Overdiagnosis of Newborn Hyperbilirubinemia: A Natural Experiment in Quality Improvement Fundamentals.

Two hospitals noted increased newborn hyperbilirubinemia coinciding with an undisclosed total serum bilirubin (TSB) assay change. Clinicians rapidly applied quality improvement methodologies to ascertain increased jaundice evaluations, readmissions, and possible safety issues. Methods: In January 2020, 2 hospitals (A and B) transitioned to a new method of measuring TSB using a new clinical chemistry analyzer (Siemens Atellica CH), which measured TSB by vanadate oxidase assay instead of the previous diazo assay. Five affiliated hospitals (C-G) continued to utilize the diazo assay. This natural experiment led to a comparison of data across the 7 hospitals. We analyzed: (1) TSB levels, (2) hospital hyperbilirubinemia readmissions, and (3) paired TSB measurements comparing the diazo assay and vanadate oxidase method. Results: Compared to the 2019 baseline, Hospitals A and B had a significant increase in TSBs ≥17.0 mg/dl and TSBs ≥20 mg/dl in 2020; Hospitals C-G did not. Readmissions for phototherapy significantly increased in hospitals A and B in 2020 compared to 2019. Paired blood samples showed bias-elevated TSBs by vanadate assay compared to the diazo method. By 2021, the laboratory resumed processing TSB samples by diazo assay, and the frequency of elevated TSBs and hyperbilirubinemia readmissions returned to 2019 levels. Conclusions: Factitious TSB elevation related to an assay change significantly increased newborn hyperbilirubinemia evaluations and phototherapy readmissions. Imbedded quality improvement methodologies of careful structure, process, and outcomes review hastened resolution.

Impact of the AACC Global Laboratory Quality Initiative in Partnership with Professional Societies and Universities in Latin America and the Caribbean.

The Global Lab Quality Initiative (GLQI), formerly known as the Emerging Countries program, was funded through a generous endowment from the Wallace H. Coulter Foundation. The aims of GLQI are to develop and implement innovative programs to promote education and training in laboratory medicine for low- or lower middle-income countries worldwide. From its inception in 2010, the GLQI was focused solely on the Latin America and Caribbean (LAC) region under the purview of AACC's Latin American Working Group (LAWG), the members of which have strong ties to the region thereby facilitating the partnerships with national societies. The LAWG has provided in-person workshops in the LAC countries, at the AACC Annual Scientific Meeting, and on-demand webinars. The LAWG aims to implement the GLQI aims in the LAC region. In-person workshops are based on best-practice recommendations and sources such as Clinical Laboratory Standard Institute guidelines and supplemented with professional experiences of the LAWG's lecturers and local experts of the countries visited. In 2015, the GLQI expanded to other regions of the world. Here we report the experience of the LAWG workshops, results of participant surveys, in-person visits to laboratories post-workshop, and the lessons learned throughout the years across different geographic areas. We are hopeful this report provides insights into the challenges and successes of the LAWG in LAC to help support the expansion of the GLQI.

Professional Certification in Point-of-Care Testing.

Professional certification is affirmation and documentation that the certified individual has the knowledge, training, and skills necessary to practice some aspect of medicine or other profession. Herein is a description of the genesis of a professional certification in point of care testing (POCT), inclusive of rationale and goals. A distinction between professional certification and certificate training programs is made. Details regarding eligibility to sit for the board exam are provided along with a list exam content areas. Finally, successes of this professional certification program are highlighted.

African Americans Demonstrate Significantly Lower Serum Alanine Aminotransferase Compared to Non-African Americans.

