Retrospective Data Analysis Reveals Unusual Metabolism Pattern of Ethanol in Pediatrics as Compared to Adult and Geriatric Populations.

BACKGROUND: About 95% of consumed ethanol is metabolized by oxidative pathways. Less than 1% is metabolized via nonoxidative pathways: glucuronidation, sulfation, and the formation of fatty acid esters of ethanol. In neonates, the glucuronidation pathway has been reported to be underdeveloped but matures with age. This work compared the test results of patients' random urine samples submitted to our facility for ethyl glucuronide (EtG) and ethyl sulfate (EtS) measurements across pediatric and adult populations. METHODS: Test results (n = 63 498) from urine samples tested for EtG and EtS by quantitative liquid chromatography-tandem mass spectrometry at our facility were utilized for this study. EtG and EtS concentrations were compared across the age partitions 0 to 17 years (pediatric), 18 to 80 years (adult), and 81 to 100 years (geriatric). Eight pediatric patients from a tertiary academic hospital contributed clinical context via abstracted clinical information. RESULTS: Across the individual age partitions, 60% to 65% of patients had both EtG and EtS present in urine. Approximately 5% to 10% of patients had only EtG, and 25% to 35% had neither metabolite present. The lowest percentages (<1.5%) had EtS present in the absence of EtG. Markedly, no pediatric patients had only EtS present; compared to the adult population, this was statistically significant (Fisher exact test, P = 0.025). CONCLUSIONS: From the data presented in this work, EtG is more prevalent relative to EtS in urine samples of patients assessed for ethanol exposure.

Impact of sex used for assignment of reference intervals in a population of patients taking gender-affirming hormones.

Background: Gender-affirming hormone therapy with either estradiol or testosterone for transgender persons can significantly impact chemistry and hematology laboratory tests. The sex used for assignment of reference intervals (RIs) in the electronic health record (EHR) will influence normal/abnormal flagging of test results. Objective: To analyze common non-hormonal laboratory tests with sex-specific RIs ordered in patients with sexual orientation/gender identify (SOGI) field differences (one or more differences between legal sex, sex assigned at birth, and gender identity) in the EHR at an academic medical center in midwestern United States. Methods: We utilized a previously characterized data set of patients at our institution that included chart review information on gender identity and gender-affirming therapy. We focused on the subset of these patients that had orders for 18 common laboratory tests in calendar year 2021. Results: A total of 1336 patients with SOGI field differences (1218 or 91.2% identifying as gender-expansive; 892 or 66.8% receiving estradiol or testosterone as gender-affirming therapy) had a total of 9374 orders for 18 laboratory tests with sex-specific RIs. Hemoglobin, creatinine, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, and high-density lipoprotein were the most frequently ordered tests. For patients taking estradiol, 128 of 970 (13.2%) creatinine and 39 of 193 (20.2%) hemoglobin measurements were within the RI for one sex but not the other. For those taking testosterone, 119 of 531 (22.4%) creatinine and 49 of 120 (40.8%) hemoglobin measurements were within the RI for one sex but not the other. Values above the cisgender female RI but within the cisgender male RI were common for hemoglobin, alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase in patients taking testosterone. Conclusions: Clinicians should be aware of the potential impact of gender-affirming therapy on laboratory tests and what sex/gender is being used in the EHR to assign RIs.

Reflex strategy to ensure accurate total testosterone results from consumer initiated, self-collected capillary samples.

BACKGROUND: Self-collected capillary samples are convenient for direct access testing (DAT), but exogenous testosterone use may cause falsely elevated total testosterone (TT) results. We designed a quality assurance workflow to differentiate between accurate or erroneous supraphysiological TT concentrations. METHODS: Clinical samples with TT > 1500 ng/dL were reflexed to luteinizing hormone (LH) and follicle stimulating hormone (FSH) and screened for exogenous testosterone use. Samples (n = 120) with normal TT were reflexed to LH/FSH as a control. RESULTS: A total of 8572 TT samples were evaluated, of which 533 (6.2 %) had TT > 1500 ng/dL and were reflexed. Of these, 441 (82.7 %) had significantly decreased LH/FSH (<0.85/<0.7mIU/mL, respectively), 72 (13.5 %) had normal or borderline normal LH/FSH, and 20 (3.8 %) had insufficient plasma volume. In patients with TT > 1500 ng/dL, injectable exogenous testosterone use was most commonly accompanied by significantly decreased LH/FSH, while topical testosterone use was most commonly accompanied by detectable LH/FSH. Control samples were almost all (99.2 %) within or above the LH/FSH reference intervals. Unique patients ordered 351 TT tests where at least one TT result was > 1500 ng/dL. Based on TT and LH/FSH results, we hypothesized that patients were intermittently or consistently overusing exogenous testosterone, resolved elevated TT with recollection, or repeatedly contaminated their sample. CONCLUSION: Self-collected capillary specimens are acceptable for TT testing. A quality assurance reflex to LH/FSH can determine the validity of supraphysiological TT results in a consumer initiated/DAT population.

