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. We hypothesized that the variability of measurement results obtained from identical samples with a larger number of identical devices by different operators, expressed as the method-specific reproducibility of measurement results reported in External Quality Assessment (EQA) schemes, is an indicator for this characteristic. MATERIALS AND METHODS: Legal frameworks in the EU, the USA and Australia were evaluated about their requirements for NPT/POCT. EQA reproducibility of seven SARS-CoV-2-NAAT systems, all but one designated as "POCT", was calculated from variabilities in Ct values obtained from the respective device types in three different EQA schemes for virus genome detection. RESULTS: A matrix for characterizing test systems based on their technical complexity and the required operator competence was derived from requirements of the European In Vitro Diagnostic Regulation (IVDR) 2017/746. Good EQA reproducibility of the measurement results of the test systems investigated implies that different users in different locations have no recognizable influence on their measurement results. CONCLUSION: The fundamental suitability of test systems for NPT/POCT use according to IVDR can be easily verified using the evaluation matrix presented. EQA reproducibility is a specific characteristic indicating independence from operator activities of NPT/POCT assays. EQA reproducibility of other systems than those investigated here remains to be determined.

Comparative analysis of high CRP-levels in human blood using point-of-care and laboratory-based methods.

OBJECTIVES: The use of point-of-care (POC) methods and the measurements of C-reactive protein (CRP) as a diagnostic marker have both increased over the past years. This has led to an increase in POC-methods analysing CRP. High CRP levels are often seen as an indication for the subscription of antibiotics. The quality of POC-systems compared to routine diagnostic measurements for the analysis of CRP is thereby of main importance, since many small practises will use POC-methods. This study compared high-level CRP concentrations (above 100 mg/L) using an i-CHROMATM with 2 routinely used laboratory-based systems (Architect and ABX). DESIGN: and Methods: A total of 199 patient samples with a CRP concentration above 100 mg/L were analysed with the i-CHROMATM POC system and the turbidimetric routine methods using the Architect and ABX equipment. RESULTS: The results of the i-CHROMATM device showed a significant decrease in the CRP levels compared to those obtained with the Architect and the ABX (i-CHROMATM vs. Architect: y â€‹= â€‹0.6792x + 94.701; R2 = 0.4980, i-CHROMATM vs. ABX: y â€‹= â€‹0.3674x + 118.05; R2 â€‹= â€‹0.3964, Architect vs. ABX: y â€‹= â€‹0.7657x + 36.337; R2 = 0.9311). Furthermore, data analysis showed a partition of the i-CHROMATM measurements in two defined clouds, which could not be explained with any of the available sample information. CONCLUSIONS: This analysis showed the limitations of the i-CHROMATM CRP analyser. In addition, it illustrates the need for strict regulations on the information and output provided by companies regarding the boundaries of novel and existing diagnostic methods.

Evaluation of reference intervals of haematological and biochemical markers in an Austrian adolescent study cohort.

Background Reference intervals are a prerequisite for the interpretation of laboratory data related to diagnostic issues and treatment strategies. In adolescents, biomarker concentrations change with age, necessitating a continuous age-related definition of the reference intervals. The purpose of this pilot study was to evaluate the reference intervals for a healthy population of adolescents in Salzburg and compare these, when possible, with age- and gender-matched published data. Methods Anthropometrical parameters and blood samples were collected from adolescents (male and female; 14-17 years) in a school setting. Haematological samples were measured using Sysmex XS-1000i, lipid and carbohydrate metabolism markers as well as enzymes and hormones were determined by Cobas c311, Vitros ECiQ® or ELISA. The reference intervals were calculated according to the CLSI guidelines C28-A3c. Results Samples of 102 participants were included. Compared to age- and gender-matched reference intervals, the BMI levels were in the lower normal rage. Most haematological parameters and biomedical makers reveal similar ranges to values published in other studies. Conclusions This data analysis allowed for a partial comparison of reference values with published data and enabled a new determination of paediatric reference intervals for an Austrian cohort.

Can smartphone-based logging support diabetologists in solving glycemic control problems?

Treatment of diabetic patients strongly relies on the continuous logging of parameters relevant to glycemic control. Keeping diabetes diaries can be tedious which can affect the data quality and completeness. Mobile technologies could provide means to overcome these limitations. However, studies analyzing the direct effect on the treatment of patients are rare. In the presented study diabetic patients were supplied with a smartphone application to record various parameters relevant for glycemic control. Questions regarding the completeness of diabetes diaries were answered by the patients before and after the study. The attending diabetologist analyzed the data obtained from the smartphone-based diaries to determine whether these provided solutions for problems in glycemic control. The analysis of the available smartphone data provided the basis for therapeutic recommendations that can improve the daily glycemic control for almost all participants. Importantly, especially the newly developed implicit-activity logging, registering the participants' movements, provided important means to generate these recommendations.

Glucose acts as a regulator of serum iron by increasing serum hepcidin concentrations.

Mutual clinical and molecular interactions between iron and glucose metabolism have been reported. We aimed to investigate a potential effect of glucose on iron homeostasis. We found that serum iron concentrations gradually decreased over 180 min after the administration of 75 g of glucose from 109.8 ± 45.4 mg/L to 94.4 ± 40.4 mg/L (P<.001; N=40) but remained unchanged in control subjects receiving tap water (N=21). Serum hepcidin, the key iron regulatory hormone which is mainly derived from hepatocytes but also expressed in pancreatic ß-cells, increased within 120 min after glucose ingestion from 19.7 ± 9.9 nmol/L to 31.4 ± 21.0 nmol/L (P<.001). In cell culture, glucose induced the secretion of hepcidin and insulin into the supernatant of INS-1E cultures, but did not change the amount of hepcidin detectable in the hepatocyte cell culture HepG2. We additionally confirmed the expression of hepcidin in a human islet cell preparation. These results suggest that glucose acts as a regulator of serum iron concentrations, most likely by triggering the release of hepcidin from ß-cells.