Platelet-poor Plasma Samples Research Articles

Serotonin Levels and Chemotherapy-Induced Nausea and Vomiting in Cancer Patients: A Cross-Sectional Study.

Nausea and vomiting are distressing symptoms experienced by cancer patients undergoing treatment, impacting their physical well-being and quality of life. Serotonin, a neurotransmitter known for its role in regulating mood and gastrointestinal function, has been implicated in chemotherapy-induced nausea and vomiting (CINV). This study aimed to investigate serotonin level differences between CINV and non-CINV groups among cancer patients undergoing chemotherapy. An analytical observational investigation utilizing a cross-sectional design was conducted at Dr. Kariadi General Hospital from 2021-2022. Non-random consecutive sampling was employed to select participants meeting inclusion criteria, including age between 18 and 65 years, undergoing chemotherapy, non-smoking, and no recent antibiotic use. Platelet-poor plasma samples were analyzed for serotonin levels using a radioimmunoassay kit (Microplate reader ELx800). This study included 61 subjects compared serotonin levels in two groups to investigate their potential association with chemotherapy-induced nausea and vomiting (CINV). The non-CINV group (n=31) had a median serotonin level of 70 (IQR: 20) ng/mL, while the CINV group (n=30) had a significantly higher median of 170 ng/mL (IQR: 50) ng/mL. Age was associated with a 1.2 ng/mL increase in serotonin per year (95% CI: 0.5-1.9, p = 0.002), adjusted for sex. Being male correlated with a 40 ng/mL increase (95% CI: 10-70, p = 0.010), adjusted for age. This study underscores the importance of understanding serotonin's role in CINV and highlights the need for tailored treatment approaches based on chemotherapy emetogenicity.

Data-independent LC-MS/MS analysis of ME/CFS plasma reveals a dysregulated coagulation system, endothelial dysfunction, downregulation of complement machinery

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating chronic condition that is characterized by unresolved fatigue, post-exertion symptom exacerbation (PESE), cognitive dysfunction, orthostatic intolerance, and other symptoms. ME/CFS lacks established clinical biomarkers and requires further elucidation of disease mechanisms. A growing number of studies demonstrate signs of hematological and cardiovascular pathology in ME/CFS cohorts, including hyperactivated platelets, endothelial dysfunction, vascular dysregulation, and anomalous clotting processes. To build on these findings, and to identify potential biomarkers that can be related to pathophysiology, we measured differences in protein expression in platelet-poor plasma (PPP) samples from 15 ME/CFS study participants and 10 controls not previously infected with SARS-CoV-2, using DIA LC-MS/MS. We identified 24 proteins that are significantly increased in the ME/CFS group compared to the controls, and 21 proteins that are significantly downregulated. Proteins related to clotting processes – thrombospondin-1 (important in platelet activation), platelet factor 4, and protein S – were differentially expressed in the ME/CFS group, suggestive of a dysregulated coagulation system and abnormal endothelial function. Complement machinery was also significantly downregulated, including C9 which forms part of the membrane attack complex. Additionally, we identified a significant upregulation of lactotransferrin, protein S100-A9, and an immunoglobulin variant. The findings from this experiment further implicate the coagulation and immune system in ME/CFS, and bring to attention the pathology of or imposed on the endothelium. This study highlights potential systems and proteins that require further research with regards to their contribution to the pathogenesis of ME/CFS, symptom manifestation, and biomarker potential, and also gives insight into the hematological and cardiovascular risk for ME/CFS individuals affected by diabetes mellitus.Graphical abstract

EXPLORING THE HAEMOSTATIC POTENTIAL OF PANCHAVALKALA KASHAYA AND PANCHAVALKALA AQUEOUS EXTRACT: AN IN VITRO STUDY

Acharya Susrutha under the context of Rakthasthambhanopaya (methods of haemostasis) has explained about the different methods to attain Rakthasthambhana or haemostasis. which include Skandana (clotting of blood), Santhana (uniting), Pachana (ripening or digestive measures) and Dahana (thermal cauterisation). Acharya Susrutha while explaining about agantuja vrana chikitsa (treatment of wound) has explained that ‘Pittavat sheeta kriya’ should be done prior to santhana to mitigate the ‘Kshatoshmana’. So, from this it is evident the primary method of management should be done with sheeta (cold) followed by Kashaya rasa dravya (astringent taste drugs) for Santhana. Panchavalkala is a group drug with sheeta veerya (cold potency) and Kashaya rasa (astringent taste) mentioned in Dalhana commentary for Skandana. This study investigates the haemostatic effect of Panchavalkala Kashaya and Panchavalkala aqueous extract by in vitro method. Preliminary phytochemical screening of both trial drugs was done. A total of 10 samples of healthy human platelet poor plasma were mixed in trial drugs, Prothrombin and Activated Partial Thromboplastin time were determined. Data was analysed using Kruskal Wallis test. Phytochemical analysis confirmed that the Panchavalkala kashaya contain alkaloids, tannins, glycosides and saponins. Panchavalkala aqueous extract sample consist of flavonoids, alkaloids, glycosides, tannins and saponins. LCMS Q-TOF analysis shows the presence of compounds Gallic acid, Epicatechin, Leucocynidin and Procyanidin B1. And the HPLC study confirmed that Gallic acid is an active phytoconstituent present in the Panchavalkala aqueous extract. In the present study the trial group Panchavalkala aqueous extract showed more desirable haemostatic effect than Panchavalkala Kashaya on comparison.

