Comparison of lipemia interference created with native lipemic material and intravenous lipid emulsion in emergency laboratory tests

Introduction

This study aimed to investigate the effects of lipemia on clinical chemistry and coagulation parameters in native ultralipemic (NULM) and intravenous lipid emulsion (IVLE) spiked samples.

Materials and methods

The evaluation of biochemistry (photometric, ion-selective electrode, immunoturbidimetric method), cardiac (electrochemiluminescence immunoassay method) and coagulation (the viscosity-based mechanical method for prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen and the immunoturbidimetric method for D-dimer) parameters were conducted. In addition to the main pools, five pools were prepared for both types of lipemia, each with triglyceride (TG) concentrations of approximately 2.8, 5.7, 11.3, 17.0 and 22.6 mmol/L. All parameters' mean differences (MD%) were presented as interferographs and compared with the desirable specification for the inaccuracy (bias%). Data were also evaluated by repeated measures of ANOVA.

Results

Prothrombin time and APTT showed no clinically relevant interference in IVLE-added pools but were negatively affected in NULM pools(P < 0.001 in both parameters). For biochemistry, the most striking difference was seen for CRP; it is up to 134 MD% value with NULM (P < 0.001) at the highest TG concentration, whereas it was up to - 2.49 MD% value with IVLE (P = 0.009). Albumin was affected negatively upward of 5.7 mmol/L TG with IVLE, while there was no effect for NULM. Creatinine displayed significant positive interferences with NULM starting at the lowest TG concentration (P = 0.028). There was no clinically relevant interference in cardiac markers for both lipemia types.

Conclusions

Significant differences were scrutinized in interference patterns of lipemia types, emphasizing the need for careful consideration of lipemia interferences in clinical laboratories. It is crucial to note that lipid emulsions inadequately replicate lipemic samples.

Evaluation of D-dimer and prothrombin time in alcohol related liver cirrhosis with comparison of machine learning analyses

OBJECTIVES

Liver cirrhosis (LC) can be caused by obesity, alcohol consumption, viral infection, and autoimmune disease. Early diagnosis and management of LC is important for patient quality of life. Non-invasive diagnostic methods are useful for predicting the current status and mortality risk of LC. The purpose of this study is to identify relevant diagnostic factors measured in routine laboratory test of alcohol-related liver cirrhosis (ALC) patients.

METHODS

This study analyzed data from 127 patients with ALC, including their laboratory test results and clinical information, including coagulation parameters, hematologic parameters, and biochemical parameters. These data were used to compare the performance of the prediction models from three machine learning algorithms including K-nearest neighbor (KNN), support vector machine (SVM), and random forest (RF).

RESULTS

Higher Model for End-stage Liver Disease (MELD) score were associated with prothrombin time (PT) and D-dimer. Logistic and multiple linear regression analyses revealed significant factors predicting mortality in the MELD group. Machine learning approaches were used to predict death in ALC patients using some laboratory parameters associated with mortality. The prediction model based on SVM exhibited better prediction performance than others.

CONCLUSION

PT and D-dimer were the factors that were most strongly associated with 90-day mortality, and machine learning methods can create prediction models with good predictive power.

[Vertebral fractures combined with prolonged activated partial prothrombin time: A case report]

With the development of modern medical standards, autoimmune diseases and their associated successive osteoporosis have received increasing attention in recent years. Patients with autoimmune diseases, due to the characteristics of the disease and the prolonged use of glucocorticoid hormone therapy, may affect the bone formation and bone absorption of the patient, followed by severe successive osteoporosis, thereby increasing the risk of osteoporotic vertebral fractures. Vertebral compression fractures of the spine are common fracture types in patients with osteoporotic fractures. Osteoporosis is a common complication after glucocorticoid therapy in patients with autoimmune diseases. Percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP) are minimally invasive operation and are commonly used surgical methods for the treatment of osteoporotic vertebral compression fractures. However, due to the operation of spinal puncture during the operation, there are serious surgical risks such as bone cement leakage, spinal epidural hemorrhage, subdural hemorrhage, and subarachnoid hemorrhage in both PVP and PKP. As a result, it is necessary to evaluate the patient' s body before surgery carefully, especially in the case of blood coagulation. This article reports a case of autoimmune disease patient admitted to Peking University People' s Hospital due to lumbar 4 vertebral compression fracture combined with Sjögren' s syndrome. The patient' s preoperative examination showed that the activated partial thromboplastin time (APTT) was significantly prolonged. After completing the APTT extended screening experiment and lupus anticoagulant factor testing, the multi-disciplinary team (MDT) of Peking University People' s Hospital jointly discussed the conclusion that the patient' s test results were caused by an abnormal self-immunity anti-copulant lupus (LAC). Based on the results of the laboratory examination, the patient was considered to be diagnosed with combined antiphospholipid syndrome (APS). For such patients, compared with the patient' s tendency to bleed, we should pay more attention to the risk of high blood clotting in the lower limbs of the patient, pulmonary clots and so on. With timely anti-coagulation treatment, the patient safely passed the peripheral period and was successfully discharged from the hospital. Therefore, for patients with autoimmune diseases with prolonged APTT in the perioperative period, doctors need to carefully identify the actual cause and carry out targeted treatment in order to minimize the risk of surgical and perioperative complications and bring satisfactory treatment results to the patients.

Exploring coagulation parameters as predictive biomarkers of Plasmodium infection: A comprehensive analysis of coagulation parameters

BACKGROUND

Malaria affects the intravascular environment, leading to abnormal coagulation activation, prolonged prothrombin time, and activated partial thromboplastin time. Despite the high prevalence of malaria in the study area, there has been little published research on the effects of Plasmodium infection on coagulation parameters.

OBJECTIVE

The aim was to assess the effect of malaria on basic coagulation parameters among patients attending Dembia Primary Hospital and Makisegnit Health Center.

METHODS

A cross-sectional study was carried out from January to March 2020. The study involved 120 participants. Blood specimens were collected, which were analyzed using a Huma Clot Due Plus analyzer. The collected data were entered into EpiData and exported to SPSS version 21 for analysis. Non-parametric statistical methods were employed to analyze the data. The results were considered statistically significant if the p-value was less than 0.05.

RESULTS

Individuals infected with Plasmodium exhibit coagulation disorders with elevated levels of PT (Prothrombin Time), APTT (Activated Partial Thromboplastin Time), and INR (International Normalization Ratio) in comparison to healthy controls. The median PT, APTT, and INR values for infected cases were measured at 20.5 [8.6], 39.5 [17.9], and 1.8 [0.9], respectively, while healthy controls had measurements of 15.1 [2.5], 28.8 [8.3], and 1.3 [0.2] (p ≤ 0.001). The severity of coagulation disorders increased with an increase in parasitemia levels. The type of Plasmodium species present had a significant impact on PT and INR values (p ≤ 0.001), whereas APTT did not show any significant impact across the Plasmodium species (p > 0.05).

CONCLUSION

The results of this study found that malaria has a substantial impact on various blood clotting parameters, including PT, APTT, and INR. Parasitemia severity is significantly associated with extended PT and INR, implying that the higher the parasitemia, the longer it takes for blood to clot. Furthermore, the study discovered that the PT and INR levels differed based on the type of Plasmodium species responsible for the infection.

