An Evaluation Framework for a Novel Process to Codevelop Written and Computable Guidelines

Clinical practice guidelines (CPGs) support individual and population health by translating new, evidence-based knowledge into recommendations for health practice. CPGs can be provided as computable, machine-readable guidelines that support the translation of recommendations into shareable, interoperable clinical decision support and other digital tools (eg, quality measures, case reports, care plans). Interdisciplinary collaboration among guideline developers and health information technology experts can facilitate the translation of written guidelines into computable ones. The benefits of interdisciplinary work include a focus on the needs of end-users who apply guidelines in practice through clinic decision support systems as part of the Centers for Disease Control and Prevention's (CDC's) Adapting Clinical Guidelines for the Digital Age (ACG) initiative, a group of interdisciplinary experts proposed a process to facilitate the codevelopment of written and computable CPGs, referred to as the "integrated process (IP)."1 This paper presents a framework for evaluating the IP based on a combination of vetted evaluation models and expert opinions. This framework combines 3 types of evaluations: process, product, and outcomes. These evaluations assess the value of interdisciplinary expert collaboration in carrying out the IP, the quality, usefulness, timeliness, and acceptance of the guideline, and the guideline's health impact, respectively. A case study is presented that illustrates application of the framework.

An Integrated Process for Co-Developing and Implementing Written and Computable Clinical Practice Guidelines

The goal of this article is to describe an integrated parallel process for the co-development of written and computable clinical practice guidelines (CPGs) to accelerate adoption and increase the impact of guideline recommendations in clinical practice. From February 2018 through December 2021, interdisciplinary work groups were formed after an initial Kaizen event and using expert consensus and available literature, produced a 12-phase integrated process (IP). The IP includes activities, resources, and iterative feedback loops for developing, implementing, disseminating, communicating, and evaluating CPGs. The IP incorporates guideline standards and informatics practices and clarifies how informaticians, implementers, health communicators, evaluators, and clinicians can help guideline developers throughout the development and implementation cycle to effectively co-develop written and computable guidelines. More efficient processes are essential to create actionable CPGs, disseminate and communicate recommendations to clinical end users, and evaluate CPG performance. Pilot testing is underway to determine how this IP expedites the implementation of CPGs into clinical practice and improves guideline uptake and health outcomes.

The Clinical Laboratory Is an Integral Component to Health Care Delivery : An Expanded Representation of the Total Testing Process

OBJECTIVES

Developing an expanded representation of the total testing process that includes contemporary elements of laboratory practice can be useful to understanding and optimizing testing workflows across clinical laboratory and patient care settings.

METHODS

Published literature and meeting reports were used by the coauthors to inform the development of the expanded representation of the total testing process and relevant examples describing its uses.

RESULTS

A visual representation of the total testing process was developed and contextualized to patient care scenarios using a number of examples covering the detection of blood culture contamination, use of next-generation sequencing, and pharmacogenetic testing.

CONCLUSIONS

The expanded representation of the total testing process can serve as a model and framework to document and improve the use of clinical testing within the broader context of health care delivery. This representation recognizes increased engagement among clinical laboratory professionals with patients and other health care providers as essential to making informed decisions. The increasing use of data is highlighted as important to ensuring quality, appropriate test utilization, and sustaining an efficient workflow across clinical laboratory and patient care settings. Maintaining a properly resourced and competent workforce is also featured as an essential component to the testing process.

Creation of an Expert Curated Variant List for Clinical Genomic Test Development and Validation: A ClinGen and GeT-RM Collaborative Project

Modern genomic sequencing tests often interrogate large numbers of genes. Identification of appropriate reference materials for development, validation studies, and quality assurance of these tests poses a significant challenge for laboratories. It is difficult to develop and maintain expert knowledge to identify all variants that must be validated to ensure analytic and clinical validity. Additionally, it is usually not possible to procure appropriate and characterized genomic DNA reference materials containing the number and scope of variants required. To address these challenges, the Centers for Disease Control and Prevention's Genetic Testing Reference Material Program (GeT-RM) has partnered with the Clinical Genome Resource (ClinGen) to develop a publicly available list of expert curated, clinically important variants. ClinGen Variant Curation Expert Panels nominated 546 variants found in 84 disease-associated genes, including common pathogenic and difficult-to-detect variants. Variant types nominated included 346 single nucleotide variants, 104 deletions, 37 copy number variants, 25 duplications, 18 deletion-insertions, 5 inversions, 4 insertions, 2 complex rearrangements, 3 difficult-to-sequence regions, and 2 fusions. This expert-curated variant list is a resource that provides a foundation for designing comprehensive validation studies and for creating in silico reference materials for clinical genomic test development and validation.

Use of large scale EHR data to evaluate A1c utilization among sickle cell disease patients

BACKGROUND

The glycated hemoglobin (A1c) test is not recommended for sickle cell disease (SCD) patients. We examine ordering patterns of diabetes-related tests for SCD patients to explore misutilization of tests among this underserved population.

METHODS

We used de-identified electronic health record (EHR) data in the Cerner Health Facts™ (HF) data warehouse to evaluate the frequency of A1c and fructosamine tests during 2010 to 2016, for 37,151 SCD patients from 393 healthcare facilities across the United States. After excluding facilities with no A1c data, we defined three groups of facilities based on the prevalence of SCD patients with A1c test(s): adherent facilities (no SCD patients with A1c test(s)), minor non-adherent facilities, major non-adherent facilities.

RESULTS

We determined that 11% of SCD patients (3927 patients) treated at 393 facilities in the US received orders for at least one A1c test. Of the 3927 SCD patients with an A1c test, only 89 patients (2.3%) received an order for a fructosamine test. At the minor non-adherent facilities, 5% of the SCD patients received an A1c test while 58% of the SCD patients at the least adherent facilities had at least one A1c test. Overall, the percent of A1c tests ordered for SCD patients between 2010 and 2016 remained similar.

