Fast blood impedance measurements as quality indicators in the pre-analytical phase to prevent laboratory errors

In clinical laboratories, the major proportion of errors regarding blood analyses occurs in the pre-analytical phase. Pre-analytical conditions are key, necessary factors in maintaining the high quality of specimens, limiting day-to-day and batch variations, and guaranteeing the absolute reliability and accuracy of clinical results and related diagnoses. The quality of serum samples must be very high in order to avoid interferences due to hemolysis, thereby preventing measurement errors. In addition, the quality of the blood should always be fast monitored to identify inadequacies and guarantee their complete usability in transfusion procedures. In the near future, the solution could be to supply laboratories with smart and portable devices that are able to perform fast quality tests for every sample. Electrical impedance has relevant potential in analyzing and monitoring blood quality. We propose a new, simple impedancebased biosensor that can perform accurate and efficient single and multi-frequency impedance measurements in the pre-analytical phase and to check the quality of blood samples using quantitative thresholds as useful indicators to ensure the reliability of results and thereby prevent laboratory errors. The proposed sensor allows for discriminating different blood components, identifying hemolysis in serum, evaluating blood quality, and rapidly quantifying its hematocrit

Improved GMP compliant approach to manipulate lipoaspirates, to cryopreserve stromal vascular fraction, and to expand adipose stem cells in xeno-free media

Abstract Background The stromal vascular fraction (SVF) derived from adipose tissue contains adipose-derived stromal/stem cells (ASC) and can be used for regenerative applications. Thus, a validated protocol for SVF isolation, freezing, and thawing is required to manage product administration. To comply with Good Manufacturing Practice (GMP), fetal bovine serum (FBS), used to expand ASC in vitro, could be replaced by growth factors from platelet concentrates. Methods Throughout each protocol, GMP-compliant reagents and devices were used. SVF cells were isolated from lipoaspirates by a standardized enzymatic protocol. Cells were cryopreserved in solutions containing different albumin or serum and dimethylsulfoxide (DMSO) concentrations. Before and after cryopreservation, we analyzed: cell viability (by Trypan blue); immunophenotype (by flow cytometry); colony-forming unit-fibroblast (CFU-F) formation; and differentiation potential. ASC, seeded at different densities, were expanded in presence of 10% FBS or 5% supernatant rich in growth factors (SRGF) from platelets. The differentiation potential and cell transformation grade were tested in expanded ASC. Results We demonstrated that SVF can be obtained with a consistent yield (about 185 × 103 cells/ml lipoaspirate) and viability (about 82%). Lipoaspirate manipulation after overnight storage at +4 °C reduced cell viability (−11.6%). The relative abundance of ASC (CD34+CD45−CD31–) and endothelial precursors (CD34+CD45−CD31+) in the SVF product was about 59% and 42%, respectively. A period of 2 months cryostorage in autologous serum with added DMSO minimally affected post-thaw SVF cell viability as well as clonogenic and differentiation potentials. Viability was negatively affected when SVF was frozen at a cell concentration below 1.3 × 106 cells/ml. Cell viability was not significantly affected after a freezing period of 1 year. Independent of seeding density, ASC cultured in 5% SRGF exhibited higher growth rates when compared with 10% FBS. ASC expanded in both media showed unaltered identity (by flow cytometry) and were exempt from genetic lesions. Both 5% SRGF- and 10% FBS-expanded ASC efficiently differentiated to adipocytes, osteocytes, and chondrocytes. Conclusions This paper reports a GMP-compliant approach for freezing SVF cells isolated from adipose tissue by a standardized protocol. Moreover, an ASC expansion method in controlled culture conditions and without involvement of animal-derived additives was reported

A new method for accurate platelet thrombi volume measurement using a confocal microscope

The accuracy of quantitative measurements represents an essential pre-requisite to the characterization and definition of the complex dynamic phenomena occurring in the field of cell biology. In research projects that involve the induction of blood coagulation under flow in microfluidic artificial channels, thrombus volume is an important quantity for estimation as a significant index related to the individual thrombotic risk profile. Concerning its importance in the early diagnosis of cardiovascular diseases, the estimated thrombus volume should reflect and represent reality. In 3D confocal microscopy, systematic errors can arise from distortions of the axial distance, whose accurate calibration remains a challenge. As a result, the 3D reconstructions show a noticeable axial elongation, and the volume measurements are thus overestimated. In this paper, a 400-600 % volume overestimation is demonstrated, and a new easy to use and automatic calibration procedure is outlined for this specific microfluidic and optical context. The adaptive algorithm proposed leads to the automatic compensation of the elongation error and to the accurate thrombus volume measurement. The method has been calibrated using fluorescent beads of known volume, validated with groups of several distinct platelets and finally applied on platelet thrombi

Acute Delta Hepatitis in Italy spanning three decades (1991–2019): Evidence for the effectiveness of the hepatitis B vaccination campaign

Updated incidence data of acute Delta virus hepatitis (HDV) are lacking worldwide. Our aim was to evaluate incidence of and risk factors for acute HDV in Italy after the introduction of the compulsory vaccination against hepatitis B virus (HBV) in 1991. Data were obtained from the National Surveillance System of acute viral hepatitis (SEIEVA). Independent predictors of HDV were assessed by logistic-regression analysis. The incidence of acute HDV per 1-million population declined from 3.2 cases in 1987 to 0.04 in 2019, parallel to that of acute HBV per 100,000 from 10.0 to 0.39 cases during the same period. The median age of cases increased from 27 years in the decade 1991-1999 to 44 years in the decade 2010-2019 (p < .001). Over the same period, the male/female ratio decreased from 3.8 to 2.1, the proportion of coinfections increased from 55% to 75% (p = .003) and that of HBsAg positive acute hepatitis tested for by IgM anti-HDV linearly decreased from 50.1% to 34.1% (p < .001). People born abroad accounted for 24.6% of cases in 2004-2010 and 32.1% in 2011-2019. In the period 2010-2019, risky sexual behaviour (O.R. 4.2; 95%CI: 1.4-12.8) was the sole independent predictor of acute HDV; conversely intravenous drug use was no longer associated (O.R. 1.25; 95%CI: 0.15-10.22) with this. In conclusion, HBV vaccination was an effective measure to control acute HDV. Intravenous drug use is no longer an efficient mode of HDV spread. Testing for IgM-anti HDV is a grey area requiring alert. Acute HDV in foreigners should be monitored in the years to come