Defining a metrologically traceable and sustainable calibration hierarchy of international normalized ratio for monitoring of vitamin K antagonist treatment in accordance with International Organization for Standardization (ISO) 17511:2020 standard: communication from the International Federation of Clinical Chemistry and Laboratory Medicine-SSC/ISTH working group on prothrombin time/international normalized ratio standardization

Calibration of prothrombin time (PT) in terms of international normalized ratio (INR) has been outlined in "Guidelines for thromboplastins and plasmas used to control oral anticoagulant therapy" (World Health Organization, 2013). The international standard ISO 17511:2020 presents requirements for manufacturers of in vitro diagnostic (IVD) medical devices (MDs) for documenting the calibration hierarchy for a measured quantity in human samples using a specified IVD MD. The objective of this article is to define an unequivocal, metrologically traceable calibration hierarchy for the INR measured in plasma as well as in whole blood samples. Calibration of PT and INR for IVD MDs according to World Health Organization guidelines is similar to that in cases where there is a reference measurement procedure that defines the measurand for value assignment as described in ISO 17511:2020. We conclude that, for PT/INR standardization, the optimal calibration hierarchy includes a primary process to prepare an international reference reagent and measurement procedure that defines the measurand by a value assignment protocol conforming to clause 5.3 of ISO 17511:2020. A panel of freshly prepared human plasma samples from healthy adult individuals and patients on vitamin K antagonists is used as a commutable secondary calibrator as described in ISO 17511:2020. A sustainable metrologically traceable calibration hierarchy for INR should be based on an international protocol for value assignment with a single primary reference thromboplastin and the harmonized manual tilt tube technique for clotting time determination. The primary international reference thromboplastin reagent should be used only for calibration of successive batches of the secondary reference thromboplastin reagent.

Active monitoring of long-eared owl (Asio otus) nestlings reveals widespread exposure to anticoagulant rodenticides across different agricultural landscapes

The widespread use of anticoagulant rodenticides (ARs) poses a worldwide threat to farmland wildlife. These compounds accumulate in tissues of both target and non-target species, potentially endangering both direct consumers and their predators. However, investigations on ARs in blood of free-ranging predatory birds are rare. Here, the long-eared owl (Asio otus) has been used as a model predator to assess AR exposure in different agricultural landscapes from a Mediterranean semiarid region. A total of 69 owlets from 38 nests were blood-sampled over 2021 and 2022, aiming to detect AR residues and explore factors that determine their exposure, such as land uses. In addition, prothrombin time (PT) test was conducted to assess potential effects of AR contamination. Overall, nearly all the samples (98.6 %) tested positive for at least one compound and multiple ARs were found in most of the individuals (82.6 %). Among the ARs detected, flocoumafen was the most common compound (88.4 % of the samples). AR total concentration (ΣARs) in blood ranged from 0.06 to 34.18 ng mL-1, detecting the highest levels in the most intensively cultivated area. The analysis of owl pellets from 19 breeding territories showed relevant among-site differences in the contribution of rodents and birds into the diet of long-eared owls, supporting its high dietary plasticity and indicating AR presence at multiple trophic levels. Moreover, a positive and significant correlation was found between ΣARs and PT (Rho = 0.547, p < 0.001), which demonstrates the direct effect of ARs on free-living nestlings. Our results provide a preliminary overview of AR exposure in a little-studied owl species inhabiting agricultural and rural landscapes. Despite the low detected levels, these findings indicate widespread exposure -often to multiple compounds- from early life stages, which raises concern and draws attention to an ongoing and unresolved contamination issue.

Effect of residual platelets in frozen-thawed plasma on results of dilute Russell's viper venom time assay for lupus anticoagulant testing

OBJECTIVES

To determine the impact of residual platelets on dilute Russell's viper venom time (DRVVT) assay in frozen-thawed plasma submitted for lupus anticoagulant (LAC) testing.

METHODS

We measured platelet counts in frozen-thawed samples submitted for LAC testing and evaluated the association between platelet count and the DRVVT screening time and ratios. We also spiked platelets into a LAC-positive sample to observe the effect on the DRVVT.

RESULTS

Progressive increase in platelet count resulted in a statistically significant shortening of the DRVVT assay results on plasma after 1 freeze-thaw cycle. A similar effect was noted on the LAC-positive sample.

CONCLUSIONS

Residual platelets in plasma samples result in shortening of DRVVT assay after 1 freeze-thaw cycle. This may result in a false-negative LAC test result.

Prothrombin time predicts steroid response in severe alcohol-related hepatitis

BACKGROUND AND AIMS

Alcohol-related hepatitis (AH) is the most severe form of acute alcohol-related liver disease. Maddrey's discriminant function ≥32 defines the severe form of AH, which is associated with a high mortality. Steroid therapy represents the main medical treatment that may reduce short-term mortality. Lille score at day 7 assesses the therapeutic response to steroid therapy. At present, no parameters able to predict the response to steroid therapy have been highlighted. The aim of the present study was to evaluate if baseline prothrombin time (BPT) could predict the response to steroid in severe AH (sAH).

METHODS

Patients consecutively admitted in two Italian Liver Units, from 2017 to 2022, suffering from sAH were included. Data were collected prospectively. In order to evaluate if BPT could predict steroid response, we assessed the correlation between BPT using the Lille score at day 7.

RESULTS

A total of 52 patients received steroid treatment were enrolled in the study. The response to therapy was assessed by Lille score at day 7. Responders were 34 patients (65%), non-responders 18 patients (34%). BPT significantly predicted the steroid response (p < .001). The likelihood of not responding to the steroid therapy was significantly higher in patients with higher BPT (OR = 2.954).

CONCLUSIONS

BPT value predicted steroid response in patients with sAH. BPT could quickly identify non-responder patients to steroid therapy, reducing the risk of infections and it could allow the early evaluation for liver transplantation.

Kinetic-pharmacodynamic model of warfarin for prothrombin time-international normalized ratio in Japanese patients

AIMS

Genotype-guided dosing algorithms can explain about half of the interindividual variability in prothrombin time-international normalized ratio (PT-INR) under warfarin treatment. This study aimed to refine a published kinetic-pharmacodynamic model and guide warfarin dosage for an optimal PT-INR based on renal function.

METHODS

Using a retrospective cohort of adult patients (>20 years) who were administered warfarin and underwent PT-INR measurements, we refined the kinetic-pharmacodynamic model with age and the genotypes of cytochrome P450 2C9 and vitamin K epoxide reductase complex subunit 1 using the PRIOR subroutine in the nonlinear-mixed-effect modelling programme. We searched the significant covariates for parameters, such as the dose rate for 50% inhibition of coagulation (EDR50 ), using a stepwise forward and backward method. Monte Carlo simulation determined a required daily dose of warfarin with a target range of PT-INR (2.0-3.0 or 1.6-2.6) based on the significant covariates.

RESULTS

A total of 350 patients with 2762 PT-INR measurements were enrolled (estimated glomerular filtration rate [eGFR]: 47.5 [range: 2.6-199.0] mL/min/1.73 m2 ). The final kinetic-pharmacodynamic model showed that the EDR50 changed power functionally with body surface area, serum albumin level and eGFR. Monte Carlo simulation revealed that a lower daily dose of warfarin was required to attain the target PT-INR range as eGFR decreased.

CONCLUSIONS

Model-informed precision dosing of warfarin is a valuable approach for estimating its dosage in patients with renal impairment.

Magnetic coagulometry: towards a new nanotechnological tool for ex vivo monitoring coagulation in human whole blood

Blood clotting disorders consisting of unwanted blood clot formation or excessive bleeding are some of the main causes of death worldwide. However, there are significant limitations in the current methods used to clinically monitor the dynamics of clot formation in human whole blood ex vivo. Here a new magnetic coagulometry platform for testing ex vivo coagulation is described. This platform exploits the sensitivity of the out-of-phase component of alternating current (AC) magnetic susceptibility (χ'') to variations in mobility and agglomeration of magnetic nanoparticles when trapped during blood clot formation. By labelling human whole blood with magnetic nanoparticles, the out-of-phase component of AC magnetic susceptibility shows that the dynamics of blood clot formation correlates with a decrease in the out-of-phase component χ'' over time activation of coagulation. This is caused by a rapid immobilisation of nanoparticles upon blood coagulation and compaction. In contrast, this rapid fall in the out-of-phase component χ'' is significantly slowed down when blood is pre-treated with three different anticoagulant drugs. Remarkably, the system showed sensitivity towards the effect of clinically used direct oral anticoagulation (DOAC) drugs in whole blood coagulation, in contrast to the inability of clinical routine tests prothrombin time (PT) and partial thromboplastin time (PTT) to efficiently monitor this effect. Translation of this nanomagnetic approach into clinic can provide a superior method for monitoring blood coagulation and improve the efficiency of the current diagnostic techniques.

