US Clinical Laboratories Research Articles

Moving forward from Cockcroft-Gault creatinine clearance to race-free estimated glomerular filtration rate to improve medication-related decision-making in adults across healthcare settings: A consensus of the National Kidney Foundation Workgroup for Implementation of Race-Free eGFR-Based Medication-Related Decisions

Abstract Purpose The goals of this paper are to (1) provide evidence and expert consensus to support a unified approach to estimating kidney filtration in adults with stable kidney function using race-free estimated glomerular filtration rate (eGFR) in place of Cockcroft-Gault estimated creatinine clearance (C-G eCrCL) for medical and medication-related decisions, and (2) demonstrate how adjusting eGFR results for an individual’s body surface area (BSA) when it is higher or lower than 1.73 m2 will improve results for medication-related decisions. Summary C-G eCrCL is predominantly used by US pharmacists to determine eGFR for the purposes of medication-related decisions, even though more accurate eGFR equations exist. Several driving factors make it the ideal time to shift clinical practice from using C-G eCrCL to eGFR. These factors include the following: (1) 2024 Food and Drug Administration (FDA) guidance for industry recommends eGFR over C-G eCrCL to evaluate the impact on pharmacokinetics in patients with impaired kidney function; (2) a joint National Kidney Foundation (NKF) and American Society of Nephrology task force recommends 3 race-free Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) eGFR equations for medical and medication-related decision-making; (3) the almost ubiquitous use of standardized serum creatinine assay methods in US clinical laboratories; and (4) increasing availability and use of serum cystatin C for eGFR assessment. This publication guides practitioners through the rationale for using race-free eGFR equations for medication-related decisions and how to implement this practice change. Conclusion The NKF Workgroup for Implementation of Race-Free eGFR-Based Medication-Related Decisions suggests that health systems, health settings, clinical laboratories, electronic health record systems, compendia and data vendors, and healthcare practitioners involved with medication-related decision-making transition away from C-G eCrCL and towards the race-free eGFR equations for more accurate assessment of kidney filtration and consistency in medication and medical decision-making across the US.

Strengthening the Application of the DAIDS GCLP Guidelines: The Implementation of an Integrated Laboratory Oversight Framework.

The Division of AIDS (DAIDS) Good Clinical Laboratory Practice (GCLP) Guidelines establish a framework to guide the oversight of laboratories supporting DAIDS-sponsored clinical research or trials. Compliance with these guidelines promotes data reliability, validity, and safety of the clinical research or trial participants and laboratory staff and ensures adherence to regulatory requirements. Acknowledgment and adoption of the DAIDS GCLP Guidelines are critical in building laboratory capacity and preparedness for conducting clinical trials. In collaboration with DAIDS, laboratory experts support the implementation of the DAIDS Integrated Laboratory Oversight Framework (Framework) activities. This article describes the implementation of the GCLP Guidelines, the Framework activities, and the coordinated efforts to strengthen laboratory performance. The Framework activities include four components: Quality Assurance Oversight, GCLP Audits, GCLP Training, and Laboratory Quality Improvement. Comparison of GCLP Guidelines with other regulations or standards, including U.S. Clinical Laboratory Improvement Amendments regulation 42 CFR 493, College of American Pathologists, World Health Organization GCLP, and International Organization for Standardization, ISO 15189:2012 standards, highlighted the differences and similarities to guide integration and harmonization efforts. Processes related to the Framework activities are outlined in detail, including key data derived from the managed activities of over 175 laboratories worldwide. Via the evolution of the DAIDS GCLP Guidelines and laboratory oversight workflows, the laboratories participating in DAIDS-sponsored clinical research and trials have successfully participated in internal and external regulatory audits. The collaborative and integrated oversight approach promotes knowledge-sharing and accountability to support the implementation of the DAIDS GCLP Guidelines and compliance monitoring. Lessons learned have helped with the implementation of the DAIDS integrated laboratory oversight approach and quality oversight programs at multiple laboratories worldwide.

Social Determinants of Hepatitis C Virus Infection in the United States, 2016-2021.