Biological Testing and Interpretation of Laboratory Results Associated with Detecting Newborns with Substance Exposure.

BACKGROUND: Substance use during pregnancy is common, as is biological testing that is intended to help identify prenatal exposures. However, there is no standardized requirement for biological testing with either maternal or newborn specimens, nor is there standardization related to when testing occurs, how frequently testing occurs, what specimen(s) to test, what substances to test for, or how to perform testing. CONTENT: We review common specimen types tested to detect maternal and newborn substance exposure with a focus on urine, meconium, and umbilical cord tissue. We also review common analytical methods used to perform testing, including immunoassay, and mass spectrometry platforms. Considerations regarding the utilization of testing relative to the purpose of testing, the drug analyte(s) of interest, the specific testing employed, and the interpretation of results are emphasized to help guide decisions about clinical utilization of testing. We also highlight specific examples of unexpected results that can be used to guide interpretation and appropriate next steps. SUMMARY: There are strengths and limitations associated with all approaches to detecting substance exposure in pregnant persons as well as biological testing to evaluate a newborn with possible substance exposure. Standardization is needed to better inform decisions surrounding evaluation of substance exposures in pregnant people and newborns. If biological sampling is pursued, testing options and results must be reviewed in clinical context, acknowledging that false-positive and -negative results can and do occur.

Causes of acquired methemoglobinemia - A retrospective study at a large academic hospital.

Methemoglobinemia is a potentially life-threatening condition caused by the formation of methemoglobin, a form of hemoglobin that cannot bind oxygen. While there are some rare congenital causes of methemoglobinemia, most cases are acquired from the effects of specific drugs or environmental exposures. In this retrospective study, we analyzed a large data set of whole blood samples analyzed for methemoglobin at an academic medical center in Midwestern United States that provides both pediatric and adult services. For a 14 year timeframe (May 2009- June 2023), we performed detailed chart analysis of all patients with a methemoglobin concentration of 3.1 % or higher. For an earlier 13 year timeframe (January 1996-April 2009), we performed chart review for all patients with a methemoglobin concentration of 10.0 % or higher. For the 2009-2023 data, dapsone was the most frequent cause of methemoglobinemia (methemoglobin 3.1 % or higher) in both pediatric (73.3 %, 115 clinical encounters, 105 unique patients) and adult (65.3 %, 195 clinical encounters, 190 unique patients) populations. Inhaled nitric oxide as medical therapy was the next most frequent cause in both pediatric (18.1 %) and adult (13.2 %) populations. Causes associated with two or more unique episodes with methemoglobin concentrations of 10.0 % and higher included the following: dapsone (n = 40 episodes), benzocaine (n = 10), recreational use of amyl or isobutyl nitrite (n = 3), suicide attempt with sodium nitrite (n = 3 with 1 fatality; all 3 cases within last 3 years), food contaminated with nitrates (n = 2), and sepsis (n = 2). A total of 18 patients received treatment with methylene blue including 5 cases associated with benzocaine and all of the cases associated with amyl nitrite, isobutyl nitrite, sodium nitrite, and contaminated food. Only 3 patients with dapsone-associated methemoglobinemia received methylene blue, reflecting primary management by dose reduction or discontinuation of drug. Overall, our data reinforce previous studies showing dapsone, inhaled nitric oxide, and nitrites as common agents causing methemoglobinemia in a patient population seen at a medical center. Our data also are consistent with recent epidemiology trends showing increase in suicide attempts using sodium nitrite.

A Holistic Framework for the Evaluation of Kidney Function in a Gender-Diverse Landscape.