CONCLUSIONS

Inappropriate A1c test orders among a sickle cell population is a significant quality gap. Interventions to advance adoption of professional recommendations that advocate for alternate tests, such as fructosamine, can guide clinicians in test selection to reduce this quality gap are discussed. The informatics strategy used in this work can inform other largescale analyses of lab test utilization using de-identified EHR data.

Bringing the clinical laboratory into the strategy to advance diagnostic excellence

OBJECTIVES

Clinical laboratory testing provides essential data for making medical diagnoses. Generating accurate and timely test results clearly communicated to the treating clinician, and ultimately the patient, is a critical component that supports diagnostic excellence. On the other hand, failure to achieve this can lead to diagnostic errors that manifest in missed, delayed and wrong diagnoses.

CONTENT

Innovations that support diagnostic excellence address: 1) test utilization, 2) leveraging clinical and laboratory data, 3) promoting the use of credible information resources, 4) enhancing communication among laboratory professionals, health care providers and the patient, and 5) advancing the use of diagnostic management teams. Integrating evidence-based laboratory and patient-care quality management approaches may provide a strategy to support diagnostic excellence. Professional societies, government agencies, and healthcare systems are actively engaged in efforts to advance diagnostic excellence. Leveraging clinical laboratory capabilities within a healthcare system can measurably improve the diagnostic process and reduce diagnostic errors.

SUMMARY

An expanded quality management approach that builds on existing processes and measures can promote diagnostic excellence and provide a pathway to transition innovative concepts to practice.

OUTLOOK

There are increasing opportunities for clinical laboratory professionals and organizations to be part of a strategy to improve diagnoses.

Challenges and opportunities for integrating genetic testing into a diagnostic workflow: heritable long QT syndrome as a model

BACKGROUND

An increasing number of diagnostic evaluations incorporate genetic testing to facilitate accurate and timely diagnoses. The increasing number and complexity of genetic tests continue to pose challenges in deciding when to test, selecting the correct test(s), and using results to inform medical diagnoses, especially for medical professionals lacking genetic expertise. Careful consideration of a diagnostic workflow can be helpful in understanding the appropriate uses of genetic testing within a broader diagnostic workup.

CONTENT

The diagnosis of long QT syndrome (LQTS), a life-threatening cardiac arrhythmia, provides an example for this approach. Electrocardiography is the preferred means for diagnosing LQTS but can be uninformative for some patients due to the variable presentation of the condition. Family history and genetic testing can augment physiological testing to inform a diagnosis and subsequent therapy. Clinical and laboratory professionals informed by peer- reviewed literature and professional recommendations constructed a generalized LQTS diagnostic workflow. This workflow served to explore decisions regarding the use of genetic testing for diagnosing LQTS.

SUMMARY AND OUTLOOK

Understanding the complexities and approaches to integrating genetic testing into a broader diagnostic evaluation is anticipated to support appropriate test utilization, optimize diagnostic evaluation, and facilitate a multidisciplinary approach essential for achieving accurate and timely diagnoses.

Technology-Enabled Outreach to Patients Taking High-Risk Medications Reduces a Quality Gap in Completion of Clinical Laboratory Testing

Clinical laboratory quality improvement (QI) efforts can include population test utilization. The authors used a health care organization's Medical Data Warehouse (MDW) to characterize a gap in guideline-concordant laboratory testing recommended for safe use of antirheumatic agents, then tested the effectiveness of laboratory-led, technology-enabled outreach to patients at reducing this gap. Data linkages available through the Kaiser Permanente Colorado MDW and electronic health record were used to identify ambulatory adults taking antirheumatic agents who were due/overdue for alanine aminotransferase (ALT), aspartate aminotransferase (AST), complete blood count (CBC), or serum creatinine (SCr) testing. Outreach was implemented using an interactive voice response system to send patients text or phone call reminders. Interrupted time series analysis was used to estimate reminder effectiveness. Rates of guideline-concordant testing and testing timeliness in baseline vs. intervention periods were determined using generalized linear models for repeated measures. Results revealed a decrease in percentage of 3763 patients taking antirheumatic agents due/overdue for testing at any given time: baseline 24.3% vs. intervention 17.5% (P < 0.001). Among 3205 patients taking conventional antirheumatic agents, concordance for all ALT testing was baseline 52.8% vs. intervention 65.4% (P < 0.001) among patients chronically using these agents and baseline 20.6% vs. intervention 26.1% (P < 0.001) among patients newly starting these agents. The 95^th percentiles for days to ALT testing were baseline 149 vs. intervention 117 among chronic users and baseline 134 vs. intervention 92 among new starts. AST, CBC, and SCr findings were similar. Technology-enabled outreach reminding patients to obtain laboratory testing improves health care system outcomes.

Identifying Preanalytic and Postanalytic Laboratory Quality Gaps Using a Data Warehouse and Structured Multidisciplinary Process

CONTEXT.—

The laboratory total testing process includes preanalytic, analytic, and postanalytic phases, but most laboratory quality improvement efforts address the analytic phase. Expanding quality improvement to preanalytic and postanalytic phases via use of medical data warehouses, repositories that include clinical, utilization, and administrative data, can improve patient care by ensuring appropriate test utilization. Cross-department, multidisciplinary collaboration to address gaps and improve patient and system outcomes is beneficial.

OBJECTIVE.—

To demonstrate medical data warehouse utility for characterizing laboratory-associated quality gaps amenable to preanalytic or postanalytic interventions.

DESIGN.—

A multidisciplinary team identified quality gaps. Medical data warehouse data were queried to characterize gaps. Organizational leaders were interviewed about quality improvement priorities. A decision aid with elements including national guidelines, local and national importance, and measurable outcomes was completed for each gap.

RESULTS.—

Gaps identified included (1) test ordering; (2) diagnosis, detection, and documentation, and (3) high-risk medication monitoring. After examination of medical data warehouse data including enrollment, diagnoses, laboratory, pharmacy, and procedures for baseline performance, high-risk medication monitoring was selected, specifically alanine aminotransferase, aspartate aminotransferase, complete blood count, and creatinine testing among patients receiving disease-modifying antirheumatic drugs. The test utilization gap was in monitoring timeliness (eg, >60% of patients had a monitoring gap exceeding the guideline recommended frequency). Other contributors to selecting this gap were organizational enthusiasm, regulatory labeling, and feasibility of a significant laboratory role in addressing the gap.