This cross-sectional study assessed hepatitis C virus (HCV) antibody and RNA test results performed from 2016 to 2021 at a large US clinical reference laboratory. When individual patient factors (ie, income, education, and race/ethnicity) were not available, estimates from the US Census were linked to the residential zip code. The final analytic cohort comprised 19,543,908 individuals with 23,233,827 HCV antibody and RNA test results. An analysis of progressively increasing poverty quintiles demonstrated an increasing trend in both HCV antibody positivity (from 2.6% in the lowest quintile to 6.9% in the highest, P < 0.001 for trend) and HCV RNA positivity (from 1.0% to 3.6%, P < 0.001 for trend). Increasing levels of education were associated with a decreasing trend in both HCV antibody positivity (from 8.4% in the least educated quintile to 3.0% in the most, P < 0.001 for trend) and HCV RNA positivity (from 4.7% to 1.2%, P < 0.001 for trend). Persistent differences in positivity rates by these social determinants were observed over time. HCV antibody and RNA positivity rates were nearly identical in predominantly Black non-Hispanic, Hispanic, and White non-Hispanic zip codes. However, after adjustment for all other factors in the study, residents of predominantly Black non-Hispanic and Hispanic zip codes were significantly less likely to test positive for HCV RNA (adjusted odds ratios [AOR]: 0.51, 95% confidence interval [CI]: 0.51-0.52; AOR: 0.46, 95% CI: 0.46-0.46, respectively). These findings may benefit targeted intervention initiatives by public health agencies.

Optimizing Identification of Allergic Sensitization to Seasonal Inhalant Allergens in the USA: Implications for Constructing Optimal Panels to Evaluate Patients with Allergy

Introduction: While a specific number and type of antigens are recognized to detect perennial inhalant allergies, the optimal number and combination of allergens to reliably identify seasonal allergic sensitization is unclear due to limited national data. This study analyzed aeroallergen testing data from a large US clinical reference laboratory to provide guidance for optimizing seasonal allergen test selection. Methods: The 2019 serum IgE tests for seasonal inhalant allergens were identified from the Quest Diagnostics database. Patients with results for at least 1 of 31 seasonal allergens across 4 allergen classes (11 trees, 7 weeds, 5 grasses, and 8 molds) were analyzed. A step-by-step conditional approach was employed to determine the minimum number and species of allergens needed to identify at least 98% of sensitized patients for each class. Results: Of 88,042 patients tested for ≥1 seasonal allergen, 1.5%, 1.8%, 1.3%, and 1.6% were tested for all trees, weeds, grasses, and molds, respectively. Of those tested for all allergens within a class, 40.4%, 38.6%, 29.5%, and 21.2% were sensitized to at least one tree, weed, grass, or mold allergen, respectively. Identification of ≥98% of sensitized patients within a class required 8 allergens for trees (mountain cedar, maple box elder, walnut, white ash, elm, birch, cottonwood, and hickory/pecan), 5 for weeds (common ragweed short, rough pigweed, English plantain, lamb's quarters/goosefoot, and Russian thistle), 3 for grasses (June/Kentucky blue grass, Johnson grass, and Bermuda grass), and 7 for molds (Alternaria alternata, Aspergillus fumigatus, Mucor racemosus, Epicoccum purpurascens, Penicillium notatum, Helminthosporium halodes, and Fusarium moniliforme). Conclusion: A minimum of 23 antigens is required to optimally detect sensitization to four classes of seasonal allergens (i.e., ≥98% identification). The addition of these allergens to unique perennial allergens (cat, dog, mouse, cockroach, and 2 dust mite species) results in a comprehensive elucidation of inhalant allergen sensitization. This knowledge provides a pivotal guide for clinical laboratories as they construct allergen panels to optimize diagnostic yield.

