Discovery of a Cushing's syndrome protein kinase A mutant that biases signaling through type I AKAPs.

Adrenal Cushing's syndrome is a disease of cortisol hypersecretion often caused by mutations in protein kinase A catalytic subunit (PKAc). Using a personalized medicine screening platform, we discovered a Cushing's driver mutation, PKAc-W196G, in ~20% of patient samples analyzed. Proximity proteomics and photokinetic imaging reveal that PKAcW196G is unexpectedly distinct from other described Cushing's variants, exhibiting retained association with type I regulatory subunits (RI) and their corresponding A kinase anchoring proteins (AKAPs). Molecular dynamics simulations predict that substitution of tryptophan-196 with glycine creates a 653-cubic angstrom cleft between the catalytic core of PKAcW196G and type II regulatory subunits (RII), but only a 395-cubic angstrom cleft with RI. Endocrine measurements show that overexpression of RIα or redistribution of PKAcW196G via AKAP recruitment counteracts stress hormone overproduction. We conclude that a W196G mutation in the kinase catalytic core skews R subunit selectivity and biases AKAP association to drive Cushing's syndrome.

Benzodiazepine analysis by an improved LC-MS/MS method illustrates usage patterns in Washington State.

BACKGROUND: The standard approach for benzodiazepine detection often includes immunoassay followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The illicit use of non-prescribed benzodiazepines has been trending up nationally. METHODS: We developed and validated an improved LC-MS/MS assay for benzodiazepine detection in urine. We expanded the testing panel by adding five drugs to the previous panel of ten. We determined the prevalence of individual benzodiazepines in our patient population. Immunoassay results were compared with LC-MS/MS to evaluate assay performance. RESULTS: Clonazepam and alprazolam were the most common benzodiazepines present. Etizolam and flualprazolam were also prevalent in Washington State. Compared with the LC-MS/MS assay, the immunoassay had variable cross-reactivity, which explained false negative and false positive immunoassay results. The inclusion of new drugs in the LC-MS/MS panel significantly reduced the incidence of immunoassay results interpreted as falsely positive. CONCLUSION: New illicit benzodiazepines have emerged regionally and nationally. The inclusion of novel drugs in LC-MS/MS assay was helpful in properly characterizing the epidemiology of benzodiazepine use in our patient population. This information will lead to better assay result interpretations and patient care, and our experiences provide a roadmap for other clinical laboratories looking to expand their testing menu or transition to new instrumentation.

A web application to support the coordination of reflexive, interpretative toxicology testing.

Background: Reflexive laboratory testing workflows can improve the assessment of patients receiving pain medications chronically, but complex workflows requiring pathologist input and interpretation may not be well-supported by traditional laboratory information systems. In this work, we describe the development of a web application that improves the efficiency of pathologists and laboratory staff in delivering actionable toxicology results. Method: Before designing the application, we set out to understand the entire workflow including the laboratory workflow and pathologist review. Additionally, we gathered requirements and specifications from stakeholders. Finally, to assess the performance of the implementation of the application, we surveyed stakeholders and documented the approximate amount of time that is required in each step of the workflow. Results: A web-based application was chosen for the ease of access for users. Relevant clinical data was routinely received and displayed in the application. The workflows in the laboratory and during the interpretation process served as the basis of the user interface. With the addition of auto-filing software, the return on investment was significant. The laboratory saved the equivalent of one full-time employee in time by automating file management and result entry. Discussion: Implementation of a purpose-built application to support reflex and interpretation workflows in a clinical pathology practice has led to a significant improvement in laboratory efficiency. Custom- and purpose-built applications can help reduce staff burnout, reduce transcription errors, and allow staff to focus on more critical issues around quality.

A Second-generation opioid LC-MS/MS assay improves laboratory workflow and capacity.

The widespread use of opioid drugs has contributed to escalating rates of addiction, overdoses, and drug-related deaths. Targeted urine drug screening plays an important role in supporting the care of patients with chronic pain or addiction. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) can provide excellent sensitivity and specificity, and, as a result, remains the definitive choice for confirmatory urine drug testing. However, the complexities of LC-MS/MS operation present major challenges to the clinical laboratory. In this study, we leveraged upgraded instrumentation to develop and validate a simplified "dilute-and-shoot" LC-MS/MS opioid assay. By modifying the chromatographic gradient, isobaric interferences were well-resolved and eliminated. Analytical ranges were expanded by utilizing alternative mass transitions, and updated quality assurance parameters were established. Results from 204 clinical samples correlated well between the new method and a previous version. The upgraded systems provided better sensitivity, greater dynamic ranges, and the new method reduced carryover, which enabled us to eliminate extra injections and chromatogram reviews. The new method also reduced turnaround time and doubled testing capacity. These improvements could serve as a model for other laboratories approaching a similar transition in mass spectrometric instrumentation.