Ascorbic acid prevents stress-induced hypercoagulability in overweight and obese individuals

Ascorbic acid (AA) may contribute to restoring hemostatic balance after mental stress (MS) in overweight/obese adults. We aimed to determine the effects of AA administration on hemostatic responses to MS in overweight/obese men. Fourteen overweight/obesity men (27 ± 7 years; BMI: 29.7 ± 2.6 kg m-2) performed the Stroop color-word stress task for 5 min after non-simultaneous infusion of placebo (PL, 0.9% NaCl) and AA (3 g). Blood was collected at baseline, during MS, and 60 min after MS to measure: activated partial thromboplastin time, prothrombin time, and fibrinogen concentration, by coagulometer; platelet-derived microvesicles (PMV, mv/μL), by flow cytometry; nitrite (μM), by chemiluminescence. In PL session, MS led to decreases in PTs (stress, p = 0.03; 60 min, p < 0.001), PT-INR (stress, p < 0.001; 60 min, p < 0.01), aPTTs (60 min, p = 0.03), aPTT ratio (60 min, p = 0.04) and fibrinogen (60 min, p = 0.04), while increased PT activity (60 min, p = 0.01) when compared to baseline. Furthermore, AA increased PTs (60 min, p < 0.001), PT-INR (60 min, p = 0.03) and decreased PT activity (60 min, p < 0.001) and fibrinogen (stress, p = 0.04) when compared to PL. Nitrite was increased in response to stress during AA session (p < 0.001 vs PL). There was no difference in PMV. Ascorbic acid prevented the impaired hemostatic profile and improved nitrite response to stress in the overweight and obese adults.

Establishment of Normal Reference Intervals for Coagulation Test Indicators in Children

BACKGROUND

The objective of this study is to determine the standard reference intervals for coagulation function and coagulation factors in children across various age groups.

METHODS

A statistical analysis was conducted on prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (Fib), thrombin time (TT), and coagulation factors (II, V, VII, X, VIII, IX, XI, and XII) in 389 healthy children who underwent health checkups and presurgical examinations at the Children's Hospital of Zhejiang University School of Medicine. The children were categorized into four age groups.

RESULTS

The established normal reference ranges are as follows: PT (seconds): 10.00 - 12.26 for 1 month - 3 years, 10.24 - 12.66 for 3 - 18 years; APTT (seconds) : 24.82 - 35.65 for 1 month - 1 year, 25.20 - 32.30 for 1 - 18 years; Fib (g/L): 1.21 - 2.44 for 1 month - 1 year, 1.48 - 2.70 for 1 - 3 years, 1.69 - 3.60 for 3 - 18 years; TT (seconds): 18.48 - 23.06 for 1 month - 1 year, 17.80 - 21.26 for 1 - 18 years; coagulation factor II (%): 68.77 - 105.07 for 1 month - 1 year, 78.20 - 119.40 for 1 - 18 years; V (%): 74.24 - 140.96 for 1 month - 3 years, 70.64 - 132.01 for 3 - 18 years; VII (%): 56.34 - 113.00 for 1 month - 18 years; X (%): 49.17 - 105.57 for 1 month - 1 year, 64.34 - 115.24 for 1 - 18 years; VIII (%): 43.53 - 130.07 for 1 month - 1 year, 45.92 - 144.90 for 1 - 18 years; IX (%): 28.55 - 69.17 for 1 month - 1 year, 46.29 - 97.48 for 1 - 18 years; XI (%): 44.64 - 139.00 for 1 month - 1 year, 57.50 - 139.98 for 1 - 18 years; XII (%): 30.16 - 94.48 for 1 month - 1 year, 36.88 - 115.50 for 1 - 18 years.

CONCLUSIONS

This study successfully established standard reference intervals for coagulation function and coagulation factors in children of various age groups in Hangzhou, China.

Interpreting coagulation mixing study results in the era of direct oral anticoagulants

Interpretation of coagulation mixing studies is complicated by interference arising from direct oral anticoagulants (DOACs), which are increasingly prescribed. In this retrospective study, we reviewed 1035 consecutive coagulation mixing studies performed from 2017 to 2021. Three hundred and ninety-nine cases with normal prothrombin time (PT) and activated partial thromboplastin time (aPTT) were excluded. aPTT mixing studies were performed at time 0 and after 60 min of incubation. We confirmed the presence of interfering factors with additional laboratory testing, medication records, and medical history. Mixing corrected most prolonged PT samples (93%), but 32 cases showed incomplete correction. Of these 32 cases, 18 were confounded by DOAC use, and 3 by factor V (FV) inhibitor. We observed an unusual pattern of prolongation of aPTT after incubation, which was previously considered a characteristic of specific factor inhibitors, most commonly FVIII inhibitor. However, we found that lupus anticoagulant (28%) and DOAC (25%) contributed to this pattern similarly as specific factor inhibitors (28%). Coagulation laboratories should be aware of interference arising from DOACs and other factors in PT/aPTT mixing studies, especially in some unusual correction patterns.

Comparison of the Correlation Between Coagulation Indices and Rivaroxaban Concentrations

BACKGROUND

Rivaroxaban has predictable pharmacokinetics and pharmacodynamics. However, monitoring rivaroxaban concentrations should be provided for special patients with hepatic insufficiency, high bleeding risk, and high thrombotic risk.

OBJECTIVE

This study aimed to correlate chromogenic anti-Xa assay, prothrombin time (PT), activated partial thromboplastin time (APTT), thromboelastogram reaction time (TEG R-time), and rivaroxaban concentration measured by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) (MS-Riva).

METHODS

Peripheral venous blood was collected from recruited patients 30 minutes before and 2 to 4 hours after drug administration. High-performance liquid chromatography-tandem mass spectrometry and chromogenic anti-Xa assay measured rivaroxaban concentration. Different assays were compared by Pearson correlation coefficient and Bland-Altman analysis.

RESULTS

A total of 104 patients with 191 plasma were included in the study. Overall analysis shows that chromogenic anti-Xa assay, PT, APTT, and TEG R-time strongly correlated with MS-Riva (r = 0.986; r = 0.884; r = 0.741; r = 0.739; P < 0.001). Rivaroxaban peak concentration detected by HPLC-MS/MS (MS-peak) showed a very strong correlation with the chromogenic anti-Xa assay (r = 0.977, P < 0.001) and moderate correlation with PT, APTT, and TEG R-time (r = 0.670; r = 0.571; r = 0.481, P < 0.001). Rivaroxaban trough concentration detected by HPLC-MS/MS (MS-trough) correlated strongly with the chromogenic anti-Xa assay (r = 0.884, P < 0.001), weakly with APTT (r = 0.313; P = 0.043), and not significantly with PT and TEG R-time (P = 0.140; P = 0.341).

CONCLUSION AND RELEVANCE

High-performance liquid chromatography-tandem mass spectrometry/MS is the preferred choice for monitoring peak and tough concentrations, followed by anti-Xa, while PT is only suitable for peak concentrations. This study can help the clinicians to better adjust the medication regimen and reduce the risk of recurrence of thrombosis as well as the risk of bleeding.

