Journal of Applied Laboratory Medicine最新文献

Background: The presence of anti-interferon (IFN)-α2 autoantibodies is a strong indicator of severe disease course during viral infections and is observed in autoimmune diseases (e.g., myasthenia gravis). Detection of these autoantibodies during severe bacterial infections is understudied. Multiple anti-IFN-α2 autoantibody screening assays are available. However, the results do not always correlate with the neutralizing capacity of the autoantibodies.

Methods: Anti-IFN-α2 antibodies were measured by a Luminex-based assay in serum samples from individuals admitted to the intensive care unit infected with influenza (n = 38), invasive bacteria (n = 152), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (n = 52). Anti-IFN-α2 antibodies were also studied in individuals with myasthenia gravis (n = 22) and in healthy individuals (n = 37). Individuals testing positive by Luminex were subsequently tested by enzyme-linked immunosorbent assay (ELISA) and tested for nonspecific reactivity and neutralization.

Results: Three of 16 Luminex-positive samples had nonspecific reactivity, 11/16 were positive by ELISA, and 10/16 had neutralizing activity. Anti-IFN-α2 antibodies were found in individuals infected with SARS-CoV-2 (7/52), influenza (3/38), invasive bacteria [2/152, of which 1 was Legionella pneumophilia and was 1 Escherichia coli (E. coli) (out of 39 E. coli infections)], and in individuals with myasthenia gravis (2/22).

Conclusions: Anti-IFN-α2 autoantibodies were detected in viral infections, myasthenia gravis, and rarely in bacterial infections. ELISA and Luminex screening assays do not give similar results. Nonspecific reactivity and functional assays are necessary to validate the screening test result.

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: TRIzolTM is widely used for RNA and DNA extraction. However, this method is laborious and time-consuming. The objective of this study was to validate a time-effective and labor-saving protocol.

Methods: The TRIzol method was used to separate the aqueous phase, protein, and phenol layer of bone marrow samples from 12 patients with hematological diseases. Subsequently, RNA and DNA were extracted from the aqueous layer containing RNA and phenol layer containing DNA, respectively, using magnetic bead extraction kits. The quantity and purity of extracted RNA and DNA were examined using a NanoDrop spectrophotometer. Quantitative fluorescence PCR amplification of the ABL1 gene was performed to verify the effectiveness of the extracted RNA and DNA for downstream experiments. RNA and DNA from another 16 bone marrow samples were extracted to compare the performance of the two methods.

Results: Co-extraction of RNA and DNA was completed within 1 h. The data showed that RNA and DNA yield ranged from 13.1 to 204.5 ng/µL and 33.1 to 228.8 ng/µL, respectively. The A260/A280 ratios of RNA and DNA samples ranged from 1.82 to 2.01 and 1.73 to 1.91, respectively. RNA and DNA extracted using this scheme exhibited ideal performance in quantitative fluorescence PCR. The present protocol showed better quality and effectiveness in extracting RNA and DNA compared to the TRIzol method.

Conclusions: This protocol for RNA and DNA co-extraction is fast, labor-saving, and high throughput. It can be adopted for routine molecular biology analyses, particularly for non-reproducible specimens.

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.