Vaginitis Polymerase Chain Reaction (PCR) Testing and Occurrence of Mixed Infections: Results from a Large US Clinical Laboratory

Vaginitis Polymerase Chain Reaction (PCR) Testing and Occurrence of Mixed Infections: Results from a Large US Clinical Laboratory

Cascade testing after exome sequencing: Retrospective analysis of linked family data at 2 US laboratories

PurposeCascade testing, the process of testing a proband’s at-risk relatives, is integral to realizing the full value of genomic sequencing. However, there is little empirical evidence on the uptake of cascade testing after a positive exome sequencing (ES) result in a population of probands with diverse clinical indications. MethodsWe retrospectively reviewed administrative data from 2 US clinical laboratories that perform ES. For each proband with a positive ES result, we used linked family data to describe the frequency of relatives’ cascade testing performed at the same laboratory, variant detection yield of cascade tests, and characteristics of probands and relatives categorized on the basis of cascade testing completion. ResultsAmong the 3723 positive ES results across both laboratories, 426 relatives of 282 probands completed cascade testing (uptake = 7.6%). An average of 1.5 relatives (SD = 0.9) were tested per proband. Of the 426 relatives tested, 200 had a variant of interest detected (variant detection yield = 47.0%). ConclusionIn our real-world data analysis, a small proportion of probands with a positive ES result subsequently had relatives complete cascade testing at the same laboratory. However, approximately half of the tested relatives received a clinically significant result that could have implications for clinical management or reproductive planning. Additional research on ways to increase cascade testing uptake is warranted.

Reported Awareness and Adoption of 2021 Estimated Glomerular Filtration Rate Equations Among US Clinical Laboratories, March 2022

This study includes clinical laboratories that participated in the first general chemistry proficiency testing survey in 2022 to assess awareness and adoption of new equations from the Chronic Kidney Disease Epidemiology Collaboration for estimated glomerular filtration rate (eGFR) that eliminated race-adjustment factors, including one based on creatinine and one based on creatinine and cystatin C.

Comparison of Drug Resistance of Bile Isolated Bacteria in Nanjing from 2017 to 2020

Background: Analyzed pathogenic bacteria isolated from bile samples of patients with biliary tract infection and their drug resistance in the first Affiliated Hospital of Nanjing Medical University from 2017 to 2020, so as to provide evidence for the treatment of biliary tract infection. Methods: Clinical strains isolated from bile specimens of patients suspected of biliary infection in the First Affiliated Hospital of Nanjing Medical University from 2017 to 2020 were collected, The drug susceptibility criteria are based on the standards published by the National Standardization Committee of the US Clinical Laboratories. WHONET 5.6 software was used to analyze the distribution of pathogens and drug resistance. Results: From January 2017 to December 2020, a total of 2006 strains of bile pathogenic bacteria were cultured and identified. There were 1253 cases of gram-negative bacilli, 638 cases of gram-positive cocci, 98 cases of fungi, and 17 cases of Gram-positive bacilli. The top five pathogens of Gram negative bacilli were Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas aeruginosa, Acinetobacter baumannii. The top five pathogens of gram positive cocci were Enterococcus faecium, Enterococcus faecalis, Enterococcus gallinarum, Enterococcus faecalis and Staphylococcus epidermidis. the resistance rate of Escherichia coli to ampicillin, ampicillin / sulbactam, cefotetan, ceftazidime, ceftriaxone,cefepime, itronam, compound trimethoprim decreased, the resistance rate of Klebsiella pneumoniae to gentamicin, levofloxacin decreased, the resistance rate of Enterobacter cloacae to ciprofloxacin, levofloxacin decreased. the resistance rate of Pseudomonas aeruginosa to ceftazidime, cefepime, gentamicin decreased. the resistance rate of Acinetobacter baumannii to ceftazidime, ciprofloxacin decreased. the resistance rate of Enterococcus faecium to penicillin G, high concentration streptomycin, erythromycin decreased. Conclusions: Enterogenic pathogens were the main pathogens in China. Such as Escherichia coli, Klebsiella pneumoniae, Enterococcus faecalis and Enterococcus faecalis; Nosocomial infection pathogens. For example, Pseudomonas aeruginosa and Acinetobacter also need to be paid attention to. Clinicians should improve their awareness of microbiological examination and provide more reliable pathogenic evidence for the selection of clinical antibiotic.

Cervical Visual Inspection with Acetic Acid (VIA) and Oncogenic Human Papillomavirus Screening in Rural Indigenous Guatemalan Women: Time to Rethink VIA.