Microclots, as defined by amyloid-fibrinogen aggregates, predict risks of disseminated intravascular coagulation and mortality

AbstractMicroclots have been associated with various conditions, including postacute sequelae of severe acute respiratory syndrome coronavirus 2 infection. They have been postulated to be amyloid-fibrin(ogen) aggregates, but their role as a prognostic biomarker remains unclear. To examine their possible clinical utility, blood samples were collected for the first 96 hours from critically ill patients (n = 104) admitted to the intensive care unit (ICU). Detection was by staining platelet-poor plasma samples with thioflavin T and visualized by fluorescent microscopy. Image J software was trained to identify and quantify microclots, which were detected in 44 patients (42.3%) on ICU admission but not in the remaining 60 (57.7%) or the 20 healthy controls (0.0%). Microclots on admission to ICU were associated with a primary diagnosis of sepsis (microclots present in sepsis, 23/44 [52.3%] vs microclots absent in sepsis, 19/60 [31.7%]; P = .044). Multicolor immunofluorescence demonstrated that microclots consisted of amyloid-fibrinogen aggregates, which was supported by proteomic analysis. Patients with either a high number or larger-sized microclots had a higher likelihood of developing disseminated intravascular coagulation (odds ratio [OR], 51.4; 95% confidence interval [CI], 6.3-6721.1; P < .001) and had an increased probability of 28-day mortality (OR, 5.3; 95% CI, 2.0-15.6; P < .001). This study concludes that microclots, as defined by amyloid-fibrin(ogen) aggregates, are potentially useful in identifying sepsis and predicting adverse coagulopathic and clinical outcomes.

An in Vitro Pilot Study of the Role of Factor IX As an Alternative to Bypassing Agents in the Treatment of Breakthrough Bleeds in Patients with Hemophilia a and Inhibitors Treated with Emicizumab

Introduction: Hemophilia A(HA) is an X linked disorder characterized by a deficiency in Factor VIII. 30% of patients with severe HA develop alloantibodies that inhibit the coagulant activity of FVIII. Emicizumab, a substitution therapy that bridges factor IX and X, is approved in patients with severe HA with and without inhibitors. Indeed, it is now the standard of care prophylactic therapy for patients with inhibitors. Breakthrough bleeds and perioperative management require the use of bypassing agents in addition to emicizumab, with recombinant VIIa deemed the safest of these options. Nevertheless there are still concerns about thrombotic risks and inability to monitor bypassing agents given to patients on emicizumab. Since the rate limiting step for FXa generation in the plasma of patients receiving emicizumab is the concentration of generated FIXa, we conducted an in vitro pilot study to evaluate the hemostatic effect of adding FIX to the plasma of patients on emicizumab prophylaxis. Methods: After informed consent was obtained, blood was collected in citrated tubes prefilled with 1.45mM of corn trypsin inhibitor(CTI) from 25 patients with HA receiving emicizumab prophylaxis. Aligning with previously published data, the added hemostatic effect of rFVIIa was studied in platelet rich plasma (PRP), while all other products were studied in platelet poor plasma (PPP). PRP was spiked with 0, 45, 90 and 270mg/kg of rFVIIa, and PPP was spiked with 0, 10, 20, 30 and 50 IU/kg of activated prothrombin complex concentrate (aPCC); 0, 25, 50 and 100 IU/kg of recombinant FIX(rFIX) and 0, 25, 50 and 100 IU/kg of plasma derived FIX(pdFIX). Thrombin generation was run on these spiked samples using the CAT method. Coagulation was triggered in PRP samples with tissue factor 1pM. PPP samples were activated using 1pM of TF and 1.5pM FIXa. Mean endogenous thrombin potential (ETP, area under the thrombin generation curve) values were compared between the different experiments and with samples obtained from controls. Baseline FIX concentrations were determined in these patients using bovine chromogenic assay. The mean plasma emicizumab concentration (+Standard Deviation) was 44.45 µg/mL (+15.83). Results: As shown in fig 1, ETP was significantly improved with increasing concentrations of aPCC, rFIX and pdFIX in PPP(p&amp;lt;0.005). Fig 2 shows that ETP normalized with the addition of rFVIIa 45mg/kg (p&amp;lt;0.0001) in most of the patients tested. Moreover, we did not see ETP above the upper limit of the normal range when FIX was added, while 50 IU/kg of aPCC and 270 mg/kg of rFVIIa clearly surpassed the upper limit of the normal range, suggesting a risk of hypercoagulability and thrombosis. FIX levels varied between 63.9% and 248.9% with a mean of 134.27%. ETP obtained after adding rFIX 100 IU/kg was significantly greater than that attained with pdFIX (p=0.027), that might be explained by the presence of the activated form of FIX in rFIX concentrates. No statistical significant difference between the doses of 50 IU/Kg of FIX and 100 IU/KG was observed (p&amp;gt;0.05), with a noted tendency to increased ETP with 100IU/KG dose. Conclusion: Our in vitro study demonstrates excess thrombin generation (and potential thrombosis risk) with higher concentrations of rFVIIa and aPCC that are used in the clinical care of patients. While addition of FIX at a range of doses appears to improve thrombin generation without exceeding the upper normal limits. These data suggest that FIX therapy may safely improve hemostasis in patients with HA and inhibitors receiving emicizumab prophylaxis. A clinical study looking at a starting dose of rFIX at 50 IU/KG for mild to moderate bleeds and 100 IU/Kg for more severe bleeds is warranted. In addition to the advantage of monitoring levels with FIX therapy, the longer half-life of FIX offers the potential advantage of controlling hemostasis with single dose administration. Future prospective clinical trials are needed to investigate the efficacy and safety of this therapy in this patient population.