The most commonly used equations to estimate glomerular filtration rate incorporate a binary male-female sex coefficient, which has important implications for the care of transgender, gender-diverse, and nonbinary (TGD) people. Whether "sex assigned at birth" or a binary "gender identity" is most appropriate for the computation of estimated glomerular filtration rate (eGFR) is unknown. Furthermore, the use of gender-affirming hormone therapy (GAHT) for the development of physical changes to align TGD people with their affirmed gender is increasingly common, and may result in changes in serum creatinine and cystatin C, the biomarkers commonly used to estimate glomerular filtration rate. The paucity of current literature evaluating chronic kidney disease (CKD) prevalence and outcomes in TGD individuals on GAHT makes it difficult to assess any effects of GAHT on kidney function. Whether alterations in serum creatinine reflect changes in glomerular filtration rate or simply changes in muscle mass is unknown. Therefore, we propose a holistic framework to evaluate kidney function in TGD people. The framework focuses on kidney disease prevalence, risk factors, sex hormones, eGFR, other kidney function assessment tools, and the mitigation of health inequities in TGD people.

Laboratorian Interpretation of Drug Testing Results in Pain Management: Lessons From College of American Pathologists Proficiency Testing.

CONTEXT.­: Accurate interpretation of drug test results is key to appropriate patient care in numerous settings including pain management. Despite recommendations that providers should consult laboratory professionals for guidance when necessary, literature demonstrating laboratorian expertise in drug test interpretation is lacking. OBJECTIVE.­: To evaluate participating laboratories' performance on the case-based, interpretive ("dry") challenge included with each Drug Monitoring for Pain Management proficiency testing program from 2012-2023. DESIGN.­: All challenges (n = 23) required participants to identify if drug test results were consistent or inconsistent with prescribed medications in the case history. Relevant medications, presumptive and confirmatory drug test results, and participant responses were extracted from program summary reports and examined for performance and common themes. RESULTS.­: Overall, 91.8% (6821 of 7431) of participant responses correctly identified whether drug testing was consistent with medications. There were 8 challenges with participant scores below 91.8% (range, 59.8% [49 of 82 responses] to 88.9% [193 of 217 responses]). Common knowledge gaps identified in these challenges included false-positive presumptive (screening) results, minor metabolism of opiates, and recognizing that presence of a nonprescribed drug is inconsistent with prescribed medications. Although some participants repeatedly responded incorrectly, there were no associations between laboratory type, personnel responding, or analytical performance with incorrect responses to interpretative challenges. CONCLUSIONS.­: Program participants performed well overall, but several concerning educational gaps were identified. Laboratorians have a role in providing interpretative guidance for drug testing and should emphasize ongoing education to ensure competence in the setting of constantly changing prescribed and nonprescribed drug use.

Falsely elevated serum testosterone measurements resulting from testosterone topical gel contamination of the venipuncture site: Case Series and retrospective review.

Testosterone as replacement therapy for male hypogonadism or as gender-affirming hormone therapy for transgender and non-binary patients has increased worldwide. Commonly used formulations of testosterone include intramuscular, transdermal patch, and topical gel, each of which has differing pharmacokinetics and practical challenges. In monitoring testosterone serum concentrations, contamination of the phlebotomy site by testosterone topical gel can lead to supraphysiologic (>1000 ng/dL or 34.7 nmol/L) serum concentrations of testosterone, as demonstrated in a few published case reports. The frequency of this issue is currently not known. The present study involves a retrospective search over a 13-year period across all clinical sites at an academic medical center. Out of 578 unique patients using testosterone topical gel, a total of 48 patients had at least 1 testosterone serum concentration exceed 1000 ng/dL. Documentation in the electronic health record revealed 7 patients where contamination of the phlebotomy site by topical gel was strongly supported as the cause of supraphysiologic testosterone serum concentrations. These included 5 males with primary hypogonadism, 1 male with panhypopituitarism, and a non-binary patient with gender dysphoria. The high testosterone concentrations prompted further work-up, including retesting and endocrinology consultation. There were additional cases of high testosterone serum concentration that may have been falsely elevated due to gel contamination but without sufficient supporting evidence available in the health record. Overall, we present 7 cases of spuriously high testosterone concentrations strongly suspected to be due to venipuncture performed near or at the location of prior testosterone gel application. Gel contamination should be considered as a possible cause of otherwise unexplained high testosterone serum concentration in patients receiving topical testosterone gel formulations. Patient counseling and provider awareness of this potential cause of spuriously high testosterone serum concentrations is important.

