Journal of Applied Laboratory Medicine最新文献

Background: Enzyme-linked immunosorbent assay (ELISA) is the most-used method for neurofilament light chain (NfL) quantification in cerebrospinal fluid (CSF). Recently, fully automated immunoassays for NfL measurement in CSF and blood have allowed high reproducibility among laboratories, making NfLs suitable for routine use in clinical practice. In this study, we compared the Uman Diagnostics NF-light ELISA with the fully automated platform Lumipulse.

Methods: We enrolled 60 patients with cognitive decline, including Alzheimer disease (AD). CSF NfL levels were measured by a NF-light ELISA kit (UmanDiagnostics), and chemiluminescent enzyme immunoassay (CLEIA) on the Lumipulse G1200 platform (Fujirebio Diagnostics). Serum NfLs levels were measured by CLEIA on the Lumipulse G1200.

Results: We found a significant, very strong correlation [Spearman rho = 0.94 (0.90-0.96)] between CLEIA and ELISA in CSF, and a significant moderate correlation between CSF and serum with both analytical methods [CLEIA vs serum CLEIA 0.41 (0.16-0.61); ELISA vs serum CLEIA 0.40 (0.15-0.60)]. It is worth noting that CSF CLEIA measurements were approximately 136.12 times higher than the serum measurements.

Conclusions: Our findings show a robust correlation between ELISA Uman Diagnostic and the standardized Lumipulse G1200 platform for CSF NfL measurements.

Background: The COVID-19 pandemic reportedly had a significant impact on drug and alcohol use. In this article, we determine positivity rates for urine drugs of abuse and blood alcohol in 5 emergency departments (ED) in the greater Boston metropolitan area over a 4-year period (pre-, during, and post-COVID-19 pandemic).

Methods: Positivity rates for the urine drug screening (UDS) panel and blood alcohol concentration (>80 mg/dL; over the legal limit in MA) were calculated in patients presenting to one of the 5 ED (2 academic hospitals in Boston, MA and 3 community hospitals outside Boston, MA) during each of the 4 different time periods: pre-COVID (January 1, 2019 to December 31, 2019), stay-at-home (March 24, 2020 to May 18, 2020), during COVID (May 19, 2020 to March 28, 2021), and post-COVID (May 12, 2023 to August 31, 2023). Trend analysis was performed. Additionally, positivity rates during and post-COVID were compared to pre-COVID to determine any significant changes in drug positivity.

Results: Stimulant (amphetamines and cocaine), cannabinoid, and methadone positivity increased during the pandemic and cocaine, cannabinoid, and methadone positivity remains elevated. By contrast, benzodiazepine and opioid (opiates, fentanyl, oxycodone) positivity decreased and remains lower post-COVID compared to pre-COVID. Patients in the ED with blood alcohol over the legal limit decreased both during and post-COVID.

Conclusion: Our study showed that the COVID-19 pandemic significantly affected drug and alcohol positivity rates in patients presenting to the ED in greater Boston area. We encourage other institutions to perform similar analyses to help determine local drug use patterns and appropriate composition of UDS panels.

Background: Glycated albumin (GA) has shown promise in predicting risk of adverse neonatal outcomes (ANO) in pregnant women with type 2 diabetes (T2DM) and gestational diabetes (GDM). However, previous studies showing a negative correlation between GA and body mass index (BMI) suggest that lower predictive cutoffs may be needed in populations with elevated BMI.

Methods: We performed a case-control study of prospectively enrolled pregnant women with T2DM or GDM and BMI ≥25 kg/m2 matched to biobanked controls without diabetes. Serum collected during the second and/or third trimesters was used to measure the percentage of GA (% GA). Receiver operating characteristic (ROC) curves were used to examine % GA to predict an ANO composite, including macrosomia, hypoglycemia, respiratory distress syndrome, and/or hyperbilirubinemia for the second and third trimesters.

Results: The median BMIs for cases and controls were 34.0 and 31.0 kg/m2, respectively. The area under the ROC curve to predict the ANO composite was significant for second trimester values but ambiguous for third trimester due to its wide 95% CI. A cutoff of 12.3% GA during second trimester showed 100% sensitivity and 73% specificity. Transference of previously published reference ranges did not validate, suggesting lower ranges are needed for women with overweight/obesity.

Conclusions: In this pilot study, % GA shows promise to stratify pregnant patients with diabetes and obesity into risk categories for ANO with excellent predictive ability in the second trimester. If this holds in larger studies, using second trimester % GA could allow additional intervention to improve blood glucose control and minimize ANO.

Background: Point-of-care testing (POCT) is increasingly being used in healthcare, including hospitals, and POCT-style tests are also used within some laboratories. The principles of biosafety, including risk assessment and containment of biohazardous agents, can be utilized as a foundation to establish policies and procedures guiding safe performance of POCT. However, specific biosafety guidelines for POCT are generally lacking, particularly for those performed outside laboratories by healthcare workers. This study aims to explore POCT biosafety program decision-making infrastructure and oversight in Ontario.

Content: The Institute of Quality Management in Healthcare distributed a survey to 249 laboratories in Ontario. There were 11 questions on POCT biosafety practices.