Mislocalization of protein kinase A drives pathology in Cushing's syndrome.

Mutations in the catalytic subunit of protein kinase A (PKAc) drive the stress hormone disorder adrenal Cushing's syndrome. We define mechanisms of action for the PKAc-L205R and W196R variants. Proximity proteomic techniques demonstrate that both Cushing's mutants are excluded from A kinase-anchoring protein (AKAP)-signaling islands, whereas live-cell photoactivation microscopy reveals that these kinase mutants indiscriminately diffuse throughout the cell. Only cAMP analog drugs that displace native PKAc from AKAPs enhance cortisol release. Rescue experiments that incorporate PKAc mutants into AKAP complexes abolish cortisol overproduction, indicating that kinase anchoring restores normal endocrine function. Analyses of adrenal-specific PKAc-W196R knockin mice and Cushing's syndrome patient tissue reveal defective signaling mechanisms of the disease. Surprisingly each Cushing's mutant engages a different mitogenic-signaling pathway, with upregulation of YAP/TAZ by PKAc-L205R and ERK kinase activation by PKAc-W196R. Thus, aberrant spatiotemporal regulation of each Cushing's variant promotes the transmission of distinct downstream pathogenic signals.

Investigation of Fentanyl Usage in the Seattle Area.

BACKGROUND: Fentanyl was developed in the 1960s as an alternative to morphine, but quickly became a drug of abuse due to its potency, inexpensiveness, and ease of synthesis. One source of exposure is mixing fentanyl into other drugs of abuse (e.g., heroin), but users also actively seek out this potent opioid. While monitoring for pain medication compliance and office-based opioid treatment, we noticed increasing fentanyl use. We sought to investigate this increase in the local population, and see if this reflected the regional health, morbidity, and mortality statistics. METHODS: This data review was determined not to involve "human subjects" as defined by federal regulations by the University of Washington (UW) Human Subjects Division (STUDY00014988). Local data were extracted from the laboratory information system and analyzed. Data from the King County Medical Examiner's Office derives from cases sent to the Washington State Toxicology Laboratory. The Addictions, Drug, and Alcohol Institute (ADAI) at the UW compiled data from the Washington State Department of Health, the Forensic Laboratory Services Bureau, Washington State Patrol, and the state Office of Financial Management. RESULTS: We found a significant increase in fentanyl positivity in clinical LC-MS/MS assays, an increase in deaths due to fentanyl, and an increase in the fentanyl usage documented by the public health laboratory. CONCLUSIONS: Clinical data from community toxicology testing performed at academic medical centers can reflect trends in society at large, and as such, there may be a compelling reason to publish and use these data to inform public health approaches.

Calculating estimated glomerular filtration rate without the race correction factor: Observations at a large academic medical system.

BACKGROUND AND AIMS: Creatinine-based MDRD and CKD-EPI equations include a race correction factor, which results in higher eGFR in Black patients. We evaluated the impact on our patient population upon adoption of the CKD-EPI equation and the removal of the race correction factor from the equation. MATERIALS AND METHODS: Retrospective analysis of blood creatinine results and respective eGFR values calculated by the MDRD or CKD-EPI equation without the race correction factor (CKD-EPINoRace) in a large academic medical system over a 20.5-month period. RESULTS: In our population, when changing from MDRD to CKD-EPINoRace, we observed that 3.5% of all patients were reclassified to categorically have worse kidney function. However, we also observed fewer patients overall with eGFR below 60 mL/min/1.73 m2. Around 60 and 20 mL/min/1.73 m2, 2.96% and 0.16% of all patients > 65 years of age were reclassified, as were 4.29% and 0.03% of all Black patients, respectively. When calculated with CKD-EPINoRace, median eGFR was not meaningfully different between Black and non-Black patients (p = 0.02). CONCLUSIONS: Changing from MDRD to CKD-EPINoRace could lead to a lower referral rate to nephrology. The distributions of creatinine and eGFR calculated with CKD-EPINoRace were not meaningfully different in Black and non-Black patients.