Impact of a switch to immediate release on the patient viewing of diagnostic test results in an online portal at an academic medical center.

Patient portals allow patients to access their personal health information. The 21st Century Cures Act in the United States sought to eliminate 'information blocking', requiring timely release upon request of electronic health information including diagnostic test results. Some health systems, including the one in the present study, chose a systematic switch to immediate release of all or nearly all diagnostic test results to patient portals as part of compliance with the Cures Act. Our primary objective was to study changes in the time to view test results by patients before and after implementation of Cures Act-related changes. This retrospective pre-post study included data from two 10-month time periods before and after implementation of Cures Act-related changes at an academic medical center. The study included all patients (adult and pediatric) with diagnostic testing (laboratory and imaging) performed in the outpatient, inpatient, or emergency department settings. Between February 9, 2020 and December 9, 2021, there was a total of 3 809 397 diagnostic tests from 204 605 unique patients (3 320 423 tests for adult patients; 488 974 for pediatric patients). Overall, 56.5% (115 627) of patients were female, 84.1% (172 048) white, and 96.5% (197 517) preferred English as primary language. The odds of viewing test results within 1 and 30 days after portal release increased monthly throughout both time periods before and after the Cures Act for all patients. The rate of increase was significantly higher after implementation only in the subgroup of tests belonging to adult patients with active MyChart accounts. Immediate release shifted a higher proportion of result/report release to weekends (3.2% pre-Cures vs 15.3% post-Cures), although patient viewing patterns by day of week and time of day were similar before and after immediate release changes. The switch to immediate release of diagnostic test results to the patient portal resulted in a higher fraction of results viewed within 1 day across outpatient, inpatient, and emergency department settings.

Patterns of gender identity data within electronic health record databases can be used as a tool for identifying and estimating the prevalence of gender-expansive people.

Objective: Electronic health records (EHRs) within the United States increasingly include sexual orientation and gender identity (SOGI) fields. We assess how well SOGI fields, along with International Statistical Classification of Diseases and Related Health Problems, 10th Revision (ICD-10) codes and medication records, identify gender-expansive patients. Materials and Methods: The study used a data set of all patients that had in-person inpatient or outpatient encounters at an academic medical center in a rural state between December 1, 2018 and February 17, 2022. Chart review was performed for all patients meeting at least one of the following criteria: differences between legal sex, sex assigned at birth, and gender identity (excluding blank fields) in the EHR SOGI fields; ICD-10 codes related to gender dysphoria or unspecified endocrine disorder; prescription for estradiol or testosterone suggesting use of gender-affirming hormones. Results: Out of 123 441 total unique patients with in-person encounters, we identified a total of 2236 patients identifying as gender-expansive, with 1506 taking gender-affirming hormones. SOGI field differences or ICD-10 codes related to gender dysphoria or both were found in 2219 of 2236 (99.2%) patients who identify as gender-expansive, and 1500 of 1506 (99.6%) taking gender-affirming hormones. For the gender-expansive population, assigned female at birth was more common in the 12-29 year age range, while assigned male at birth was more common for those 40 years and older. Conclusions: SOGI fields and ICD-10 codes identify a high percentage of gender-expansive patients at an academic medical center.

Cannabis positivity rates in 17 emergency departments across the United States with varying degrees of marijuana legalization.

BACKGROUND: Many states in the United States have progressed towards legalization of marijuana including decriminalization, medicinal and/or recreational use. We studied the impact of legalization on cannabis-related emergency department visits in states with varying degrees of legalization. METHODS: Seventeen healthcare institutions in fifteen states (California, Colorado, Connecticut, Florida, Iowa, Kentucky, Maryland, Massachusetts, Missouri, New Hampshire, Oregon, South Carolina, Tennessee, Texas, Washington) participated. Cannabinoid immunoassay results and cannabis-related International Classification of Diseases (ninth and tenth versions) codes were obtained for emergency department visits over a 3- to 8-year period during various stages of legalization: no state laws, decriminalized, medical approval before dispensaries, medical dispensaries available, recreational approval before dispensaries and recreational dispensaries available. Trends and monthly rates of cannabinoid immunoassay and cannabis-related International Classification of Diseases code positivity were determined during these legalization periods. RESULTS: For most states, there was a significant increase in both cannabinoid immunoassay and International Classification of Diseases code positivity as legalization progressed; however, positivity rates differed. The availability of dispensaries may impact positivity in states with medical and/or recreational approval. In most states with no laws, there was a significant but smaller increase in cannabinoid immunoassay positivity rates. CONCLUSIONS: States may experience an increase in cannabis-related emergency department visits with progression toward marijuana legalization. The differences between states, including those in which no impact was seen, are likely multifactorial and include cultural norms, attitudes of local law enforcement, differing patient populations, legalization in surrounding states, availability of dispensaries, various ordering protocols in the emergency department, and the prevalence of non-regulated cannabis products.

