Activated Partial Thromboplastin Time Test Research Articles

An Investigative Study of Prothrombin Time, Activated Partial Thromboplastin Time and Antithrombin Levels in Patients with Ischaemic Stroke

Background: The haemostatic system maintains a balance between prothrombotic and antithrombotic components in the body. The role of this system in ischaemic stroke is not certain. Objective: Prothrombin time (PT) and Activated Partial Thromboplastin Time(APTT) are widely used screening tests to assess the haemostatic cascade. We sought to evaluate the relevance of these test and antithrombin (AT) levels in patients with ischaemic stroke. Methods: AT, platelet count, PT and APTT tests were carried out for 65 patients with ischaemic stroke and 65 controls with no history of stroke. Results: The mean age of stroke subjects was 60.4 ± 12.3yrs. PT and APTT in the test and control groups were similar and Antithrombin levels did not show significant difference. But there was a significant association between functional AT deficiency and diabetes mellitus in the ischaemic stroke group. A significant negative correlation existed between functional AT activity and prothrombin and between AT Ag levels and APTT Conclusion: There was no difference in the Antithrombin levels, PT and APTT values in patients with ischaemic stroke and those without a history of stroke and carrying out these tests routinely to assess hypercoagulable states in ischaemic stroke patients may not have any diagnostic value in our population.

Novel magnetic iron oxide-dextran sulphate nanocomposites as potential anticoagulants: Investigating interactions with blood components and assessing cytotoxicity

Examining the critical role of anticoagulants in medical practice, particularly their central function in preventing abnormal blood clotting, is of the utmost importance. However, the study of interactions between blood proteins and alternative anticoagulant nano-surfaces is still understood poorly. In this study, novel approach involving direct functionalisation of magnetic iron oxide nanoparticles (MNPs) as carriers with sulphated dextran (s-dext) is presented, with the aim of evaluating the potential of magnetically-responsive MNPs@s-dext as anticoagulants. The physicochemical characterisation of the synthesised MNPs@s-dext includes crystal structure analysis, morphology study, surface and electrokinetic properties, thermogravimetric analysis and magnetic properties` evaluation, which confirms the successful preparation of the nanocomposite with sulfonate groups. The anticoagulant potential of MNPs@s-dext was investigated using a standardised activated partial thromboplastin time (APTT) test and a modified APTT test with a quartz crystal microbalance with dissipation (QCM-D) which confirmed the anticoagulant effect. Time-resolved solid-liquid interactions between the MNPs@s-dext and model blood proteins bovine serum albumin and fibrinogen were also investigated, to gain insight into their hemocompatibility, and revealed protein-repellence of MNPs@s-dext against blood proteins. The study also addressed comprehensive cytotoxicity studies of prepared nanocomposites, and provided valuable insights into potential applicability of MNPs@s-dext as a promising magnetic anticoagulant in biomedical contexts.

False Prolongation of Activated Partial Thromboplastin Time with Aminoglycoside Antimicrobial Agents: A Case Report

BACKGROUND: Activated partial thromboplastin time (APTT) is a clotting time assay for screening bleeding tendency, evaluating coagulation factor production capacity, assessing preoperatively, monitoring anticoagulant drugs, and searching for blood coagulation abnormalities such as hemophilia and antiphospholipid syndrome. CASE PRESENTATION: Here, we present a 77-year-old male patient with dyspnea who was suspected to have a drug-resistant Pseudomonas aeruginosa infection and pulmonary mycosis. The patient had no history of bleeding tendencies or anticoagulant medication use. The laboratory test results revealed an abnormally prolonged activated partial thromboplastin time (APTT) of 120.3 s using the Coagpia® APTT-N reagent. The APTT test is frequently used to evaluate blood clotting function and assess for bleeding disorders. Prolonged APTT can indicate coagulation factor deficiencies or the presence of certain conditions such as von Willebr and disease, hemophilia, and disseminated intravascular syndrome. However, APTT standardization has not been achieved, causing discrepancies in test results due to variations in the reagents used. The prolonged APTT, in this case, was initially suspected to be caused by contamination or other artifacts, but repeat blood collections and cross-mixing tests revealed the Coagpia® APTT-N reagent as the cause of false prolongation. The reagent was changed to HemosIL SynthASil APTT, which revealed a normal APTT result. The patient had been receiving the aminoglycoside antimicrobial agent tobramycin, and the blood sample taken at the peak tobramycin level demonstrated the longest APTT time. The APTT shortened over time, corresponding to the decrease in tobramycin blood levels. CONCLUSION: Overall, this paper reports a case of false APTT prolongation due to a specific APTT reagent in the presence of aminoglycoside antimicrobial agents. The findings underscore the difficulties in standar PTT testing and the importance of considering reagent performance characteristics in result interpretations.