Coagulation Testing in Real-World Setting: Insights From a Comprehensive Survey

The objective of this survey was to gain a real-world perspective on coagulation testing by evaluating the availability of various coagulation laboratory tests, assessing specific analytic and postanalytic steps in clinical laboratories in Korea.Participants were surveyed using a 65-question questionnaire specifically focused on their coagulation testing practices related to prothrombin time (PT), activated partial thromboplastin time (aPTT), plasma-mixing studies, lupus anticoagulant (LA) tests, platelet function tests, coagulation factor assays, and the composition of hemostasis and thrombosis test panels. The survey was performed between July and September 2022.The survey achieved a 77.9% (81 of 104) response rate. PT or aPTT tests were performed directly at all participating institutions, followed by D-dimer and fibrinogen tests, platelet function test, and plasma-mixing studies in order of frequency. Variations existed in the performance of mixing test and LA assessment. Patterns of coagulating testing differed depending on the size of the hospital. The survey revealed that most laboratories conducted coagulation tests following the international guidelines such as Clinical Laboratory Standards Institute guidelines and the Korean Laboratory Certification system. However, some coagulation tests, including mixing test and LA tests, are yet to be standardized in Korea.Continuous education on coagulation test methods and internal and external quality control are required to encourage laboratories to enhance the performance of coagulation testing.

Effect of Reduced INR in Early Pregnancy on the Occurrence of Preeclampsia: A Retrospective Cohort Study

To investigate the effect of reduced early-pregnancy activated partial thrombin time (APTT), prothrombin time (PT), and international standardized ratio (INR) on the risk of preeclampsia. A total of 8549 pregnant women with singleton births were included. Early pregnancy APTT, PT, and INR levels, with age, birth, prepregnancy body mass index, fibrinogen (FBG), thrombin time (TT), D-dimer (DD2), antithrombin III (ATIII), fibrin degradation products (FDP) as confounders, generalized linear model of APTT, the relative risk of PT and INR when INR reduction. After adequate adjustment for confounders, the relative risk of preeclampsia was 0.703 for every 1 s increase in plasma PT results in early pregnancy, and for every 0.1 increase in plasma INR results, the relative risk of preeclampsia was 0.767. With a PT less than the P25 quantile (<11 s), the relative risk of preeclampsia was 1.328. The relative risk of preeclampsia at an INR less than the P25 quantile (<0.92) was 1.24. There was no statistical association between APTT on the risk of preeclampsia. The relative risk of preeclampsia is strongly associated with a decrease in PT and INR in early pregnancy. PT and INR in early pregnancy were a potential marker in the risk stratification of preeclampsia. Focusing on reduced PT and INR levels in early pregnancy can help to identify early pregnancies at risk for preeclampsia.

Whole blood PT/aPTT assay based on non-contact drop-of-sample acoustic tweezing spectroscopy

Most coagulation tests are photo-optical turbidimetric assays that require the removal of cellular components from whole blood for optical clearing. If the resulting blood plasma samples are hemolyzed, they may become unsuitable for turbidimetric analysis. To resolve this issue, whole-blood analogs to plasma turbidimetric assays need to be developed. Using samples collected from non-smokers (normal group), smokers (thrombotic group), and hemophilia A (bleeding group) patients, we demonstrate that the reaction time assessed from whole blood viscosity data of the drop-of-blood acoustic tweezing spectroscopy (ATS) technique strongly correlates (Rp ≥ 0.95) with PT/aPTT values obtained from plasma turbidimetric data. Linear correlation (Rp ≥ 0.88) was also obtained between the viscous and elastic outputs of the ATS technique and the fibrinogen concentration. The integration of ATS data enabled the assessment of the functional level of fibrin cross-linkers such as factor XIII. Overall, ATS allows comprehensive sample-sparing analysis of whole blood coagulation for reliable and safe diagnosis of bleeding/thrombosis risks.

Clot waveform analysis in acute promyelocytic leukemia

The aim of this study was to evaluate the activated partial thromboplastin time (APTT) and prothrombin time (PT)-based clot waveform analysis (CWA) in patients diagnosed with acute promyelocytic leukemia (APL). APTT-based and PT-based CWA parameters of patients diagnosed with APL were analyzed and compared with healthy volunteers. Four APTT-CWA parameters were noted, maximum velocity corresponding to the first peak of the first derivative (max1), maximum acceleration corresponding to the first peak of the second derivative (max2) and the corresponding peak times of max1 and max2 (Tmax1, Tmax2). For the PT-CWA, two PT-CWA parameters were noted, maximum velocity (max1') and the corresponding timing (Tmax1'). The results were expressed in medians. Mann-Whitney U test was used to compare the CWA parameters. Correlations were examined using the Spearman correlation test. Tmax1 and Tmax2 were significantly prolonged in patients with APL in comparison with healthy volunteers. Although max1 and max2 were lower in APL patients compared with healthy volunteers, no significant difference was noted. There was a strong and significant correlation between the DIC score and the parameters max1, max2 and max1' and a very strong and significant correlation between fibrinogen levels and max1, max2 and max1'. When comparing DIC patients with hypofibrinogenemia and DIC without hypofibrinogenemia, a significant difference was noted in max1, max2, Tmax1 and Tmax2. The APTT and PT-based CWA analysis is a good tool to evaluate the bleeding tendency in APL, as it offers a novel approach for evaluating global hemostasis, predicting the bleeding risk and delivering improvements to APL patients management.

Development of a machine learning model to predict intraoperative transfusion and guide type and screen ordering

STUDY OBJECTIVE

To develop an algorithm to predict intraoperative Red Blood Cell (RBC) transfusion from preoperative variables contained in the electronic medical record of our institution, with the goal of guiding type and screen ordering.

DESIGN

Machine Learning model development on retrospective single-center hospital data.

SETTING

Preoperative period and operating room.

PATIENTS

The study included patients ≥18 years old who underwent surgery during 2019-2022 and excluded those who refused transfusion, underwent emergency surgery, or surgery for organ donation after cardiac or brain death.

INTERVENTION

Prediction of intraoperative transfusion vs. no intraoperative transfusion.

MEASUREMENTS

The outcome variable was intraoperative transfusion of RBCs. Predictive variables were surgery, surgeon, anesthesiologist, age, sex, body mass index, race or ethnicity, preoperative hemoglobin (g/dL), partial thromboplastin time (s), platelet count x 109 per liter, and prothrombin time. We compared the performances of seven machine learning algorithms. After training and optimization on the 2019-2021 dataset, model thresholds were set to the current institutional performance level of sensitivity (93%). To qualify for comparison, models had to maintain clinically relevant sensitivity (>90%) when predicting on 2022 data; overall accuracy was the comparative metric.

MAIN RESULTS

Out of 100,813 cases that met study criteria from 2019 to 2021, intraoperative transfusion occurred in 5488 (5.4%) of cases. The LightGBM model was the highest performing algorithm in external temporal validity experiments, with overall accuracy of (76.1%) [95% confidence interval (CI), 75.6-76.5], while maintaining clinically relevant sensitivity of (91.2%) [95% CI, 89.8-92.5]. If type and screens were ordered based upon the LightGBM model, the predicted type and screen to transfusion ratio would improve from 8.4 to 5.1.

CONCLUSIONS

Machine learning approaches are feasible in predicting intraoperative transfusion from preoperative variables and may improve preoperative type and screen ordering practices when incorporated into the electronic health record.

PDCA cycle management combined with detailed management of postoperative deep vein thrombosis in patients undergoing hip replacement surgery

OBJECTIVE

This study aimed to analyze and explore the effect of Plan-Do-Check-Act (PDCA) cycle management combined with detailed management on postoperative deep venous thrombosis in patients undergoing hip replacement surgery.

PATIENTS AND METHODS

Patients who underwent hip replacement surgery in our hospital between November 2021 and April 2023 were recruited for the study. After screening, patients who met all the inclusion criteria were assessed for eligibility. Finally, 80 adults were enrolled. All patients were assigned into observation and control groups (1:1) according to the sequence of admission, i.e., patients admitted between November 2021 and August 2022 were the control group, and patients admitted between September 2022 and April 2023 were the observation group.

RESULTS

The intraoperative blood loss and hospital stay in the observation group were significantly less than those in the control group (p<0.05). After the intervention, the levels of plasma prothrombin time (PT), thrombin time (TT), and thromboplastin time (APTT) in the observation group were higher than those in the control group, and the DD level was lower than that in the control group (p<0.05). There was one patient in the observation group who developed deep venous thrombosis after the operation, and the incidence was 2.50%. The rate was significantly lower than that of the control group (p<0.05). The hip joint function score of the observation group was higher than that of the control group, and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scale score was lower than that of the control group (p<0.05). The incidence of adverse reactions in the observation group was significantly lower than that in the control group (p<0.05).