BACKGROUND AND AIMS: Normal ranges of serum alanine aminotransferase (ALT) may vary by race. However, results from research studies are contradictory, and many of these studies have included only small numbers of African Americans. We investigated ALT values in patients without evidence of liver disease to determine whether normal ranges differ across race groups. We also evaluated whether a race- and sex-dependent upper limit of normal (ULN) would improve the ability of ALT to predict liver disease compared to the sex-dependent ULN currently in use. METHODS: We identified ICD9 codes for liver conditions and diabetes in medical records from a sample of 6719 patients. Analysis of variance (ANOVA) was used to assess differences in ALT log-transformed distributions by race. Logistic regression was used to evaluate whether the addition of race to the current sex-dependent ULN improves the ability of ALT to predict liver disease (assessed by area under the receiver operating characteristic curve (AUROC)). RESULTS: Among 1200 patients with BMI 18.5 < 25 and no evidence of liver disease or type 2 diabetes in their medical record, African Americans demonstrated significantly lower ALT (23.47 IU/L; 95% CL 22.87-24.10) than a combined group of Asian American/White/Other patients (25.71 IU/L; 95% CL 24.69-26.77). This difference remained across BMI categories. The race- and sex-dependent model demonstrated significantly better predictive ability than the sex-dependent model (AUROC = 66.6% versus 59.6%, respectively; p < 0.0001). CONCLUSIONS: In a large, racially diverse sample, African Americans demonstrated significantly lower ALT compared to non-African Americans; this difference remained as BMI increased. The establishment of race-specific normal ranges for ALT could contribute to better screening and care for African American patients.

Effects of hemoglobin (Hb) E and HbD traits on measurements of glycated Hb (HbA1c) by 23 methods.

BACKGROUND: Glycohemoglobin (GHB), reported as hemoglobin (Hb) A(1c), is a marker of long-term glycemic control in patients with diabetes and is directly related to risk for diabetic complications. HbE and HbD are the second and fourth most common Hb variants worldwide. We investigated the accuracy of HbA(1c) measurement in the presence of HbE and/or HbD traits. METHODS: We evaluated 23 HbA(1c) methods; 9 were immunoassay methods, 10 were ion-exchange HPLC methods, and 4 were capillary electrophoresis, affinity chromatography, or enzymatic methods. An overall test of coincidence of 2 least-squares linear regression lines was performed to determine whether the presence of HbE or HbD traits caused a statistically significant difference from HbAA results relative to the boronate affinity HPLC comparative method. Deming regression analysis was performed to determine whether the presence of these traits produced a clinically significant effect on HbA(1c) results with the use of +/-10% relative bias at 6% and 9% HbA(1c) as evaluation limits. RESULTS: Statistically significant differences were found in more than half of the methods tested. Only 22% and 13% showed clinically significant interference for HbE and HbD traits, respectively. CONCLUSIONS: Some current HbA(1c) methods show clinically significant interferences with samples containing HbE or HbD traits. To avoid reporting of inaccurate results, ion-exchange chromatograms must be carefully examined to identify possible interference from these Hb variants. For some methods, manufacturers' instructions do not provide adequate information for making correct decisions about reporting results.

Effects of hemoglobin C and S traits on the results of 14 commercial glycated hemoglobin assays.

Glycated hemoglobin is widely used in the management of diabetes mellitus. At least 300,000 Americans with diabetes mellitus have the hemoglobin (Hb) C or S trait. The accuracy of HbA1c methods can be adversely affected by the presence of these traits. We evaluated the effects of HbC and HbS traits on the results of 14 commercial HbA1c methods that use boronate affinity, enzymatic, immunoassay, and ion exchange methods. Whole blood samples from people homozygous for HbA or heterozygous for HbC or HbS were analyzed for HbA1c. Results for each sample type were compared with those from the CLC 330 comparative method (Primus Diagnostics, Kansas City, MO). After correcting for calibration bias by comparing results from the homozygous HbA group, method bias attributable to the presence of HbC or HbS trait was evaluated with a clinically significant difference being more than 10% (ie, 0.6% at 6% HbA1c). One immunoassay method exhibited clinically significant differences owing to the presence of HbC and HbS traits.

A direct comparison between lamellar body counts and fluorescent polarization methods for predicting respiratory distress syndrome.

Our objective was to directly compare the diagnostic usefulness of lamellar body counting (LBC) and the TDx-FLM II assay (Abbott Laboratories, Abbott Park, IL) for predicting respiratory distress syndrome (RDS). This was a 5-year, retrospective, cohort study. A diagnosis of RDS was given to infants who received surfactant treatment and/or required ventilator support and/or continuous positive airway pressure for more than 24 hours. There were 172 infants without RDS and 12 with RDS included in the study. By using a TDx-FLM II cutoff of 55 mg/g or more for maturity, the sensitivity was 83%, specificity was 65%, predictive value of a mature result was 98%, and predictive value of an immature result was 14%. These results were similar to LBC using a cutoff of 50,000/microL or more with sensitivity of 92%, a specificity of 60%, a predictive value of a mature result of 99%, and a predictive value of an immature result of 14%. The LBC and TDx-FLM II methods have similar clinical usefulness.