CONCLUSIONS.—

A multidisciplinary process facilitated identification and selection of a laboratory medicine quality gap. Medical data warehouse data were instrumental in characterizing gaps.

Guidelines for Validation of Next-Generation Sequencing-Based Oncology Panels: A Joint Consensus Recommendation of the Association for Molecular Pathology and College of American Pathologists

Next-generation sequencing (NGS) methods for cancer testing have been rapidly adopted by clinical laboratories. To establish analytical validation best practice guidelines for NGS gene panel testing of somatic variants, a working group was convened by the Association of Molecular Pathology with liaison representation from the College of American Pathologists. These joint consensus recommendations address NGS test development, optimization, and validation, including recommendations on panel content selection and rationale for optimization and familiarization phase conducted before test validation; utilization of reference cell lines and reference materials for evaluation of assay performance; determining of positive percentage agreement and positive predictive value for each variant type; and requirements for minimal depth of coverage and minimum number of samples that should be used to establish test performance characteristics. The recommendations emphasize the role of laboratory director in using an error-based approach that identifies potential sources of errors that may occur throughout the analytical process and addressing these potential errors through test design, method validation, or quality controls so that no harm comes to the patient. The recommendations contained herein are intended to assist clinical laboratories with the validation and ongoing monitoring of NGS testing for detection of somatic variants and to ensure high quality of sequencing results.

Principles and Recommendations for Standardizing the Use of the Next-Generation Sequencing Variant File in Clinical Settings

A national workgroup convened by the Centers for Disease Control and Prevention identified principles and made recommendations for standardizing the description of sequence data contained within the variant file generated during the course of clinical next-generation sequence analysis for diagnosing human heritable conditions. The specifications for variant files were initially developed to be flexible with regard to content representation to support a variety of research applications. This flexibility permits variation with regard to how sequence findings are described and this depends, in part, on the conventions used. For clinical laboratory testing, this poses a problem because these differences can compromise the capability to compare sequence findings among laboratories to confirm results and to query databases to identify clinically relevant variants. To provide for a more consistent representation of sequence findings described within variant files, the workgroup made several recommendations that considered alignment to a common reference sequence, variant caller settings, use of genomic coordinates, and gene and variant naming conventions. These recommendations were considered with regard to the existing variant file specifications presently used in the clinical setting. Adoption of these recommendations is anticipated to reduce the potential for ambiguity in describing sequence findings and facilitate the sharing of genomic data among clinical laboratories and other entities.

Reporting incidental findings in genomic scale clinical sequencing--a clinical laboratory perspective: a report of the Association for Molecular Pathology

Advances in sequencing technologies have facilitated concurrent testing for many disorders, and the results generated may provide information about a patient's health that is unrelated to the clinical indication, commonly referred to as incidental findings. This is a paradigm shift from traditional genetic testing in which testing and reporting are tailored to a patient's specific clinical condition. Clinical laboratories and physicians are wrestling with this increased complexity in genomic testing and reporting of the incidental findings to patients. An enormous amount of discussion has taken place since the release of a set of recommendations from the American College of Medical Genetics and Genomics. This discussion has largely focused on the content of the incidental findings, but the laboratory perspective and patient autonomy have been overlooked. This report by the Association of Molecular Pathology workgroup discusses the pros and cons of next-generation sequencing technology, potential benefits, and harms for reporting of incidental findings, including the effect on both the laboratory and the patient, and compares those with other areas of medicine. The importance of genetic counseling to preserve patient autonomy is also reviewed. The discussion and recommendations presented by the workgroup underline the need for continued research and discussion among all stakeholders to improve our understanding of the effect of different policies on patients, providers, and laboratories.

Current landscape and new paradigms of proficiency testing and external quality assessment for molecular genetics

CONTEXT

Participation in proficiency testing (PT) or external quality assessment (EQA) programs allows the assessment and comparison of test performance among different clinical laboratories and technologies. In addition to the approximately 2300 tests for individual genetic disorders, recent advances in technology have enabled the development of clinical tests that quickly and economically analyze the entire human genome. New PT/EQA approaches are needed to ensure the continued quality of these complex tests.

OBJECTIVES

To review the availability and scope of PT/EQA for molecular genetic testing for inherited conditions in Europe, Australasia, and the United States; to evaluate the successes and demonstrated value of available PT/EQA programs; and to examine the challenges to the provision of comprehensive PT/EQA posed by new laboratory practices and methodologies.

DATA SOURCES

The available literature on this topic was reviewed and supplemented with personal experiences of several PT/EQA providers.

CONCLUSIONS

Proficiency testing/EQA schemes are available for common genetic disorders tested in many clinical laboratories but are not available for most genetic tests offered by only one or a few laboratories. Provision of broad, method-based PT schemes, such as DNA sequencing, would allow assessment of many tests for which formal PT is not currently available. Participation in PT/EQA improves the quality of testing by identifying inaccuracies that laboratories can trace to errors in their testing processes. Areas of research and development to ensure that PT/EQA programs can meet the needs of new and evolving genetic tests and technologies are identified and discussed.

Opportunities and challenges associated with clinical diagnostic genome sequencing: a report of the Association for Molecular Pathology

This report of the Whole Genome Analysis group of the Association for Molecular Pathology illuminates the opportunities and challenges associated with clinical diagnostic genome sequencing. With the reality of clinical application of next-generation sequencing, technical aspects of molecular testing can be accomplished at greater speed and with higher volume, while much information is obtained. Although this testing is a next logical step for molecular pathology laboratories, the potential impact on the diagnostic process and clinical correlations is extraordinary and clinical interpretation will be challenging. We review the rapidly evolving technologies; provide application examples; discuss aspects of clinical utility, ethics, and consent; and address the analytic, postanalytic, and professional implications.

