Hemolysis Detection in Sub-Microliter Volumes of Blood Plasma

Novel In-Line Hemolysis Detection on a Blood Gas Analyzer and Impact on Whole Blood Potassium Results

BACKGROUND

Preanalytical error due to hemolyzed blood samples is a common challenge in laboratory and point-of-care (POC) settings. Whole blood potassium (K+) measurements routinely measured on blood gas analyzers are particularly susceptible to hemolysis, which poses a risk for incorrect K+ results. The GEM Premier 7000 with IQM3 (GEM 7000) blood gas analyzer provides novel integrated hemolysis detection within the sample measurement process. Therefore, the GEM 7000 can detect and flag hemolyzed whole blood samples at the POC, warning the operator of potentially erroneous results.

METHODS

Heparinized venous or arterial whole blood samples were used for K+ interference studies and assessed for hemolysis agreement utilizing either a traditional volumetric method or chemistry analyzer serum index measurements with the Roche cobas c311 or Abbott Alinity c.

RESULTS

Hemolysis interference studies performed at 2 different K+ concentrations (3.8 and 5.3 mmol/L) identified that a plasma free hemoglobin ≥116 mg/dL can impact K+ results on the GEM 7000. Hemolysis agreement studies demonstrated an excellent agreement of >99% with the volumetric method, 98.8% with cobas H index, and 96.4% with Alinity H index. GEM 7000 K+ results were correctly flagged for both native and spiked samples.

CONCLUSION

GEM 7000 hemolysis detection provides a novel technology to detect hemolysis in whole blood samples. Moreover, the GEM 7000 demonstrates excellent agreement with traditional laboratory hemolysis detection methods and offers an integrated technological solution for assuring the quality of whole blood K+ results in POC settings.

Fibrinolytic Platelet Decoys Reduce Cancer Metastasis by Dissociating Circulating Tumor Cell Clusters

During metastasis, circulating tumor cells (CTCs) can travel in the bloodstream as individual cells or clusters, associated with fibrin and platelets. Clusters have a higher metastatic potential due to their increased ability to withstand shear stress and arrest in small vessels. Moreover, CTC-platelet interaction protects CTCs from shear stress and immune detection. The objective of this project is to develop a fibrinolytic platelet system to leverage platelet-CTC interactions and dissociate CTC clusters. For this approach, tissue plasminogen activator (tPA) is loaded onto two modified platelet systems: platelet Decoys and lyophilized platelets. The activities of the systems are characterized using a Förster Resonance Energy Transfer-based assay and an angiogenic assay. Furthermore, the ability of the system to dissociate cancer cell clusters in vitro is assessed using light transmission aggregometry. The data demonstrates that the fibrinolytic platelets can maintain tPA activity, interact with CTCs, and dissociate cancer cell clusters. Finally, fibrinolytic platelets are assessed in vivo, demonstrating a decreased tumor load and increased survival with tPA-Decoy treatment, which is selected as the optimal treatment based on favorable in vitro results and in vivo trials. Therefore, this fibrinolytic platelet approach is a promising method for leveraging platelet-CTC interactions to disperse CTC clusters and reduce metastasis.

Exploring Optimal Biomarker Sources: A Comparative Analysis of Exosomes and Whole Plasma in Fasting and Non-Fasting Conditions for Liquid Biopsy Applications

The study of liquid biopsy with plasma samples is being conducted to identify biomarkers for clinical use. Exosomes, containing nucleic acids and metabolites, have emerged as possible sources for biomarkers. To evaluate the effectiveness of exosomes over plasma, we analyzed the small non-coding RNAs (sncRNAs) and metabolites extracted from exosomes in comparison to those directly extracted from whole plasma under both fasting and non-fasting conditions. We found that sncRNA profiles were not affected by fasting in either exosome or plasma samples. Our results showed that exosomal sncRNAs were found to have more consistent profiles. The plasma miRNA profiles contained high concentrations of cell-derived miRNAs that were likely due to hemolysis. We determined that certain metabolites in whole plasma exhibited noteworthy concentration shifts in relation to fasting status, while others did not. Here, we propose that (1) fasting is not required for a liquid biopsy study that involves both sncRNA and metabolomic profiling, as long as metabolites that are not influenced by fasting status are selected, and (2) the utilization of exosomal RNAs promotes robust and consistent findings in plasma samples, mitigating the impact of batch effects derived from hemolysis. These findings advance the optimization of liquid biopsy methodologies for clinical applications.