Localized sampling, electrophoresis, and biosensor analysis of Xenopus laevis cytoplasm for subcellular biochemical assays.

The Xenopus oocyte is a widely used model cell for studies of signal transduction mechanisms. Advances in microanalytical methods have made it feasible to perform rapid, localized collection of cytoplasm from individual Xenopus oocytes. Analytes contained in the cytoplasmic sample are separated by electrophoresis in a capillary and simultaneously transferred to a detection region. The development of bioengineered cells as sensitive detectors of intracellular components made quantitative measurements of native signaling molecules within the electrophoresed sample possible. Local determination of the second messenger inositol 1,4,5-trisphosphate is described to illustrate the methods for the sampling, electrophoresis, detection, and quantification of signaling molecules in single oocytes.

Gene expression profiling of primary tumor cell populations using laser capture microdissection, RNA transcript amplification, and GeneChip microarrays.

Gene expression profiling from microdissected cell populations is a powerful approach to explore molecular processes involved in development and solid tumor biology. In this chapter, we detail robust and validated methods for tissue preparation and isolation of high-quality RNA from microdissected cell populations. A protocol is also provided for linear transcript amplification using as little as 10 ng of total RNA to produce labeled cRNA targets for hybridization to GeneChip high-density oligonucleotide microarrays. Particular emphasis is placed on troubleshooting each technical step in the protocol and measures of quality assurance for both RNA isolation and resulting microarray data.

Analytic performance of immunoassays for drugs of abuse below established cutoff values.

BACKGROUND: The analytic performance and accuracy of drug detection below Substance Abuse and Mental Health Services Administration (SAMHSA) cutoffs is not well known. In some patient populations, clinically significant concentrations of abused drugs in urine may not be detected when current SAMHSA cutoffs are used. Our objectives were to define the precision profiles of three immunoassay systems for drugs of abuse and to evaluate the accuracy of testing at concentrations at which the CV was <20%. METHODS: Drug-free urine was supplemented with analytes to assess the precision in three commercial drugs-of-abuse immunoassay systems below the SAMHSA-dictated cutoffs for amphetamines, opiates, benzoylecgonine, phencyclidine, and cannabinoids. Consecutive urine samples with signals associated with a CV <20% by Emit immunoassay and below SAMHSA cutoffs were then subjected to confirmatory analysis. RESULTS: The CV of all immunoassay systems tested remained <20% to drug concentrations well below SAMHSA cutoffs. The accuracy of urine drug-screening results between the SAMHSA-specified cutoffs and the precision-based cutoffs was less than accuracy for specimens above the SAMHSA cutoffs, but the use of the precision-based cutoff produced a 15.6% increase in the number of screen-positive specimens and a 7.8% increase in the detection of specimens that yielded positive results on confirmatory testing. CONCLUSION: The precision of three commercial immunoassay systems for drugs-of-abuse screening is adequate to detect drugs below SAMHSA cutoffs. Knowledge of the positive predictive values of screening immunoassays at lower cutoff concentrations could enable efficient use of confirmatory testing resources and improved detection of illicit drug use.

Accurate and reproducible gene expression profiles from laser capture microdissection, transcript amplification, and high density oligonucleotide microarray analysis.

Gene expression profiling using high density oligonucleotide arrays is a powerful method to generate an unbiased survey of a cell's transcriptional landscape. Increasingly complex biological questions require that this approach be applicable to the small numbers of cells that are obtained from sources such as laser capture microdissection (LCM) of solid tissues. In this report, we demonstrate that two rounds of transcript amplification can generate accurate and reproducible gene expression profiles using high density oligonucleotide microarrays, starting with as little as 10 ng of total RNA. Biased amplification of the 3' end of transcripts does not have a major impact on the overall transcript profile due to the 3' bias of probe sets incorporated in the array design. Furthermore, greater than 95% of all genes detected demonstrate less than a twofold difference in expression when independent tissue dissections of identical cell populations are compared. The accuracy and technical reproducibility of the method suggests that expression profiling using transcript amplification and high density oligonucleotide microarrays can be used on a routine basis.