Analysis of APTT Based Clot Waveform Parameters in Various Clinical Conditions – A Study at A Tertiary Care Center

Various coagulation tests like Prothrombin Time (PT) and Activated Partial Thromboplastin Time (APTT) are estimated by automated coagulation analyzers. The newer fully automated analyzers generate clot wave forms aPTT-CWA for these parameters are derived. In this study, the objective was to analyze clot wave form characteristics morphology and its first and second derivative values in cases with abnormal APTT. ACL TOP 300 generated curves for APTT in a total 125 patients with 20 normal controls are included. First derivative, second derivative, morphology of curve: sigmoid, biphasic, prolonged pre-coagulation phase, second derivative morphology like early and late shoulder, biphasic peak, delayed deceleration were the analyzed parameters. Wave clot forms of 125 patients were included in this study. Patients (M:F - 2.2:1, mean age: 46.9 ± 20 years). A spectrum of clinical conditions was Covid (20%), liver disease (23%), polytrauma (10.4%), cardiac diseases (8.8%), sepsis/DIC (7.2%), thromboembolism (7.2%), renal diseases (6.4%), bacterial infections (4%), dengue (4%), snake bite (1.6%) and factor deficiency (1.6%). Liver and heart disease showed a significant difference in acceleration and deceleration peaks followed by sepsis, dengue, polytrauma and sepsis/DIC. Deceleration peak was prolonged in patients of Covid (p<0.05). Sepsis and liver diseases showed prolonged first derivative peak (p<0.05). CWA is very easily available on all automated coagulation analyzers. It is inexpensive with fast turn round time. Both quantitative as well as qualitative informations such as velocity, acceleration of clot formation and wave pattern details were recorded. Our study highlights importance of quantitative and qualitative CWA parameters acquired by performing APTT test for the automated analyzers.

Reducing use of coagulation tests in a family medicine practice setting: An implementation study

IntroductionClinicians often order the international normalized ratio (INR) and activated partial thromboplastin time (APTT) to evaluate for the possibility of inherited bleeding disorders despite sensitivities and specificities of 1%–2%. The most accurate tool to evaluate for bleeding disorders is a validated bleeding assessment tool (BAT). Our aim was to reduce coagulation testing by >50% in a large family practice in Ontario, Canada. MethodsWe conducted an implementation study from May 2016 to February 2020. Iterative interventions included introduction of a validated BAT into the electronic medical record (EMR); removal of the APTT as a prepopulated selection from the laboratory requisition; and education targeting family medicine teams and laboratory personnel. The primary outcome was the rate of pre‐ and post‐APTT testing. Creatinine testing was the control. Data were analyzed via an interrupted time series analysis using Stata 13. ResultsImmediately following education of the laboratory personnel on coagulation testing, the APTT rate level dropped by 1.26 tests per 100 patient visits per month (p < 0.001) and was sustained until the end of the study. Meanwhile, the PT/INR and creatinine testing rate levels did not change (rate level = −0.02 per 100 visits per month, p = 0.79 and 0.49, p = 0.22 respectively). There was good uptake of the BAT following integration and 18/88 (20%) obtained a referral to hematology after BAT completion. ConclusionsMultidisciplinary, iterative interventions reduced APTT testing and enabled the use of BATs to guide hematology referrals in a large family practice.