Plasma-derived extracellular vesicle surface markers CD45, CD326 and CD56 correlate with the stage of osteoarthritis: a primary study of a novel and promising diagnostic tool of the disease

Recently, there is a growing interest in the research based on extracellular vesicles (EVs) which represent paracrine factors secreted by almost all cell types. Both, normal and pathological cells are able to release various types of EVs with different physiological properties, functions and compositions. EVs play an important role in intercellular communication, mechanism and tissue repair. Moreover, EVs could help not only in the treatment of diseases but also in their diagnostics. This work focused on the evaluation of the potential of EVs being used as biomarkers for the diagnosis of osteoarthritis (OA) based on a comparison of the composition of EVs separated from platelet-poor plasma (PPP) of healthy donors and OA patients at different stages of OA. OA is established as a complex syndrome with extensive impact on multiple tissues within the synovial joint. It is a chronic disease of musculoskeletal system that mainly affects the elderly. Depending on the use of the Kellgren–Lawrence classification system, there are four grades of OA which have a negative impact on patients' quality of life. It is very difficult to detect OA in its early stages, so it is necessary to find a new diagnostic method for its timely detection. PPP samples were prepared from whole blood. PPP-EVs were separated from 3 groups of donors—healthy control, early stage OA, end-stage OA, and their content was compared and correlated. EVs from PPP were separated by size exclusion chromatography and characterized in terms of their size, yield and purity by NTA, western blotting, ELISA and flow cytometry. Detection of surface markers expression in EVs was performed using MACSPlex approach. Inflammatory and growth factors in EVs were analysed using MAGPix technology. Our study confirmed significant differences between EVs surface markers of patients and healthy controls correlating with the age of donor (CD63, CD31 and ROR1) and stage of OA (CD45, CD326 and CD56), respectively. Circulating EVs have been under extensive investigation for their capability to predict OA pathology diagnosis as potential targets for biomarker discovery. Taken together, obtained results indicated that PPP-EVs surface markers could be used as potential biomarkers in the early diagnosis of OA.

Prothrombotic Profile in Patients with Active Multiple Myeloma and the Impact of Immunomodulators: The Roadmap-MM Study

