Behind the scenes of EQA-characteristics, capabilities, benefits and assets of external quality assessment (EQA).

The main stakeholders in external quality assessment (EQA) programs are the participants, in whose interests these challenges are ultimately organised. EQA schemes in the medical field contribute to improving the quality of patient care by evaluating the analytical and diagnostic quality of laboratory and point-of-care tests (POCT) by independent third parties and, if necessary, pointing out erroneous measurement results and analytical or diagnostic improvement potential. Other benefits include the option of using EQA samples for other important laboratory procedures, such as the verification or validation of diagnostic medical devices (IVD-MDs), a contribution to the estimation of measurement uncertainty, a means of training and educating laboratory staff through educational EQA programmes or samples, or even for independent and documented monitoring of staff competence, such as on samples with unusual or even exceptional characteristics.

Behind the scenes of EQA - characteristics, capabilities, benefits and assets of external quality assessment (EQA).

External quality assessment (EQA) cycles are the smallest complete units within EQA programs that laboratories can use to obtain external assessments of their performance. In each cycle, several samples are distributed to the laboratories registered for participation, and ideally, EQA programs not only cover the examination procedures but also the pre- and post-examination procedures. The properties and concentration range of measurands in individual samples are selected with regard to the intended challenge for the participants so that each sample fulfils its purpose.

Behind the scenes of EQA - characteristics, capabilities, benefits and assets of external quality assessment (EQA).

Providers of external quality assessment (EQA) programs evaluate data or information obtained and reported by participant laboratories using their routine procedures to examine properties or measurands in samples provided for this purpose. EQA samples must offer participants an equal chance to obtain accurate results, while being designed to provide results in clinically relevant ranges. It is the responsibility of the EQA provider to meet the necessary requirements for homogeneity, stability and some other properties of the EQA items in order to offer participants a fair, reliable and technically interesting EQA experience.

[Position paper of DGKL and DIVI on requirements for laboratory services in intensive care and emergency medicine].

Background And Objectives: The timely determination and evaluation of laboratory parameters in patients with acute life- or organ-threatening diseases and disease states in the emergency room or intensive care units can be essential for diagnosis, initiation of therapy, and outcome. The aim of the position paper is to define the time requirements for the provision of laboratory results in emergency and intensive care medicine. Requirements for point-of-care testing (POCT) and the (central) laboratory can be derived from the urgency.

Evaluation of a host-protein signature score for differentiating between bacterial and viral infections: real-life evidence from a German tertiary hospital.

Purpose: A host-protein signature score, consisting of serum-concentrations of C-reactive protein, tumour necrosis factor-related apoptosis-inducing ligand, and interferon gamma-induced protein 10, was validated for distinguishing between bacterial and viral infections as an antimicrobial stewardship measure for routine clinical practice among adult patients in a German tertiary hospital.

Methods: This single-centre, explorative study prospectively assessed the host-protein signature score, comparing it with serum procalcitonin (PCT) in patients with blood stream infections (BSI) and evaluating its efficacy in patients with viral infections against the standard of care (SOC) to assess the need for antibiotics due to suspected bacterial super/coinfection. Manufacturer-specified threshold scores were used to differentiate viral (< 35) and bacterial (> 65) infections.

Point-of-care testing: state-of-the art and perspectives.

Point-of-care testing (POCT) is becoming an increasingly popular way to perform laboratory tests closer to the patient. This option has several recognized advantages, such as accessibility, portability, speed, convenience, ease of use, ever-growing test panels, lower cumulative healthcare costs when used within appropriate clinical pathways, better patient empowerment and engagement, and reduction of certain pre-analytical errors, especially those related to specimen transportation. On the other hand, POCT also poses some limitations and risks, namely the risk of lower accuracy and reliability compared to traditional laboratory tests, quality control and connectivity issues, high dependence on operators (with varying levels of expertise or training), challenges related to patient data management, higher costs per individual test, regulatory and compliance issues such as the need for appropriate validation prior to clinical use (especially for rapid diagnostic tests; RDTs), as well as additional preanalytical sources of error that may remain undetected in this type of testing, which is usually based on whole blood samples (i.

The influence of undetected hemolysis on POCT potassium results in the emergency department.

Objectives: This study aimed to evaluate discrepancies in potassium measurements between point-of-care testing (POCT) and central laboratory (CL) methods, focusing on the impact of hemolysis on these measurements and its impact in the clinical practice in the emergency department (ED).

Methods: A retrospective analysis was conducted using data from three European university hospitals: Technische Universitat München (Germany), Hospital Universitario La Paz (Spain), and Erasmus University Medical Center (The Netherlands). The study compared POCT potassium measurements in EDs with CL measurements.

