Search

Context.--Substantial variability between different antibody titration methods has been identified since the development and introduction of the uniform procedure in 2008. Objective.--To determine whether more recent methods or techniques decrease interlaboratory and intralaboratory variation measured using proficiency testing. Design.--Proficiency test data for antibody titration between 2014 and 2018 were obtained from the College of American Pathologists. Interlaboratory and intralaboratory variations were compared by analyzing the distribution of titer results by method and phase, comparing the results against the supplier's quality control titer, and by evaluating the distribution of paired titer results when each laboratory received a sample with the same titer twice. Results.--A total of 1337 laboratories participated in the antibody titer proficiency test during the study period. Only 54.1% (5874 of 10 852) of anti-D and 63.4% (3603 of 5680) of anti-A reported responses were within 1 titer of the supplier's intended result. Review of the agreement between laboratories of the same methodology found that 78.4% (3139 of 4004) for anti-A and 89.0% (9655 of 10 852) of laboratory responses for anti-D fell within 1 titer of the mode response. When provided with 2 consecutive samples of the same titer (anti-D titer: 16), 85% (367 of 434) of laboratories using the uniform procedure and 80% (458 of 576) using the other method reported a titer difference of 1 or less. Conclusions.--Despite advances, interlaboratory and intralaboratory variance for this assay remains high in comparison with the strong reliance on titer results in clinical practice. There needs to be a reevaluation of the role of this test in clinical decision-making. [ABSTRACT FROM AUTHOR]

* Context.--Next-generation sequencing-based approaches using RNA have increasingly been used by clinical laboratories for the detection of fusion genes, intragenic rearrangements, and exon-skipping events. Correspondingly, the College of American Pathologists (CAP) has advanced RNA sequencing proficiency testing (PT) to ensure optimal performance of these assays. Objective.--To report on laboratory performance and practices of RNA sequencing for the detection of fusion genes, intragenic rearrangements, and exon-skipping events using CAP PT data from 8 mailings (2018-A through 2021-B). Design.--CAP PT RNA sequencing program results from 153 laboratories across 24 proficiency test specimens, interrogating 22 distinct engineered fusion transcripts, were analyzed for correct identification of the fusion event, associated performance variables, and laboratory practices. Results.--Overall, the 4-year program detection rate (sensitivity) was 95.5% (1486 of 1556 results). False-negative rates were 3.6% (53 of 1463) and 18.3% (17 of 93) for fusion gene and intragenic rearrangement/exon-skipping events, respectively. Only 19 false-positive results were reported among the 8 PT mailings, and most were likely the result of preanalytical or postanalytical errors. There were no practice characteristics (eg, instrumentation, sequencing method) significantly associated with the fusion detection results. Conclusions.--These data reveal a high overall sensitivity and specificity for fusion gene detection by participating laboratories using clinical RNA sequencing. Performance was comparable across all laboratories, regardless of methodology. The fraction of false-negative results for intragenic rearrangement/exon-skipping events was greater than that for the chimeric fusion genes. False-negative results could not be attributed to any specific practice characteristics., Fusion oncogenes represent valuable biomarkers that aid in diagnostic classification and prognostication, as well as serving as therapeutic targets. (1-4) Examples of structural alterations/mutations that may lead to chimeric fusions [...]

Context.--Two major categories of laboratories performing nonwaived testing under the Clinical Laboratory Improvement Amendments of 1988 (CLIA) are the Certificate of Accreditation (CoA) and Certificate of Compliance (CoC) laboratories. Accreditation organizations collect more detailed laboratory personnel information than the Centers for Medicare & Medicaid Services (CMS) Quality Improvement and Evaluation System (QIES). Objective.--To estimate total numbers of testing personnel and testing volumes in CoA and CoC laboratories, by laboratory type and state. Design.--We developed a statistical inference method by using the respective correlations between testing personnel counts and test volume by laboratory type. Results.--QIES reported 33 033 active CoA and CoC laboratories in July 2021. We estimated testing personnel to be 328 000 (95% CI, 309 000-348 000), which is supported by the count of 318 780 reported by the US Bureau of Labor Statistics. There were twice as many testing personnel in hospital laboratories as in independent laboratories (158 778 versus 74 904, P < .001). Independent laboratories had the highest test volume per person, which was twice as high as physician office laboratories (62 228 versus 30102, P < .001). Hospital and independent laboratories comprised 34% of all CoA and CoC laboratories but performed the largest portion of testing (81 %). Physician office laboratories, accounting for 44% of all CoA and CoC laboratories, performed a comparatively low proportion of total tests (9%). Conclusions.--Numbers of testing personnel vary considerably by laboratory type and across states. These data can provide valuable insight when assessing laboratory workforce training needs and planning for public health emergencies. doi: 10.5858/arpa.2022-0345-0A, Clinical laboratory testing plays a critical role in health care, public health surveillance, and emergency response. A detailed study by the Lewin Group for the Centers for Disease Control and [...]