The Hidden Cost of the Opioid Epidemic in the United States: Drug Screening in Insurance Claims.

BACKGROUND: The opioid crisis has had a substantial financial impact on the health care system in the United States. This study evaluates how health plans have been affected financially and shows how a laboratory benefit management (LBM) program can be used to address related drug testing in an outpatient setting. METHODS: Monthly claims data from private health plans were collected from June 1, 2016 to February 29, 2020. The total number of claims (units) for definitive and presumptive drug testing were calculated and the number of paid claims recorded. Claims distribution by laboratory type and medical code billed, the paid rate and compound annual growth rate, and the test distribution and paid rate of rendering providers who had submitted a minimum of 1000 claims were determined. RESULTS: In total, 2,004,230 drug testing claims were submitted. After the LBM program was implemented, the percentage of paid claims for definitive drug testing (Healthcare Common Procedure Coding System code G0483) decreased and the paid rate for the low-cost tests (HCPCS code G0480) in physician office and independent laboratory settings increased. The compound annual growth rate for G0483 claims submitted indicated a 70.5% and 31.9% decrease in payments to physician offices and independent laboratories, respectively, for the period ending February 2020. CONCLUSIONS: An LBM program can positively address policy enforcement while reducing unnecessarily complex tests and limiting potential fraud, waste, and abuse by directing testing toward laboratories amenable to cost-efficient contractual savings. Moreover, for definitive drug testing, the enforcement of the use of Healthcare Common Procedure Coding System codes and a move toward more cost-efficient tests (G0480), when clinically applicable, supported by clinical practice guidelines, or evidence-based medicine, is an approach to providing medical benefits while maintaining health costs.

Application of Health Technology Assessment (HTA) to Evaluate New Laboratory Tests in a Health System: A Case Study of Bladder Cancer Testing.

We describe the methods and decision from a health technology assessment of a new molecular test for bladder cancer (Cxbladder), which was proposed for adoption to our send-out test menu by urology providers. The Cxbladder health technology assessment report contained mixed evidence; predominant concerns were related to the test's low specificity and high cost. The low specificity indicated a high false-positive rate, which our laboratory formulary committee concluded would result in unnecessary confirmatory testing and follow-up. Our committee voted unanimously to not adopt the test system-wide for use for the initial diagnosis of bladder cancer but supported a pilot study for bladder cancer recurrence surveillance. The pilot study used real-world data from patient management in the scenario in which a patient is evaluated for possible recurrent bladder cancer after a finding of atypical cytopathology in the urine. We evaluated the type and number of follow-up tests conducted including urine cytopathology, imaging studies, repeat cystoscopy evaluation, biopsy, and repeat Cxbladder and their test results. The pilot identified ordering challenges and suggested potential use cases in which the results of Cxbladder affected a change in management. Our health technology assessment provided an objective process to efficiently review test performance and guide new test adoption. Based on our pilot, there were real-world data indicating improved clinician decision-making among select patients who underwent Cxbladder testing.

Integrating Formal Technology Assessment into an Integrated Healthcare Delivery System: Smart Innovation.

OBJECTIVES: We designed, developed, and implemented a new hospital-based health technology assessment (HB-HTA) program called Smart Innovation. Smart Innovation is a decision framework that reviews and makes technology adoption decisions. Smart Innovation was meant to replace the fragmented and complex process of procurement and adoption decisions at our institution. Because use of new medical technologies accounts for approximately 50 percent of the growth in healthcare spending, hospitals and integrated delivery systems are working to develop better processes and methods to sharpen their approach to adoption and management of high cost medical innovations. METHODS: The program has streamlined the decision-making process and added a robust evidence review for new medical technologies, aiming to balance efficiency with rigorous evidence standards. To promote system-wide adoption, the program engaged a broad representation of leaders, physicians, and administrators to gain support. RESULTS: To date, Smart Innovation has conducted eleven HB-HTAs and made clinician-led adoption decisions that have resulted in over $5 million dollars in cost avoidance. These are comprised of five laboratory tests, three software-assisted systems, two surgical devices, and one capital purchase. CONCLUSIONS: Smart Innovation has achieved cost savings, avoided uncertain or low-value technologies, and assisted in the implementation of new technologies that have strong evidence. The keys to its success have been the program's collaborative and efficient decision-making systems, partnerships with clinicians, executive support, and proactive role with vendors.

