Association between SARS-CoV-2 Symptoms, Ct Values, and Serological Response in Vaccinated and Unvaccinated Healthcare Personnel.

Background: SARS-CoV-2 vaccines are effective at reducing symptomatic and asymptomatic COVID-19. Limited studies have compared symptoms, threshold cycle (Ct) values from reverse transcription (RT)-PCR testing, and serological testing results between previously vaccinated vs unvaccinated populations with SARS-CoV-2 infection.

Methods: Healthcare personnel (HCP) with a positive SARS-CoV-2 RT-PCR test within the previous 14 to 28 days completed surveys including questions about demographics, medical conditions, social factors, and symptoms of COVID-19.

Method Comparison and Workflow Differences Using the Same Free Light Chain Assay on 2 Analyzer Platforms.

Background: The Freelite assay (The Binding Site) is utilized to quantify serum immunoglobulin free light chains (sFLC), which is crucial for diagnosing and monitoring plasma cell dyscrasias (PCDs). Using the Freelite test, we compared methods and evaluated workflow differences across two analyzer platforms.

Methods: sFLC concentrations were measured in 306 fresh serum specimens (cohort A) and 48 frozen specimens with documented sFLC >20 mg/dL (cohort B).

Longitudinal analysis of risk factors associated with severe acute respiratory coronavirus virus 2 (SARS-CoV-2) infection among hemodialysis patients and healthcare personnel in outpatient hemodialysis centers.

In this prospective, longitudinal study, we examined the risk factors for severe acute respiratory coronavirus virus 2 (SARS-CoV-2) infection among a cohort of chronic hemodialysis (HD) patients and healthcare personnel (HCPs) over a 6-month period. The risk of SARS-CoV-2 infection among HD patients and HCPs was consistently associated with a household member having SARS-CoV-2 infection.

Predictors of humoral response to SARS-CoV-2 mRNA vaccine BNT162b2 in patients receiving maintenance dialysis.

Objective: Patients on dialysis are at high risk for severe COVID-19 and associated morbidity and mortality. We examined the humoral response to SARS-CoV-2 mRNA vaccine BNT162b2 in a maintenance dialysis population.

Design: Single-center cohort study.

HLA-B evolutionary divergence is associated with outcomes after SARS-CoV-2 infection.

We examined the correlation between class I HLA evolutionary divergence (HED), a surrogate for the capacity to present different peptides, and the outcomes of 234 adult inpatients with confirmed SARS-CoV-2 infection. Genomic DNA was extracted from peripheral blood and genotyped by next-generation sequencing (NGS). HED scores for HLA class I (HLA-A, -B, and -C) genotypes were calculated using Grantham's distance.

SARS-CoV-2 Infection Risk Factors among Maintenance Hemodialysis Patients and Health Care Personnel In Outpatient Hemodialysis Centers.

Increased risk of SARS-CoV-2 infection was associated with community prevalence.Increased risk of SARS-CoV-2 infection was associated with exposure to infected family members and personal infection prevention measures.

Clinical Performance of a Lateral Flow SARS-CoV-2 Total Antibody Assay.

Background: Serological assays for SARS-CoV-2 are important tools for diagnosis in patients with negative RT-PCR testing, pediatric patients with multisystem inflammatory syndrome, and serosurveillance studies. However, lateral flow-based serological assays have previously demonstrated poor analytical and clinical performance, limiting their utility.

Methods: We assessed the ADEXUSDx COVID-19 lateral flow assay for agreement with diagnostic RT-PCR testing using 120 specimens from RT-PCR-positive patients, 77 specimens from symptomatic RT-PCR-negative patients, and 47 specimens obtained prepandemic.

Qualitative and quantitative detection of SARS-CoV-2 antibodies from dried blood spots.

Introduction: Dried blood spot (DBS) sampling is a minimally invasive method for specimen collection with potential multifaceted uses, particularly for serosurveillance of previous SARS-CoV-2 infection. In this study, we assessed DBS as a potential specimen type for assessing IgG and total (including IgG and IgM) antibodies to SARS-CoV-2 in vaccinated and naturally infected patients.

Methods: Six candidate buffers were assessed for eluting blood from DBS cards.

HLA genetic polymorphism in patients with Coronavirus Disease 2019 in Midwestern United States.

The experience of individuals with Coronavirus Disease 2019 (COVID-19) ranges from asymptomatic to life threatening multi-organ dysfunction. Specific HLA alleles may affect the predisposition to severe COVID-19 because of their role in presenting viral peptides to launch the adaptive immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this population-based case-control study in the midwestern United States, we performed high-resolution HLA typing of 234 cases hospitalized for COVID-19 in the St.