Summary: The survey had a high response rate of 88.7%. How POCT biosafety decisions were made was variable among respondents. For POCT-style tests conducted within laboratories, the biosafety officer (BSO) and/or the microbiologist were involved in biosafety decisions in 95% of microbiology labs or 55% of other labs. Only 27% of the respondents reported that biosafety decisions were made by BSOs and/or microbiologists when POCT was conducted outside the laboratory. When POCT is performed outside the laboratory, biosafety decisions were made largely by Infection Prevention and Control (IPAC) and POCT laboratory staff. Similarly, training and auditing of staff who perform POCT were mainly done by IPAC and POCT laboratory staff. The survey showed that a wide variety of POCT was being conducted for COVID-19 patients during the pandemic.

Background: To evaluate the clinical performance and effectiveness of a multiplex apolipoprotein panel in the context of cardiovascular precision diagnostics, clinical samples of patients with recent acute coronary syndrome in the ODYSSEY OUTCOMES trial were measured by quantitative clinical chemistry proteomics (qCCP). The ISO15189-accredited laboratory setting, including the total testing process (TTP), served as a foundation for this study. Consequently, tailored quality assurance measures needed to be designed and implemented to suit the demands of a multiplex LC-MS/MS test.

Methods: Nine serum apolipoproteins were measured in 23 376 samples with a laboratory-developed multiplex apolipoprotein test on 4 Agilent 6495 LC-MS/MS systems. A fit-for-purpose process was designed with tailored additions enhancing the accredited laboratory infrastructure and the TTP. Quality assurance was organized in 3 steps: system suitability testing (SST), internal quality control (IQC) evaluation with adjusted Westgard rules to fit a multiplex test, and interpeptide agreement analysis. Data was semi-automatically evaluated with a custom R script.

Results: LC-MS/MS analyses were performed with the following between-run CVs: for apolipoprotein (Apo) (a) 6.2%, Apo A-I 2.3%, Apo A-II 2.1%, Apo A-IV 2.9%, Apo B 1.9%, Apo C-I 3.3%, Apo C-II 3.3%, Apo C-III 2.7%, and for Apo E 3.3% and an average interpeptide agreement Pearson r of 0.981.

Conclusions: This is the first study of its kind in which qCCP was performed at this scale. This research successfully demonstrates the feasibility of high-throughput LC-MS/MS applications in large clinical trials. ClinicalTrials.gov Registration Number: NCT01663402.

Background: Analytical criteria for laboratory analysis based on biological variation are considered state-of-the-art. While biological variance should ideally be measured in patient populations for whom the tests are relevant, data are mostly only available from healthy individuals. We determined the biological variance of activated partial thromboplasmin time (APTT), prothrombin time (PT), fibrinogen, and trough dabigatran levels in patients with atrial fibrillation (AF) who were treated with dabigatran.

Methods: Between 2019 and 2022, patients with AF treated >3 months with dabigatran were included. Blood was collected monthly up to 10 times for the measurement of APTT, PT, fibrinogen, and trough dabigatran levels. Between-subject variance (CVG), within-subject variance (CVI), and analytical variance (CVA) were calculated.

Results: Eighteen participants (median age 65.8 years, 22.2% women) were included, with 130 samples in total. For APTT, the CVG was 11.5%, the CVI 8.8%, and the CVA 1.1%. For PT, these values were 5.2%, 4.0%, and 1.0% and for fibrinogen 13.6%, 11.8%, and 1.6%, respectively. For the dabigatran levels, the percentages were 37.9%, 33.0%, and 3.4%, respectively.

Conclusions: We assessed the biological variance of APTT, PT, fibrinogen, and dabigatran in a patient population with long-term dabigatran use. The analytical performances of coagulation laboratory tests in patients with AF treated with dabigatran were comparable to those in healthy volunteers.CCMO Registration Number: NL67304.078.18.

Background: Benzodiazepines are commonly prescribed medications frequently linked to instances of abuse and overdose. Historically, FDA-cleared benzodiazepine urine immunoassays cross-react poorly with glucuronidated benzodiazepine metabolites, leading to false negatives. Clinical laboratories have addressed this deficiency by creating laboratory-developed tests (LDTs) that incorporate a beta-glucuronidase hydrolysis step to increase the clinical sensitivity of these assays.

Methods: Performance characteristics of 2 FDA-cleared benzodiazepine urine immunoassays (Benzodiazepines Plus, no glucuronidase and Benzodiazepines II, with glucuronidase; Roche Diagnostics) and a previously described benzodiazepine immunoassay LDT (with glucuronidase) were evaluated using 258 clinical urine specimens. The positive immunoassay cutoff was set at 200 ng/mL of nordiazepam and results were compared to an LC-MS/MS benzodiazepine LDT. Clinical sensitivity, specificity, precision, and immunoassay cross-reactivity were determined for all 3 immunoassays.

Results: The Benzodiazepines II and LDT immunoassays exhibited greater clinical sensitivity (100% and 95.2%) compared to the Benzodiazepines Plus assay (66.7%). Clinical specificity of 100% was observed for all 3 assays. Immunoassay response of the Benzodiazepines II assay was greater across the range of concentrations tested (100-1000 ng/mL) relative to the other immunoassays and was the most sensitive immunoassay for the detection of lorazepam glucuronide.

Conclusions: The Benzodiazepines II immunoassay demonstrated the greatest clinical and analytical sensitivity compared to the Benzodiazepines Plus and LDT immunoassays. The incorporation of beta-glucuronidase was crucial, as the Benzodiazepines II and LDT immunoassays demonstrated superior clinical sensitivity when compared to the Benzodiazepines Plus immunoassay that does not incorporate a beta-glucuronidase hydrolysis step.