Relevance, pathogenesis, and testing algorithm for mismatch repair-defective colorectal carcinomas: a report of the association for molecular pathology

Loss-of-function defects in DNA mismatch repair (MMR), which manifest as high levels of microsatellite instability (MSI), occur in approximately 15% of all colorectal carcinomas (CRCs). This molecular subset of CRC characterizes patients with better stage-specific prognoses who experience no benefit from 5-fluorouracil chemotherapy. Most MMR-deficient (dMMR) CRCs are sporadic, but 15% to 20% are due to inherited predisposition (Lynch syndrome). High penetrance of CRCs in germline MMR gene mutation carriers emphasizes the importance of accurate diagnosis of Lynch syndrome carriers. Family-based (Amsterdam), patient/family-based (Bethesda), morphology-based, microsatellite-based, and IHC-based screening criteria do not individually detect all germline mutation carriers. These limitations support the use of multiple concurrent tests and the screening of all patients with newly diagnosed CRC. This approach is resource intensive but would increase detection of inherited and de novo germline mutations to guide family screening. Although CRC prognosis and prediction of 5-fluorouracil response are similar in both the Lynch and sporadic dMMR subgroups, these subgroups differ significantly with regard to the implications for family members. We recommend that new CRCs should be classified into sporadic MMR-proficient, sporadic dMMR, or Lynch dMMR subgroups. The concurrent use of MSI testing, MMR protein IHC, and BRAF c.1799T>A mutation analysis would detect almost all dMMR CRCs, would classify 94% of all new CRCs into these MMR subgroups, and would guide secondary molecular testing of the remainder.

Clinician perspectives about molecular genetic testing for heritable conditions and development of a clinician-friendly laboratory report

The use of molecular genetic tests for heritable conditions is expected to increase in medical settings, where genetic knowledge is often limited. As part of a project to improve the clarity of genetic test result reports to minimize misunderstandings that could compromise patient care, we sought input about format and content from practicing primary care clinicians. In facilitated workgroup discussions, clinicians from pediatric, obstetrics-gynecology, and family practice provided their perspectives about molecular genetic testing with a focus on the laboratory reporting of test results. Common principles for enhancing the readability and comprehension of test result reports were derived from these discussions. These principles address the presentation of patient- and test-specific information, the test result interpretation, and guidance for future steps. Model test result reports for DNA-based cystic fibrosis testing are presented that were developed based on workgroup discussions, previous studies, and professional guidelines. The format of these model test reports, which are applicable to a variety of molecular genetic tests, should be useful for communicating essential information from the laboratory to health care professionals.

Ordering molecular genetic tests and reporting results: practices in laboratory and clinical settings

Previous studies have suggested that patient care may be compromised as a consequence of poor communication between clinicians and laboratory professionals in cases in which molecular genetic test results are reported. To understand better the contributing factors to such compromised care, we investigated both pre- and postanalytical processes using cystic fibrosis mutation analysis as our model. We found that although the majority of test requisition forms requested patient/family information that was necessary for the proper interpretation of test results, in many cases, these data were not provided by the individuals filling out the forms. We found instances in which result reports for simulated diagnostic testing described individuals as carriers where only a single mutation was found with no comment pertaining to a diagnosis of cystic fibrosis. Similarly, reports based on simulated scenarios for carrier testing were problematic when no mutations were identified, and the patient's race/ethnicity and family history were not discussed in reference to residual risk of disease. Remarkably, a pilot survey of obstetrician-gynecologists revealed that office staff, including secretaries, often helped order genetic tests and reported test results to patients, raising questions about what efforts are undertaken to ensure personnel competency. These findings are reviewed in light of what efforts should be taken to improve the quality of test-ordering and result-reporting practices.

Report of an International Survey of Molecular Genetic Testing Laboratories

OBJECTIVE

To collect data on the practices of molecular genetic testing (MGT) laboratories for the development of national and international policies for quality assurance (QA).

METHODS

A web-based survey of MGT laboratory directors (n = 827; response rate 63%) in 18 countries on 3 continents. QA and reporting indices were developed and calculated for each responding laboratory.

RESULTS

Laboratory setting varied among and within countries, as did qualifications of the directors. Respondents in every country indicated that their laboratory receives specimens from outside their national borders (64%, n = 529). Pair-wise comparisons of the QA index revealed a significant association with the director having formal training in molecular genetics (p < 0.005), affiliation with a genetics unit (p = 0.003), accreditation of the laboratory (p < 0.005) and participation in proficiency testing (p < 0.005). Research labs had a lower mean report score compared to all other settings (p < 0.05) as did laboratories accessioning <150 samples per year.

CONCLUSION

MGT is provided under widely varying conditions and regulatory frameworks. The data provided here may be a useful guide for policy action at both governmental and professional levels.

A primer on genetic testing

Use of genetic tests in the clinical practice setting is a current reality, and an increasing number of patients are asking about and requesting genetic testing. The push to translate genetic research findings and technological innovations into clinical practice will continue as our understanding of the genetic basis of disease increases. Special consideration is required when ordering genetic tests, beyond that of other laboratory tests, and an understanding of the unique aspects involved will help optimize clinical outcomes. The purpose of this primer is to provide a basic understanding of genetic testing, discuss current issues related to the use of tests, and outline practical steps for critically using genetic tests in clinical practice.

Developing a sustainable process to provide quality control materials for genetic testing

PURPOSE

To provide a summary of the outcomes of two working conferences organized by the Centers for Disease Control and Prevention (CDC), to develop recommendations for practical, sustainable mechanisms to make quality control (QC) materials available to the genetic testing community.

METHODS

Participants were selected to include experts in genetic testing and molecular diagnostics from professional organizations, government agencies, industry, laboratories, academic institutions, cell repositories, and proficiency testing (PT)/external Quality Assessment (EQA) programs. Current efforts to develop QC materials for genetic tests were reviewed; key issues and areas of need were identified; and workgroups were formed to address each area of need and to formulate recommendations and next steps.

RESULTS

Recommendations were developed toward establishing a sustainable process to improve the availability of appropriate QC materials for genetic testing, with an emphasis on molecular genetic testing as an initial step.

