ABSTRACT
Introduction: Acquired thrombotic thrombocytopenic purpura (TTP) is a severe, rare, thrombotic microangiopathy (TMA). A diagnosis of acquired TTP is confirmed by a severe deficiency (< 10%) of ADAMTS13 activity. Recently, maybe because of Sars-COV2 Pandemic, in our laboratory we had the impression that normal reference ranges of our ADAMT13 activity assay HemosiL Acustar ADAMTS13 rapid immunoassay, could be larger than manufacturer's. The objective of this study was to evaluate whether manufacturer's are suitable normal reference values for this assay in our laboratory Methods: To evaluate manufacturer's reference limits (60-130.6%) in our laboratory we decided to assay with HemosIL Acustar ADAMTS13 activity test 30 plasma samples from normal subjects. Result(s): 3 out of 20 normal subjects tested showed ADAMTS13 activity outside manufacturer's limits (1 below 60.6% and 2 above 130.6%), therefore even if calculated in a small number of subjects (30 individuals) we decide to try to calculate in house ADAMTS13 reference values. They ranged from 47.5 (10th perc.), 72.5 (25th perc.) and 41.6 (mean- 2sd) to 150.0 (99th perce.), 119,6 (75th perc.) and 152.7 (mean+2sd). To investigate the analytical performance of manufacturer's and calculated cut-offs limits, we re-evaluate one year of ADAMTS13 activity results (95 subjects). ADAMTS13 activity was severely reduced (< 0.7%) in 10 acute TTPs;20 patients with Hemolytic Uremic Syndrome showed ADAMTS13 activity above manufacturer's and in all calculated cut-offs;21/45 patients with TTPs in remission phase showed ADAMTS activity below all in house calculated cut off and 24/45 showed ADAMTS activity below manufacturer's;12/20 other patients showed ADAMTS activity below all in house calculated and manufacturer's cut offs, all of them were Sars COV2 positive subjects Conclusion(s): In conclusion HemosiL Acustar ADAMTS13 activity calculated cut-offs in our laboratory were larger than manufacturer's reference range. By the analysis of one year ADAMTS13 activity dosages both manufacturer's and calculated cut-offs showed similar performances but our calculated reference ranges even if obtained by the analysis of a small number of normal subjects were found to be more similar to literature ELISA (40-130%) and FRET (45-147%) ADAMTS13 activity normal values.
ABSTRACT
Introduction: Heparin-induced thrombocytopenia (HIT) is a severe adverse reaction to heparin caused by heparin-dependent, platelet-activating anti-plateletfactor 4 (PF4)/heparin antibodies. Vaccine-induced thrombocytopenia and thrombosis (VITT) following Astrazeneca vaccine has been described, associated with IgG anti-PF4 antibodies. Only ELISA immunoassays have been shown to detect anti-PF4 antibodies in these patients. Diagnosis of both HIT and VITT requires confirmation of heparin-dependent, platelets activating antibodies to avoid overdiagnosis and overtreatment Anti-PF4 laboratory assay requests during pandemic are in most of the cases of COVID positive vaccinated subjects, vaccinated healed from COVID19 subjects and COVID negative vaccinated subjects. Aim of our study was to investigate which laboratory test to use in patients with suspected HIT in this particular historical period Methods: Thirty patients with suspected HIT/ VITT were tested with three anti-PF4 immunoassays (HIT Ab Latex Immunoassay-Werfen, Acustar HITIgG CliA-Werfen, HPIA ELISA-Stago): 8 Astrazenca suspected VITT;1 Moderna and 1 Pfizer suspected VITT, 20 suspected HIT (9/20 COVID positive and 11/20 COVID negative patients). In order to confirm immunoassay positivity Platelet Aggregation Test (PAT) functional test was performed in all patients found to be positive for at least one assay. Result(s): 3/8 suspected Astrazenca VITT tested positive only by ELISA assay 2/3 tested positive by PAT (confirmed VITT). Both patients with suspected Pfizer and Moderna VITT tested negative for all immunoassays. 4/9 COVID patients with suspected HIT tested positive only by ELISA assay, only 1 of them tested positive by PAT. 4/11 COVID negative suspected HIT tested positive by all immunoassays performed and 1/11 tested positive only by ELISA and CliA immunoassays, among these 5 subjects only 2 were confirmed HIT by PAT functional assay Conclusion(s): With the only exception of suspected Astrazeneca VITT no superiority of IgG-ELISA over CliA or Latex immunoassay in sensitivity to HIT was observed. No single immunoassay method detected all probable HIT cases;if a single test is negative, a second immunoassay or a platelet activation assay should be considered where there is strong clinical suspicion Interestingly by using Bayesan diagnosis of HIT and CliA conservative negative cut-off < 0.13 U/ml suggested in the literature (Marchetti et al. 2020) all our CliA negative (results < manufacturer's cut-off of 1.0 U/mL) and ELISA positive suspected HIT/VITT were correctly classified as positive by CliA assay.
ABSTRACT
Introduction: critically ill COVID-19 patients are known to have a coagulopathy characterized by increased levels of D-dimer (DD) associated to a thrombotic risk and a significant increase in mortality. However, it is not known whether the associated COVID-19 coagulopathy is due to a prothrombotic state or is caused by endothelial dysfunction and inflammation. Aim of our study, was to better characterize the hypercoagulability state of COVID-19 patients using Thrombin Generation analyser (ST Genesia, Diagnostica Stago, Asnieres, France). Method(s): a total of 46 non-critically ill hospitalized COVID-19 patients were compared to 19 critically ill COVID-19 patients utilizing calibrated automated thrombography and other biochemical, hematological and coagulation parameters. Result(s): critically ill patients had a significant increase in C reactive protein (CRP), interleukin-6 (IL-6), prothrombin time (PT), DD and a significant decrease in lymphocytes count. No significant differences in Thrombin Generation Test (TGT) parameters were observed between the two groups of patients with the only exception of the "Lag Time" parameter. Discussion(s): the obtained results confirmed increased levels of DD and PT in critically ill COVID-19 patients. Of note, disease severity did not cause an increase in Thrombin Generation when compared to non-critically COVID-19 patients. The significantly prolonged Lag Time in critically ill COVID-19 patients without decreased endogenous thrombin potential suggests an hypocoagulability state in these patients. The relevance of this finding is uncertain and may appear counterintuitive since these patients are expected to have a hypercoagulability status, and requires further research. Copyright © 2022 Biomedia. All rights reserved.
ABSTRACT
The term Smart associated to cities and communities is commonly referred to a broad concept involving vehicles, humans, environment and services. In this paper we focus on a Smart solution dedicated to a specific reality, where humans are the main actors. We propose LiveSmart-CAMPUS, an intelligent system whose main goal is to improve the life quality of students, collaborators and visitors within a physical university campus. The system will enable the management of physical distancing and the optimization of shared spaces occupancy, for a safe return to work and academic environment, during the Covid post-pandemic time. We present in this paper the LiveSmart-CAMPUS application, a mobile application developed on top of the LiveSmart global solution, and envisioned for the campus community and visitors which allows them to obtain location based, calendar and time based, and users interests' based information. The presented application will give the possibility to the LiveSmart system to collect users mobility data, allowing the monitoring and the prediction of no latency information on expected rooms and corridors occupancy levels. People who tested the applications reported its usefulness in improving their comfort and their life quality within the campus spaces. © 2021 Copyright for this paper by its authors