Single-visit “screen-and-treat” strategies using visual inspection with acetic acid (VIA) and cryotherapy (liquid nitrous oxide ablation) in low-resource settings are commonly used to detect and treat precancerous lesions for cervical cancer prevention. This study compared VIA sensitivity and specificity in rural indigenous Guatemalan communities, to that of oncogenic human papillomavirus (HPV) testing for detection of precancerous changes, using cytology as the reference standard. Between 3–8 September 2017, trained nurses examined 222 women aged 23–58 years with VIA. Specimens for liquid-based cytology and HPV testing were obtained prior to VIA with a cytobrush and transported in PreservCyt to a US clinical laboratory. VIA and HPV test sensitivities were assessed as proportions of women with abnormal cytology that had abnormal VIA or HPV results, respectively, and specificities, as proportions with normal cytology with normal VIA or negative HPV tests. Of 222 women, 18 (8.1%) had abnormal cytology (1 carcinoma in a participant who received VIA-based cryotherapy in 2015, 4 high- and 5 low-grade squamous intraepithelial lesions, and 8 atypical squamous cells of undetermined significance (ASCUS)). Excluding ASCUS, sensitivities of VIA and HPV were 20.0% and 100%, respectively. VIA-based screening may not be acceptable for detecting precancerous lesions, and field cryotherapy for preventing malignancy. The World Health Organization recommended in 2021 “…using HPV DNA detection as the primary screening test rather than VIA or cytology”.

New Equations for Estimating Glomerular Filtration Rate.

The Chronic Kidney Disease Epidemiology (CKD-EPI) Collaboration has recently published new equations for calculating estimated glomerular filtration rate (eGFR) based on serum creatinine and cystatin C (1). Implementation of these new equations for routine reporting of eGFR in adults is strongly recommended (2). For approximately 15 years, US clinical laboratories have been encouraged to report eGFR with creatinine measurements in adults (3). This recommendation was based on the relatively high prevalence of chronic kidney disease, which affects approximately 14% of the US adult population, and which often goes undetected in its early stages. Changes in serum creatinine concentration may not appear significant (e.g., 0.80 mg/dL vs 1.00 mg/dL) and may even be within the typical population-based reference interval and therefore not flagged on laboratory reports. But that change represents a nearly 25% difference in eGFR (in a 65-year-old female, 78 vs 59 mL/min/1.73m2) using the current CKD-EPI creatinine eGFR equation.

Analysis of Common Pathogenic Bacteria and Drug Resistance of Biliary Tract Infection in Nanjing Area

Background: Analyze the distribution and drug resistance of pathogenic bacteria that cause biliary tract infections in Nanjing, and provide evidence for the rational use of antibacterial drugs in clinical practice. Methods: Clinical strains isolated from bile specimens of patients suspected of biliary infection in the First Affiliated Hospital of Nanjing Medical University in 2019 were collected, The drug susceptibility criteria are based on the standards published by the National Standardization Committee of the US Clinical Laboratories. WHONET 5.6 software was used to analyze the distribution of pathogens and drug resistance. Results: A total of 693 strains of pathogenic bacteria were isolated, including 448 Gram-negative bacteria(64.6%), 245 Gram-positive bacteria (35.4%). The top three pathogens were 210 strains of Escherichia coli(30.3%), 87 strains of enterococcus faecium (12.6%), 76 strains of klebsiella pneumoniae (11.0%), The resistance rates of Escherichia coli to ampicillin, cefuroxime, cefazolin, ceftriaxone, piperacillin and ampicillin / sulbactam were 80.1%, 69.4%, 67.3%, 64.1%, 63.6% and 62.8%, The resistance rates of Klebsiella pneumoniae to ampicillin / sulbactam, cefuroxime and cefazolin were 65.8%, 64.5% and 61.1%, The resistance rates of Enterobacter cloacae to ceftriaxone, ceftazidime and aztreonam were 56.2%, 53.1% and 53.1%, The resistance rates of Enterococcus faecium to moxifloxacin, clindamycin, erythromycin, penicillin G, ampicillin, ciprofloxacin and levofloxacin were 100%, 90%, 76%, 72.1%, 64.4%, 64% and 62%. Conclusions: Pathogens of biliary tract infections are mainly Enterobacteriaceae such as Escherichia coli and Klebsiella pneumoniae, followed by Enterococcus faecium and Enterococcus faecalis. There were many drug-resistant bacteria, so we should pay attention to bile specimen culture and drug sensitivity test.

