Citations

Context.— The Goldman criteria are widely used to categorize diagnostic discrepancies in autopsy reports for hospital quality assurance. Despite their adoption, little is known about how consistently they are applied across institutions. Objective.— To evaluate the interrater reliability among academic pathologists applying the Goldman criteria to classify missed diagnoses in autopsy cases. Design.— Thirty autopsy cases from 2 academic hospitals were reviewed by 5 experienced autopsy pathologists. Each reviewer independently assigned Goldman classification scores (class I–IV) to missed diagnoses based on the original 1983 definitions. Consensus was defined as at least 60% agreement (≥3 of 5 raters). Fleiss κ and Gwet AC1 were calculated to assess interrater reliability. Results.— A total of 196 missed diagnoses were identified by at least 1 rater. Only 26% (51 of 196) achieved a consensus Goldman classification, and just 4% (8 of 196) had unanimous classification agreement. Most diagnoses (65%; 127 of 196) were not identified by at least 3 raters. Among consensus classification ratings, 49% (25 of 51) were class IV. Fleiss κ was 0.176 (slight agreement) while Gwet AC1 was 0.390 (fair agreement). Collapsing major (classes I–II) and minor (classes III–IV) categories modestly improved agreement. Conclusions.— Interrater agreement in applying the Goldman criteria is only fair to moderate, suggesting significant subjectivity in their application. As the criteria are used for institutional comparison and quality metrics, efforts to standardize definitions and provide reviewer training are warranted to improve reproducibility and utility.

Abstract Measurement of D-dimer, a fibrin degradation product, is crucial for diagnosing thrombotic and fibrinolytic conditions. Despite its expanding utility, D-dimer testing faces challenges due to varying assay methodologies and nonstandardized reporting. To understand D-dimer reporting practices, the College of American Pathologists Hemostasis and Thrombosis Committee analyzed proficiency testing data from D-dimer surveys conducted between 2020 and 2023 across multiple laboratories. The data demonstrate that laboratories commonly report units that differ from the assay package insert when reporting their proficiency testing results. We sought to assess variability in reporting practices and opportunities for improvement in D-dimer reporting amongst participants. To accomplish this, we harmonized all D-dimer results to ng/mL fibrinogen equivalent units from one distributed sample and assessed distinct populations of entries per instrument/reagent combination. Notable trends emerged from this analysis. Data from laboratories using the same instrument/reagent combinations clustered around different means, suggesting issues with unit reporting and/or conversion. Entries reported in mg/L or ug/mL D-dimer units commonly exhibited significant deviations from the dominant population. For one instrument/reagent combination, most reported values differed by approximately twice the certificate of analysis value. This analysis highlights potential issues with D-dimer reporting in proficiency testing. Whether these issues translate into issues with clinical D-dimer reporting requires further study.

Abstract Background Noninvasive prenatal screening for common autosomal trisomies, sex chromosome aneuploidies and microdeletions vary by methodology and laboratory practice. The fetal portion of all cell-free DNA in the maternal circulation defines the fetal fraction (FF). The minimum specimen FF levels for reporting results vary between laboratories as well as the screening target (e.g., common trisomies vs select microdeletions). This variability can lead to confusion for both healthcare providers and patients. Methods Participants in the College of American Pathologists Non-Invasive Prenatal Testing 2021-B Exercise provided FF estimates for 3 manufactured samples. Responses to supplemental questions were also collected and analyzed. Results Overall, 72 of 77 participants responded. FF was measured by 66 participants using sequence counts (40), single nucleotide polymorphisms (15), fragment length (24), and Y chromosome sequences (24). Nearly half (48%) used multiple methods. For common trisomies, minimum FFs were none or <1% (n = 7), 1.0% to 3.9% (n = 35), 4.0% to 6.9% (n = 23), and ≥7.0% (n = 1); 4 participants did not measure FF. Challenge-specific FFs were variable with CVs of 13%, 15%, and 36%; the latter rate appears due to that sample’s fetal karyotype of 47,XYY. Comparing adjusted FF results for the 3 samples shows that 85% of participant results were within 20% of the consensus. Conclusions Using multiple methods to estimate FF was common, and cutoff levels for sample suitability varied widely. Within-laboratory FFs were less variable than between laboratories. Current FF estimates from clinical laboratories are not standardized and should be considered laboratory-specific.