Effect of immediate cold formalin fixation on phosphoprotein IHC tumor biomarker signal in liver tumors using a cold transport device.

Phosphoproteins are the key indicators of signaling network pathway activation. Many disease treatment therapies are designed to inhibit these pathways and effective diagnostics are required to evaluate the efficacy of these treatments. Phosphoprotein IHC have been impractical for diagnostics due to inconsistent results occurring from technical limitations. We have designed and tested a novel cold transport device and rapid cold plus warm formalin fixation protocol using phosphoproteins IHC. We collected 50 liver tumors that were split into two experimental conditions: 2 + 2 rapid fixation (2 hours cold then 2 hour warm formalin) or 4 hour room-temperature formalin. We analyzed primary hepatocellular carcinoma (n = 10) and metastatic gastrointestinal tumors (n = 28) for phosphoprotein IHC markers pAKT, pERK, pSRC, pSTAT3, and pSMAD2 and compared them to slides obtained from the clinical blocks. Expression of pERK and pSRC, present in the metastatic colorectal carcinoma, were better preserved with the rapid processing protocol while pSTAT3 expression was detected in hepatocellular carcinoma. Differences in pSMAD2 expression were difficult to detect due to the ubiquitous nature of protein expression. There were only 3 cases expressing pAKT and all exhibited a dramatic loss of signal for the standard clinical workflow. The rapid cold preservation shows improvement in phosphoprotein preservation.

Predicting Unbound Phenytoin Concentrations: Effects of Albumin Concentration and Kidney Dysfunction.

STUDY OBJECTIVE: Several methods are available to predict unbound (free) phenytoin concentrations in patients with hypoalbuminemia; however, predictive methods have not been evaluated in patients with concurrent hypoalbuminemia and kidney dysfunction or in patients with mild to moderate (estimated glomerular filtration rate [eGFR] 30-90 ml/min/1.73 m2 ) kidney dysfunction alone. Thus the objective was to evaluate the accuracy and precision of predictive methods to estimate free phenytoin concentrations in patients with varying albumin concentrations and/or kidney dysfunction. DESIGN: Retrospective chart review. SETTING: Large academic medical center. PATIENTS: A total of 344 patients with free and total phenytoin, albumin, and serum creatinine concentrations obtained between November 2012 and May 2017. MEASUREMENTS AND MAIN RESULTS: Free phenytoin concentrations were estimated in patients without kidney dysfunction using the Winter-Tozer, Anderson, Kane, and Cheng equations. For the analysis in patients with eGFR lower than 90 ml/min/1.73 m2 , free phenytoin concentrations were estimated using the Shiner-Tozer derivation with adjusted affinity coefficients (C = 0.15, 0.20, 0.25, and 0.30). For both analyses, accuracy of predictive methods was evaluated by P20, the proportion of estimations within 20% of the measured free phenytoin concentration. In 158 patients with normal kidney function/normal albumin concentrations, 73 with normal kidney function/hypoalbuminemia, or 47 with mild kidney dysfunction/normal albumin concentrations, the Anderson method had the highest accuracy (86%, 82%, and 92%, respectively) and highest precision compared with the other methods. In 47 patients with normal albumin concentrations and mild kidney dysfunction or 13 with moderate kidney dysfunction, the free fraction was unchanged, and total phenytoin concentrations accurately reflected free concentrations. In 17 patients with hypoalbuminemia and mild or 17 with moderate kidney dysfunction, the Winter-Tozer (67% and 50%, respectively) and the Anderson (56% and 67%, respectively) methods had the highest accuracy compared with other methods with significantly lower accuracy compared with patients with normal kidney function. In the 14 patients with severe kidney dysfunction and hypoalbuminemia, none of the coefficients had a P20 accuracy greater than 45%. CONCLUSION: In patients with normal albumin concentrations, with or without mild or moderate kidney dysfunction and not receiving a protein-binding displacer, the free fraction of phenytoin is unchanged, and it is not necessary to measure a free phenytoin concentration. Free phenytoin concentrations should be measured directly in patients with hypoalbuminemia and kidney dysfunction.

Monitoring Dehydration and Clearing in Tissue Processing for High-Quality Clinical Pathology.