Context.--In 2014, the College of American Pathologists developed an evidence-based guideline to address analytic validation of immunohistochemical assays. Fourteen recommendations were offered. Per the National Academy of Medicine standards for developing trustworthy guidelines, guidelines should be updated when new evidence suggests modifications. Objective.--To assess evidence published since the release of the original guideline and develop updated evidence-based recommendations. Design.--The College of American Pathologists convened an expert panel to perform a systematic review of the literature and update the original guideline recommendations using the Grading of Recommendations Assessment, Development and Evaluation approach. Results.--Two strong recommendations, 1 conditional recommendation, and 12 good practice statements are offered in this updated guideline. They address analytic validation or verification of predictive and nonpredictive assays, and recommended revalidation procedures following changes in assay conditions. Conclusions.--While many of the original guideline statements remain similar, new recommendations address analytic validation of assays with distinct scoring systems, such as programmed death receptor-1 and analytic verification of US Food and Drug Administration approved/cleared assays; more specific guidance is offered for validating immunohistochemistry performed on cytology specimens. [ABSTRACT FROM AUTHOR]

Context.--Increased band neutrophils in blood smear differential counts ("bandemia") are entrenched in medicine as a flag for sepsis. However, laboratory hematology experts have long advocated for discontinuation of reporting bands separately from segmented neutrophils because of poor sensitivity and specificity, poor interobserver agreement, and availability of alternative biomarkers for sepsis. Objective.--To describe band neutrophil reporting practices and reproducibility of band classification among laboratories participating in the College of American Pathologists (CAP) proficiency testing (PT) program. Design.--A survey questionnaire was distributed to hematology PT participants. A subsequent morphologic challenge included 12 preselected cell identifications of segmented neutrophils, bands, and metamyelocytes, and a 100-cell manual differential count of a digitally scanned blood smear. Results.--Among laboratories that reported manual differentials, most respondents reported bands (4554 of 5268; 86.4%). Only 3222 of 4412 respondents (73.0%) provided band reference ranges. Though participants classified "easy" band neutrophils well (78.0%-98.3%), categorization of cell identifications for "moderate" and "difficult" bands was poor (3.1%-39.0% of laboratories), with classification instead as segmented neutrophils. This pattern was seen regardless of laboratory demographic characteristics. Marked variability in band counts was observed on the 100-cell differential count for both CAP PT participants and CAP Hematology and Clinical Microscopy Committee (HCMC) members (coefficients of variation, 55.8% and 32.9%, respectively). Variability was significantly improved when segmented and band neutrophils were grouped together (coefficients of variation, 6.2% and 5.0%, respectively). Conclusions.--Most CAP PT-participating laboratories report band counts, many without reference ranges. The survey confirms significant interlaboratory variability of band enumeration when bands are separately identified from segmented neutrophils. This study reaffirms the CAP Hematology and Clinical Microscopy Committee's strong recommendation to group segmented and band neutrophils together in manual differential counts. [ABSTRACT FROM AUTHOR]