CONCLUSIONS

Improving the availability of appropriate QC materials is of critical importance for assuring the quality of genetic testing, enhancing performance evaluation and PT/EQA programs, and facilitating new test development. To meet the needs of the rapidly expanding capacity of genetic testing in clinical and public health settings, a comprehensive, coordinated program should be developed. A Genetic Testing Quality Control Materials Program has therefore been established by CDC in March 2005 to serve these needs.

Results of a Survey of Hospital Coagulation Laboratories in the United States, 2001

Context.—Coagulation and bleeding problems are associated with substantial morbidity and mortality, and inappropriate testing practices may lead to bleeding or thrombotic complications.

Objective.—To evaluate practices reported by hospital coagulation laboratories in the United States and to determine if the number of beds in a hospital was associated with different practices.

Design.—From a sampling frame of institutions listed in the 1999 directory of the American Hospital Association, stratified into hospitals with 200 or more beds (“large hospitals”) and those with fewer than 200 beds (“small hospitals”), we randomly selected 425 large hospitals (sampling rate, 25.6%) and 375 small hospitals (sampling rate, 8.8%) and sent a survey to them between June and October 2001. Of these, 321 large hospitals (75.5%) and 311 small hospitals (82.9%) responded.

Results.—An estimated 97.1% of respondents reported performing some coagulation laboratory tests. Of these, 71.6% reported using 3.2% sodium citrate as the specimen anticoagulant to determine prothrombin time (81.3% of large vs 67.7% of small hospitals, P &lt; .001). Of the same respondents, 45.3% reported selecting thromboplastins insensitive to heparin in the therapeutic range when measuring prothrombin time (59.4% of large vs 39.8% of small hospitals, P &lt; .001), and 58.8% reported having a therapeutic range for heparin (72.9% of large vs 53.2% of small hospitals, P &lt; .001). An estimated 96.3% of respondents assayed specimens for activated partial thromboplastin time within 4 hours after phlebotomy, and 89.4% of respondents centrifuged specimens within 1 hour of collection. An estimated 12.1% reported monitoring low-molecular-weight heparin therapy, and to do so, 79% used an assay for activated partial thromboplastin time (58% of large vs 96% of small hospitals, P = .001), whereas 38% used an antifactor Xa assay (65% of large vs 18% of small hospitals, P = .001).

Conclusions.—Substantial variability in certain laboratory practices was evident. Where significant differences existed between the hospital groups, usually large hospitals adhered to accepted practice guidelines to a greater extent. Some reported practices are not consistent with current recommendations, showing a need to understand the reasons for noncompliance so that better adherence to accepted standards of laboratory practice can be promoted.

Genetic laboratory practices related to testing of the GJB2 (Connexin-26) gene in the United States in 1999 and 2000

Given the rapidly growing area of molecular genetic laboratory testing, we sought to assess changing issues over a 2-year period of time pertaining to the availability of testing for GJB2 mutations associated with non-syndromic hearing loss. Laboratory assessments carried out by telephone interviews with directors or other key personnel revealed variations among laboratories in informed consent practices, evaluation of test requests for appropriateness, and the reporting of results. From 1999 to 2000, referral patterns shifted as did sources for reimbursement, policies regarding evaluation of incoming test requests, and reporting procedures. We propose that these results reflect changes occurring as a result of a new test moving from the research to the clinical phase.

Quality assurance in human molecular genetics testing: status and recommendations

OBJECTIVE

The role of genetic testing has expanded with rapidly developing technology and completion of the International Human Genome Project. Development of universally acceptable quality control methods and quality assurance standards trails technology. The principle that high-quality genetic testing is important for public health motivated the Centers for Disease Control and Prevention to formulate ways for improving quality assurance of human molecular genetics testing.

PARTICIPANTS

Twenty-eight panelists were chosen based on expertise in molecular genetics testing and knowledge of quality assurance practices. Representatives of professional organizations, industries, and federal agencies participated in one or more of 3 panel meetings. Consensus recommendations were developed by the 15 panelists in the third meeting.

EVIDENCE

Evidence was derived from experts' opinion during 3 panel meetings. Data compiled through laboratory visits and literature review were used as reference information. Need for this project was derived from the Final Report of the Task Force on Genetic Testing, produced by the National Institutes of Health and the Department of Energy in 1997, and the Summary Report of the Subcommittee Meeting on Genetics of the Clinical Laboratory Improvement Act Advisory Committee in 1997.

CONSENSUS PROCESS

Research and development needs were identified using a participatory visioning approach. A modified nominal group process was used to reach consensus.

CONCLUSIONS

Five core consensus recommendations were made: research for developing positive samples for quality assurance purposes, performance evaluation programs supplementing those in existence, establishment and support of laboratory-oriented consortia, establishment of a laboratory-focused database, and support of molecular genetics training programs.

Physicians' perceived usefulness of and satisfaction with test reports for cystic fibrosis (DeltaF508) and factor V Leiden

PURPOSE

We sought to determine whether variation in test-report content for cystic fibrosis (CF DeltaF508) and factor V Leiden (fVL) would impact physician-perceived usefulness of and satisfaction with test reports.

METHODS

A cross-sectional survey of US physicians from specialties likely to order the tests was performed. Physicians received an introductory letter with a clinical scenario, one randomly assigned mock report, and a one-page survey. The analyses evaluated usefulness of and satisfaction with report elements.

RESULTS

For CF and fVL, there were significant differences by mock-report version for most of the survey report items (P < 0.05) and for satisfaction (P < 0.0001); results revealed greater usefulness and satisfaction with more comprehensive reports. The three items in CF and fVL reports where physician-perceived usefulness was most highly correlated (R > 0.70) with satisfaction were (1.clinical decision-making information, (2). genetic counseling information, and (3). implications for family members.

CONCLUSION

Opportunities exist to improve the usefulness of genetic test reports in clinical practice.