OPTIMIZATION OF THE EVALUATION METHOD OF THE PERFORMANCE OF THERAPY USING INDIRECT ACTION ANTICOAGULANTS

Aim. Treatment by indirect anticoagulants (vitamin K antagonists) requires a personalized approach for controlling the overall level of prothrombin and the accumulation of its decarboxylated forms. The purpose of this work was to optimize the method for monitoring of the therapy with indirect anticoagulants. Methods. An analysis was performed of 41 blood plasma samples from patients with cardiovascula pathologies. Activated partial thromboplastin time (APTT), prothrombin time, ecamulin time, statistical data analysis (“Statistica 7”) have been used. Results. APTT test allowed identifying the individual sensitivity of patients to indirect anticoagulants. In particular, 20% of patients showed a decrease in the total level of prothrombin, which, together with the accumulation of decarboxylated forms, leads to a risk of bleeding. Individual insensitivity to the action of vitamin K antagonists was determined in 11% of patients. Conclusion. To control the efficacy of indirect anticoagulants therapy, we developed test in which ecamulin (protease from the venom of Echis multisquamatis) was used as a prothrombin activator, which can activate not only functionally active prothrombin, but also its decarboxylated forms. Use of ecamulin simultaneously with thromboplastin allows determining in the blood plasma the content of not only functionally active prothrombin, but also the total level of prothrombin, which makes it possible to control the accumulation of decarboxylated prothrombin.

Investigation of the Bleeding Tendency in Sudanese Female Carriers of Hemophilia B.

Background Hemophilia (HB) is an X-linked, recessive bleeding disorder characterized by the deficiency or absence of the coagulation factor IX. Usually, females are carriers of the trait, while males are affected. FIX deficiency leads to uncontrollable bleeding events, and the severity is dependent on the levels of the clotting factor. The objective of this research was to measure the prevalence of bleeding tendency in Sudanese carriers of HB. Materials and Methods In this cross-sectional study, 88 Sudanese carriers of HB participated. The activated partial thromboplastin time test (APTT) and FIX test were performed for each carrier. The frequencies of DNA polymorphism and FIX-linked restriction fragments BamHI, HhaI, and MnII were also assessed. The study was conducted in Khartoum, Sudan, during the period from 2015 to 2017. Results The study showed that 55 (62.5%) HB carriers were from the Laban village in the White Nile State, and all of them were members of the Shinkheb tribe. The mean age of the study population was 26.3 years. Among the carriers, 57 (64.7%) had abnormal coagulation profiles. The mean value of the APTT level among carriers was significantly increased (P value: 0.000), while the mean concentration of the FIX levels among the carriers was significantly decreased (P value: 0.000). The study also showed a negative correlation between PTT and F assay with P value of 0.000 and R value of 0.578. Conclusion The APTT is high in most carriers and the FIX assay level is low in most carriers. Most carriers had no symptoms and were not bleeding. The Shinkheb tribe is the most ethnic tribe carrying HB (62.5%). HhaII is more informative for carrier detection than others, but it is of significant value if both (MnII and HhaII) were performed in parallel. In Sudanese, BamHI was informative but MnII and HhaII were best in the mutation detection and for prenatal diagnosis.

Potential Anticoagulant Activity of Thymus atlanticus Leaves Part in vitro on Normal Plasma Samples

The purpose of this study was to evaluate the anticoagulant activity of Thymus atlanticus leaves. Methods and Results: This cross-sectional study was carried out in Khartoum state from March 2021 to June 2021. This study comprised 60 healthy volunteers (40% men and 60% women) aged 19-25 years. Activated partial thromboplastin time (APTT) and prothrombin time (PT) were evaluated in the blood plasma with different amounts of Thymus atlanticus leaves using Coatron M1 (TECO Medical Devices). Thymus atlanticus leaves considerably lengthened APTT and PT in all tested concentrations. Furthermore, only the APTT test at a concentration of 5.17 μl revealed a significant difference in the anticoagulant activity of Thymus atlanticus leaves between males and females. No correlation between age and anticoagulant activity of Thymus atlanticus leaves on PT and APTT in the study was found.

