Longitudinal Qualitative and Quantitative Evaluation of SARS-CoV-2 Antibodies in Immunized Health Care Workers.

Context.—: Many studies have depended on qualitative antibody assays to investigate questions related to COVID-19 infection, vaccination, and treatment.

Objective.

Assessment of laboratories offering cell-free (cf) DNA screening for Down syndrome: results of the 2018 College of American Pathology External Educational Exercises.

Purpose: Summarize and interpret results from exercises distributed to laboratories offering cell-free (cf) DNA screening for Down syndrome.

Methods: The College of American Pathologists distributed three patient-derived plasma specimens twice in 2018. Sequencing platforms, test methods, results, and responses to supplemental questions were collected.

The Case for Laboratory Developed Procedures: Quality and Positive Impact on Patient Care.

An explosion of knowledge and technology is revolutionizing medicine and patient care. Novel testing must be brought to the clinic with safety and accuracy, but also in a timely and cost-effective manner, so that patients can benefit and laboratories can offer testing consistent with current guidelines. Under the oversight provided by the Clinical Laboratory Improvement Amendments, laboratories have been able to develop and optimize laboratory procedures for use in-house.

A Cost-Effectiveness Analysis of First Trimester Non-Invasive Prenatal Screening for Fetal Trisomies in the United States.

Background: Non-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.

Is maternal plasma DNA testing impacting serum-based screening for aneuploidy in the United States?

Purpose: We sought to determine whether tests for fetal aneuploidy based on next-generation sequencing of cell-free DNA in maternal circulation have had an impact on routine serum-based screening in the general pregnant population.

Methods: We compared results from laboratory surveys in 2011 and 2014 that reported types of prenatal serum screening tests and numbers of tests performed. Testing records from two prenatal serum screening laboratories examined temporal trends in the proportion of screened women 35 years of age and older from 2008 (or 2009) to 2014.

A cost-effectiveness analysis of cell free DNA as a replacement for serum screening for Down syndrome.

Objective: The aim of this article is to determine the cost effectiveness of cell free DNA (cfDNA) as a replacement for integrated screening using a societal cost perspective.

Method: This study used Monte-Carlo simulation with one-way and probabilistic sensitivity analysis.

Results: Cell free DNA is more effective and less costly than integrated screening.

An analysis of clinical consultation activities in clinical chemistry: implications for transformation and resident training in chemical pathology.

Context: Clinical consultation is a key role of pathologists. Many have advocated that pathologists expand their consulting activities to improve laboratory utilization. Although many have suggested that residency programs need to provide experience in clinical consultation, little has been written on the nature of consultation or on the methods of training.

A tradeoff analysis of risk cutoffs for the quadruple serum screen for Down syndrome.

Objectives: In maternal serum screening for Down syndrome, a cutoff of 1 : 270 is often used as a decision point to recommend invasive confirmatory testing. However, it has not been established how well this or any other cutoff relates to patient preferences, that is, the values that pregnant women attach to various screening outcomes. The purpose of this study was to examine the clinical and economic tradeoffs of a wide range of risk cutoffs for the quadruple screen.

Screening for down syndrome in the United States: results of surveys in 2011 and 2012.

Context: Participants in a College of American Pathologists external proficiency testing program for first and second trimester Down syndrome screening.

Objectives: To determine the number of women screened for Down syndrome in the United States, along with the type of test received and to compare those results to earlier surveys in 1988 and 1992.

Design: Questionnaires regarding the type and number of Down syndrome tests performed per month were completed by participants in early 2011 and again in early 2012.

α1-Antitrypsin phenotypes and associated serum protein concentrations in a large clinical population.

Background: α1-Antitrypsin (AAT) deficiency variants reduce the concentration of serum AAT protease inhibitor and can lead to the development of pulmonary and hepatic disease. Relative frequencies of rare AAT variant phenotypes (non-M, Z, and S) and associated serum concentrations in the clinical population have not been thoroughly described.

Methods: Protein phenotypes were determined by isoelectric focusing electrophoresis for 72,229 consecutive samples.

Recent trends in performance and current state of creatinine assays.

Context: Measured plasma or serum creatinine concentration is a primary component of equations used to calculate estimated glomerular filtration rate (eGFR). In recent years, most assay manufacturers have adopted creatinine calibration procedures that are traceable to the National Institute of Standards and Technology's Standard Reference Material 967.

Objectives: To examine the current performance of creatinine assays, to compare changes in assay performance since 2003, and to examine the reliability of laboratory eGFR calculations.

Immunoassay for quantifying squamous cell carcinoma antigen in serum.

Background: Although the benefits of quantifying serum squamous cell carcinoma antigen (SCCa) have been reported, SCCa reagents were no longer available in the US by the late 1990s. Because SCCa quantification still has demonstrated clinical utility, we developed and validated a microtiter plate-based ELISA for measuring SCCa in serum.

Methods: We coated microtiter strips overnight with capture anti-SCCa monoclonal antibody, washed the wells, added blocking buffer, and lyophilized the strips.