Evaluating the utility of a two-assay serological algorithm for hepatitis C screening in a low prevalence population.

INTRODUCTION: Screening for hepatitis C virus (HCV) is performed by testing for anti-HCV antibodies, which may yield false-positive results leading to additional testing and other downstream consequences for the patient. We report our experience in a low prevalence population (<0.05%) using a two-assay algorithm aimed at testing specimens with borderline or weak positive anti-HCV reactivity in the screening assay by a second anti-HCV assay prior to confirming positive anti-HCV results with RT-PCR. MATERIALS AND METHODS: Retrospective analysis of 58,908 plasma samples was obtained over a 5-year period. Samples were initially tested using the Elecsys Anti-HCV II assay (Roche Diagnostics), with borderline or weakly positive results (defined in our algorithm as a Roche cutoff index of 0.9-19.99) reflexively analyzed using the Architect Anti-HCV assay (Abbott Diagnostics). The Abbott anti-HCV results dictated the final anti-HCV interpretation for reflexed samples. RESULTS: Our testing algorithm resulted in 180 samples requiring second-line testing, with final anti-HCV results interpreted as 9% positive, 87% negative, and 4% indeterminate. The positive predictive value (PPV) of a weakly positive Roche result was 12%, which was significantly lower than the PPV using our two-assay approach (65%). CONCLUSIONS: The incorporation of a two-assay serological testing algorithm in a low prevalence population provides a cost-effective method of improving the PPV of HCV screening in specimens with borderline or weakly positive anti-HCV results.

A dataset examining the impact of direct electronic medical record interfacing on the accuracy of point-of-care urinalysis results.

Point-of-care testing is widely used in a variety of clinical settings. While this testing provides immediate and actionable clinical information, it is prone to error in both the interpretation and reporting of results. Point-of-care urinalysis presents unique opportunities for errors, ranging from variation in visual interpretation to input of results. The data included here represent the results from 63,279 urinalyses from 36,780 unique patients performed over a span of three years at an academic medical center and its associated clinics. The data include the patient age/legal sex, methodology (instrument and test strip used), and the available test results (color, clarity, glucose, bilirubin, ketones, specific gravity, blood, pH, protein, urobilinogen, nitrite, and leukocyte esterase). Additionally, we include the method of interface between the testing instrumentation and our electronic medical record (EMR). These fell into one of three broad categories: "Interfaced" (results directly transmitted from the urinalysis instrument to the EMR via specialized data interface), "Manual" (results input by selecting from a drop-down menu in the laboratory information system), and "Enter/Edit" (results typed freely into a text field in the EMR). Analysis of this data was primarily a direct comparison of detectable errors (typos, uninterpretable results, and results outside the reportable range) as a function of the method of entry into the EMR. Secondary analysis comparing the impact of restricting drop-down menu options for urine color and clarity was also performed. These data are of use to others as they are diverse in terms of the test performed and the method of interface. Others may wish to analyze these data when making decisions as to how to perform and report these tests and when estimating risks of error with various methods of data entry.

Nicotine and Tobacco Alkaloid Testing and Challenges: Lessons Learned From a College of American Pathologists Proficiency Testing Survey.

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

Distribution of High-Sensitivity Cardiac Troponin and N-Terminal Pro-Brain Natriuretic Peptide in Healthy Transgender People.