Phenotypic and Genotypic Signatures of VWF Exon 18 in Eastern Saudi Patients Previously Diagnosed with Type 1 von Willebrand Disease.

Introductionvon Willebrand disease (VWD) is the most prevalent bleeding disease, which is associated with either low levels of von Willebrand factor (VWF) or abnormality in its structure. Three types of the disease have been described; type 1 (VWD1) and 3 (VWD3) are caused by deficiency of VWF and type 2 (VWD2) is caused by production of defective VWF. The aim of the current study was to characterize gene variants of VWF gene; exon 18 in particular, in a cohort of Saudi families as well as healthy control subjects.MethodsA total of 19 families comprising 60 subjects of type 1 VWD were enrolled in the study. Participants were divided into 22 index cases, 21 affected family members and 17 unaffected family members ranging in age from 6 to 70 years. Blood samples were collected from all participants to measure activated partial thromboplastin time test (APTT), von Willebrand antigen level (VWF:Ag), Factor VIII activity (FVIII:C) and ristocetin cofactor activity (VWF:RCo), platelet count, determining the ABO blood group and for genetic analysis by Sanger sequencing.ResultsThe results indicated that VWD1 patients have lower levels of VWF and factor VIII than the non-affected family members and the control subjects. In addition, five gene variants were reported in VWF exon 18; of these, c.2365A>G and c.2385T>C were more common in the control group and might be protective from VWD.DiscussionIn conclusion, VWF levels are influenced by blood group, and there was no association between variants in exon 18 of VWF gene reported in all groups and the disease status; however, blood group analysis and genome-wide genotyping could help to highlight high-risk groups and improve clinical management of VWD.

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.

Effect of Time and Haemolysis on Prothrombin Time (PT) and Activated Partial Thromboplastin Time (APTT) Measurement on Blood Samples

Background: Coagulation, also known as blood clotting, is the process by which blood convert from a liquid to a gel, forming a blood clot. It referred to haemostasis, the stopping of blood loss from a damaged vessel, followed by repair.&#x0D; Material and methods: This was cross sectional study conducted at the albawasla medical laboratory, Khartoum, Sudan during the period August to November, 2021 and to evaluate the effect of time and hemolysis on prothrombin time and activated partial thromboplastin time tests. 50 samples (case group) were collected from the patients attending police teaching hospital and requested to the PT and APTT test in addition to that,50 apparently healthy donors with no history of any coagulation problems or any chronic disease were selected as control group. Three ml of venous blood samples were collected in container with Tri Sodium Citrate anticoagulant. The coagulation tests (PT and APTT) were performed using semiautomatic device (coagulometer machine MI).&#x0D; Results: The result of this study revealed that; when compared the measurement of PT and APTT immediately and after one hour there was insignificant differences (p. v.&gt;0.05). also when compared the measurement of PT and APTT between hemolyzed and non-hemolyzed samples there was significant differences ( p. v.&lt;0.05) in addition when compared case and control for the PT and APTT immediately, after one hour, hemolyzed and non-hemolyzed sample there was significant differences ( p. v.&lt;0.05) except the APTT hemolyzed samples and insignificant differences with age and gender ( p. v.&gt;0.05). For the correlation there was significant correlation in the case group for the PT and APTT immediately, after one hour, and hemolyzed samples.&#x0D; Conclusion: In the cases group results showed insignificant differences in the results of PT and APTT between immediate sample and after 1 hour in and significant differences in the results of PT and APTT between hemolyzed and non-hemolyzed samples, also there was insignificant differences between age and gender, immediately, after one hr. and hemolyzed sample in PT and APTT.&#x0D; Keywords: Homeostasis, hemolyzed sample, PT and APTT

In vitro Anticoagulant Effect of Grape Seed Extract (Vitis vinifera) on Human Normal Blood Sample