AbstractObjectiveDetermine current analytical methods and number of cell‐free (cf) DNA prenatal screening tests performed for common trisomies.MethodsThe College of American Pathologists 2022‐B Noninvasive Prenatal Testing exercise was distributed in December 2022 to 93 participants in 22 countries. Supplemental questions included the number of tests performed in a recent month and the proportion of samples originating outside the United States (US).ResultsEighty‐three participants from three continents returned results; 74 (89%) were suitable for the analyses. Nine manufacturer/platform combinations were identified, most commonly Illumina/Nextseq (55%). The most common methodology was whole genome sequencing (76%). Annualized cfDNA tests were 2.80 million, with Asian, European and North American participants representing 10.6%, 6.5% and 82.9% of tests, respectively. When restricted to US in‐country tests, the annualized rate was 2.18 million, with four of 20 participants testing 79.2%. Among 73 respondents, 63 (86%) were for‐profit, eight (11%) were non‐profit academic or government supported and the remaining two included hospital‐based and private non‐profit. Eighteen (25%) supported relevant academic training.ConclusionIn 2011, screening for common trisomies was based on serum/ultrasound markers with an estimated 2.96 million US pregnancies screened in 131 laboratories. In 2022, cfDNA‐based screening was offered by 20 laboratories testing 2.18 million US pregnancies.

AbstractVon Willebrand factor (VWF) level and/or function is altered in von Willebrand disease (VWD), the most common heritable bleeding disorder worldwide. Laboratory assessment of VWF is continually evolving. Historically, the primary method for the assessment of VWF platelet-binding activity was the ristocetin cofactor assay (VWF:RCo). Contemporary alternative measures of VWF platelet-binding activity include VWF:GPIbR (recombinant; using ristocetin), VWF:GPIbM (recombinant; gain-of-function mutant), and monoclonal antibody. Recently, the American Society of Hematology, International Society on Thrombosis and Haemostasis, National Hemophilia Foundation, and World Federation of Hemophilia collaboration issued guidelines recommending the use of newer assays of VWF platelet-binding activity (VWF: GPIbM, VWF: GPIbR) over VWF:RCo, given known limitations of the VWF:RCo assay. Despite this recommendation, the newer VWF:GPIbM and VWF:GPIbR assays are not United States Food and Drug Administration cleared, limiting their availability in the United States. We sought to assess assay utilization trends, agreement of VWF testing methods, and imprecision of VWF testing (based on assigned sample type) from the College of American Pathologists Proficiency Testing Surveys. The analysis confirms that, while VWF antigen testing has low imprecision, the various VWF activity assays have significant interassay variability, with VWF:RCo showing greater imprecision than the newer GPIb-binding assays. The overall trends in assay utilization reflect the barriers to complete compliance with modern VWD diagnostic guidelines in North America.

AbstractVon Willebrand factor (VWF) level and/or function is altered in von Willebrand disease (VWD), the most common heritable bleeding disorder worldwide. Laboratory assessment of VWF is continually evolving. Historically, the primary method for the assessment of VWF platelet-binding activity was the ristocetin cofactor assay (VWF:RCo). Contemporary alternative measures of VWF platelet-binding activity include VWF:GPIbR (recombinant; using ristocetin), VWF:GPIbM (recombinant; gain-of-function mutant), and monoclonal antibody. Recently, the American Society of Hematology, International Society on Thrombosis and Haemostasis, National Hemophilia Foundation, and World Federation of Hemophilia collaboration issued guidelines recommending the use of newer assays of VWF platelet-binding activity (VWF: GPIbM, VWF: GPIbR) over VWF:RCo, given known limitations of the VWF:RCo assay. Despite this recommendation, the newer VWF:GPIbM and VWF:GPIbR assays are not United States Food and Drug Administration cleared, limiting their availability in the United States. We sought to assess assay utilization trends, agreement of VWF testing methods, and imprecision of VWF testing (based on assigned sample type) from the College of American Pathologists Proficiency Testing Surveys. The analysis confirms that, while VWF antigen testing has low imprecision, the various VWF activity assays have significant interassay variability, with VWF:RCo showing greater imprecision than the newer GPIb-binding assays. The overall trends in assay utilization reflect the barriers to complete compliance with modern VWD diagnostic guidelines in North America.

Context.— Organ weights are an essential part of autopsy analysis. Deviations from normal organ weights provide important clues to disease processes. The assessment of normal organ weights depends on reliable reference tables, but most widely available reference tables are based on data that are either decades old or derived from relatively small sample sizes. Objective.— To provide an updated reference table of organ weights based on contemporary sources and a large sample size. Design.— Organ weights from 4197 carefully screened autopsies performed on adults at the Palm Beach County Medical Examiner's Office in West Palm Beach, Florida, and the Mayo Clinic Hospital in Rochester, Minnesota. Results.— Height and body weight data in this study reflect the well-recognized increases in both variables, but most particularly in body weight, seen during the last decades. The study data show a strong positive association between organ weight and body weight for the heart, liver, and spleen. There is a similar but weaker association between body weight and the weight of the lungs and kidneys. Brain weight is independent of body weight but shows a strong negative association with age. Even when controlling for body weight, men's organs are heavier, except for the weight of the liver, which is comparable in men and women. These associations are in agreement with the findings of previous studies. The current study suggests that, for some of the commonly weighed organs, there has been an increase in median organ weight when compared with existing references. Conclusions.— The tables presented here provide an updated reference that should prove useful to autopsy pathologists in the forensic and hospital settings.