Decreased influenza activity during the COVID-19 pandemic-United States, Australia, Chile, and South Africa, 2020.

Transplant recipients are among the groups for whom the updated recommendations for 2020–2021 influenza vaccination should generally be considered essential, notably in the face of the COVID‐19 pandemic.

A Comparison of US Clinical Laboratory Chlamydia and Gonorrhea Testing Practices Before and After the 2014 Centers for Disease Control and Prevention Testing Recommendations.

Adherence to recommended laboratory testing practices is crucial for sexually transmitted infection prevention and control. The objective of this article is to compare Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) testing practices of US clinical laboratories in 2013 before the updated 2014 Centers for Disease Control and Prevention recommendations and in 2015 after the updated recommendations. A total of 236 clinical laboratories participated in surveys about their 2013 and 2015 CT and NG testing practices, including questions on specimen types collected and assays used. There was an increase of 5 laboratories offering CT nucleic acid amplification testing (NAAT) from 2013 to 2015 and an increase of 5 laboratories offering NG NAAT. There was a net increase of 3 laboratories accepting urine for CT and NG NAAT, the preferred specimen type for male individuals. There was not a net increase in the total number of laboratories accepting vaginal swabs for CT NAAT (n = 89 in 2013 and 2015), the preferred specimen type for female individuals, but there was an increase of 3 laboratories accepting vaginal swabs for NG NAAT. The number of laboratories performing NG susceptibility testing decreased from 100 in 2013 to 89 in 2015 (χ2 = 1.07, P > 0.10). There were no major changes in testing practices in the 2-year period from 2013 to 2015. However, there were some small shifts, including increases in the use of NAATs, acceptance of Centers for Disease Control and Prevention-preferred specimen types for CT/NG, and changes in usage of assays by manufacturer.

Routine HIV Test Results in 6 US Clinical Laboratories Using the Recommended Laboratory HIV Testing Algorithm With Geenius HIV 1/2 Supplemental Assay.

Geenius HIV 1/2 Supplemental Assay (Geenius; Bio-Rad Laboratories) is the only Food and Drug Administration-approved HIV-1/HIV-2 antibody differentiation test for the second step in the HIV laboratory testing algorithm. We characterized the occurrence of true HIV-1 and HIV-2 infections as well as false results in 6 US clinical laboratories using Geenius. We examined routine HIV testing outcome data from the time the laboratories began using the algorithm with Geenius until September 30, 2017. We calculated the positive predictive value for Geenius HIV-1 and HIV-2 reactivity separately. Of 5,046,684 specimens tested, 41,791 had reactive antigen/antibody test results. Most specimens with reactive antigen/antibody results were HIV-1 antibody-positive established infections (n = 32,421), 1,865 of which also had indeterminate HIV-2 bands present. Ninety-three specimens were HIV-2 antibody positive or untypable for HIV-1/HIV-2 antibody. Acute HIV-1 infections were found in 528 specimens; 881 specimens lacked the nucleic acid test to determine the possibility of acute HIV-1 infection. False-positive antigen/antibody test results were present in 7505 specimens. Few specimens (n = 363) had false-positive antigen/antibody results with indeterminate Geenius and negative HIV-1 nucleic acid test results. The positive predictive values of Geenius reactivity were 99.4% for HIV-1 and 4.3% for HIV-2. Routine testing using the laboratory testing algorithm with Geenius resulted in most specimens resolving as HIV negative or HIV-1 positive. The occurrence of indeterminate HIV-2 bands with a Geenius final assay interpretation of HIV-1 positive was more common than true HIV-2 infections. Reporting indeterminate HIV-2 results in this situation may cause confusion with interpreting HIV infection status.