Background: Scientists have used herbs nowadays for curing many diseases because they are safer and to overcome the side effect of the chemical drugs. Grape is one of the ancient herbs that used for diseases of the heart and blood vessels, high blood pressure, high cholesterol, skin care and many other conditions. Grape seeds have significantly higher concentrations of polyphenols which has anticoagulant and antithrombotic effect.&#x0D; Materials and Methods: In this study 20 normal blood samples from healthy individuals with age range (19-38) years were enrolled in this study]. Prothrombin time (PT) and activated partial thromboplastin time (APTT) tests were performed before adding grape seed extraction (GSE) (as control) and after adding GSE with different concentrations (25%, 50% and 75%).&#x0D; Results: The results revealed that grape seed extract has an anticoagulant effect as proven by the increase of Prothrombin time and Activated partial thromboplastin time results of the blood samples in different concentrations of the extract. The GSE showed a high statistical significant (P= 0.000) in all concentrations of both PT and APTT tests.&#x0D; Conclusion: This study suggests that GSE has a strong anticoagulant effect; so it can potentially be used as a supplementary anticoagulant agent to prevent thrombosis and cardiovascular diseases.

Association of circulating proprotein convertase subtilisin/kexin type 9 concentration with prothrombin time in patients with chest pain

Abstract Background Proprotein convertase subtilisin/kexin type 9 (PCSK9) has multiple roles in the development and progression of atherosclerosis. Recent studies have indicated an association of PCSK9 with thrombotic process. Purpose We aimed to examine whether there exists a relationship between plasma PCSK9 concentration and the most commonly coagulation parameters including prothrombin time (PT) and activated partial thromboplastin time (APTT). Methods A total of 2293 consecutive patients with angina-like chest pain who had no treatment of lipid-lowering drugs were enrolled in this study. The baseline clinical and laboratory data were collected. PT and APTT tests were performed. Circulating PCSK9 concentrations were determined by ELISA and classified into three subgroups according to their levels of PCSK9 tertiles. The relation of PCSK9 concentration to PT or APTT were analyzed. Results Firstly, we found that the patients with high PCSK9 levels trended to have lower PT and APTT (p&amp;lt;0.0001, p=0.003) according to results of PCSK9 tertiles. Then, pearson correlation analysis showed that log-transformed PCSK9 concentration was negatively correlated with PT (r=−0.194, p&amp;lt;0.0001) and was significantly but weakly related with APTT (r=−0.075, p&amp;lt;0.0001). The stepwise multivariable regression analysis revealed that PCSK9 was independently related with PT after adjusting traditional atherosclerotic risk factors and coagulation parameters (β=−0.137, p&amp;lt;0.0001; β=−0.121, p&amp;lt;0.0001, respectively). Conclusion Circulating PCSK9 concentration was independently negative associated with PT, suggesting a potential link between PCSK9 and PT that may be involved in atherogenesis and atherothrombosis. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences

Focus on coronavirus disease 2019 associated coagulopathy.

Focus on coronavirus disease 2019 associated coagulopathy.

Purification and characterization of Protein C activator from Agkistrodon acutus Venom

Protein C (PC) plays an important role in the balance of coagulation and anticoagulation. Thus, the detection of PC activity is diagnostically significant for patients with cardiovascular diseases. Presently, the key methods to detect PC activity are the chromogenic assay and activated partial thromboplastin time (APTT) test. PROTAC used in the chromogenic assay is isolated from Agkistrodon contortrix venom as protein C activator (PCA). However, the use of the chromogenic assay is limited because of the high price of PROTAC. In this study, PCA was successfully purified from Agkistrodon acutus venom (AAV) by ion-exchange and gel chromatography. PCA from AAV has a relative molecular mass of 24 kD, calculated from the measurement of 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The components of PCA were identified by MALDI-TOF/TOF-MS and mascot searches revealed that the coverage rate between PCA and zinc metalloproteinase AaPA from AAV was 21%. The chromogenic assay and APTT test were used to measure the enzymatic activity of PCA, and the results showed that PCA from AAV could specifically activate PC. In summary, the chromogenic assay described herein is highly sensitive and easy to perform.