Backround: Thromboembolism occurs in about 10% of patients with multiple myeloma (MM). The incidence of VTE is higher in newly diagnosed MM patients as compared to those with relapsed or refractory disease and it is higher during the first 3 to 6 months after the initial diagnosis and treatment initiation. Some of the treatments administered to patients with MM are independent risk factors for VTE. Immunomodulatory agents (IMiDs) among anti-myeloma treatments stand out as having a considerable prothrombotic effect. Recognizing the significant risk associated with the use of immunomodulatory agents (the International Myeloma Working Group (IMWG) 2014 statement, and the European Myeloma Network Guidelines in 2015 both included guidance on the prevention of VTE in MM patients who receive IMiDs. The prospective, longitudinal observational study ROADMAP-MM CAT was designed to explore alternative strategies for the development of risk stratification tools in patients with multiple myeloma. To this target we evaluated the baseline profile of hypercoagulability in multiple myeloma patients with various disease status. Blood borne hypercoagulabity partly consisted of enhanced thrombin generation, a common phenomenon in patients with malignancies . It remains to be seen whether this phenomenon appears for multiple myeloma patients during the physical course of the disease. Aim: We conducted a study to explore the relationship between stages of MM and alterations of various thrombosis-related biomarkers in patients with MM and their relationship with MM therapy. Materials and Methods Patients with MM (n=162) were recruited and stratified to the following groups: 59 newly diagnosed treatment-naïve patients (ND), 49 patients receiving IMiDs (IM), 52 in complete remission (CR) and 12 patients in partial remission on IMiDs (PR/IM). Patients on anticoagulant treatment were excluded from the study. The control group (CG) consisted of 30 healthy age and sex-matched individuals. Samples of platelet-poor plasma (PPP) were assessed for thrombin generation (TG) with the TF 5pM PPP-Reagent® on Calibrated Automated Thrombogram (Diagnostica Stago, France). Plasminogen activator inhibitor-1 (PAI-1), soluble endothelial protein C receptor (sEPCR), and soluble vascular cell adhesion molecule-1 (sVCAM-1), Procoag-PPL were measured using antibody-based ELISA kits (Invitrogen International Inc., CA, USA, and Diagnostica Stago, France ). TF expression MPC-derived microparticles (MPC-dMPs) were detected using a Zymuphen MP-TF activity kit (Hyphen BioMed, Neuville sur Oise, France). The upper and lower normal limits (LNL and UNL) were calculated by the mean±2 SD. Results A total of 162 patients were enrolled (age 66.0±12.0 yrs; 53% male). Distribution of disease stage was as follows: 32% ISS I, 23% ISS II, 45% ISS III. Bone disease was present in 71% of patients and 19% of patients had high risk cytogenetic lesions. Patients with ongoing MM (ND, IM, PR/IM) had significantly lower Peak, ETP and MRI as compared to the CG. In contrast, patients in CR had Peak, ETP, MRI values similar to the CG. Patients with PR had lower ETP and MRI values as compared to the CR group. In ND 9% had TG &amp;gt;UNL and 22% had TG&amp;lt;LNL. In IM 10% had TG&amp;gt;UNL and 67% had TG&amp;lt;LNL. None in PR/IM had TG&amp;gt;UNL and 35% had TG&amp;lt;LNL. In CR, 23% had TG&amp;gt;UNL and 12% had TG&amp;lt;LNL. MP-TF levels and PPL were higher in untreated MM (CR) patients compared to control. MP-TF and PPL levels decreased significantly after chemotherapy in PR/IM but MP-TF remained high at CR. The plasma concentrations, PAI-1, sEPCR, and sVCAM-1 were higher in MM patients than controls. , Treatment with IMDs reduced all biomarker levels gradually from PR/IM to CR (Table 1). Conclusion Patients with active MM showed attenuated TG which was enhanced in the presence of IMiDs treatment. Complete remission was associated with normalization of TG. The plasma concentrations, TF-MP , PAI-1, sEPCR, and sVCAM-1 were increased in MM patients suggesting vascular aggression which is followed by release of these markers that could contribute to the procoagulant environment. Attention should be paid to therapy-related thrombosis indeed the effect the suggested role of IMiDs in hypercoagulability does not seem to be confirmed and requires further studies .

Evaluation of thrombin generation in dogs administered clopidogrel.

The antiplatelet effect of clopidogrel can vary between patients. A modified thromboelastography (TEG) protocol (TEG-Platelet Mapping assay® [TEG-PM]) can be used for clopidogrel monitoring but is not widely available. Thrombin generation (TG) assays could offer a novel alternative. The main objective of this pilot study was to assess TG assay variables (lag time, peak, endogenous thrombin potential [ETP]) in dogs before and after 7 days of clopidogrel administration and compare with TEG-PM variables (maximum amplitude [MA]-ADP and percentage (%) inhibition). Six healthy mix-breed dogs were enrolled in this pilot study. Blood samples for platelet count, TG assays, and TEG-PM were obtained at two time points, corresponding to baseline, and after 7 days of clopidogrel administration (mean 2.3 +/- 0.3 mg/kg PO q24 hours). Data were then compared with a Student's t-test. There was no significant change in TG assay variables performed on platelet poor plasma after 7 days of clopidogrel administration: lag time (Day 1: 1.8 +/- 0.2 min, Day 7: 1.8 +/- 0.2 min, p = 0.42); peak (Day 1: 76 +/- 7 nM, Day 7: 72 +/- 10 nM, p = 0.49); and ETP (Day 1: 399 +/- 27 nM*min, Day 7: 392 +/- 32 nM*min; p = 0.49). There were significant changes in TEG MA-ADP (Day 1: 19 +/- 8 mm, Day 7: 9 +/- 6 mm, p = 0.04) and % inhibition (Day 1: 58 +/- 27, Day 7: 99 +/- 0.3, p = 0.02). Clopidogrel administration did not lead to changes in TG assay variables performed on platelet poor plasma samples, despite concomitant changes in TEG-PM variables consistent with platelet inhibition. Based on this pilot study, thrombin generation performed on platelet poor plasma may not be a useful antiplatelet monitoring tool in dogs.