CONCLUSIONS

PDCA cycle management plus detailed management in patients with hip replacement surgery yields a favorable clinical outcome, which can effectively prevent postoperative deep vein thrombosis, and improve surgical indicators and postoperative coagulation function. Also, it reduces the incidence of adverse reactions in patients and facilitates recovery. It has a beneficial impact on the prognosis of patients and deserves promotion.

Triple-positive antiphospholipid syndrome does not guarantee positivity in each lupus anticoagulant assay

BACKGROUND

Triple positivity for all 3 criteria antiphospholipid antibodies confers high risk of symptom development in carriers, and recurrence in antiphospholipid syndrome (APS). Most triple-positivity studies report lupus anticoagulant (LA) testing as positive without distinguishing between positivity with dilute Russell's viper venom time (dRVVT) and activated partial thromboplastin time (APTT) and single-assay positivity or only perform dRVVT. Single LA assay repertoires remain in use in some centers, which risks missing some triple positives. Positivity with both assays may identify higher risk.

OBJECTIVES

The aim of this study is to investigate the frequency of single LA assay positivity in triple-positive patients.

METHODS

Three hundred forty-two triple-positive profiles from nonanticoagulated patients (237 APS, 45 systemic lupus erythematosus without APS symptoms, and 60 nonclinical criteria) were identified from laboratory databases and assessed for LA positivity by dRVVT and/or APTT.

RESULTS

Seventy-three of 237 (30.8%) APS samples were LA-positive with 1 assay, 40/237 (16.9%) by dRVVT only, and 33/237 (13.9%) with APTT only. Nineteen of 45 (42.2%) were LA-positive with 1 assay in the systemic lupus erythematosus cohort; 12/45 (26.7%) with dRVVT only and 7/45 (15.5%) with APTT only. Thirty-three of 60 (55.0%) were LA-positive with 1 assay in the nonclinical criteria cohort; 24/60 (40.0%) with dRVVT only and 9/60 (15.0%) with APTT only. The most common solid-phase assay profile was elevated immunoglobulin G aCL and aβ2GPI.

CONCLUSION

Up to 55.0% of triple-positive samples were positive in 1 LA assay, representing significant potential for misdiagnosis and inappropriate management via single LA assay repertoires.

Blood Coagulation Activities of Cotton-Alginate-Copper Composites

Alginate-based materials have gained significant attention in the medical industry due to their biochemical properties. In this article, we aimed to synthesize Cotton-Alginate-Copper Composite Materials (COT-Alg(-)Cu(2+)). The main purpose of this study was to assess the biochemical properties of new composites in the area of blood plasma coagulation processes, including activated partial thromboplastin time (aPTT), prothrombin time (PT), and thrombin time (TT). This study also involved in vitro antimicrobial activity evaluation of materials against representative colonies of Gram-positive and Gram-negative bacteria and antifungal susceptibility tests. The materials were prepared by immersing cotton fibers in an aqueous solution of sodium alginate, followed by ionic cross-linking of alginate chains within the fibers with Cu(II) ions to yield antimicrobial activity. The results showed that the obtained cotton-alginate-copper composites were promising materials to be used in biomedical applications, e.g., wound dressing.

KeepRunning: A MoCap-Based Rapid Test to Prevent Musculoskeletal Running Injuries

The worldwide popularisation of running as a sport and recreational practice has led to a high rate of musculoskeletal injuries, usually caused by a lack of knowledge about the most suitable running technique for each runner. This running technique is determined by a runner's anthropometric body characteristics, dexterity and skill. Therefore, this study aims to develop a motion capture-based running analysis test on a treadmill called KeepRunning to obtain running patterns rapidly, which will aid coaches and clinicians in assessing changes in running technique considering changes in the study variables. Therefore, a review and proposal of the most representative events and variables of analysis in running was conducted to develop the KeepRunning test. Likewise, the minimal detectable change (MDC) in these variables was obtained using test-retest reliability to demonstrate the reproducibility and viability of the test, as well as the use of MDC as a threshold for future assessments. The test-retest consisted of 32 healthy volunteer athletes with a running training routine of at least 15 km per week repeating the test twice. In each test, clusters of markers were placed on the runners' body segments using elastic bands and the volunteers' movements were captured while running on a treadmill. In this study, reproducibility was defined by the intraclass correlation coefficient (ICC) and MDC, obtaining a mean value of ICC = 0.94 ± 0.05 for all variables and MDC = 2.73 ± 1.16° for the angular kinematic variables. The results obtained in the test-retest reveal that the reproducibility of the test was similar or better than that found in the literature. KeepRunning is a running analysis test that provides data from the involved body segments rapidly and easily interpretable. This data allows clinicians and coaches to objectively provide indications for runners to improve their running technique and avoid possible injury. The proposed test can be used in the future with inertial motion capture and other wearable technologies.

A next generation FVIII mimetic bispecific antibody, Mim8, the impact on non-factor VIII related haemostasis assays

INTRODUCTION AND AIMS

Mim8 is a next generation bispecific antibody developed for the treatment of haemophilia A (HA). Mim8 has an increased potency compared to first generation molecules. The impact on Mim8 on non-FVIII measuring haemostasis assays was assessed in plasma containing Mim8.

METHODS

Congenital severe HA plasma was spiked with increasing concentrations of Mim8 (0-20 μg/mL). 28 routine and specialist haemostasis assays were used to measure activities. These included tests for prothrombin time (PT), fibrinogen, thrombin, D-dimer, anti-Xa, heparin induced thrombocytopenia (HIT), clotting factors II-XII, factor XIII, von Willebrand factor (VWF), thrombophilia and DRVVT.

RESULTS AND CONCLUSIONS

Less than 10 % difference was calculated between plasma without Mim8 and plasma spiked to 15 μg/mL Mim8 in all assays except thrombin time (-10.5%), APTT-based factor IX, XI and XII, Werfen VWF:RCo (10.6%) and Siemens LA1 (-26.4%) and LA2 (-16.9%). At the expected therapeutic steady state levels of Mim8 (5-8 μg/mL), less than 10% difference was calculated for thrombin time and Werfen VWF:RCo. APTT-based assays of FIX, XI and XII are significantly elevated in the presence of Mim8 and should not be performed. A chromogenic FIX assay could be used to accurately measure FIX activity in the presence of Mim8. There was some interference in the DRVVT method we used so local assessment of other DRVVT methods is advised. Differences in all other tests would not be predicted to affect patient management.

Proper position of single and large (≥5 cm) hepatocellular carcinoma in Barcelona Clinic Liver Cancer classification

The purpose of this study was to evaluate the proper position of single large hepatocellular carcinoma (HCC) in the Barcelona Clinic Liver Cancer (BCLC) staging system. The data were collected from the nationwide multicentre database of the Korean Liver Cancer Association. Patients with single large (≥5 cm) HCC were separated from BCLC stage A patients and designated as Group X. The remaining BCLC stage A and stage B patients were classified as Group A and Group B, respectively. The survival outcomes of propensity score-matched groups were compared. Among the 3965 randomly selected patients, the number of patients in Group X, Group A, and Group B was 414, 2787, and 760, respectively. TriMatch analysis allowed us to obtain 116 well-balanced triplets. The 1-, 3-, and 5-year overall survival rates in Group X were worse than in Group A (91%, 71%, and 48% vs 90%, 78%, and 64%, respectively; P < .000). However, the rates were not different compared with those in Group B (91%, 71%, and 48% vs 90%, 69%, and 48%, respectively; P < .09). In multivariate analysis, Group X, Group B, age over 60 years, prothrombin time-international normalized ratio, and creatinine level were independent predictors of worse overall survival. Our findings suggest that Group X should be relocated to BCLC stage B rather than BCLC stage A.