Context.— Assessing direct oral anticoagulant (DOAC) drug levels by reliable laboratory assays is necessary in a number of clinical scenarios. Objective.— To evaluate the performance of DOAC-specific assays for various concentrations of dabigatran and rivaroxaban, assess the interlaboratory variability in measurement of these DOACs, and investigate the responsiveness of the routine clotting assays to various concentrations of these oral anticoagulants. Design.— College of American Pathologists proficiency testing survey data from 2013 to 2016 were summarized and analyzed. Results.— For dabigatran, the interlaboratory coefficient of variation (CV) of ecarin chromogenic assay was broad (ranging from 7.5% to 29.1%, 6.3% to 15.5%, and 6.8% to 9.0% for 100-ng/mL, 200-ng/mL, and 400-ng/mL targeted drug concentrations, respectively). The CV for diluted thrombin time for dabigatran was better overall (ranging from 11.6% to 17.2%, 9.3% to 12.3, and 7.1% to 11.2% for 100 ng/mL, 200 ng/mL, and 400 ng/mL, respectively). The rivaroxaban-calibrated anti-Xa assay CVs also showed variability (ranging from 11.5% to 22.2%, 7.2% to 10.9%, and 6.4% to 8.1% for 50-ng/mL, 200-ng/mL, and 400-ng/mL targeted drug concentrations, respectively). The prothrombin time (PT) and activated partial thromboplastin time (aPTT) showed variable dose- and reagent-dependent responsiveness to DOACs: PT was more responsive to rivaroxaban and aPTT to dabigatran. The undiluted thrombin time showed maximum prolongation across all 3 dabigatran concentrations, making it too sensitive for drug-level monitoring, but supporting its use as a qualitative screening assay. Conclusions.— DOAC-specific assays performed reasonably well. While PT and aPTT cannot be used safely to determine DOAC degree of anticoagulation, a normal thrombin time excludes the presence of dabigatran.

Context.— Therapeutic drug monitoring has traditionally been widely used for first-generation antiepileptic drugs (AEDs) such as carbamazepine and phenytoin. The last 2 decades have seen the introduction of second- and third-generation AEDs (eg, lamotrigine, levetiracetam, and topiramate) into clinical practice. Objective.— To use data from the College of American Pathologists Therapeutic Drug Monitoring, Extended Proficiency Testing Survey to determine the performance of assays used for therapeutic drug monitoring of newer AEDs, including comparison of enzyme immunoassay and chromatographic techniques. Design.— Six years of proficiency testing surveys were reviewed (2013–2018). Results.— Steady growth was seen in participant volumes for newer AEDs. The analytical performance of automated enzyme immunoassays for lamotrigine, levetiracetam, and topiramate was similar to that of chromatographic methods, consistent with published literature using patient samples for comparisons. The majority of participating laboratories now use enzyme immunoassays to measure levetiracetam. Conclusions.— Survey results reflect steadily growing interest in therapeutic drug monitoring of newer AEDs. The increasing availability of robust immunoassays for new AEDs should facilitate their clinical utility, especially for clinical laboratories that do not perform chromatographic assays for therapeutic drug monitoring.

Context.— Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a recently emerged, currently pandemic virus, and the etiologic agent of coronavirus disease 2019 (COVID-19). Clinical testing for antibodies to SARS-CoV-2 has rapidly become widespread, but data regarding the interlaboratory performance of these serologic assays are limited. Objective.— To describe the development and initial results of the College of American Pathologists (CAP) SARS-CoV-2 Serology Survey. Design.— Members from the CAP Microbiology and Diagnostic Immunology and Flow Cytometry Committees formed a working group to support development of a new proficiency testing survey for anti–SARS-CoV-2 antibody assays. Supplemental questions in the survey assessed the state of SARS-CoV-2 serologic testing among participating laboratories as of July 2020. Results were analyzed for agreement by immunoglobulin (Ig) isotype tested, assay manufacturer, and methodology. Results.— A total of 4125 qualitative results were received from 1110 laboratories participating in the first survey. Qualitative agreement for assays measuring anti–SARS-CoV-2 total antibodies or IgG was greater than 90% for all 3 samples in the survey. Qualitative agreement for IgM and IgA for the negative sample was greater than 95%, but lacked consensus for the other 2 samples. Conclusions.— These initial data suggest overall excellent agreement and comparable performance for most qualitative anti–SARS-CoV-2 IgG and total antibody assays across all participating clinical laboratories, regardless of specific target antigen or assay methodology.