Personnel standards and quality assurance practices of biochemical genetic testing laboratories in the United States

CONTEXT

It has been suggested that specific regulation of laboratories performing genetic testing may be needed to ensure standards and quality assurance, and to safeguard the rights of patients with regard to confidentiality and providing informed consent. Previously, a comprehensive analysis of current practices of molecular genetic testing laboratories was conducted, the results of which have assisted in the assessment of the need for regulation and its impact on access to testing. However, a study designed to determine clinical laboratory practices with regard to biochemical genetic testing has not been carried out.

OBJECTIVE

To collect and analyze data regarding availability of clinical biochemical genetic testing, personnel standards, and laboratory quality assurance practices.

DESIGN

A mail survey of biochemical genetic testing laboratory directors and assignment of a quality assurance score based on responses to genetic testing process items.

SETTING

Hospital-based, independent, and research-based biochemical genetic testing laboratories in the United States.

PARTICIPANTS

Directors of biochemical genetic testing laboratories (n = 133; response rate 68.5%).

MAIN OUTCOME MEASURE

Laboratory process quality assurance score based on the standards defined by the American College of Medical Genetics Laboratory Practice Committee.

RESULTS

Personnel qualifications varied, although all directors had doctoral degrees. The mean quality assurance score was 77% (range 28%-100%). Higher scores were associated with the following variables: test director having an MD degree versus PhD degree (P = .002), director board certification in biochemical genetics (P = .002), research and hospital laboratory versus independent laboratory setting (P < .001), and participation in a proficiency testing program (P = .03). Twelve percent of participants had a confidentiality policy, and 19% required informed consent before testing.

CONCLUSION

The finding that a number of laboratories had quality assurance scores that may reflect suboptimal laboratory practices, particularly with regard to reporting practices, suggests that personnel qualification and laboratory practice standards may be in need of improvement to ensure quality in clinical biochemical genetic testing laboratories, as well as the appropriate clinical use of the test results.

Medical genetic test reporting for cystic fibrosis (deltaF508) and factor V Leiden in North American laboratories

PURPOSE

Physicians are ordering an increasing number of genetic tests. Results and additional information provided in the test result report are vital to the physician in making appropriate patient management decisions. Because variability in test result reports can impact patient care, we sought to determine whether variations exist in test reports for cystic fibrosis (CF) and factor V Leiden (fVL) with specific comparison to professional guidelines and recommendations.

METHODS

A cross-sectional study design analyzing for the presence of 16 critical elements in CF reports and 12 critical elements in fVL reports solicited from United States and Canadian laboratories.

RESULTS

Of 44 laboratories performing CF testing and 72 laboratories performing fVL testing, 64% responded. For CF reports, 21% included ethnicity, 64% described methodology, and 61% discussed genetic counseling. For fVL reports, 80% described methodology and 52% discussed the need for genetic counseling in mutation-positive reports.

CONCLUSIONS

Variability exists in report content among North American laboratories performing CF and fVL testing. Many reports lack information deemed critical by professional guidelines and recommendations.

Public health impact of genetic tests at the end of the 20th century

PURPOSE

To evaluate genetics tests available for clinical, research, and public health purposes in terms of their public health impact as measured by the number of people who could potentially be tested.

METHODS

Genetic tests for the 751 inherited diseases or conditions listed in the GeneTests database as of November 2000, were classified on the basis of their use for population-based testing and the prevalence of the disease or condition being tested. The GeneTests database divides the tests into two groups: those offered for clinical use and those available for research only.

RESULTS

Of the 423 clinical tests, 51 had potentially greater impact on public health because of their use in statewide newborn screening programs, other population screening programs, or testing for common diseases with a prevalence over 1 in 2,000 people. Among the 328 tests performed for research purposes only, 18 met the criteria for potentially greater public health impact.

CONCLUSIONS

Our classification scheme indicated that fewer than 10% of the genetic tests listed in the GeneTests database at the end of 2000 are highly relevant to public health. The majority of genetic tests are used in diagnosis and/or genetic counseling for rare, single-gene disorders in a limited number of people. However, as more tests are being considered for newborn screening, and associations between genes and common diseases are being discovered, the impact of genetic testing on public health is likely to increase.

HFE Genotyping Using Multiplex Allele-Specific Polymerase Chain Reaction and Capillary Electrophoresis

Context.—Hereditary hemochromatosis is recognized as one of the most common autosomal recessive disorders, with a prevalence of 1 in 200 to 400 in the white population. Early detection and treatment are completely effective in preventing pathology. It is anticipated that testing for hereditary hemochromatosis will increase, as will the need for a technology that can handle the demand.

Objective.—To describe a high-throughput, single-tube, allele-specific multiplex polymerase chain reaction assay for identifying the 2 mutations in the HFE gene associated with hereditary hemochromatosis.

Design.—Fluorescence-labeled polymerase chain reaction products from a multiplex polymerase chain reaction are analyzed by automated capillary electrophoresis.

Data Analysis.—The assay was validated by analysis of 25 blinded samples, and results were concordant with an established laboratory assay.

Conclusion.—The assay described offers a significant improvement over manual laboratory assays in throughput, reduced technologist time, and cost.

HFE genotyping using multiplex allele-specific polymerase chain reaction and capillary electrophoresis

CONTEXT

Hereditary hemochromatosis is recognized as one of the most common autosomal recessive disorders, with a prevalence of 1 in 200 to 400 in the white population. Early detection and treatment are completely effective in preventing pathology. It is anticipated that testing for hereditary hemochromatosis will increase, as will the need for a technology that can handle the demand.

OBJECTIVE

To describe a high-throughput, single-tube, allele-specific multiplex polymerase chain reaction assay for identifying the 2 mutations in the HFE gene associated with hereditary hemochromatosis.

DESIGN

Fluorescence-labeled polymerase chain reaction products from a multiplex polymerase chain reaction are analyzed by automated capillary electrophoresis.

DATA ANALYSIS

The assay was validated by analysis of 25 blinded samples, and results were concordant with an established laboratory assay.

CONCLUSION

The assay described offers a significant improvement over manual laboratory assays in throughput, reduced technologist time, and cost.