A Comparison between Thromboelastography and Conventional Clotting Tests in Pediatric Patients After Cardiopulmonary Bypass Procedure

BACKGROUND

The coagulation system is more complicated in younger infants because the hemostatic system is not completely mature before 6 months. There is confusion among pediatricians to choose conventional coagulation tests and thromboelastography (TEG) to evaluate coagulation function for infants in major surgery. This study was undertaken to perform a comparison between the two methods for pediatric patients who underwent cardio-pulmonary bypass (CPB) surgery.

METHODS

Infant patients who underwent CPB surgery were divided into two groups - younger group (age < 6 months old, n = 72) and older group (age from 6 months old to 12 years old, n = 76). Prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), and fibrinogen (Fib) of conventional coagulation tests and reaction time (R-time), speed of fibrin building up (ɑ-Angle), clot conformation time (K-time), maximum colt amplitude (MA) of TEG results before and after CPB, as well as increasing or decreasing rate of all the values after CPB, were compared between the two groups. Postoperative transfusion details were summarized.

RESULTS

PT, APTT, R-time, and K-time markedly increased (p < 0.05) and Fib, ɑ-Angle, and MA decreased (p < 0.05) after CPB in both groups. The younger group had a much higher rate of postoperative transfusion with suspended red cells (54.17% vs. 17.11%), fresh frozen plasma (29.17% vs. 9.21%), cryoprecipitate (9.72% vs. 1.32%), and apheresis platelet (5.56% vs. 0) than the older group. Increasing rate of R-time and K-time and decreasing rate of ɑ-Angle and MA after CPB in the younger group were significantly higher than that in the older group (p < 0.01), whereas no significant differences were observed in conventional coagulation tests (p > 0.2).

CONCLUSIONS

TEG was more sensitive than conventional coagulation tests in response to variation of coagulation function for younger infants after major surgery.

The prothrombin time/international normalized ratio predicts prognosis in cardiogenic shock

OBJECTIVE

The study investigates the prognostic impact of the prothrombin time/international normalized ratio (PT/INR) in patients with cardiogenic shock.

BACKGROUND

Despite ongoing improvements regarding the treatment of cardiogenic shock patients, intensive care unit (ICU)-related mortality in cardiogenic shock patients remains unacceptably high. Limited data regarding the prognostic value of the PT/INR during the course of cardiogenic shock treatment is available.

METHODS

All consecutive patients with cardiogenic shock from 2019 to 2021 were included at one institution. Laboratory values were collected from the day of disease onset (day 1) and days 2, 3, 4 and 8. The prognostic impact of the PT/INR was tested for 30-day all-cause mortality, as well as the prognostic role of PT/INR changes during course of ICU hospitalization. Statistical analyses included univariable t -test, Spearman's correlation, Kaplan-Meier analyses, C-Statistics and Cox proportional regression analyses.

RESULTS

Two hundred twenty-four cardiogenic shock patients were included with a rate of all-cause mortality at 30 days of 52%. The median PT/INR on day 1 was 1.17. The PT/INR on day 1 was able to discriminate 30-day all-cause mortality in cardiogenic shock patients [area under the curve 0.618; 95% confidence interval (CI), 0.544-0.692; P  = 0.002). Patients with PT/INR > 1.17 were associated with an increased risk of 30-day mortality [62% vs. 44%; hazard ratio (HR) = 1.692; 95% CI, 1.174-2.438; P  = 0.005], which was still evident after multivariable adjustment (HR = 1.551; 95% CI, 1.043-2.305; P  = 0.030). Furthermore, especially patients with an increment of the PT/INR by ≥10% from day 1 to day 2 were associated with an increased risk of 30-day all-cause mortality (64% vs. 42%; log-rank P  = 0.014; HR = 1.833; 95% CI, 1.106-3.038; P  = 0.019).

CONCLUSION

Baseline PT/INR and an increase of the PT/INR during the course of ICU treatment were associated with the risk of 30-day all-cause mortality in cardiogenic shock patients.

Activated Partial Thromboplastin Time and Prothrombin Time Mixing Studies: Current State of the Art

Mixing studies have long been in the clinical laboratory armamentarium for investigating unexpected, prolonged activated partial thromboplastin time (aPTT) or prothrombin time (PT). The purpose of the mixing study is to identify whether the aPTT/PT prolongation is secondary to a factor deficiency versus an inhibitor, which would present as a "corrected" and "noncorrected" mixing study, respectively. The differentiation between a factor deficiency and inhibitor may likely further direct clinical decisions, including additional diagnostic testing or factor replacement therapy. While aPTT/PT mixing studies are simple tests to perform, there is a lack of standardization for both the testing protocol and the interpretation of what is considered to be a corrected or noncorrected mixing study result. This review will describe the common indications for the mixing test, preanalytic variables that may affect mixing study performance, and describe several methods for interpreting the results of aPTT and PT mixing tests.

Comparison of the Two Coagulation Techniques: Thrombolyzer XRM and Diagon Coag XL

BACKGROUND

The aim of this study was to evaluate the performance characteristics of the Thrombolyzer XRM against the Diagon Coag XL during the exchange of the coagulation analyzer.

METHODS

The Partial Thromboplastin Time (PTT) and prothrombin time (PT) measurements were performed by using the Thrombolyzer XRM and Diagon CoagXL analyzers. The precision, accuracy, method comparison, and reference range verification studies were performed on the Thrombolyzer XRM based on Clinical Laboratory Standards Institute guidelines.

RESULTS

The precision study was performed with normal and pathologic controls for the PT and PTT tests, all co-efficients of variation (%) were found ≤ 2.5%. In the accuracy study, both analyzers displayed less than 6.3% and 10.8% bias for PT and PTT tests, respectively. The method comparison study demonstrated good agreement for the Bland-Altman plots for PTT and PT with a bias of -2.0 and -3.3 between each analyzer, respectively. The Passing and Bablok analysis showed no significant differences for PTT and PT between each analyzer (p = 0.65 and p = 0.33, respectively). However, there was a proportional bias for PT with a slope of 1.40 (95% CI 1.2 - 1.8). The manufacturer ranges were acceptable as a result of the reference range verification study.

CONCLUSIONS

The routine coagulation analysis can be performed on the Thrombolyzer XRM with satisfactory precision and the obtained minor differences can be eliminated in future standardization studies.

Clot Waveform Analysis for Monitoring Hemostasis

Clot waveform analysis (CWA) is a recently developed global coagulation assessment, based on the continuous observation of changes in light transmittance, absorbance, or light scattering that occurs as fibrin formed in a plasma sample during routine clotting tests such as activated partial thromboplastin time (aPTT) and prothrombin time (PT). CWA can utilize qualitative waveform patterns as well as sensitive quantitative parameters and can be used as a simple method to assess global hemostasis, and can be applied to various challenging clinical situations. Although not all coagulation analyzers currently in use are able to provide CWA, the number of analyzers available to do so is increasing, as the usefulness of this process has become more widely recognized. CWA can be based on the coagulation mechanism of aPTT, an intrinsic trigger, and this has been reported in many studies, including diagnosis and treatment of patients with hemophilia, disseminated intravascular coagulation, and monitoring of anticoagulants and thrombosis. CWA using trace amounts of tissue factors also has the potential to expand the applications of this technology. Recently, there have been reports of the combined evaluation of fibrinolytic dynamics. Among the existing global coagulation assays, CWA may prove to be the easiest to standardize in clinical practice. However, more extensive testing using standardized methods in various clinical settings is needed to determine the true role of CWA in the evaluation of hemostasis and thrombosis in the future.

Effect of fibrinogen concentrate on the initial fibrinogen level in trauma and postpartum hemorrhage

OBJECTIVE

Massive hemorrhage is a serious event that threatens the lives of patients. Fibrinogen concentrate (FC) can control bleeding without causing viral complications and without volume loading, which can happen in transfusion-associated circulatory overload and transfusion-associated acute lung injury. FC application is easy and does not require dissolution or extra devices. It is a cost-effective agent when considering the blood and products used in large quantities.