Context.-- The Sustainable Predictive Oncology Therapeutics and Diagnostics quality assurance pilot study (SPOT/Dx pilot) on molecular oncology next-generation sequencing (NGS) reportedly demonstrated performance limitations of NGS laboratory-developed tests, including discrepancies with a US Food and Drug Administration-approved companion diagnostic. The SPOT/Dx pilot methods differ from those used in proficiency testing (PT) programs. Objective.-- To reanalyze SPOT/Dx pilot data using PT program methods and compare to PT program data.Also see p. 136. Design.-- The College of American Pathologists (CAP) Molecular Oncology Committee reanalyzed SPOT/Dx pilot data applying PT program methods, adjusting for confounding conditions, and compared them to CAP NGS PT program performance (2019-2022). Results.-- Overall detection rates of KRAS and NRAS single-nucleotide variants (SNVs) and multinucleotide variants (MNVs) by SPOT/Dx pilot laboratories were 96.8% (716 of 740) and 81.1% (129 of 159), respectively. In CAP PT programs, the overall detection rates for the same SNVs and MNVs were 97.2% (2671 of 2748) and 91.8% (1853 of 2019), respectively. In 2022, the overall detection rate for 5 KRAS and NRAS MNVs in CAP PT programs was 97.3% (1161 of 1193). Conclusions.-- CAP PT program data demonstrate that laboratories consistently have high detection rates for KRAS and NRAS variants. The SPOT/Dx pilot has multiple design and analytic differences with established PT programs. Reanalyzed pilot data that adjust for confounding conditions demonstrate that laboratories proficiently detect SNVs and less successfully detect rare to never-observed MNVs. The SPOT/Dx pilot results are not generalizable to all molecular oncology testing and should not be used to market products or change policy affecting all molecular oncology testing. [ABSTRACT FROM AUTHOR]

Context.--Therapy targeted at human epidermal growth factor receptor 2 (HER2; also known as ERBB2) was used initially for breast and gastroesophageal carcinoma and has more recently been adopted for endometrial serous carcinoma (ESC) and colorectal carcinoma (CRC). There is evidence that predictive biomarker testing algorithms for HER2 must be tumor type specific and that an algorithm validated for one tumor type cannot be applied to another. Objective.--To describe current laboratory practices for HER2 assessment in ESC and CRC. Design.--We surveyed laboratories participating in the 2021 College of American Pathologists (CAP) HER2 immunohistochemistry proficiency testing program. Results.--The survey was distributed to 1548 laboratories and returned by 1195, of which 83.5% (998) were in the United States. For ESC, 24.0% (287) of laboratories reported performing in-house testing for HER2 by immunohistochemical staining and/or in situ hybridization; of these, 44.3% (127) performed it reflexively on all cases of ESC. The most common criterion for evaluating HER2 was the American Society of Clinical Oncology/CAP 2018 guideline for breast carcinoma (69.0%; 194 of 281), whereas only 16.0% (45) of laboratories used guidelines specific to ESC. For CRC, 20.2% (239 of 1185) of laboratories performed in-house HER2 testing, and 82.0% of these (196) did the test only at the clinician's request. A plurality (49.4%; 115 of 233) used gastroesophageal cancer guidelines when scoring CRC, 30.0% (70) used the CRC scoring system from the HERACLES trial, and 16.3% (38) used the American Society of Clinical Oncology/CAP 2018 guideline for breast carcinoma. Conclusions.--Laboratories vary in their approach to HER2 testing in ESC and CRC. Most laboratories did not report using tumor type--specific recommendations for HER2 interpretation. The lack of standardization could present a challenge to evidence-based practice when considering targeted therapy for these diseases. [ABSTRACT FROM AUTHOR]

Context.--Consequences related to nicotine (NIC) use remain a major health concern, leading to demand for testing to detect NIC, metabolites such as cotinine (COT), and related tobacco alkaloids, including anabasine (ANAB). NIC-related testing is not standardized among laboratories, nor are there clinical or regulatory guidelines to inform decisions such as appropriate screening cutoffs or limits of quantitation. Objective.--To evaluate analytical performance and reporting practices of laboratories that perform NIC-related testing by reviewing participant responses to the Nicotine and Tobacco Alkaloid (NTA) Proficiency Testing Survey. Design.--NTA results were retrieved from 2017 (the first year of the survey) through 2020. Survey participants, methodologies, and results were evaluated for all analytes, and simulated grading was performed for COT. Additional data, including limits of quantitation, qualitative cutoffs, and reasons for testing, were reviewed. Results.--Participant growth was steady for qualitative COT testing. Participation was stable for NIC, ANAB, and quantitative COT testing. Overall, participants performed well on survey challenges. However, reporting thresholds were widely divergent, ranging from 10 to 3000 ng/mL and 0.5 to 300 ng/mL, respectively, for qualitative and quantitative COT testing. Screening cutoffs were as high as 100 ng/mL for ANAB and 1000 ng/mL for NIC. Conclusions.--Although participating laboratories performed well on the NTA Survey, the wide diversity of qualitative and quantitative reporting thresholds creates substantial risk for misinterpretation of results, and could lead to analytical concerns such as excessively high false-negative or false-positive rates. NIC-related testing would benefit from evidence-based guidelines to drive standardization of reporting. [ABSTRACT FROM AUTHOR]

The article stresses the need to expand proficiency testing (PT) to cover telepathology across institutions. It suggests the addition of a PT program for telepathology given the fact that the College of American Pathologists' educational program does not assess the accuracy of the diagnoses or assessments of biomarker analyses made from digital slides. It also discusses the incorporation of digital telepathology into clinical decision-making for rapid on-site specimen evaluation.

