Spironolactone metabolite causes falsely increased progesterone in the Abbott Architect immunoassay.

Background: Immunoassays are important for routine clinical testing and medical diagnosis. However, they are limited by cross-reactivity especially at low analyte concentrations. There is a critical need to investigate compounds that can interfere with immunoassays.

Cross-Institutional Evaluation of the Abbott ARCHITECT SARS-CoV-2 IgG Immunoassay.

Objective: To describe a cross-institutional approach to verify the Abbott ARCHITECT SARS-CoV-2 antibody assay and to document the kinetics of the serological response.

Methods: We conducted analytical performance evaluation studies using the Abbott ARCHITECT SARS-CoV-2 antibody assay on 5 Abbott ARCHITECT i2000 automated analyzers at 2 academic medical centers.

Results: Within-run and between-run coefficients of variance (CVs) for the antibody assay did not exceed 5.

A Novel Laboratory Assay to Monitor Unfractionated Heparin Dosing in Patients Taking Apixaban Prior to Hospital Admission.

Introduction: When monitoring heparin, anti-Xa assays are susceptible to interference from apixaban taken before admission and can result in inappropriate dose adjustments that can negatively affect patient care.

Methods: We derived a novel assay, termed corrected heparin (CH), using quantified values from a chromogenic anti-Xa assay with heparin calibrators before and after heparinase treatment to eliminate any interference from apixaban within the patient sample. We retrospectively assessed 469 specimens from 72 patients at our institution who had their unfractionated heparin infusion monitored using the CH assay because of known apixaban use.

Streamlining Quality Review of Mass Spectrometry Data in the Clinical Laboratory by Use of Machine Learning.

Context.—: Turnaround time and productivity of clinical mass spectrometric (MS) testing are hampered by time-consuming manual review of the analytical quality of MS data before release of patient results.

Objective.

The sample that would not clot.

Background: Vitamin K is a vital component within both the intrinsic and extrinsic coagulation cascade as certain factors (II, VII, IX, X and protein C and S) utilize vitamin K as a cofactor during post translational modification. Deficiency of vitamin K can result in the inability to properly form blood clots, both in vivo and in vitro, due to reduced vitamin K dependent factor levels and function. Vitamin K deficiency can result from congenital causes, such as VKOR or CYP2C9 mutations, or acquired causes, such as nutritional deficiencies, antibiotic therapy, or supra-therapeutic warfarin dosing.

Improved Clinical Sensitivity of a Reflexive Algorithm to Minimize False-Negative Test Results by a Urine Benzodiazepine Immunoassay Screen.

Background: Urine drug testing is an essential component of treating patients for chronic pain and/or anxiety and is used to monitor compliance during treatment. A common algorithm is to use an immunoassay as a urine drug screen (UDS), followed by mass spectrometry to confirm all presumptive positive samples. Many UDSs, however, have significant limitations, and false-negative test results can be common due to lack of antibody specificity.

Recognition of rare hemoglobin variants by hemoglobin A measurement procedures.

Background: Unrecognized hemoglobinopathies can lead to measured hemoglobin A (Hb A) concentrations that are erroneous or misleading. We determined the effects of rare hemoglobin variants on capillary electrophoresis (CE) and HPLC methods for measurement of Hb A.

Methods: We prospectively investigated samples in which Hb A was measured by CE during a 14-month period.

The ARTμS: a novel microfluidic CD4+ T-cell enumeration system for monitoring antiretroviral therapy in HIV patients.

We report on a novel and cost-effective microfluidic platform that integrates immunomagnetic separation and cell enumeration via DNA-induced bead aggregation. Using a two-stage immunocapture microdevice, 10 μL of whole blood was processed to isolate CD4+ T-cells. The first stage involved the immuno-subtraction of monocytes by anti-CD14 magnetic beads, followed by CD4+ T-cell capture with anti-CD4 magnetic beads.

Correction: Ultrafast immunoassays by coupling dielectrophoretic biomarker enrichment in nanoslit channel with electrochemical detection on graphene.