In Vitro Anticoagulant Activity of Crude Protease of Bacillus tequilensis HSFI-5

obtained from the fermented intestine of Holothuria scabra (sand sea cucumber). Strain HSFI-5 had been reported to be able to produce proteases, which had shown several characteristics of an antithrombotic agent, i.e., fibrinolytic and clot-lysis activities. However, its anticoagulation activity test is yest to be done. This study aimed to determine the anticoagulant activity of the crude protease HSFI-5 in vitro. The study design was a completely randomized design with a sample size of 90 calculated using the Federer formula. The material used was crude protease from B. tequilensis in skim milk broth. Prothrombin time (PT), activated partial thromboplastin time (aPTT), and plasma recalcification time (PRT) were carried out to test the anticoagulant activity. Citrated platelet poor plasma samples were divided into positive control, normal control, direct examination with crude enzyme in volumes of 50 and 100 µL and pre-incubation at 37ºC for 5, 10, and 15 min with crude enzyme volumes of 50 and 100 µL. The data normality was tested with the Kolmogorov-Smirnov test and the different tests were analyzed by one-way ANOVA with the Post hoc LSD test. The results of one-way ANOVA both on PT, aPTT, and PRT examinations showed that there was a significant difference between the treatment groups (p&lt;0.05). The longest results of PT, aPTT, and PRT are positive controls, and the shortest results are normal controls for PT, and 15’ 50 group for aPTT and PRT. It is clear that crude protease B. tequilensis HSFI-5 exhibits anticoagulant as well as thrombolytic action, raising the possibility that it could function as an antithrombotic drug.

Small extracellular vesicles are released ex vivo from platelets into serum and from residual blood cells into stored plasma

AbstractSmall extracellular vesicles (sEV) purified from blood have great potential clinically as biomarkers for systemic disease; however interpretation is complicated by release of sEV ex vivo after blood taking. To quantify the problem and devise ways to minimise it, we characterised sEV in paired serum, plasma and platelet poor plasma (PPP) samples from healthy donors. Immunoblotting showed twofold greater abundance of CD9 in sEV fractions from fresh serum than from fresh plasma or PPP. MACSPlex confirmed this, and showed that proteins expressed on platelet sEV, either exclusively (CD41b, CD42a and CD62P) or more widely (HLA‐ABC, CD24, CD29 and CD31) were also twofold more abundant; by contrast non‐platelet proteins (including CD81) were no different. Storage of plasma (but not serum) increased abundance of platelet and selected leukocyte sEV proteins to at least that of serum, and this could be recapitulated by activating cells in fresh plasma by Ca2+, an effect abrogated in PPP. This suggests that a substantial proportion of sEV in serum and stored plasma were generated ex vivo, which is not the case for fresh plasma or PPP. Thus we provide strategies to minimise ex vivo sEV generation and criteria for identifying those that were present in vivo.

Evaluation of Platelet-Rich Plasma by means of PRGF®-Endoret® protocol in leukemia cats: PDGF-BB and TGF-ß1 valuation.

Feline leukemia virus (FeLV) is a chronic disease that leads to the weakening of a cat's immune system. Platelet-rich plasma (PRP) offers therapeutic effects for multiple diseases, the use of PRP and growth factors (GFs) determination could be an alternative treatment to improve the quality of life in these patients. The objectives of this study were to determine and compare the concentration of platelets (PLTs), red blood cells (RBCs) and white blood cells (WBCs) between samples of whole blood (WB), PRP and platelet-poor plasma (PPP) fractions, and to evaluate the concentration of platelet-derived growth factor BB (PDGF-BB) and transforming growth factor β1 (TGF-β1) in both fractions in FeLV cats using a PRGF®-Endoret® protocol previously standardized in this species. WB was collected from 11 asymptomatic FeLV-positive cats. PRP and PPP was obtained following PRGF®-Endoret® technology according to centrifugation at 265 g for 10 min. Cellular components, RBCs, WBCs, PLTs, and the PDGF-BB and TGF-β1 concentrations in PRP and PPP fractions were determined. PLT in the PRP fraction was statistically higher than WB and PPP fraction, with no statistical differences between WB and PPP. PLT concentration increased 1.4 times in PRP fraction compared to WB. Mean platelet volume (MPV) did not differ significantly between the WB, PRP, and PPP fractions. Compared to WB, the absolute numbers of RBCs and WBCs were decreased by 99% and more than 95% in the PRP and PPP fractions, respectively. TGF-ß1 concentrations increased in PRP vs. PPP, with no changes in PDGF-BB. Based on the degree of PLT enrichment and the absence of RBCs and WBCs, this blood product could be classified as a Pure Platelet-Rich Plasma (P-PRP). The presence of GFs in PRP and PPP samples suggests that the PRGF®-Endoret® methodology is suitable for obtaining PRP in FeLV cats, despite future studies are necessary to optimize the technique, standardize the results and assess clinical efficacy.

Deciphering the role of platelets in severe allergy by an integrative omics approach.

Mechanisms causing the onset and perpetuation of inflammation in severe allergic patients remain unknown. Our previous studies suggested that severe allergic inflammation is linked to platelet dysfunction. Platelet-rich plasma (PRP) and platelet-poor plasma (PPP) samples were obtained by platelet-apheresis from severe (n= 7) and mild (n= 10) allergic patients and nonallergic subjects (n= 9) to perform platelet lipidomics by liquid chromatography coupled to mass spectrometry (LC-MS) and RNA-seq analysis. Significant metabolites and transcripts were used to identify compromised biological pathways in the severe phenotype. Platelet and inflammation-related proteins were quantified by Luminex. Platelets from severe allergic patients were characterized by high levels of ceramides, phosphoinositols, phosphocholines, and sphingomyelins. In contrast, they showed a decrease in eicosanoid precursor levels. Biological pathway analysis performed with the significant lipids revealed the alteration of phospholipases, calcium-dependent events, and linolenic metabolism. RNAseq confirmed mRNA overexpression of genes related to platelet activation and arachidonic acid metabolism in the severe phenotypes. Pathway analysis indicated the alteration of NOD, MAPK, TLR, TNF, and IL-17 pathways in the severe phenotype. P-Selectin and IL-17AF proteins were increased in the severe phenotype. This study demonstrates that platelet lipid, mRNA, and protein content is different according to allergy severity. These findings suggest that platelet load is a potential source of biomarkers and a new chance for therapeutic targets in severe inflammatory pathologies.

