Search

* Context.--Many studies have depended on qualitative antibody assays to investigate questions related to COVID-19 infection, vaccination, and treatment. Objective.--To evaluate immunoglobulin G (IgG) levels in vaccinated individuals over time and characterize limitations of qualitative and quantitative antibody assays. Design.--Longitudinal serum samples (n = 339) were collected from 72 health care workers vaccinated against COVID-19. SARS-CoV-2 IgG levels before, during, and after vaccination were measured by using a qualitative anti-spike protein IgG assay and a quantitative anti-S1 IgG assay. Assay results were compared to understand antibody dynamics related to vaccination. Results.--Qualitative testing demonstrated 100% seroconversion after the first vaccine dose, peak IgG levels after the second vaccine dose, and a progressive 50% decline during the next 8 months. Quantitative testing demonstrated that IgG levels during and after vaccination were above the analytical measurement range. Conclusions.--Qualitative testing demonstrates expected changes in SARS-CoV-2 IgG levels related to sequential vaccine doses and time since antigen exposure. However, proportional changes in the associated numerical signals are very likely inaccurate. Adoption of standardized quantitative SARS-CoV-2 antibody testing with a broad analytical measurement range is essential to determine a correlate of protection from COVID-19 that can be scaled for widespread use. (Arch Pathol Lab Med. 2024;148:e36-e39; doi: 10.5858/arpa.2023-0014-OA), Serologic antibody testing is commonly used as a surrogate marker for the adaptive immune response. The potential clinical and epidemiologic utility of SARS-CoV-2 antibody testing is undermined by several factors, [...]

Increased attention has been focused on the future role of pathologists. The College of American Pathologists has initiated a Transformation Program to explore this question. (1) One part of that [...], 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. Objective.--To characterize the content of consultations and to describe training in consultation in chemical pathology within the residency program at the University of Utah, Salt Lake City. Design.--Retrospective review of the consultation database for the period between July 2011 and July 2012. Results.--Residents performed an average of 159 consultations a month covering 276 topics during the course of a year. Each topic involved 1 or more specific tests. Eighty percent of the topics received fewer than 12 calls. The most common topics involved virus testing (eg, hepatitis B virus, hepatitis C virus, human immunodeficiency virus). Consultations most often involved test interpretation (53%), selection (38%), and performance characteristics (21%). Twenty-seven percent of consultations involved 2 or more consultation categories (eg, interpretation and performance). Conclusions.--Consultation calls in chemical pathology are widely distributed across topics. Consultations most often involve test interpretation and selection. Methods to assess the effectiveness of consultations and resident teaching should be devised. (Arch Pathol Lab Med. 2014; 138:671-677; doi: 10.5858/arpa.2013-0017-OA)

Screening programs for open neural tube defects began in the late 1970s, following documentation that elevated levels of maternal serum a-fetoprotein (AFP) in the second trimester were associated with open [...], * 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. Results.--After accounting for some of the missing responses, data from up to 131 laboratories indicated that 67% (2 764 020 of 4 130 000) to 72% (2012: 2 963 592 of 4 130 000) of US pregnancies received prenatal screening for Down syndrome. Second trimester tests were most common (2012: 60%; 1 770 024 of 2 963 592), followed by integrated (2012: 21%; 627 876 of 2 963 592), and first trimester (2012: 19%; 565 692 of 2 963 592). The 6 largest laboratories tested 61% of screened pregnancies and offered the widest array of tests, while the smallest 32 tested 1% and almost always offered only second trimester tests. Conclusions.--The current population estimate of 72% pregnancies screened annually is higher than estimates from 1988 (25%) and 1992 (50%). Available testing choices are also more varied, and all testing methods perform better than those methods available 10 years ago. Clinicians should ensure that women are offered tests that follow recommended best-practice testing protocols, and screening laboratories should assess whether patient needs are being met. (Arch Pathol Lab Med. 2013;137:921-926; doi: 10.5858/arpa.2012-0319-CP)

Measurement of plasma or serum creatinine is indicated for the assessment of renal function. That measurement is a primary component of the equations that provide estimated glomerular filtration rate (eGFR) [...], 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. Design.--Serum samples spiked with different concentrations of creatinine were analyzed by participating laboratories in the College of American Pathologists' LN24 survey. Participants' reported values were compared against values measured by liquid chromatography-isotope dilution mass spectrometry. Participants were asked to calculate the eGFR for certain samples, and results were compared with those obtained from the 4-parameter Modification of Diet in Renal Disease equation. Results.--Biases among current creatinine methods are in the range of -5% to 10%, compared with -7% to 34% seen in a 2003 study. This degree of bias in eGFR calculations is of clinical significance only for concentrations near the cut points used to stage chronic kidney disease. Approximately 20% of laboratories report eGFR values that exceed ±1 mL/min per 1.73 [m.sup.2] from the expected eGFR using the 4-parameter Modification of Diet in Renal Disease equation. Conclusions.--Since 2003, there have been improvements in the performance of creatinine assays, which appear to be related to the adoption of standard reference materials for calibration. The effect of the observed method biases in clinical practice now appears minimal. Laboratories should continue to monitor the accuracy of eGFR calculations. (Arch Pathol Lab Med. 2013;137:496-502; doi: 10.5858/arpa.2012-0134-CP)

EXECUTIVE SUMMARY Pathology's future depends on training pathologists who are as facile with new technologies as they are with the microscope. Trainees must absorb, assimilate, and be ready to apply [...]

* Context.--Harmonization and standardization of results among different clinical laboratories is necessary for clinical practice guidelines to be established. Objective.--To evaluate the state of the art in measuring 10 routine chemistry analytes. Design.--A specimen prepared as off-the-clot pooled sera and 4 conventionally prepared specimens were sent to participants in the College of American Pathologists Chemistry Survey. Analyte concentrations were assigned by reference measurement procedures. Participants.--Approximately 6000 clinical laboratories. Results.--For glucose, iron, potassium, and uric acid, more than 87.5% of peer groups meet the desirable bias goals based on biologic variability criteria. The remaining 6 analytes had less than 52% of peer groups that met the desirable bias criteria. Conclusions.--Routine measurement procedures for some analytes had acceptable traceability to reference systems. Conventionally prepared proficiency testing specimens were not adequately commutable with a fresh frozen specimen to be used to evaluate trueness of methods compared with a reference measurement procedure. (Arch Pathol Lab Med. 2008;132:838-846), Along-standing objective of clinical laboratory medicine has been to produce harmonized test results among laboratories and methods. (1) Harmonized results are those that agree within clinically acceptable limits among different [...]