1782. Real-World HIV Diagnostic Testing Patterns in the United States

BackgroundCurrent HIV diagnostic laboratory testing guidelines from the US Centers for Disease Control and Prevention (CDC) recommend a sequence of tests for detection, differentiation, and confirmation of HIV-1 and HIV-2 diagnosis. There is a gap in knowledge about real-world implementation of the testing algorithm. The aim of this study was to characterize the population that underwent HIV antibody differentiation and confirmatory testing and to describe subsequent testing patterns from a large US clinical laboratory database.MethodsPatients who received one or more HIV-1/2 antibody differentiation test (BioRad Geenius™ HIV 1/2 Supplemental Assay [Geenius]) in the Quest Diagnostics laboratory database between January 1, 2017 and December 31, 2017 were selected into the study; earliest test date was index date. Geenius tests, HIV-1 qualitative RNA (Aptima HIV-1 RNA Qualitative Assay [Aptima]), and HIV-2 DNA/RNA confirmatory tests subsequent to index date were captured. Study measures included pt demographic characteristics, testing frequency and sequencing, and test results. For patients with >1 Geenius test in 2017, concordance between index and subsequent test results was assessed.ResultsThere were 26,319 unique patients identified who received ≥1 HIV antibody differentiation result from the Geenius assay. Mean age was 40.7 ± 14.3 years, 66.4% were male, and 42.5% were from southern states. Among the study population, there were 28,954 Geenius, 7,234 Aptima, and 298 HIV-2 DNA/RNA confirmatory tests. 26.4% of Geenius test results were discordant with the initial positive fourth-generation HIV screening results and required subsequent confirmatory testing. In terms of sequencing, the CDC-recommended HIV diagnostic algorithm was followed 74% of the time after screening. 8.5% of patients had >1 Geenius test in 2017; 11.2% of the retests returned different results compared with the first test.ConclusionThe CDC recommended algorithm for HIV diagnosis is complex for laboratories to implement and currently available assays do not support testing efficiency. To mitigate observed inefficiencies and reduce the laboratory burden of HIV testing, a more accurate and reliable approach for HIV differentiation and confirmatory testing is needed.Disclosures All authors: No reported disclosures.

Sources of Variability and Accuracy of Performance Assessment in the Clinical Pharmacology Quality Assurance Proficiency Testing Program for Antiretrovirals.

The Clinical Pharmacology Quality Assurance (CPQA) program provides semiannual proficiency testing (PT) of antiretroviral analytes for 11 US and international clinical pharmacology laboratories (CPLs) to ensure interlaboratory comparability. In this article, we provide estimates of the main sources of variability and assess the accuracy of the algorithm for the assessment of performance. Descriptive statistics are reported from 13 PT rounds from 2010 to 2016. Eight of the most common antiretroviral analytes were examined. Variance components analysis was used to rank the relative contributions of CPLs, antiretroviral analyte, and concentration category (low, medium, and high) to bias and variability using mixed models. Binary classification metrics of the PT assessment algorithm are calculated in comparison with a model using 95% prediction limits around estimated regression equations. CPLs provided 4109 reported concentrations of 65 unique samples for each of the 8 antiretroviral analytes across 13 PT rounds. Individual CPL accounted for the greatest amount of total variability (4.4%). Individual CPL and analyte combination (interaction) accounted for the greatest amount of bias (8.1%). Analyte alone accounted for 0.5% or less for total variability and bias. Overall, using a ±20% acceptance window around the final target, 97% of individual reported concentrations were scored acceptable, and 96% of antiretroviral/round scores were deemed satisfactory. Comparison with the regression model gave 100% sensitivity but only 34.47% specificity. Narrowing the acceptance window to ±15% improved specificity to 84.47% while maintaining a 99.17% sensitivity. The current CPQA PT scoring algorithm that use a ±20% acceptance window seems to suffer from a low specificity and may be too lenient. A stricter ±15% acceptance window would increase specificity and overall accuracy while lowering the overall pass rate by only 3%.

HLA alleles and haplotypes observed in 263 US families

The 17th International HLA and Immunogenetics Workshop (IHIW) conducted a project entitled “The Study of Haplotypes in Families by NGS HLA”. We investigated the HLA haplotypes of 1017 subjects in 263 nuclear families sourced from five US clinical immunogenetics laboratories, primarily as part of the evaluation of related donor candidates for hematopoietic stem cell and solid organ transplantation. The parents in these families belonged to five broad groups – African (72 parents), Asian (115), European (210), Hispanic (118) and “Other” (11). High-resolution HLA genotypes were generated for each subject using next-generation sequencing (NGS) HLA typing systems. We identified the HLA haplotypes in each family using HaplObserve, software that builds haplotypes in families by reviewing HLA allele segregation from parents to children. We calculated haplotype frequencies within each broad group, by treating the parents in each family as unrelated individuals. We also calculated standard measures of global linkage disequilibrium (LD) and conditional asymmetric LD for each ethnic group, and used untruncated and two-field allele names to investigate LD patterns. Finally we demonstrated the utility of consensus DNA sequences in identifying novel variants, confirming them using HLA allele segregation at the DNA sequence level.