Abstract 15637: Detection and Characterization of Fibrin/Amyloid Microclots in Patients With Post-Acute Sequelae of Covid-19

LongCovid or Post-Acute Sequelae of COVID-19 (PASC) is a diagnosis given to patients who experience a wide range of debilitating chronic symptoms after infection with SARS-CoV-2. The majority of individuals are PCR negative, indicating microbiological recovery. There are currently few LongCovid/PASC blood-based biomarkers. We used fluorescence microcopy to identify unique fibrin/amyloid micro-thrombosis and hyperactivated platelets in individuals with PASC. These fibrin/amyloid microclots may impede blood flow to tissue. Methods: Whole blood was collected in citrate tubes from 30 matched healthy subjects and 30 PASC subjects. Platelet poor plasma (PPP) was prepared by centrifugation and stored at -80 °C. PPP was then exposed to thioflavin T (ThT), a fluorescence marker known to bind to and open hydrophobic areas on damaged amyloidogenic protein. Samples were viewed with fluorescence microscopy using a 63x/1.4 Oil DIC M27 objective (excitation wavelength 450nm-488nm, emission 499nm- 529nm). After a double-trypsin PPP digestion method, proteomic analysis of the PPP samples was performed. Results: Significant microclot load was observed in the PPP of participants with PASC compared to healthy participants (Fig. 1). Proteomic analysis revealed the presence of inflammatory molecules within digested microclots. Conclusion: Preliminary results suggest that the presence of microclots in PPP may be used as a diagnostic biomarker for the PASC. Characterization of inflammatory molecules and antibodies trapped within microclots might provide insight into the pathogenesis of PASC and serve as a basis for novel treatment strategies or preventative medicine. Figure: Representative specimens A) Microclots in healthy plasma. B) Microclots in PASC plasma.

Development of an ELISA displaying similar reactivity with reduced and oxidized human Thioredoxin-1 (Trx1): The plasma level of Trx1 in early onset psychosis disorders

The plasma level of human thioredoxin-1 (Trx1) has been shown to be increased in various somatic diseases and psychiatric disorders. However, when comparing the reported plasma levels of Trx1, a great inter-study variability, as well as variability in study outcomes of differences between patients and control subjects has been observed, ultimately limiting the possibility to make comparative analyses. Trx1 is a highly redox active protein prone to form various redox forms, e.g. dimers, oligomers or Trx1-protein complexes. We have recently shown that ELISA systems may vary in reactivity to various Trx1 redox forms. The primary aim of the present study was to develop an ELISA system with similar reactivity to various Trx1 redox forms. By evaluating a panel of novel monoclonal antibodies (mAbs), in various paired combinations, three ELISA systems were generated, with observed large variability in reactivity to various Trx1 redox forms. Importantly, an ELISA system (capture mAb MT17R6 and detection mAb MT13X3-biotin), was identified that displayed similar reactivity to oxidized and DTT reduced Trx1. The ELISA system (MT17R6/MT13X3-biotin), was subsequently used to analyze the level of Trx1 in plasma from patients (<18 years) with early onset psychosis disorders (EOP). However, no significant (p > 0.7) difference in plasma Trx1 levels between patients with EOP (n = 23) and healthy age matched controls (HC) (n = 20) were observed. Furthermore, reliable measurement was shown to be dependent on the establishment of platelet poor plasma samples, enabled by rigorous blood sample centrifugation and by efficient blocking of potentially interfering heterophilic antibodies. In conclusion, we report the design and characterization of a Trx1 ELISA system with similar reactivity to various Trx1 redox forms. Importantly, data indicated that generated ELISA systems show large variability in reactivity to various redox forms with ultimate impact on measured levels of Trx1. Overall, results from this study suggests that future studies may be strongly improved by the use of Trx1 ELISA systems with characterized specificity to various redox forms.

The expression level of mir-21-3p in platelet-rich plasma: A potential effective factor and predictive biomarker in recurrent implantation failure.