Residues Glu2181-Val2243 contain a major determinant of the inhibitory epitope in the C2 domain of human factor VIII

The human blood coagulation factor VIII C2 domain (Ser2173-Tyr2332) contains an epitope recognized by most polyclonal inhibitory anti-factor VIII alloantibodies and autoantibodies. We took advantage of the differential reactivity of inhibitory antibodies with human and porcine factor VIII and mapped a major determinant of the C2 epitope by using a series of active recombinant hybrid human/porcine factor VIII molecules. A series of five C2-specific human antibodies and a murine anti-factor VIII monoclonal antibody, NMC-VIII/5, inhibited a hybrid containing a substitution of porcine sequence for Glu2181-Val2243 significantly less than human factor VIII. In contrast, four of the five patient antibodies and NMC-VIII/5 inhibited a hybrid containing a substitution of porcine sequence for Thr2253-Tyr2332 equally well as human factor VIII. Thus, a major factor VIII inhibitor epitope determinant is bounded by Glu2181-Val2243 at the NH2-terminal end of the C2 domain. Because C2 inhibitors block the binding of factor VIII to phospholipid and von Willebrand factor, for which binding sites have been localized to Thr2303-Tyr2332, these results imply that the segment bounded by Glu2181-Val2243 also is involved in these macromolecular interactions.

Analysis of the human factor VIII A2 inhibitor epitope by alanine scanning mutagenesis

Antibodies directed to the A2 domain of factor VIII (fVIII) are usually an important component of the polyclonal response in patients who have clinically significant inhibitory antibodies to fVIII. A major determinant of the A2 epitope has been located by homolog scanning mutagenesis using recombinant hybrid human/porcine fVIII molecules to a sequence bounded by Arg484-Ile508 (Healey, J. F. , Lubin, I. M., Nakai, H., Saenko, E. L., Hoyer, L. W., Scandella, D. , and Lollar, P. (1995) J. Biol. Chem. 270, 14505-14509). Within this region, human residues Arg484, Pro485, Tyr487, Ser488, Arg489, Pro492, Val495, Phe501, and Ile508 differ from porcine fVIII. We stably expressed in mammalian cells nine active B-domainless human fVIII molecules containing single alanine substitutions at these sites. Their inhibition by a murine anti-A2 monoclonal antibody, monoclonal antibody (mAb) 413, and by three A2-specific alloimmune and two A2-specific autoimmune human inhibitor plasmas was measured by the Bethesda assay. The inhibition of Arg484 --> Ala, Tyr487 --> Ala, Arg489 --> Ala, and Arg492 --> Ala by mAb413 was reduced by greater than 90% compared with wild-type, B-domainless human fVIII. mAb413 inhibited the most severely affected mutant, Arg489 --> Ala, 0.01% as well as wild-type fVIII. For all five patient plasmas, the Tyr487 --> Ala mutant displayed the greatest reduction in inhibition. The inhibition of the Tyr487 --> Ala mutant by these antibodies ranged from 10% to 20% that of wild-type fVIII. The inhibition of the Ser488 --> Ala, Arg489 --> Ala, Pro492 --> Ala, Val495 --> Ala, Phe501 --> Ala, and Ile508 --> Ala mutants by most of the plasmas also was significantly reduced. In contrast, the Arg484 --> Ala and Pro485 --> Ala mutants were relatively unaffected. Thus, although mAb413 binds to the same region as human A2 inhibitors, it recognizes a different set of amino acid side chains. The side chains recognized by human A2 inhibitors appear to be similar, despite the differing immune settings that give rise to fVIII alloantibodies and autoantibodies.

The cDNA and derived amino acid sequence of porcine factor VIII

The cDNA corresponding to 137 bp of the 5' untranslated region, the signal peptide, and the A1, A3, C1, and C2 domains of porcine factor VIII (fVIII) have been cloned and sequenced. Along with previously determined sequences of the porcine fVIII B domain and the A2 domain, this completes the sequence determination of the cDNA corresponding to the translated protein. Alignments of the derived amino acid sequence of porcine fVIII with human and murine fVIII indicate that the A1, A2, A3, C1, and C2 domains are more conserved than the B domains or the proteolytic cleavage peptides corresponding to residues 337-372 and 1649-1689. The knowledge of the porcine fVIII cDNA may be useful to understand functional and immunological differences between human and porcine fVIII and may lead to improved fVIII replacement products for hemophilia. A patients through the development of recombinant porcine fVIII or hybrid human/porcine fVIII derivatives.

Residues 484-508 contain a major determinant of the inhibitory epitope in the A2 domain of human factor VIII

The A2 domain (residues 373-740) of human blood coagulation factor VIII (fVIII) contains a major epitope for inhibitory alloantibodies and autoantibodies. We took advantage of the differential reactivity of inhibitory antibodies with human and porcine fVIII and mapped a major determinant of the A2 epitope by using a series of active recombinant hybrid human/porcine fVIII molecules. Hybrids containing a substitution of porcine sequence at segment 410-508, 445-508, or 484-508 of the human A2 domain were not inhibited by a murine monoclonal antibody A2 inhibitory, mAb 413, whereas hybrids containing substitutions at 387-403, 387-444, and 387-468 were inhibited by mAb 413. This indicates that the segment bounded by Arg484 and Ile508 contains a major determinant of the A2 epitope. mAb 413 did not inhibit two more hybrids that contained porcine substitutions at residues 484-488 and 489-508, indicating that amino acid side chains on both sides of the Ser488-Arg489 bond within the Arg484-Ile508 segment contribute to the A2 epitope. The 484-508, 484-488, and 489-508 porcine substitution hybrids displayed decreased inhibition by A2 inhibitors from four patient plasmas, suggesting that there is little variation in the structure of the A2 epitope in the inhibitor population.

Elimination of a major inhibitor epitope in factor VIII

The A2 and C2 domains of human blood coagulation factor VIII (fVIII) contain the epitopes targeted by most inhibitory allo- and autoantibodies. Human inhibitors usually display limited or no reaction with porcine fVIII. We constructed an active, recombinant hybrid human/porcine fVIII molecule by replacing the putative human fVIII A2 domain epitope with the homologous porcine sequence. The hybrid retained full activity in the presence of antibodies with specificity restricted to the human A2 epitope. In contrast, the hybrid was neutralized by an anti-C2 antibody. These findings provide a basis for fine epitope mapping and for therapy of the inhibitor patient.