Influence of sample centrifugation on plasma platelet count and activated partial thromboplastin time using patient samples

BackgroundDiagnostic coagulation testing is vulnerable to factors of the pre-analytical phase such as sample centrifugation. Despite this, centrifugation conditions differ widely among European laboratories. Here we use samples from patients referred for Activated partial thromboplastin time (APTT) testing to investigate if different centrifugation conditions result in platelet-poor plasma (PPP) (plasma platelet count < 10 × 109/L) and how the variation in centrifugation conditions affect APTT measurements. MethodsCentrifugation of 2000g (10 min) were compared with 3000g (10 min) using samples from patients referred for APTT testing (n = 70). Plasma platelet count and APTT were measured to investigate the influence of the centrifugation conditions. Differences were evaluated using Bland Altman Plots and Student’s t-test. ResultsCentrifugation at 3000g for 10 min produced PPP for more of the samples (64%) than centrifugation at 2000g (6%) (p < 0.001). No statistically significant difference for APTT (p = 0.265) was found for samples with APTT < 37 s while samples with prolonged APTT (>37 s) showed a statistically significant difference (p = 0.025). The Bland Altman plot did not reveal a clinically significant difference (mean difference 0.30 s/0.68%) when compared to a maximum acceptable bias of 10%. ConclusionNone of the centrifugation conditions used in this study adequately secured PPP for all samples. Despite a statistically significant difference between samples with prolonged APTT, no clinically significant difference was observed when comparing all APTT measurements.

Influence of hemolysis, icterus and lipemia on coagulation tests as performed on Cobas t511 new analyzer.

: In the coagulation laboratory, spurious hemolysis, icterus and lipemia (HIL) in test samples represent by far the leading diagnostic prenalytical challenges. The aim of this study was to assess the performance of the preanalytical module on the new hemostasis analyser Cobas Roche t511. We assessed the influence of HIL on prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (Fib), antithrombin and D-dimer on plasma pools aliquots with different interference degrees. Moreover, we evaluated spontaneous hemolysis by comparing results on 50 paired samples (hemolysed versus nonhemolysed). Spurious hemolysis interference studies highlight the absence of a clinical significant impact on PT, APTT and antithrombin test results at all hemoglobin concentration investigated. For Fib and D-dimer assays a clinically significant difference was observed in the most hemolysed aliquot for Fib and in the two most hemolysed aliquots for D-dimer. Spontaneous hemolysis interference studies showed no clinical significant differences for PT and antithrombin assays, instead for APTT, Fib and D-dimer we found significant statistical and clinical differences between hemolysed and non hemolysed specimens. Bilirubin interference studies and lipemic samples interference studies enable us to confirm that the differences in the results obtained between the different aliquots and reference pool is not clinically significant for all assays. HIL check preanalytical module of Cobas Roche t511 analyzer displaied excellent performance for routine use in clinical laboratories. Regardless of analytical considerations, the type of interference encountered with spurious HIL is substantially different and requires different approaches.

Interferences between Clot in the Erythrocyte Sediment and Hemostasis Exploration.

The selection and rejection of non-conforming coagulation specimens is essential in safeguarding quality management in hemostasis laboratories that provide routine testing for bleeding and thrombotic disorders. In order to increase quality, it is important to reduce pre-analytical errors that generally account for 60 - 70% of total laboratory failure. The accidental presence of clots in vitro, in the pre-analytical phase of the coagulation, is a reason for coagulation specimen rejection, given that the reliability of test results can be adversely compromised. This study aimed to ascertain the effect of clots identified in the post-analytical phase within the blood sample sediments upon standard laboratory tests such as PT (prothrombin time) and APTT (activated partial thromboplastin time). From a total of 24,670 coagulation specimens gathered and prospectively collected and analyzed at the Haematology Laboratory of the ˮSf. Spiridonˮ Emergency County Hospital Iasi, Romania, during four months, 671 were identified with clot. Of the coagulated samples, 153 (22.80%) were considered for this study, including those specimens pinpointed with sediment clot through a post-analytical new reverification procedure. The comparative study of the PT and APTT results obtained based on the samples identified with sediment clots in relation to the actual results recorded after the repetition of the sampling, pointed out 43.93% false results for PT1 test, with a significant difference between the variances of the values at the two evaluated moments (t = 2.961, p = 0.0037). The pattern was congruent in the case of the APTT test as well, exhibiting 69.04% false results, for which the variances of values at the two evaluated moments displayed significant differences (t = 2.208, p = 0.0306). In both of the cases significantly lower mean values were noted in the second determination of PT (PT1: 33.1 ± 39.6 vs. PT2: 25.8 ± 30.5) and APTT (APTT1: 42.8 ± 42.7 vs. APTT2: 38.1 ± 26.1. Results are important as they highlight the actual interference between the clot in the erythrocyte sediment and the evaluation of the patient's hemostasis. Our results confirm that the presence of clots in the erythrocyte sediment, with no identification prior to centrifugation, significantly affect the PT and APTT analysis, their accurate results being critical for the proper diagnosis and monitoring of anticoagulant therapy.

