically treated diabetes was present in 318 patients (24%), 105 of whom required insulin. RESULTS: Among patients with diabetes, the TAXUS stent, compared to the bare-metal stent, reduced the rate of 9-month binary angiographic restenosis by 81% (6.4% vs. 34.5%, p < 0.0001), and reduced the 12-month rates of target lesion revascularization by 65% (7.4% vs. 20.9%, p = 0.0008), target vessel revascularization by 53% (11.3% vs. 24%, p < 0.004), and composite major adverse cardiac events by 44% (15.6% vs. 27.7%, p = 0.01). The one-year rates of cardiac death (1.9% vs. 2.5%), myocardial infarction (3.2% vs. 6.4%), and subacute thrombosis (0.6% vs. 1.2%) were comparable between the paclitaxel-eluting and control stents, respectively. In the insulin-requiring subgroup, the TAXUS stent reduced angiographic restenosis by 82% (7.7% vs. 42.9%, p = 0.0065), and reduced the one-year rate of target lesion revascularization by 68% (6.2% vs. 19.4%, p = 0.07), a relative reduction similar to patients without diabetes. CONCLUSIONS: The site-specific delivery of paclitaxel after coronary stent implantation is highly effective in reducing clinical and angiographic restenosis in patients with diabetes mellitus.