Quality assessment of glucose measurement with regard to epidemiology and clinical management of diabetes mellitus in Germany.

Background: During the last decade, Germany has seen an increased prevalence and a redistribution from undetected to diagnosed diabetes mellitus. Due to this substantial epidemiological development, the number of people with documented type 2 diabetes was 8.7 million in 2022.

Longitudinal analysis of external quality assessment of immunoassay-based steroid hormone measurement indicates potential for improvement in standardization.

As hormonal disorders are linked to several diseases, the accurate quantitation of steroid hormone levels in serum is crucial in order to provide patients with a reliable diagnosis. Mass spectrometry-based methods are regarded as having the highest level of specificity and sensitivity. However, immunoassays are more commonly used in routine diagnostics to measure steroid levels as they are more cost effective and straightforward to conduct.

SERS-based detection of the antibiotic ceftriaxone in spiked fresh plasma and microdialysate matrix by using silver-functionalized silicon nanowire substrates.

Therapeutic drug monitoring (TDM) is an important tool in precision medicine as it allows estimating pharmacodynamic and pharmacokinetic effects of drugs in clinical settings. An accurate, fast and real-time determination of the drug concentrations in patients ensures fast decision-making processes at the bedside to optimize the clinical treatment. Surface-enhanced Raman spectroscopy (SERS), which is based on the application of metallic nanostructured substrates to amplify the inherent weak Raman signal, is a promising technique in medical research due to its molecular specificity and trace sensitivity accompanied with short detection times.

Recombinantly Expressed Tagged SUrface Protein (RETSUP) assay: a new diagnostic system for the detection of antibodies to platelets.

Background: Current assays for the detection of (allo)antibodies to platelet antigens are often laborious and widely based on the presence of well-characterized donor platelets.

Objectives: To develop an easy-to-perform, sensitive, and specific test for the detection of antibodies against platelet antigens, in particular, glycoprotein (GP) antigens, called "Recombinantly Expressed Tagged SUrface Protein" (RETSUP) assay, which does not require donor platelets.

Methods: Twin-Strep-tagged GP complexes were recombinantly expressed in human embryonic kidney 293 cells after stable transfection.

Goal-directed Perioperative Albumin Substitution Versus Standard of Care to Reduce Postoperative Complications: A Randomized Clinical Trial (SuperAdd Trial).

Objective: To investigate whether goal-directed albumin substitution during surgery and postanesthesia care to maintain a serum albumin concentration >30 g/L can reduce postoperative complications.

Background: Hypoalbuminemia is associated with numerous postoperative complications. Since albumin has important physiological functions, substitution of patients with hypoalbuminemia is worth considering.

Rapid Diagnostic Platform for Personalized Vitamin B6 Detection in Erythrocytes PLP Cofactor Mimics.

Personalized assessment of vitamin levels in point-of-care (POC) devices is urgently needed to advance the recognition of diseases associated with malnutrition and unbalanced diets. We here introduce a diagnostic platform, which showcases an easy and rapid readout of vitamin B6 (pyridoxal phosphate, PLP) levels in erythrocytes as a first step toward a home-use POC. The technology is based on fluorescent probes, which bind to PLP-dependent enzymes (PLP-DEs) and thereby indirectly report their occupancy with endogenous B6.

Classification of "Near-patient" and "Point-of-Care" SARS-CoV-2 Nucleic Acid Amplification Test Systems and a first approach to evaluate their analytical independence of operator activities.

Background: European legislation defines as "near-patient testing" (NPT) what is popularly and in other legislations specified as "point-of-care testing" (POCT). Systems intended for NPT/POCT use must be characterized by independence from operator activities during the analytic procedure. However, tools for evaluating this are lacking.

Surface plasmon resonance assays for the therapeutic drug monitoring of infliximab indicate clinical relevance of anti-infliximab antibody binding properties.

Objectives: The therapeutic antibody infliximab (IFX) has improved the life quality of numerous autoinflammatory disease patients. However, IFX can trigger the generation of anti-drug antibodies (ADA), whose optimal evaluation and management are currently subject of controversial discussions. We present two novel surface plasmon resonance (SPR) biosensor assays for therapeutic drug monitoring of IFX and characterization of ADA and investigated the diagnostic value of ADA binding properties.

Robust Preanalytical Performance of Soluble PD-1, PD-L1 and PD-L2 Assessed by Sensitive ELISAs in Blood.