PATIENTS AND METHODS

A total of 67 postpartum hemorrhage (PPH) and trauma patients' medical records, who had ASA I-III classification (The American Society of Anesthesiologists classification of physical status), were obtained. Patients were divided into two groups (fibrinogen level ≤ 100 mg/dl and ≥ 101 mg/dl). The following information was obtained from patient files: demographic parameters, history of operations, and laboratory findings (i.e., complete blood counts, coagulation tests, and fibrinogen levels). Also, the duration of intensive care unit stays and mechanical ventilation application days, the administration of fresh frozen plasma (FFP), erythrocytes, platelets, and FC numbers, and tranexamic acid infusion were recorded.

RESULTS

There was no mortality in PPH patients in either group (fibrinogen level ≤ 100 mg/dl and ≥ 101 mg/dl). The mortality rate in trauma patients was significantly higher in the group with fibrinogen levels ≤ 100. A total of 170 g of FC were given to PPH patients and 92 g to trauma patients. There were statistically significant differences between the preoperative PT (prothrombin time), postoperative APTT (activated partial thromboplastin time), postoperative PT, and postoperative INR (international normalized ratio) levels of the patients in the group with fibrinogen levels ≤ 100. Mortality rates were also significantly higher, and hospital stays significantly longer in trauma patients in the group with fibrinogen levels ≤ 100.

CONCLUSIONS

Therapy may be considered during massive bleeding and transfusion, as it can help to increase fibrinogen levels quickly and efficiently. Compared with FFP, fibrinogen concentrate may have some advantages in reducing the risk of fluid overload. FFP contains a range of clotting factors, including fibrinogen. It also contains other proteins and fluids that can lead to fluid overload, especially when given in large volumes during massive transfusions.

Systematic Comprehensive Evaluation of the Mindray CX-9000 Coagulation Analyzer Performance

BACKGROUND

The aim of the study was to conduct a comprehensive performance evaluation of the Mindray CX-9000 fully automated coagulation analyzer for the detection of the seven coagulation items.

METHODS

The performance of activated partial thromboplastin time (APTT), prothrombin time (PT), fibrinogen (FIB), thrombin time (TT), D-dimer (D-D), fibrinogen degradation product (FDP), and antithrombin Ⅲ (AT) was validated for precision, linear range, carryover contamination rate, reference interval validation, inter-method agreement, and anti-interference ability.

RESULTS

The intra- and inter-precision (coefficient of variation, CV%) of all seven items was less than the target CV%; the carryover contamination rates for different concentrations and between items were < 10%. The slope of the linear regression equation for the theoretical and measured values of the linear range was within 1 ± 0.05 and R ≥ 0.975. The reference interval quoted from the manufacturer's reference interval passed ≥ 95%. The CX-9000 was compared with the results of the reference instrument STAGO R MAX (STA-R MAX) and the p-values for all items ranged from 0.822 to 0.987. Within the concentration range claimed by the manufacturer, the interference errors produced by all items met the manufacturer's claimed criteria, except for triglycerides which produced interference errors > 10% for the FIB, D-D, FDP, and bilirubin which produced interference errors for the FIB and D-D assays.

CONCLUSIONS

The CX-9000 automatic coagulation analyzer has good stability and repeatability, a wide linear range of detection, low carryover contamination rate, and high resistance to interference, making it suitable for the testing of clinical specimens.

Effects of Hemolysis on Routine Coagulation Tests when Tested on an Optical Coagulation Analyzer

BACKGROUND

The Clinical and Laboratory Standards Institute recommends rejecting hemolyzed samples for coagulation tests. Sysmex CS5100 analyzer using an optical method is commonly used in laboratories. The influence of hemolysis on coagulation test has rarely been studied when tested on Sysmex CS5100. Determining this influence is necessary.

METHODS

Freshly collected samples were artificially hemolyzed to simulate the hemolysis processes. Coagulation tests were conducted on a Sysmex CS5100 coagulation analyzer. Detection values before and after hemolysis were compared.

RESULTS

The results showed that after hemolysis detection, the prothrombin time (PT) statistically decreased, while the partial thromboplastin time (APTT) statistically increased. There were no significant differences in fibrinogen (Fg), thrombin time (TT), D-dimer (DD) or fibrinogen degradation products (FDPs). Antithrombin activity was elevated in hemolyzed samples.

CONCLUSIONS

Although differences in PT and APTT were statistically significant, there was no need for rejection of hemolyzed samples due to insufficient clinical effects when tested on Sysmex CS5100 analyzer. Falsely elevated AT result may lead to misdiagnosis in patients with severe diseases, which should be carefully considered.

Mild Prolongation of Prothrombin Time Does Not Affect the Safety and Prognosis of Transjugular Intrahepatic Portal Shunt: Based on Real-World Data

BACKGROUND/AIMS

The aim was to investigate the safety and prognosis of transjugular intrahepatic portal shunt in patients with mildly prolonged prothrombin time.

MATERIALS AND METHODS

Two hundred fifty-three patients with portal hypertension who received transjugular intrahepatic portal shunt from November 2015 to May 2021 in Wuhan Union Hospital were retrospectively selected. According to the preoperative prothrombin time, they were divided into 2 groups: 126 patients in the non-clinical significance group (prothrombin time prolongation <3 seconds) and 127 patients in the clinical significance group (3 seconds ≤ prothrombin time prolongation <6 seconds). A line chart of postoperative liver and kidney function was drawn, and Kaplan-Meier curve was used to analyze and compare the prognosis of the 2 groups.

RESULTS

Transjugular intrahepatic portal shunt was successfully performed in all patients; the technical success rate was 100%, and no puncture-related complications occurred during perioperative period. The mean preoperative prothrombin time was 14.9 ± 0.7 seconds in the non-clinical significance group and 17.2 ± 0.8 seconds in the clinical significance group. During follow-up, 1-year stent dysfunction rates in the non-clinical significance group and clinical significance group were 3.5% and 6.9%, respectively, with no statistically significant difference (hazard ratio = 0.77, 95% CI = 0.30-1.93, log-rank P = .575). In addition, there were no significant differences in the cumulative survival rate (log rank P = .255), rebleeding rate (log-rank P = .392), and incidence of hepatic encephalopathy (log-rank P = .404) between the 2 groups. Subgroup analysis of the clinical significance group showed no significant difference in safety and prognosis between the 2 subgroups.

CONCLUSION

Transjugular intrahepatic portal shunt is safe for portal hypertension patients with prothrombin time prolongation <6 seconds. There was no significant difference in prognosis between the non-clinical significance group and the clinical significance group.

Association between admission prothrombin time activity and hospital readmission in heart failure: A retrospective study

BACKGROUND

Coagulopathy is a common complication of heart failure (HF), but the prognostic significance of coagulation abnormalities for HF is still poorly understood. This investigation sought to elucidate the association between admission prothrombin time activity (PTA) and short-term readmission in HF.

METHODS

In this retrospective study, we extracted data from a publicly accessible database for hospitalized HF patients in China. The admission laboratory findings were screened by the least absolute shrinkage and selection operator (LASSO) regression. Afterward, the study population was stratified according to the admission PTA level. In univariate and multivariate analysis, we employed logistics regression model to evaluate the association of admission PTA level with short-term readmission. Subgroup analysis was preformed to examine the interaction effect between admission PTA level and covariates, including age, sex, and systolic blood pressure (SBP).

RESULTS

A total of 1505 HF patients were included, of whom 58.7% were female and 35.6% were between 70 and 79 y. In LASSO procedure, admission PTA level was included in optimized models for short-term readmission, and readmitted patients tended to have a lower admission PTA level. Multivariate analysis suggested that the low admission PTA level (admission PTA ≤ 62.3%) was associated with increased risk of 90-day readmission (odds ratio 1.63 [95% CI, 1.09 to 2.46]; P = 0.02) and 180-day readmission (odds ratio 1.65 [95% CI, 1.18 to 2.33]; P = 0.01) compared with patients with the highest admission PTA level (admission PTA ≥ 76.8%) after full adjustment. Moreover, no significant interaction effect was observed in the subgroup analysis, except for admission SBP.