The article discusses research which examined the prevalence of syphilis serology testing algorithm among laboratory participants in the College of American Pathologists proficiency testing program. The study surveyed the prevalence in the use of reverse-sequence algorithm, traditional algorithm and individual syphilis tests. Advantages of reverse-sequence testing algorithm include earlier diagnosis, higher sensitivity in late latent and tertiary syphilis and fewer biological false positives.

* Context.--In 2016, the College of American Pathologists (CAP) launched the first next-generation sequencing (NGS) in silico bioinformatics proficiency testing survey to evaluate the performance of clinical laboratory bioinformatics pipelines for the detection of oncology-associated variants at varying allele fractions. This survey focused on 2 commonly used oncology panels, the Illumina TruSeq Amplicon Cancer Panel and the Thermo Fisher Ion AmpliSeq Cancer Hotspot v2 Panel. Objective.--To review the analytical performance of laboratories participating in the CAP NGS bioinformatics (NGSB) surveys, comprising NGSB1 for Illumina users and NGSB2 for Thermo Fisher Ion Torrent users, between 2016 and 2019. Design.--Responses from 78 laboratories were analyzed for accuracy and associated performance characteristics. Results.--The analytical sensitivity was 90.0% (1901 of 2112) for laboratories using the Illumina platform and 94.8% (2153 of 2272) for Thermo Fisher Ion Torrent users. Variant type and variant allele fraction were significantly associated with performance. False-negative results were seen mostly for multi-nucleotide variants and variants engineered at variant allele fractions of less than 25%. Analytical specificity for all participating laboratories was 99.8% (9303 of 9320). There was no statistically significant association between deletion-insertion length and detection rate. Conclusions.--These results demonstrated high analytical sensitivity and specificity, supporting the feasibility and utility of using in silico mutagenized NGS data sets as a supplemental challenge to CAP surveys for oncologyassociated variants based on physical samples. This program demonstrates the opportunity and challenges that can guide future surveys inclusive of customized in silico programs. [ABSTRACT FROM AUTHOR]

Context.--Laboratory managers and medical directors are charged with staffing their clinical laboratories as efficiently as possible. Objective.--To report and analyze the results of 3 College of American Pathologists Q-Probes studies that surveyed the normative rates of laboratory technical staffing ratios. Design.--Participants in the College of American Pathologists Q-Probes program submitted data on the levels of staffing and test volumes performed in their laboratories in 2014, 2016, and 2019. From these data, we calculated departmental productivity ratios, defined as testing volume per full-time equivalent, and degrees of managerial oversight, defined as the ratio of nonmanagement to management full-time equivalents. Participants completed general questionnaires surveying their hospital and laboratory demographics and practices, the data from which we determined demographic and practice characteristics that were significantly associated with technical staffing ratios. Results.--Sixty-seven, 82, and 79 institutions submitted data for the years 2019, 2016, and 2014, respectively. Technical staffing ratios varied widely among the various laboratory departments within each institution and among different institutions participating in this study. With the exception of cytology departments, productivity and managerial oversight ratios did not significantly change between these 3 studies. In the 2019 study, greater testing volumes were associated with higher productivity ratios. Significant associations between managerial oversight ratios and practice characteristics were not consistent across the 3 studies. Conclusions.--Technical staffing ratios varied widely among the various laboratory departments within each institution and among different institutions participating in this study. [ABSTRACT FROM AUTHOR]