Влияние аргининсодержащих пептидов на антикоагулянтную и фибринолитическую активность плазмы крови крыс в условиях &lt;i&gt;in vitro&lt;/i&gt;

Исследовано действие олигопептидов глипролинового ряда — His-Phe-Arg-Trp-Pro-Gly-Pro (АКТГ(6-9)PGP), Thr-Lys-Pro-Arg-Pro-Gly-Pro (селанк) и Pro-Gly-Pro (PGP) – в различных концентрациях от 1 до 10 – 5 мг/мл в условиях in vitro на плазму крови крыс посредством тестов АЧТВ (активированное частичное тромбопластиновое время) и определения пластин нестабилизированного фибрина. Удлинение времени свертывания плазмы (по тесту АЧТВ) от 158 до 210 % в зависимости от концентрации пептидов при p &lt; 0,01 указывает на гипокоагуляцию под действием АКТГ(6-9)PGP и селанка. Выявлены суммарные фибринолитические эффекты пептидов в концентрациях от 1 до 10–5 мг/мл методом измерения зоны лизиса на пластинах нестабилизированного фибрина в норме и под влиянием пептидов. Наибольшей фибриндеполимеризационной активностью по данным суммарной фибринолитической активности обладал пептид АКТГ(6-9)PGP от 117 до 148 % в концентрациях от 10–3 до 1 мг/мл при p &lt; 0,05.

Anti-inflammatory and anticoagulant effects of polyphenol-rich extracts from Thymus atlanticus: An in vitro and in vivo study

Ethnopharmacological evidenceThymus atlanticus (TA) is used in traditional medicine in Morocco to treat chronic inflammatory diseases, after local and oral treatment. Aim of studyThis study aimed to investigate the in vitro and in vivo anti-inflammatory and anticoagulant activities of an aqueous extract (AE) and polyphenol fraction (PF) derived from TA. Materials and methodsThe effect of AE and PF on monocyte chemoattractant protein-1 (MCP-1) production by naïve and LPS-stimulated peritoneal macrophages isolated from C57Bl/6 mice was assessed by ELISA assay. The effect of chronic administration of the extracts at three different doses by oral rout for 2 weeks on blood coagulation and inflammation induced by carrageenan in Wistar rats was evaluated. In addition, the in vitro anticoagulant effect was tested on blood plasma collected from healthy rats using the activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT) tests. The acute toxicity of AE was investigated. Phytochemical analysis was carried out by HPLC. ResultsAnalysis by HPLC indicated rosmarinic acid as the main phenolic acid in TA extracts. Compared to control macrophages, MCP-1 level was lower in medium supplemented with AE at 50 and 500 μg/mL and PF at 500 μg/mL, but higher in medium with PF at 50 μg/mL. Rosmarinic and chicoric acids, served as controls, significantly decreased MCP-1 production. Chronic oral administration of TA extracts prevented inflammation induced by carrageenan and induced a significant prolongation of blood coagulation time, in a dose dependant manner, in Wistar rats. The results of the in vitro assay showed that the coagulation time was significantly prolonged in plasma incubated with extracts in APTT, PT and TT tests. Lethal dose 50 of AE in mice was 27.90 ± 1.19 g/kg. ConclusionThis study indicated TA as an herb with anti-inflammatory and anticoagulant proprieties and supports the traditional use of this plant for the treatment of inflammatory diseases.