Importance: Sex-specific differences in the commonly used cardiac biomarkers high-sensitivity cardiac troponin (hs-cTn) and N-terminal pro-brain natriuretic peptide (NT-proBNP) are apparent. There is an absence of medical literature delineating the concentration differences for these biomarkers in transgender individuals without cardiac disease. Objective: To determine the distribution of hs-cTn and NT-proBNP in healthy transgender people. Design, Setting, and Participants: In this cross-sectional prospective study, healthy transgender individuals prescribed testosterone or estradiol for 12 months or more were recruited from internal medicine and primary care clinics that specialize in transgender medical care between November 1, 2017, and July 1, 2018. Exposures: Testosterone or estradiol for 12 months. Main Outcomes and Measures: Concentrations for hs-cTnI (troponin I), hs-cTnT (troponin T), and NT-proBNP were measured. Results: Transgender people prescribed testosterone (n = 79; mean [SD] age, 28.8 [7.8] years) or estrogen (n = 93; mean [SD] age, 35.1 [11.7] years) were recruited. The concentration of hs-cTn was significantly higher in transgender men relative to transgender women. For Abbott hs-cTnI levels, the median (IQR) concentration observed in transgender men and women was 0.9 (0.6-1.7) ng/L and 0.6 (0.3-1.0) ng/L, respectively. Results were similar across 2 additional hs-cTn assays. In contrast, NT-proBNP level was higher in transgender women. The median (IQR) NT-proBNP concentration was significantly higher in transgender women ( 49 [32-86] ng/L) than in transgender men (17 [13-27] ng/L). Conclusions and Relevance: Findings of this cross-sectional study suggest that the differences in concentration for hs-cTn and NT-proBNP between transgender men and women were similar to what is observed between cisgender men and women. Sex hormones, rather than sex assigned at birth, may be a stronger driver of the observed concentration differences between healthy men and women for biomarkers of cardiac disease.

Data on the clinical, analytical, and laboratory factors associated with negative anion gaps at an academic medical center.

The anion gap is a calculated parameter derived from the difference between the major plasma cations and anions in serum/plasma or whole blood, with a widely used simple equation utilizing concentrations of sodium, chloride, and bicarbonate. While there is extensive literature on the clinical significance and causes of elevated anion gaps, there is comparatively less data on low anion gaps. Occasionally, anion gap calculations result in a negative number (-1 or less). From the published literature, causes of these 'negative anion gaps' include laboratory error, specimen contamination or interference, hypoalbuminemia, extreme hyperkalemia, bromism, and paraproteins from multiple myeloma or similar pathologic processes. The data in this article present results from retrospective review of clinical chemistry and blood gas analysis testing at an academic medical center. The data include electrolyte concentrations and anion gap values derived from a total of 2,948,574 specimens (2,841,863 serum/plasma specimens analyzed on Roche Diagnostics clinical chemistry analyzers, 93,987 whole blood specimens analyzed on Radiometer blood gas analyzers, and 12,724 whole blood specimens on point-of-care chemistry devices) from 371,925 unique patients, clinical area where testing was ordered (for serum/plasma samples), sex, and age. For serum/plasma specimens with a negative anion gap, the data additionally include information from detailed chart review of possible factors and disease conditions contributing to the negative anion gap, pattern of electrolyte abnormalities, presence or absence of hypoalbuminemia, and corrected anion gap (if hypoalbuminemia is present).

Reference Intervals for Clinical Chemistry Analytes for Transgender Men and Women on Stable Hormone Therapy.

BACKGROUND: Gender-affirming hormone therapy with either estradiol or testosterone is commonly prescribed for transgender individuals. Masculinizing or feminizing hormone therapy may impact clinical chemistry analytes, but there is currently a lack of published reference intervals for the transgender population. METHODS: Healthy transgender and nonbinary individuals who had been prescribed either estradiol (n = 93) or testosterone (n = 82) for at least 12 months were recruited from primary care and internal medicine clinics specializing in transgender medical care. Electrolytes, creatinine, urea nitrogen, enzymes (alkaline phosphatase, ALK; alanine aminotransferase, ALT; aspartate aminotransferase, AST; gamma-glutamyltransferase, GGT), hemoglobin A1c, lipids [total cholesterol, high-density lipoprotein (HDL), triglycerides], and high-sensitivity C-reactive protein (hsCRP) were measured on 2 clinical chemistry platforms. Reference intervals (central 95%) were calculated according to Clinical Laboratory Standards Institute guidelines. RESULTS: There was minimal impact of gender-affirming hormone therapy on electrolytes, urea nitrogen, hemoglobin A1c, and hsCRP. In general, the enzymes studied shifted toward affirmed gender. Creatinine values for both transgender cohorts overlaid the reference interval for cisgender men, with no shift toward affirmed gender for the estradiol cohort. The effects on lipids were complex, but with a clear shift to lower HDL values in the testosterone cohort relative to cisgender women. CONCLUSIONS: Transgender individuals receiving either masculinizing or feminizing hormone therapy showed significant changes in some analytes that have sex-specific variation in the cisgender population. The clearest shifts toward affirmed gender were seen with enzymes for the estradiol and testosterone cohorts and with creatinine and HDL in the testosterone cohort.