Prenatal cell‐free DNA screening for fetal aneuploidy in pregnant women at average or high risk: Results from a large US clinical laboratory

BackgroundWe evaluated the performance of a cell‐free DNA (cfDNA) prenatal screening assay for trisomies 21, 18, and 13, and sex chromosome aneuploidies (SCAs) among a population of pregnant women that included both those at average and high risk.MethodsSpecimen collection, cfDNA extraction, massively parallel sequencing, and bioinformatics analysis were conducted per laboratory protocol. Assay results, concordance with pregnancy outcomes, and performance characteristics were evaluated.ResultsA total 75,658 specimens from 72,176 individual pregnant women were received. Technical reasons accounted for 288 (0.4% of all received samples) tests not performed. In the final analysis cohort (N = 69,794), 13% of pregnancies were considered at average risk and 87% at high risk. Mean gestational age at specimen collection was 15.1 weeks. Of the 69,794 unique pregnancies, 1,359 (1.9%) had positive test results. Among the results with confirmed outcomes, PPV for trisomies 21, 18, and 13 was 98.1%, 88.2%, and 59.3%, respectively; the PPV was 69.0% for SCAs and 75.0% for microdeletions. Overall, PPV was 87.2%, sensitivity was 97.9%, and specificity was 99.9%.ConclusionThis cfDNA prenatal screening assay provides highly accurate discrimination between affected and unaffected pregnancies among a population of pregnant women at average and high risk for fetal genetic abnormalities.

An Evaluation of Reported Follicle-stimulating Hormone, Luteinizing Hormone, Estradiol, and Prolactin Reference Ranges in the United States

ObjectiveTo characterize US clinical laboratory reference range reporting and testing methods of follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol, and prolactin. MethodsOne hundred and seventeen US laboratories were surveyed. Outcomes measured were variation in lower and upper limits of normal male reference ranges for serum FSH, LH, estradiol, and prolactin, method of analysis and source of reference range ResultsThe upper limit of normal reference ranges for FSH, LH, estradiol, and prolactin varied substantially across laboratories compared to the lower limits. The range of upper limits of FSH, LH, estradiol, and prolactin respectively are 7.9-20.0, 4.9-86.5, 37.7-77.0, and 7.4-25.0. Ninety-four percent of laboratories performed measurements on in-house high throughput analyzer utilizing immunoassays. Seventy percent of reported reference ranges for each hormone were based on validation studies of the analyzer's package insert values. Ten percent of laboratories derived their own reference ranges. Both the validation studies and derivations were based on a limited number of patient samples, ranging from 20 to 200. ConclusionCurrent reference ranges are based on small population studies of men with unknown medical histories, sexual or reproductive function. Influence of race and age has not been evaluated and could potentially be important in normal variation. The absence of standard information has yielded a spectrum of upper and lower normal values, which could delay an appropriate male infertility evaluation. Our findings highlight the need for a large population study of males with known normal sexual and reproductive function to formulate more accurate clinical reference ranges.

Q fever: an under-reported reportable communicable disease.

The objective of this study was to provide real-world clinical laboratory-based data to supplement Centers for Disease Control and Prevention (CDC) reporting of Q fever. We analysed titre results of specimens submitted to a large US clinical laboratory for Coxiella burnetii IgG antibody testing from 2010 through 2016. Presumptive Q fever was defined as acute (phase II IgG titre ⩾1:128, phase I titre <1:1024) or chronic (phase I IgG titre ⩾1:1024), based on the results from a single serum specimen. During 2010-2016, an average of 328 presumptive acute Q fever cases were identified at Quest each year, nearly three times the annual average reported to the CDC (122). During the same period, the number of chronic cases identified annually at Quest Diagnostics (34) was similar to that reported to the CDC (29). These findings suggest that CDC data may underestimate the incidence of acute Q fever.