Recurrent implantation failure (RIF) is the most important complication associated with in vitro fertilization (IVF). Despite the good quality of the transferred embryo, the success rate is rather disappointing. Therefore, predictive biomarkers for implantation are critical to making decisions about transferring high-quality embryos or cryopreserving them for cycles with a higher chance of implantation. Recently, intrauterine infusion of autologous platelet-rich plasma (PRP) has been proposed to increase the endometrial receptivity in RIF patients. PRP is rich in both growth factors and microRNAs (miRNAs). We investigated the possible association of mir-21-3p, mir-21-5p, mir-494-3p, mir-145-5p, and insulin-like growth factor-I (IGF-I) levels in PRP and platelet-poor plasma (PPP) samples with the pregnancy outcomes in RIF patients. The miRNA expression level and IGF-I concentration were assessed using real-time PCR and chemiluminescence methods respectively. Mir-21-3p was upregulated in PRP samples of the pregnant group in comparison to the nonpregnant group. There was no difference in the expression of mir-21-3p in PPP samples of these groups. The concentration of IGF-I was higher in PRP and PPP samples of the nonpregnant in comparison to the pregnant group. Receiver-operating characteristic curve analysis showed that mir-21-3p can be a valuable biomarker for the prediction of pregnancy chance in RIF patients treated with PRP.

A method based on plateletpheresis to obtain functional platelet, CD3+ and CD14+ matched populations for research immunological studies.

In previous studies with peripheral blood cells, platelet factors were found to be associated with severe allergic phenotypes. A reliable method yielding highly concentrated and pure platelet samples is usually not available for immunological studies. Plateletpheresis is widely used in the clinics for donation purposes. In this study, we designed a protocol based on plateletpheresis to obtain Platelet-Rich Plasma (PRP), Platelet-Poor Plasma (PPP) as well as CD3+ and CD14+ cells matched samples from a waste plateletpheresis product for immunological studies. Twenty-seven subjects were voluntarily subjected to plateletpheresis. PRP, PPP and blood cell concentrate contained in a leukocyte reduction system chamber (LRSC) were obtained in this process. CD3+ and CD14+ cells were isolated from the LRSC by density-gradient centrifugation and positive magnetic bead isolation. RNA was isolated from PRP, CD3+ and CD14+ cell samples and used for transcriptomic studies by Affymetrix. PRP and PPP samples were used for platelet protein quantification by multiplex assays. A reliable high yield method to obtain matched samples of PRP, PPP, CD3+ and CD14+ from a single donor for RNA and protein analyses has been designed. The RNA quality indicators (RQI) routinely used for other cell types were not suitable for platelet RNA characterization. Despite this, the platelet RNA was valid for transcriptomic studies by Affymetrix, as platelet transcripts obtained in our previous studies were confirmed in PRP samples. Platelet samples were enriched in platelet factors as determined in protein multiplex analysis. We have developed a method that yields not only high content and pure platelet samples from a single donor but also CD3+ and CD14+ matched samples that can be used for RNA and protein analyses in immunological studies.

In Vitro Activity of Some Medicinal Plants on Blood Coagulation.

The concern for finding natural and curative agents without adverse side effects has prompted the interest in discovering hemostatic agents from plants. Therefore, in vitro activity of Aizoon hispanicum L. (Aizoaceae), Centaurea hyalolepis Boiss. (Asteraceae), Heliotropium maris-mortui Zohary. (Boraginaceae), Parietaria judaica L. (Urticaceae), Polygonum arenarium Waldst. & Kit. (Polygonaceae), and Verbascum sinuatum L. (Scrophulariaceae) on blood coagulation was estimated by two common tests, which are the prothrombin time test (PT) and the activated partial thromboplastin time test (aPTT). The extracted powders from the plants under this study were adjusted to be 50 mg/mL. Then, in vitro effect of these extracts on the platelet poor plasma samples was measured by an automated coagulation analyzer using PT and aPTT tests. Based on the obtained results, all plant extracts affected the coagulation cascade by rising either PT or aPTT or both, except for V. sinuatum extract, which reduced only aPTT value. Moreover, the recorded PT values showed that A. hispanicum, H. maris-mortui, and P. arenarium significantly prolonged the PT (p<0.05). Additionally, the results clearly showed that V. sinuatum acted as a coagulant agent based on aPTT values, while all other plants, in contrast, acted as strong anticoagulants. Among the plant species under study, A. hispanicum, H. maris-mortui, and P. arenarium extracts prolonged both PT and aPTT significantly (p<0.05). This could be referred to their additional effect on the common pathway. However, C. hyalolepis, P. judaica, and V. sinuatum showed no significant effect on PT values (p>0.05). The positive recorded data from this research could serve as identification of new hemostatic remedies that could be used for the commercial economic purposes and for managing several cardiovascular diseases.

Evaluation of a Standardized Protocol for Plasma Rich in Growth Factors Obtention in Cats: A Prospective Study.