Assessment of serological assays for identifying high titer convalescent plasma.

Background: The COVID-19 pandemic has been accompanied by the largest mobilization of therapeutic convalescent plasma (CCP) in over a century. Initial identification of high titer units was based on dose-response data using the Ortho VITROS IgG assay. The proliferation of severe acute respiratory syndrome coronavirus 2 serological assays and non-uniform application has led to uncertainty about their interrelationships.

Assessment of serological assays for identifying high titer convalescent plasma.

The COVID-19 pandemic has been accompanied by the largest mobilization of therapeutic convalescent plasma (CCP) in over a century. Initial identification of high titer units was based on dose-response data using the Ortho VITROS IgG assay. The proliferation of SARS-CoV-2 serological assays and non-uniform application has led to uncertainty about their interrelationships.

Clinical Performance of Two SARS-CoV-2 Serologic Assays.

Background: The recent emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in a rapid proliferation of serologic assays. However, little is known about their clinical performance. Here, we compared two commercial SARS-CoV-2 IgG assays.

Elevated serum ferritin is not specific for hemophagocytic lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis (HLH) is a rare, potentially fatal, syndrome of excessive and ineffective activation of the immune system. The majority of the reported data on HLH is from pediatric patients and lacks specificity. This makes HLH diagnosis challenging especially in adults where HLH is triggered by many conditions and can resemble many disease entities.

Use of Biomarkers to Predict Readmission for Congestive Heart Failure.

Acute decompensated heart failure (ADHF) is a major reason for repeated hospitalizations. Identifying those patients with ADHF at risk for readmission is critical so that preventive interventions can be implemented. Biomarkers such as B-type natriuretic peptide (BNP), high-sensitivity troponin I, and galectin-3 (Gal-3) assessed at discharge may be useful, although their role in predicting short-term readmission is not well defined in the literature.

Establishing reference intervals for hCG in postmenopausal women.

Background: Plasma concentrations of human chorionic gonadotropin (hCG) have been shown to increase with age due to pituitary secretion. We previously recommended that an hCG cutoff of 14.0IU/L be used for women ≥55years of age.

Short- and Long-term Biologic Variability of Galectin-3 and Other Cardiac Biomarkers in Patients with Stable Heart Failure and Healthy Adults.

Background: Galectin-3 (Gal-3) has been suggested as a prognostic biomarker in heart failure (HF) patients that may better reflect disease progression than traditional markers, including B-type natriuretic peptide (BNP) and cardiac troponins. To fully establish the utility of any biomarker in HF, its biologic variability must be characterized.

Methods: To assess biologic variability, 59 patients were prospectively recruited, including 23 male and 16 female patients with stable HF and 10 male and 10 female healthy individuals.

Diagnostic utility of plasma procalcitonin for nosocomial pneumonia in the intensive care unit setting.

Background: Nosocomial pneumonia is a difficult diagnosis to establish in the intensive care unit setting, due to the non-specific nature of the clinical and radiographic findings. Procalcitonin is a circulating biomarker that may become elevated in the presence of bacterial infection.

Methods: We conducted a prospective single-center cohort study at Barnes-Jewish Hospital, a 1,200-bed urban teaching hospital in St Louis, Missouri.

Performance characteristics of a no-pretreatment, random access sirolimus assay for the Dimension RxL clinical chemistry system.

Objectives: Current therapeutic drug monitoring methods for sirolimus require a manual pre-treatment step and batch analysis. We describe and validate a no-pretreatment, random access sirolimus assay for the Dimension RxL clinical chemistry system from Siemens Healthcare Diagnostics Inc.

Design And Methods: Whole blood samples from renal transplant patients prescribed sirolimus were analyzed by the LC-MS/MS reference method, Abbott IMx and Dimension RxL methods in accordance with CLSI recommendations.

Hitachi Hemolytic Index correlates with HBOC-201 concentrations: impact on suppression of analyte results.

Objectives: To determine the feasibility of laboratories to use an instrument's Hemolytic Index (HI) to determine if a test result would be accurate in the presence of hemoglobin-based oxygen carrier HBOC-201.

Design And Methods: HI values from the Roche Hitachi Modular P800 for samples containing HBOC-201 were determined. HI limits for 24 tests determined by addition of RBC lysate hemoglobin to serum and the instrument manufacturer's HI limits were compared to HI limits for reporting the same tests determined by adding HBOC-201 to plasma.