Impact of Interfacing Near Point of Care Clinical Chemistry and Hematology Analyzers at Urgent Care Clinics at an Academic Health System.

BACKGROUND: Point-of-care (POC) testing equipment is commonly utilized in outpatient clinics. Our institution recently interfaced POC chemistry and hematology devices at two outpatient clinics via middleware software to the central electronic health record (EHR), facilitating a comparison of manual transcription versus automatic reporting via interface. This allowed for estimation of serious/obvious error rates and manual time savings. Additional goals were to develop autoverification rules and analyze broad trends of results in response to common clinician complaints on the POC testing. MATERIAL AND METHODS: Data were obtained from two satellite clinic sites providing both primary and urgent care within an academic health system. Interface of devices was accomplished via Instrument Manager middleware software and occurred approximately halfway through the 38 month retrospective timeframe. Laboratory results for three testing POC chemistry and hematology panels were extracted with EHR tools. RESULTS: Nearly 100,000 lab values were analyzed and revealed that the rate of laboratory values outside reference range was essentially unchanged before and after interface of POC testing devices (2.0-2.1%). Serious/obvious errors, while rare overall, declined significantly, with none recorded after the interface with autoverified results and only three related to manual edits of results that failed autoverification. Fewer duplicated test results were identified after the interface, most notably with the hematology testing. Anion gap values of less than zero were observed more frequently in POC device tests when compared to central laboratory tests and are attributed to a higher proportion of Cl values greater than 110 mEq/L and CO2 values greater than 30 mEq/L with POC results. Time savings of eliminating manual data entry were calculated to be 21.6 employee hours per month. CONCLUSIONS: In a switch from manual entry to automatic interface for POC chemistry and hematology, the most notable changes were reduction of serious/obvious errors and duplicate results. Significant time employee time savings highlight an additional benefit of instrument interfacing. Lastly, a difference between POC and central laboratory instruments is a higher rate of high Cl and CO2 values relative to the central laboratory.

Oral estrogen leads to falsely low concentrations of estradiol in a common immunoassay.

Objectives: Recently, an estradiol immunoassay manufacturer (Beckman Coulter, USA) issued an 'important product notice' alerting clinical laboratories that their assay (Access Sensitive Estradiol) was not indicated for patients undergoing exogenous estradiol treatment. The objective of this analysis was to evaluate immunoassay bias relative to liquid chromatography tandem mass spectrometry (LC-MS/MS) in transgender women and to examine the influence of unconjugated estrone on measurements. Design: Cross-sectional secondary analysis. Methods: Estradiol concentrations from 89 transgender women were determined by 3 immunoassays (Access Sensitive Estradiol ('New BC') and Access Estradiol assays ('Old BC'), Beckman Coulter; Estradiol III assay ('Roche'), Roche Diagnostics) and LC-MS/MS. Bias was evaluated with and without adjustment for estrone concentrations. The number of participants who shifted between three estradiol concentration ranges for each immunoassay vs LC-MS/MS (>300 pg/mL, 70-300 pg/mL, and <70 pg/mL) was calculated. Results: The New BC assay had the largest magnitude overall bias (median: -34%) and was -40%, -22%, and -10%, among participants receiving tablet, patch, or injection preparations, respectively. Overall bias was -12% and +17% for the Roche and Old BC assays, respectively. When measured with the New BC assay, 18 participants shifted to a lower estradiol concentration range (vs 9 and 10 participants based on Roche or Old BC assays, respectively). Adjustment for estrone did not minimize bias. Conclusions: Immunoassay measurement of estradiol in transgender women may lead to falsely decreased concentrations that have the potential to affect management. A multidisciplinary health care approach is needed to ensure if appropriate analytical methods are available.