Context.--Clinical and forensic testing for ethanol biomarkers, including ethyl glucuronide (EtG) and ethyl sulfate (EtS), is used to discern alcohol use from abstinence. These markers can be key in major decisions, including transplant eligibility or retaining licensure after alcohol misuse. Accuracy, precision, and recognition of the implications of reporting cutoffs are all essential for correct interpretation. Objective.--To evaluate trends in testing for EtG and EtS, including how laboratories perform testing and how comparable participant results are. Design.--The study examined the College of American Pathologists ethanol biomarker proficiency testing survey from 2013 to 2019. Trends in methodology, reporting cutoffs, and participant performance were evaluated for qualitative and quantitative EtG testing and for quantitative EtS testing. Results.--There was little consensus in reporting cutoffs, which ranged from 10 to 1000 ng/mL for EtG and 10 to 1500 ng/mL for EtS. Although median EtG and EtS compared well with target concentrations, individual participants' results varied widely. For quantitative enzyme immunoassay, accuracy and precision were best in EtG challenges less than 1500 ng/mL. For EtG or EtS by mass spectrometry, overall accuracy was good over a wide concentration range, but variability between participants was high. Approximately 10% (409 of 4059) of results were unacceptable, which for mass spectrometry corresponded to more than 35% above or below the group mean. Conclusions.--Although many participants performed well, there was insufficient consensus in reporting cutoffs, and a consistent fraction of laboratories failed to achieve survey standards. Guidelines for assay performance and reporting could greatly benefit laboratories and end users. [ABSTRACT FROM AUTHOR]

* Context.--Presence of antibodies to nuclear antigens (ANAs) above a threshold titer is an important diagnostic feature of several autoimmune diseases, yet titers reported vary between laboratories. Proficiency survey results can help clarify factors contributing to the variability. Objective.--To determine the contribution of HEp-2 ANA kits from different manufacturers to the variation in titers, and assess whether the differences between kits are consistent over the long term. Design.--HEp-2 ANA titers reported by laboratories participating in the external quality assessment proficiency testing surveys conducted by the College of American Pathologists between 2008 and 2018 were analyzed. The ANA titers reported for each specimen were ranked according to the kits being used by testing laboratories, and the statistical significance of the differences was determined. Results.--The ANA titer results were strongly influenced by the HEp-2 ANA kit used (P, .001). During the 11 years studied, the rank order of the ANA titer for each kit relative to the other kits was remarkably consistent. The rank of ANA titer for individual ANA patterns observed for each kit was similar to the overall rank of that kit. Conclusions.--Variability in ANA titers was strongly associated with the kits used, and the differences between kits were quite consistent during the 11 years studied. Because the variability is not random, it has the potential to be managed by harmonizing kits, which could lead to improved consistency in reporting ANA titers. [ABSTRACT FROM AUTHOR]

Objectives: The diagnostic workup of lymphoma continues to evolve rapidly as experience and discovery lead to the addition of new clinicopathologic entities and techniques to differentiate them. The optimal clinically effective, efficient, and cost-effective approach to diagnosis that is safe for patients can be elusive, in both community-based and academic practice. Studies suggest that there is variation in practice in both settings.the Aim Of This Review Is To: develop an evidence-based guideline for the preanalytic phase of testing, focusing on specimen requirements for the diagnostic evaluation of lymphoma.Methods: The American Society for Clinical Pathology, the College of American Pathologists, and the American Society of Hematology convened a panel of experts in the laboratory workup of lymphoma to develop evidence-based recommendations. The panel conducted a systematic review of the literature to address key questions. Using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach, recommendations were derived based on the available evidence, the strength of that evidence, and key judgments as defined in the GRADE Evidence to Decision framework.Results: Thirteen guideline statements were established to optimize specimen selection, ancillary diagnostic testing, and appropriate follow-up for safe and accurate diagnosis of indolent and aggressive lymphoma.Conclusions: Primary diagnosis and classification of lymphoma can be achieved with a variety of specimens. Application of the recommendations can guide decisions about specimen suitability, diagnostic capabilities, and correct utilization of ancillary testing. Disease prevalence in patient populations, availability of ancillary testing, and diagnostic goals should be incorporated into algorithms tailored to each practice environment. [ABSTRACT FROM AUTHOR]