The development of precision testing for disease diagnosis has advanced medicine by specifically matching patients with drugs to treat specific diseases. High-quality diagnostics start with high-quality tissue specimens. The development and optimization of tissue handling and processing have lagged behind bioassay development. Ultrasound time-of-flight (TOF) technology has been successfully used to monitor the critical processing step of tissue fixation with formalin. In this study, we expand the use of this technology to monitor tissue dehydration and clearing by analyzing TOF signals from 270 different specimens, representing 13 different tissue types obtained through surgical resections. We determined the time constant τ90 for each tissue type for the following tissue processing solvents: 70% ethanol, 90% ethanol, 100% ethanol, and xylene. The TOF signals were correlated with tissue morphology to ensure that high-quality tissue was produced. Tissues can be grouped into those exhibiting fast and slow reagent diffusion. We monitored incomplete dehydration of tissue by skipping a key processing step, dehydration in absolute ethanol, and then correlated the τ90 with poor histomorphology, demonstrating that the technique can detect significant processing errors. Ultrasound TOF technology can therefore be used to monitor all phases of tissue processing cycle and yields an important preanalytical quality metric.

Cannabis Legalization Does Not Influence Patient Compliance with Opioid Therapy.

BACKGROUND: Prescription opioid use and opioid related deaths continue to increase nationwide. Several states have adopted legislation allowing for recreational use of cannabis. Little is known about how recreational cannabis laws impact compliance in chronic pain patients who have been prescribed opioid therapy. The goals of this study were to (1) retrospectively assess the effect of cannabis use on compliance with opioid therapy in a high-risk patient population and (2) determine the impact of legalization of recreational cannabis on patients prescribed therapeutic opioids. METHODS: We conducted a retrospective cohort study on results from a "high-risk" urine drug testing panel. Results from 1 year before and 1 year after initiation of recreational cannabis legislation were analyzed. This testing panel included qualitative assays for cannabinoids and 9 other common drugs of abuse in addition to a quantitative LC-MS/MS assay for 23 different opioids and metabolites. Opioid compliance was assigned by reviewing pathologists' interpretations. RESULTS: In the pre-legalization period, 1776 panels were performed, and in the post-legalization, 1648 panels were performed. An increase (6%) in the rate of positive cannabinoids screening results was observed after legalization of recreational cannabis; however, the overall compliance rate was consistent. CONCLUSIONS: The results of this study suggest that legalization of recreational cannabis does not affect compliance rate in patients treated with opioid therapy for chronic pain.

Clinical potential of mass spectrometry-based proteogenomics.

Cancer genomics research aims to advance personalized oncology by finding and targeting specific genetic alterations associated with cancers. In genome-driven oncology, treatments are selected for individual patients on the basis of the findings of tumour genome sequencing. This personalized approach has prolonged the survival of subsets of patients with cancer. However, many patients do not respond to the predicted therapies based on the genomic profiles of their tumours. Furthermore, studies pairing genomic and proteomic analyses of samples from the same tumours have shown that the proteome contains novel information that cannot be discerned through genomic analysis alone. This observation has led to the concept of proteogenomics, in which both types of data are leveraged for a more complete view of tumour biology that might enable patients to be more successfully matched to effective treatments than they would using genomics alone. In this Perspective, we discuss the added value of proteogenomics over the current genome-driven approach to the clinical characterization of cancers and summarize current efforts to incorporate targeted proteomic measurements based on selected/multiple reaction monitoring (SRM/MRM) mass spectrometry into the clinical laboratory to facilitate clinical proteogenomics.

The Choosing Wisely initiative and laboratory test stewardship.

The United States Choosing Wisely initiative was started in 2012 by the American Board of Internal Medicine Foundation and focused on reducing medical resource overutilization. Since its inception in the US, similar efforts have arisen in at least a dozen countries. Strongly patient-focused, and in fact started in collaboration with the consumer magazine Consumer Reports, the effort has resulted in a collection of greater than 500 recommendations from over 80 US professional societies intended to inform both patients and doctors about medical practices whose necessity should be questioned or discussed. Targets of recommendations include practices that lack a basis in scientific evidence, practices that may be duplicative of other care already received, practices that may be harmful and practices that are simply unnecessary. While critiques have been levied against the Choosing Wisely initiative over its intent, methods and efficacy, it is clear that many of its recommendations have been adopted by large medical practices, and several positive outcomes, i.e. reductions in perceived waste, have been reported in relation to many of the recommendations, including those specifically targeting laboratory tests. The future success of Choosing Wisely will likely hinge on whether or not significantly positive and durable outcomes can be demonstrated, especially at a time where there is increasing pressure to drive down costs in medical care while concomitantly increasing quality.