The tissue plasminogen activator finger domain confers fibrin-dependent enhancement of catalytic activity to single-chain urokinase-type plasminogen activator

To determine whether the fibrin-binding domains of tissue plasminogen activator (tPA) can confer enhanced catalytic activity to single-chain urokinase-type plasminogen activator (scuPA), we constructed, expressed, and characterized the kinetics of five recombinant tPA/scuPA hybrid molecules. The hybrid molecules are: 1) tPA3-50 (tPA finger)/scuPA138-411, 2) tPA177-256 (tPA kringle2)/scuPA140-411 (scuPA catalytic), 3) tPA3-50/tPA177-256/scuPA140-411, 4) scuPA1-47 (scuPA growth factor)/tPA177-256/scuPA140-411, and 5) scuPA1-138 (scuPA growth factor and kringle)tPA127-256/scuPA139-411. The amidolytic activity of all hybrids was comparable, as were the kinetics for conversion from single-chain to two-chain plasminogen activator. We found that 1) the lag time prior to achieving maximal velocity among these hybrids varied, 2) hybrids 2, 3, 4, and 5 were 2-134-fold more potent (by kcat/Km) than hybrid 1, and 3) those hybrid proteins containing the tPA finger domain (hybrids 1 and 3) gave a 2-fold increase in catalytic efficiency in the presence of DESAFIB (reptilase-digested fibrinogen). These kinetic differences are likely mediated by changes in the tertiary structure of the scuPA catalytic domain resulting from interactions between catalytic and noncatalytic domains in the presence of fibrin.

Conjugation of plasminogen activators and fibrin-specific antibodies to improve thrombolytic therapeutic agents

Here we have reviewed chemical and recombinant approaches to the construction of hybrid molecules that combine a "targeting" antibody and an "effector" enzyme activity. There are advantages and disadvantages to both chemical and recombinant methods, and one goal of this review has been to elucidate these so that the appropriate method can be used by those interested in using hybrid molecules to study questions of basic or therapeutic importance. The system studied in greatest detail has as its goal the targeting of a plasminogen activator to an occlusive intravascular thrombus. We have, therefore, used this system as an example of currently available approaches. Now that these methodologies have been studied and put into use, it is anticipated that this principle will be generalized both to other therapeutic applications, as well as to the design and construction of molecules that will allow more basic questions to be addressed.

Import of rat liver mitochondrial transhydrogenase

The biosynthesis of pyridine dinucleotide transhydrogenase has been studied in isolated rat hepatocytes and in a rabbit reticulocyte-lysate translation system supplemented with either intact isolated rat liver mitochondria or the soluble matrix fraction from isolated mitochondria. In intact hepatocytes, the transhydrogenase precursor was short-lived in the cytosol and was efficiently imported into the membranous fraction. When the cell-free translation mixture was incubated with intact mitochondria, the transhydrogenase precursor was processed to the mature form, to an extent that depended on the amount of added mitochondria. Incubation of the translation mixture with the soluble mitochondria matrix fraction converted the precursor to a mature-sized protein with 75% efficiency, this being blocked by various proteinase inhibitors such as EDTA, 1,10-phenanthroline and leupeptin.

Rhodamine 123 inhibits import of rat liver mitochondrial transhydrogenase

Rhodamine 123, a laser dye, has been demonstrated to inhibit import of the precursor to pyridine dinucleotide transhydrogenase into mitochondria in rat liver cells. When rat hepatocytes were labeled with 35[S] methionine in the presence of 0.4 mM rhodamine 123, the precursor to transhydrogenase was found to have a half-life in the cytoplasm of 15 minutes as opposed to a half-life of 1-2 minutes when cells were radiolabeled in the absence of the dye. To clarify the mechanism of import inhibition, studies were initiated to assess the effect of rhodamine 123 on mitochondrial respiration. Upon addition of the dye to a mitochondrial suspension, respiration was initially enhanced, then inhibited. The inability of FCCP, a classical uncoupler, to enhance respiration during the inhibitory phase suggests that rhodamine 123 is primarily inhibiting respiration through the electron transport system rather than through the ATPase. These results suggest that rhodamine 123 may inhibit import of the transhydrogenase precursor into mitochondria by disrupting components in the mitochondrial membrane necessary for efficient import.

Biosynthesis of rat liver transhydrogenase in vivo and in vitro

The biosynthesis of pyridine dinucleotide transhydrogenase, a homodimeric inner mitochondrial membrane redox-linked proton pump, has been studied in isolated rat hepatocytes. Newly synthesized transhydrogenase, having an apparent molecular weight identical to the enzyme of isolated liver mitochondria, was selectively immunoprecipitated from detergent extracts of isolated hepatocytes which were labeled with [35S]methionine. That the enzyme is a nuclear gene product is indicated since 1) synthesis was inhibited by cycloheximide, but not by chloramphenicol and 2) no synthesis could be demonstrated in hepatocyte ghosts which are competent only in mitochondrial translation. In addition to the mature form of the enzyme, a species about 2000 daltons larger was also immunoprecipitated from pulse-labeled cells. The half-life of the larger form during a subsequent chase at 37 degrees C was about 2 min, whereas the mature form was not degraded. The relationship between the two forms of the enzyme was established by in vitro studies. A protein approximately 2000 daltons larger than mature transhydrogenase was immunoisolated from a rabbit reticulocyte lysate system programmed with sucrose gradient fractionated rat liver mRNA. This protein was converted to a species having the same size as mature enzyme after incubation with either intact rat liver mitochondria or a soluble matrix fraction derived from mitoplasts. These studies indicate that transhydrogenase is synthesized in the cytoplasm as a higher molecular weight precursor which is post-translationally processed to the mature protein by a soluble matrix protease during or after membrane insertion.