Context.--As laboratories increasingly turn from single-analyte testing in hematologic malignancies to nextgeneration sequencing--based panel testing, there is a corresponding need for proficiency testing to ensure adequate performance of these next-generation sequencing assays for optimal patient care. Objective.--To report the performance of laboratories on proficiency testing from the first 4 College of American Pathologists Next-Generation Sequencing Hematologic Malignancy surveys. Design.--College of American Pathologists proficiency testing results for 36 different engineered variants and/or allele fractions as well as a sample with no pathogenic variants were analyzed for accuracy and associated assay performance characteristics. Results.--The overall sensitivity observed for all variants was 93.5% (2190 of 2341) with 99.8% specificity (22 800 of 22 840). The false-negative rate was 6.5% (151 of 2341), and the largest single cause of these errors was difficulty in identifying variants in the sequence of CEBPA that is rich in cytosines and guanines. False-positive results (0.18%; 40 of 22 840) were most likely the result of preanalytic or postanalytic errors. Interestingly, the variant allele fractions were almost uniformly lower than the engineered fraction (as measured by digital polymerase chain reaction). Extensive troubleshooting identified a multifactorial cause for the low variant allele fractions, a result of an interaction between the linearized nature of the plasmid and the Illumina TruSeq chemistry. Conclusions.--Laboratories demonstrated an overall accuracy of 99.2% (24 990 of 25 181) with 99.8% specificity and 93.5% sensitivity when examining 36 clinically relevant somatic single-nucleotide variants with a variant allele fraction of 10% or greater. The data also highlight an issue with artificial linearized plasmids as survey material for next-generation sequencing. [ABSTRACT FROM AUTHOR]

* Context.--Repair is a challenging diagnosis and a significant source of false-positive (FP) interpretations in cervical cytology. No large-scale study of performance of repair in the liquid-based era has been performed. Objective.--To evaluate the performance of repair in the College of American Pathologists Pap Education and Proficiency Testing (PT) programs. Design.--The FP rate for slides classified as repair was evaluated by preparation type, participant type (cytotechnologist, pathologist, or laboratory), and program. The specific misdiagnosis category and individual slide performance were also evaluated. The rate of misclassification of slides as repair by participants for other diagnostic categories in the Pap Education program was assessed. Results.--The overall FP rate was 1700 of 12 715 (13.4%). There was no significant difference by program or preparation type. Within the Education program there was no difference by participant type, but pathologists' FP rate in the PT program (47 of 514, 9.1%) was significantly better than cytotechnologists in the PT program (51 of 380, 13.4%) and pathologists in the Education program (690 of 4900, 14.1%). High-grade squamous intraepithelial lesions/cancers (HSIL+) accounted for 1380 of 1602 FP interpretations (86%) in Education, but 43 of 98 (43.9%) in PT. Most slides had a low rate of misclassification, but a small number were poor performers. False-negative diagnosis of HSIL+ as repair was less common, ranging from 0.7% to 1.8%. Conclusions.--Despite initial indications that liquidbased cytology might reduce the rate of misclassification of repair, FP interpretations remain common and are no different by preparation type. Misclassification is most commonly as HSIL or carcinoma, potentially resulting in significant patient harm. [ABSTRACT FROM AUTHOR]

Context.--Biomedical terminologies such as Logical Observation Identifiers, Names, and Codes (LOINC) were developed to enable interoperability of health care data between disparate health information systems to improve patient outcomes, public health, and research activities. Objective.--To ascertain the utilization rate and accuracy of LOINC terminology mapping to 10 commonly ordered tests by participants of the College of American Pathologists (CAP) Proficiency Testing program. Design.--Questionnaires were sent to 1916 US and Canadian laboratories participating in the 2018 CAP coagulation (CGL) and/or cardiac markers (CRT) surveys requesting information on practice setting, instrument(s) and test method(s), and LOINC code selection and usage in the laboratory and electronic health records. Results.--Ninety of 1916 CGL and/or CRT participants (4.7%) responded to the questionnaire. Of the 275 LOINC codes reported, 54 (19.6%) were incorrect: 2 codes (5934-2 and 12345-1) (0.7%) did not exist in the LOINC database and the highest error rates were observed in the property (27 of 275, 9.8%), system (27 of 275, 9.8%), and component (22 of 275, 8.0%) LOINC axes. Errors in LOINC code selection included selection of the incorrect component (eg, activated clotting time instead of activated partial thromboplastin time); selection of panels that can never be used to obtain an individual analyte (eg, prothrombin time panel instead of international normalized ratio); and selection of an incorrect specimen type. Conclusions.--These findings of real-world LOINC code implementation across a spectrum of laboratory settings should raise concern about the reliability and utility of using LOINC for clinical research or to aggregate data. [ABSTRACT FROM AUTHOR]