The interaction between programmed death-1 receptor PD-1 and its ligands PD-L1 and PD-L2 is involved in self-tolerance, immune escape of cancer, cardiovascular diseases, and COVID-19. As blood-based protein markers they bear great potential to improve oncoimmunology research and monitoring of anti-cancer immunotherapy. A variety of preanalytical conditions were tested to assure high quality plasma sample measurements: (i) different time intervals and storage temperatures before and after blood centrifugation; (ii) fresh samples and repeated freeze-thaw-cycles; (iii) different conditions of sample preparation before measurement.

High Quality Performance of Novel Immunoassays for the Sensitive Quantification of Soluble PD-1, PD-L1 and PD-L2 in Blood.

Programmed death-1 receptor PD-1(CD279) and its corresponding ligands PD-L1(CD274, B7-H1) and PD-L2(CD273, B7-DC) play important roles in physiological immune tolerance and for immune escape in cancer disease. Hence, the establishment and analytical validation of a novel enzyme-linked immunosorbent assay (ELISA) to measure soluble PD-1, PD-L1 and PD-L2 in blood samples according to high quality standards is required. Antibody pairs were used to establish novel highly sensitive ELISAs for all three markers on an open electrochemiluminescence Quickplex platform.

A randomized prospective cross over study on the effects of medium cut-off membranes on T cellular and serologic immune phenotypes in hemodialysis.

Extended cut-off filtration by medium cut-off membranes (MCO) has been shown to be safe in maintenance hemodialysis (HD). The notion of using them for the control of chronic low-grade inflammation and positively influencing cellular immune aberrations seems tempting. We conducted an open label, multicenter, randomized, 90 day 2-phase cross over clinical trial (MCO- vs.

SARS-CoV-2 viral load dynamics in immunocompromised critically ill patients on remdesivir treatment.

The relationship between SARS-CoV-2 quantitative viral load and risk of disease progression, morbidity such as long- COVID or mortality in immunosuppressed, remains largely undefined in COVID-19 patients. Critically ill immunosuppressed patients potentially benefit from remdesivir treatment because of the prolonged course of their infection. Four critically ill immunocompromised patients and the impact of remdesivir on viral dynamics in lower respiratory samples were studied.

Failure Mode and Effects Analysis (FMEA) at the preanalytical phase for POCT blood gas analysis: proposal for a shared proactive risk analysis model.

Objectives: Proposal of a risk analysis model to diminish negative impact on patient care by preanalytical errors in blood gas analysis (BGA).

Methods: Here we designed a Failure Mode and Effects Analysis (FMEA) risk assessment template for BGA, based on literature references and expertise of an international team of laboratory and clinical health care professionals.

Results: The FMEA identifies pre-analytical process steps, errors that may occur whilst performing BGA (potential failure mode), possible consequences (potential failure effect) and preventive/corrective actions (current controls).

An integrated device for fast and sensitive immunosuppressant detection.

The present paper describes a compact point of care (POC) optical device for therapeutic drug monitoring (TDM). The core of the device is a disposable plastic chip where an immunoassay for the determination of immunosuppressants takes place. The chip is designed in order to have ten parallel microchannels allowing the simultaneous detection of more than one analyte with replicate measurements.

Convalescent plasma therapy in B-cell-depleted and B-cell sufficient patients with life-threatening COVID-19 - A case series.

Objective: To investigate the effect of convalescent plasma therapy (CPT) on clinical courses of B-cell-sufficient and B-cell-depleted patients with life-threatening COVID-19.

Patients And Methods: In this case series, we retrospectively analysed clinical, laboratory and cardiopulmonary parameters of six patients with life-threatening COVID-19 receiving convalescent plasma (CP) as rescue therapy between April 11, 2020 to October 10, 2020. Clinical and laboratory parameters before and after transfusion were compared in two B-cell-depleted patients and four B-cell sufficient patients (control group).

Dynamics of serum concentrations of antibodies to infliximab: a new approach for predicting secondary loss of response in inflammatory bowel diseases.

Background: Antibodies to infliximab (ATI) in serum are associated with secondary loss of response (LOR) to infliximab (IFX) therapy in patients with inflammatory bowel disease (IBD). However, feasible ATI-related predictors of therapy success are lacking and knowledge about individual ATI dynamics is limited. Therefore, this study analyzed whether ATI dynamics are able to predict LOR to IFX therapy and compared their predictive power with known predictors of LOR to IFX.

Immunosuppressant quantification in intravenous microdialysate - towards novel quasi-continuous therapeutic drug monitoring in transplanted patients.

Objectives: Therapeutic drug monitoring (TDM) plays a crucial role in personalized medicine. It helps clinicians to tailor drug dosage for optimized therapy through understanding the underlying complex pharmacokinetics and pharmacodynamics. Conventional, non-continuous TDM fails to provide real-time information, which is particularly important for the initial phase of immunosuppressant therapy, e.