IntroductionPlatelet-rich plasma (PRP) is an autologous plasma with platelet (PLT) concentration above that of whole blood (WB). PLTs contain growth factors (GFs) that promote tissular repair.ObjectivesTo determine and compare the concentrations of PLT, red blood cells (RBC) and white blood cells (WBC) between WB samples, PRP and platelet poor plasma (PPP) samples; and to analyze the concentrations of platelet-derived growth factor BB (PDGF-BB) and transforming growth factor β1 (TGF-β1) in the PRP and PPP of healthy adult cats using a standardized protocol with PRGF®-Endoret® characteristics.Material and MethodsWB was collected from 30 cats. PRP was obtained following three centrifugation protocols using PRGF®-Endoret® technology: 255, 260, and 265 g for 10 min each. The cellular components, RBC, WBC, PLT, and the concentrations of PDGF-BB and TGF-β1 in the PRP and PPP fractions were determined for each protocol.ResultsPLTs in the PRP fraction were statistically higher than WB, with no statistical differences between PPP and WB. In PRP fraction, PLT concentration was increased 1.4 times on average at 255 g; 1.3 times at 260 g and, 1.5 times at 265 g without statistical differences among them. The mean platelet volume (MPV) was significantly higher in WB compared to PRP and PPP fractions without significant differences between protocols. Compared to WB, the number of RBCs and WBCs was reduced by 99% and by more than 95% in PRP and PPP respectively, without significant differences between protocols. PDGF-BB concentrations were statistically higher in PRP than in PPP fractions, however, TGF-ß1 concentrations did not vary between fractions at 260 g. Comparing the three protocols within PRP and PPP fractions, no differences in PDGF-BB and TGF-ß1 concentrations were observed.Clinical RelevanceThe study shows scientific evidence regarding the obtention of PRP in cats using the PRGF®-Endoret® technology for the quantification of PDGF-BB and TGF-ß1. At 265 g for 10 min, PLT concentration was increased 1.5 times with unnoticeable erythrocytes and leukocytes in the samples. These results clearly show that the PRGF®-Endoret® methodology is suitable to obtain PRP in cats. Further studies are needed to determine the clinical efficacy of the obtained PGRF in the treatment of different pathologies in cats.

A modified, optimized kinetic photometric thrombin generation assay components to measure the potency of thrombin in plasma

The purpose of the present study was to improve, optimize and modification, a kinetic photometric assay of Factor IIa activity with regard to blood sample types, calibration, analytic corrections, and activation reagents, in order to establish a rapid routine, less time consuming, and suitable method for the evaluation of large numbers of clinical samples. Our modified method was based on the continuous monitoring of the Factor IIa released from the reacting substance, in the presence of a specific chromogenic peptide substrate (S2238). The optimization of pH and of the concentrations of substrate, activator (CaCl2), EDTA, and tissue factor was carried out as well as blood sample types (Platelet-rich and platelet-poor plasma samples) so as to ensure the best compromise between reliability, specificity, and sensitivity, However, the Factor IIa activity was compared in the plasma of different donors. In conclusion, our modified and optimized FIIa generation assay is a rapid and simple method for the diagnosis and monitoring of different clinical cases, at the same time it can be easily adapted to clinical chemistry analyzers.

Assessment of Stability of Prothrombin Time, International Normalized Ratio, and Activated Partial Thromboplastin Time Under Different Storage Conditions in Human Plasma.

BackgroundIn this study, we aimed to determine the effects of storage time and temperature on commonly performed coagulation tests such as prothrombin time (PT), international normalized ratio (INR), and activated partial thromboplastin time (APTT) in human plasma.MethodologyWhole blood samples from 100 patients were collected in a 3.2% sodium citrate vacutainer. The blood was centrifuged within two hours of collection at 2,000 g for 10 minutes, and the platelet-poor plasma (PPP) obtained was analyzed for PT, INR, and APTT tests at zero hours (baseline) and repeated at 12 hours, 24 hours, and 36 hours on a fully automated coagulation analyzer at various storage conditions (room temperature, refrigerator, and freezer). The results were categorized into two groups: group 1 comprised results with normal coagulation profile and group 2 comprised results with abnormal coagulation profile. The percentage change of the results from baseline (zero hours) for PT, INR, and APTT tests was also studied. A percentage change of more than ±10% from baseline was considered as a clinically significant change.ResultsIn this study, a total of 95 PPP samples were evaluated. The median age of all patients was 44 years (range: 19-65 years). The male-to-female ratio was 0.9:1. The baseline PT, INR, and APTT values were 12.1 seconds, 1.06, and 26.5 seconds, respectively, in group 1, whereas the baseline PT, INR, and APTT values were 19.1 seconds, 1.80, and 36.0 seconds, respectively, in group 2. In the freezer, the samples were stable for PT, INR, and APTT tests at 12 hours, 24 hours, and 36 hours showing a change of <10% from baseline at all three time-points. In the refrigerator, the samples were stable for PT and INR tests for up to 24 hours showing a change of <10% from baseline. In comparison, the samples for the APTT test were not stable at 12 hours, 24 hours, and 36 hours showing a change of 12.1%, 15.5%, and 17.9%, respectively, from the baseline (zero hours). Finally, at room temperature, the samples deteriorated at 12 hours for all coagulation parameters (PT, INR, and APTT).ConclusionsThe patient plasma samples for PT, INR, and APTT tests could be safely stored for up to 36 hours in the freezer. In the refrigerator, samples for PT and INR tests could be safely stored for up to 24 hours while the samples for APTT deteriorated at 12 hours. All patient samples for PT, INR, and APTT tests deteriorated at 12 hours at room temperature.