Context.--Detection of high-risk human papillomavirus (HR-HPV) in squamous cell carcinoma is important for classification and prognostication. In situ hybridization (ISH) is a commonly used HR-HPV--specific test that targets viral RNA or DNA. The College of American Pathologists (CAP) provides proficiency testing for laboratories performing HR-HPV ISH. Objective.--To compare the analytical performance of RNA- and DNA-based ISH methods on CAP HR-HPV proficiency tests. Design.--Data from the 2016-2018 CAP HPV ISH proficiency testing surveys were reviewed. These surveys consist of well-characterized samples with known status for HR-HPV, including 1 to 2 copies, 50 to 100 copies, 300 to 500 copies, and no copies of HR-HPV per cell. Results.--Ninety-five participants submitted 1268 survey results from 20 cores. Overall, RNA ISH had a significantly higher percentage of correct responses than DNA ISH: 97.4% (450 of 462) versus 80.6% (650 of 806) (P < .001). This disparity appears to be the consequence of a superior sensitivity of RNA ISH compared to DNA ISH for samples with 1 to 2 and with 50 to 100 copies of HRHPV per cell: 95.2% (120 of 126) versus 53.8% (129 of 240), P < .001, respectively, and 100% (89 of 89) versus 76.3% (119 of 156), P < .001, respectively. Conclusions.-An assessment of CAP HR-HPV proficiency test performance indicates that RNA ISH shows significantly higher accuracy than DNA ISH owing to higher analytical sensitivity of RNA ISH in tumors with low (1-2 copies per cell) to intermediate (50-100 copies per cell) HR-HPV viral copy numbers. These data support the use of RNA over DNA ISH in clinical laboratories that perform HR-HPV testing as part of their testing algorithms. [ABSTRACT FROM AUTHOR]

Context.--The goal of the College of American Pathologists Accuracy-Based Proficiency Testing Program is to promote the quality, standardization, and harmonization of clinical laboratory results through proficiency testing specimens that are free from matrix effects, have target values that are traceable to reference methods, and that probe the limitations of current methods. Objective.--To summarize the first 6 years of the Accuracy-Based Vitamin D Survey and highlight key insights from the data generated as it relates to assay performance. Design.--Accuracy-based challenges were created by using pooled human serum samples. Certain samples were derived from participants in an institutional review board-approved protocol in which vitamin D-deficient participants were treated with ergocalciferol (vitamin D2). Reference targets for the survey were set by the Centers for Disease Control and Prevention using isotope-dilution liquid chromatography-tandem mass spectrometry. Each method was compared with the reference method procedure over the course of the program (n = 43 proficiency testing samples). Results.--Linear regression versus the reference method procedure revealed proportional biases across the methods, ranging from 0.0% to 16.7%. Pearson correlation coefficients (r2) ranged from 0.902 to 0.996. Results were influenced by the concentration of 25-hydroxyvitamin D2 as well as the C-3 epimer of 25-hydroxyvitamin D3. During the 6 years, 2 manufacturers altered their assays to match the reference method procedure more closely. Conclusions.--There is considerable bias, both proportional bias and sample-specific matrix effects, affecting many assays. This ongoing accuracy-based proficiency testing program for vitamin D will provide the data needed for laboratories and manufacturers to improve their assays and thereby patient care. [ABSTRACT FROM AUTHOR]

Objectives: To review impact of the ASCO/CAP 2018 update on HER2 testing.Methods: HER2 fluorescence in situ hybridization (FISH) test requests from primary and metastatic breast cancers between August 2018 and January 2019 were included. FISH results requiring a changed algorithm under the new guidelines (groups 2, 3, and 4) were identified and HER2:CEN17 ratios, average HER2, CEN17 signals/cell, and HER2 immunohistochemistry (IHC) results were recorded.Results: Of the HER2 FISH cases 176/812(21.7%) fell within groups 2, 3, or 4; 0/12, 1/12, and 2/152 cases were positive (3+) by IHC, and 1/12, 2/12, and 6/152 cases were positive after targeted scoring from groups 2, 3, and 4, respectively. Following 2018 updates, 8.3%, 25%, and 5.3% of the groups 2, 3, and 4 were positive, respectively.Conclusions: Groups 2, 3, and 4 constituted over 20% of HER2 FISH tests in a reference laboratory. The 2018 ASCO/CAP update significantly decreased the HER2 positivity rate. [ABSTRACT FROM AUTHOR]

