Diagnostic patterns and stress testing trends after implementing high-sensitivity troponin assay.

Objectives: High-sensitivity troponin T (hsTnT) testing was approved in the United States to better facilitate diagnosis of acute coronary syndrome (ACS). Although hsTnT has been widely studied internationally, the impact of hsTnT on discharge diagnoses and health care utilization within the United States is less known. We sought to evaluate the effects of implementing hsTnT on diagnosis patterns and stress testing utilization.

Reflexing Suspicious β-Region Findings on Capillary Serum Protein Electrophoresis to Immunofixation or Immunosubtraction for Detecting Monoclonal Proteins.

Objectives: Monoclonal immunoglobulins (M-proteins) that migrate in the β region on serum protein electrophoresis (SPEP) are often cloaked by this region's normal constituents. The present study interrogates the utility of using both quantitative and qualitative alterations in β-region bands for detection of β-migrating M-proteins.

Methods: Consecutive SPEP cases analyzed by capillary electrophoresis were searched to identify the initial workup on 1,841 patients with increased total β regions, suspicious β-region findings resulting in reflex immunofixation (IFE), or immunosubtraction (ISUB).

Mild SARS-CoV-2 Illness Is Not Associated with Reinfections and Provides Persistent Spike, Nucleocapsid, and Virus-Neutralizing Antibodies.

Uncertainty exists whether mild COVID-19 confers immunity to reinfection. Questions also remain regarding the persistence of antibodies against SARS-CoV-2 after mild infection. We prospectively followed at-risk individuals with and without SARS-CoV-2 for reinfection and monitored the spike and nucleocapsid antibodies.

Accurate point-of-care serology tests for COVID-19.

Background: As COVID-19 vaccines become available, screening individuals for prior COVID-19 infection and vaccine response in point-of-care (POC) settings has renewed interest. We prospectively screened at-risk individuals for SARS-CoV-2 spike and nucleocapsid protein antibodies in a POC setting to determine if it was a feasible method to identify antibody from prior infection.

Methods: Three EUA-approved lateral flow antibody assays were performed on POC finger-stick blood and compared with serum and a CLIA nucleocapsid antibody immunoassay.

Differences in Performance Characteristics Among Four High-Throughput Assays for the Detection of Antibodies Against SARS-CoV-2 Using a Common Set of Patient Samples.

Objectives: Serologic testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has experienced a changing landscape of available assays coupled with uncertainty surrounding performance characteristics. Studies are needed to directly compare multiple commercially available assays.

Methods: Residual serum samples were identified based on SARS-CoV-2 reverse transcription polymerase chain reaction (RT-PCR) testing, clinical test results, and collection dates.