Correction for 'Ultrafast immunoassays by coupling dielectrophoretic biomarker enrichment in nanoslit channel with electrochemical detection on graphene' by Bankim J. Sanghavi et al., Lab Chip, 2015, DOI: 10.

Ultrafast immunoassays by coupling dielectrophoretic biomarker enrichment in nanoslit channel with electrochemical detection on graphene.

Heterogeneous immunoassays usually require long incubation times to promote specific target binding and several wash steps to eliminate non-specific binding. Hence, signal saturation is rarely achieved at detection limit levels of analyte, leading to significant errors in analyte quantification due to extreme sensitivity of the signals to incubation time and methodology. The poor binding kinetics of immunoassays at detection limit levels can be alleviated through creating an enriched analyte plug in the vicinity of immobilized capture probes to enable signal saturation at higher levels and at earlier times, due to higher analyte association and its faster replenishment at the binding surface.

Steps to diagnosis of a case of surreptitious intake of one of the newer direct oral anticoagulants: a case report and literature review.

Little is known about the effects of newer oral anticoagulants on various coagulation factors. When presented with a case of intentional or suspected overdose with an abnormal coagulation profile, it is imperative to have a working diagnostic algorithm to narrow the cause to a specific drug or drug class. This may become more crucial and time sensitive when dealing with a case of acute hemorrhage.

Quantitation of 25-hydroxyvitamin D2 and D3 in serum and plasma by LCMS/MS.

Objective: We developed and validated an analytical method for quantifying 25-hydroxyvitamin D2 (25OHD2) and 25-hydroxyvitamin D3 (25OHD3) in serum and plasma.

Methods: Samples, pretreated with zinc sulfate and methanol, were extracted with hexane. Separation was achieved via UHPLC and 25OHD quantification was accomplished by a triple quadrupole mass spectrometer.

Trends in licit and illicit drug-related deaths in Florida from 2001 to 2012.

Background: Florida, the epicenter of the recent prescription drug epidemic in the United States, maintains a statewide drug mortality surveillance system. We evaluated yearly profiles, demographic characteristics, and correlation between drug trends to understand the factors influencing drug-induced mortality.

Methods: All drug-related deaths reported to the Florida Medical Examiners Commission during 2001-2012 were included (n=92,596).

The molecular biology of human iron metabolism.

Iron is one of the most important nonorganic substances that make life possible. Iron plays major roles in oxygen transport (eg, hemoglobin; -67% of total body iron [TBI]), short-term oxygen storage (eg, myoglobin; -3.5% of TBI), and energy generation (eg, cytochromes; -3% of TBI).

New detection modality for label-free quantification of DNA in biological samples via superparamagnetic bead aggregation.

Combining DNA and superparamagnetic beads in a rotating magnetic field produces multiparticle aggregates that are visually striking, enabling label-free optical detection and quantification of DNA at levels in the picogram per microliter range. DNA in biological samples can be quantified directly by simple analysis of optical images of microfluidic wells placed on a magnetic stirrer without prior DNA purification. Aggregation results from DNA/bead interactions driven either by the presence of a chaotrope (a nonspecific trigger for aggregation) or by hybridization with oligonucleotides on functionalized beads (sequence-specific).

Platinum nanoparticle-facilitated reflective surfaces for non-contact temperature control in microfluidic devices for PCR amplification.

The polymerase chain reaction (PCR) is critical for amplification of target sequences of DNA or RNA that have clinical, biological or forensic relevance. While extrinsic Fabry-Perot interferometry (EFPI) has been shown to be adequate for non-contact temperature sensing, the difficulty in defining a reflective surface that is semi-reflective, non-reactive for PCR compatibility and adherent for thermal bonding has limited its exploitation. Through the incorporation of a reflective surface fabricated using a thermally driven self-assembly of a platinum nanoparticle monolayer on the surface of the microfluidic chamber, an enhanced EFPI signal results, allowing for non-contact microfluidic temperature control instrumentation that uses infrared-mediated heating, convective forced-air cooling, and interferometic temperature sensing.