* Context.--The performance of laboratory testing has recently come under increased scrutiny as part of important and ongoing debates on regulation and reimbursement. To address this critical issue, this study compares the performance of assay methods, using either commercial kits or assays designed and implemented by single laboratories ("home brews"), including next-generation sequencing methods, on proficiency testing provided by the College of American Pathologists Molecular Oncology Committee. Objective.--To compare the performance of different assay methods on College of American Pathologists proficiency testing for variant analysis of 3 common oncology analytes: BRAF, EGFR, and KRAS. Design.--There were 6897 total responses across 35 different proficiency testing samples interrogating 13 different variants as well as wild-type sequences for BRAF, EGFR, and KRAS. Performance was analyzed by test method, kit manufacturer, variants tested, and preanalytic and postanalytic practices. Results.--Of 26 reported commercial kits, 23 achieved greater than 95% accuracy. Laboratory-developed tests with no kit specified demonstrated 96.8% or greater accuracy across all 3 analytes (1123 [96.8%] acceptable of 1160 total responses for BRAF; 848 [97.5%] acceptable of 870 total responses for EGFR; 942 [97.0%] acceptable of 971 total responses for KRAS). Next-generation sequencing platforms (summed across all analytes and 2 platforms) demonstrated 99.4% accuracy for these analytes (165 [99.4%] acceptable of 166 total next-generation sequencing responses). Slight differences in performance were noted among select commercial assays, dependent upon the particular design and specificity of the assay. Wide differences were noted in the lower limits of neoplastic cellularity laboratories accepted for testing. Conclusions.--These data demonstrate the high degree of accuracy and comparable performance across all laboratories, regardless of methodology. However, care must be taken in understanding the diagnostic specificity and reported analytic sensitivity of individual methods. [ABSTRACT FROM AUTHOR]

* Context.--There has been a rapid expansion of nextgeneration sequencing (NGS)-based assays for the detection of somatic variants in solid tumors. However, limited data are available regarding the comparative performance of NGS and non-NGS assays using standardized samples across a large number of laboratories. Objective.--To compare the performance of NGS and non-NGS assays using well-characterized proficiency testing samples provided by the College of American Pathologists (CAP) Molecular Oncology Committee. A secondary goal was to compare the use of preanalytic and postanalytic practices. Design.--A total of 17 343 responses were obtained from participants in the BRAF, EGFR, KRAS, and the Multigene Tumor Panel surveys across 84 different proficiency testing samples interrogating 16 variants and 3 wild-type sequences. Performance and preanalytic/ postanalytic practices were analyzed by method. Results.--While both NGS and non-NGS achieved an acceptable response rate of greater than 95%, the overall performance of NGS methods was significantly better than that of non-NGS methods for the identification of variants in BRAF (overall 97.8% versus 95.6% acceptable responses, P = .001) and EGFR (overall 98.5% versus 97.3%, P = .01) and was similar for KRAS (overall 98.8% and 97.6%, P = .10). There were specific variant differences, but in all discrepant cases, NGS methods outperformed non-NGS methods. NGS laboratories also more consistently used preanalytic and postanalytic practices suggested by the CAP checklist requirements than non-NGS laboratories. Conclusions.--The overall analytic performance of both methods was excellent. For specific BRAF and EGFR variants, NGS outperformed non-NGS methods and NGS laboratories report superior adherence to suggested laboratory practices. [ABSTRACT FROM AUTHOR]

Context.--Next-generation sequencing--based assays are being increasingly used in the clinical setting for the detection of somatic variants in solid tumors, but limited data are available regarding the interlaboratory performance of these assays. Objective.--To examine proficiency testing data from the initial College of American Pathologists (CAP) Next- Generation Sequencing Solid Tumor survey to report on laboratory performance. Design.--CAP proficiency testing results from 111 laboratories were analyzed for accuracy and associated assay performance characteristics. Results.--The overall accuracy observed for all variants was 98.3%. Rare false-negative results could not be attributed to sequencing platform, selection method, or other assay characteristics. The median and average of the variant allele fractions reported by the laboratories were within 10% of those orthogonally determined by digital polymerase chain reaction for each variant. The median coverage reported at the variant sites ranged from 1922 to 3297. Conclusions.--Laboratories demonstrated an overall accuracy of greater than 98% with high specificity when examining 10 clinically relevant somatic single-nucleotide variants with a variant allele fraction of 15% or greater. These initial data suggest excellent performance, but further ongoing studies are needed to evaluate the performance of lower variant allele fractions and additional variant types. [ABSTRACT FROM AUTHOR]