CONCLUSION

Low admission PTA level is associated with an increased risk of 90-day and 180-day hospital readmission in patients with HF.

Frequency of prothrombin time-international normalized ratio monitoring and the long-term prognosis in patients with mechanical valve replacement

BACKGROUND

The study aimed to assess the correlation between the monitoring frequency of PT-INR and the long-term prognosis in patients with mechanical heart valve (MHV) replacement after discharge.

METHODS

This single-center, observational study enrolled patients who underwent MHV replacement and discharged from June 2015 to May 2018. Patients or their corresponding family members were followed with a telephone questionnaire survey in July-October 2020. Based on monitoring intervals, patients were divided into frequent monitoring (FM) group (≤ 1 month) and less frequent monitoring (LFM) group (> 1 month). The primary endpoint was the composite of thromboembolic event, major bleeding or all-cause death. The secondary endpoints were thromboembolic event, major bleeding or all-cause death, respectively.

RESULTS

A total of 188 patients were included in the final analysis. The median follow-up duration was 3.6 years (Interquartile range: 2.6 to 4.4 years). 104 (55.3%) patients and 84 (44.7%) patients were classified into the FM group and the LFM group, respectively. The FM group had a significantly lower incidence of the primary endpoint than the LFM group (3.74 vs. 1.16 per 100 patient-years, adjusted HR: 3.31 [95% CI 1.05-10.42, P = 0.041]). Secondary analysis revealed that the risk of thromboembolic events and all-cause death were also reduced in the FM group.

CONCLUSIONS

The management of warfarin treatment in patients after MHV replacement remains challenging. Patients with less frequent monitoring of PT-INR might have worse clinical prognosis than those with frequent PT-INR monitoring.

Efficacy and safety of salvianolate and enoxaparin in the prevention of perioperative deep venous thrombosis in gastrointestinal surgery

OBJECTIVE

In this study, the efficacy and safety of salvianolate were compared with enoxaparin in the prevention of perioperative deep vein thrombosis in gastrointestinal surgery.

METHODS

From October 2017 to September 2019, 563 patients who underwent gastrointestinal surgery were collected. Based on the inclusion and exclusion criteria, 119 patients were divided into two groups: enoxaparin group (n = 65) and salvianolate group (n = 54). Comparisons were made regarding the outcomes: prothrombin time (PT), prothrombin activity (PTA), international normalized ratio (INR), activated partial thromboplastin time (APTT), fibrinogen (FIB), thrombin time (TT), D-dimer level (D-D), platelet count (PLT), hematokrit (HCT), and incidence of deep vein thrombosis (DVT).

RESULTS

The main outcomes showed no significance between enoxaparin group and salvianolate group (p > .05). The incidence of DVT in salvianolate group was 1.85%, significantly lower than that in enoxaparin group (12.3%) (p < .05). No serious adverse reactions occurred in the two groups during treatment.

CONCLUSION

Compared with enoxaparin, salvianolate has an advantage in the prevention of perioperative thrombosis in gastrointestinal surgery with a lower incidence of DVT.

Variations in prothrombin time-international normalized ratio caused by drug-drug interaction in patients receiving warfarin: A retrospective observational study

OBJECTIVES

Drug-drug interactions between warfarin and cytochrome P450 (CYP) 2C9 inhibitors and inducers are well known. Few studies have clarified the clinical impact of CYP2C9 inhibitors and inducers on warfarin therapy. Here, we evaluated the clinical impact of CYP2C9-mediated interactions on the pharmacodynamics of warfarin.

MATERIALS AND METHODS

This retrospective observational study enrolled patients who received warfarin between 2008 and 2020 at Mie University Hospital. We defined prothrombin time-international normalized ratio/daily warfarin dose (PT-INR/dose) as the primary outcome and conducted a multiple linear regression analysis to clarify the factors that affected the primary outcome. Additionally, we examined the clinical features of patients who received CYP2C9 inducers.

RESULTS

Out of 1,393 patients, 17 (1.2%) received carbamazepine, rifampicin, phenobarbital, or phenytoin as CYP2C9 inducers. Multiple linear regression analysis indicated that age, body mass index (BMI), serum albumin (Alb), estimated glomerular filtration rate (eGFR), and CYP2C9 inducers were associated with PT-INR/dose. The multiple regression equation was as follows: PT-INR/dose = 1.590 + 0.004 × age - 0.020 × BMI - 0.141 × Alb - 0.001 × eGFR - 0.149 × (if concomitant use of CYP2C9 inducers) (adjusted coefficient of determination = 0.106, Akaike information criterion = 267.3, p < 0.001). In patients receiving CYP2C9 inducers, lower PT-INR/dose values were observed regardless of co-administered CYP2C9 inhibitors.

CONCLUSION

In addition to age, BMI, Alb, and eGFR, concomitant use of CYP2C9 inducers should be considered when adjusting the warfarin dose and PT-INR.

Prolonged prothrombin time does not correlate with clinical bleeding symptoms in newly diagnosed paediatric leukaemia patients

Prolonged prothrombin time (PT) and/or activated partial thromboplastin time (aPTT) are frequently seen in newly diagnosed paediatric leukaemia patients (NDPLP), which can lead to delayed diagnostic and therapeutic procedures due to concern for bleeding. A single-centre retrospective chart review of NDPLP between 2015 and 2018 aged 1-21 years. We analysed 93 NDPLP of whom 33.3% had bleeding symptoms within 30 days of presentation, predominantly mucosal bleeding (80.6%) and petechiae (64.5%). Median laboratory values: white blood cell count 15.7, haemoglobin 8.1, platelets 64, PT 13.2 and a PTT 31. Red blood cells were administered in 41.2%, platelets in 52.9%, fresh frozen plasma in 7.8% and vitamin K in 21.6% of patients. Prolonged PT was found in 54.8% of patients, while aPTT was prolonged in 5.4%. Anaemia and thrombocytopenia did not correlate with prolonged PT ( P  = 0.73 and P  = 0.18, respectively), or prolonged aPTT ( P  = 0.52 and 0.42). Leukocytosis showed significant correlation with elevated PT ( P  < 0.001), but not aPTT ( P  = 0.3). Bleeding symptoms upon presentation did not correlate with prolonged PT ( P  = 0.83), prolonged aPTT ( P  = 1) or anaemia ( P  = 0.06) but had a significant correlation with thrombocytopenia ( P  ≤ 0.0001). Therefore, a prolonged PT in NDPLP may not necessitate the reflexive use of blood product replacement, in the absence of significant bleeding, which is likely related to leukocytosis than to a true coagulopathy.

The Utility of Common Blood Coagulation Examination in Identifying Hemorrhoid Complications

BACKGROUND

This observational study was designed to evaluate prothrombin time and activity (PT, PT%), prothrombin time international normalized ratio (INR), activated partial thromboplastin time (APTT), coagulation enzyme time (TT), fibrinogen content (FIB), D-dimer (D-dimer), and platelet count (Plt) in patients with hemorrhoids (HE, n = 207), hemorrhoids with bleeding (HB, n = 59), and incarcerated hemorrhoids (IH, n = 10) and the utility of these parameters in the differential diagnosis of hemorrhoids with thrombosis (HT, n = 30).

METHODS

Patients were grouped according to the relevant clinical diagnosis and classification standards. Blood coagulation-related tests, platelet counts, and relevant laboratory indicators (PT%, PT, APTT, TT, INR, FIB, D-dimer, and Plt) were carried out with samples obtained from patients with hemorrhoids.

RESULTS

In the ROC curve analysis, D-dimer could better distinguish HE from HB (AUC = 0.587, p = 0.042). D-dimer (AUC = 0.643, p = 0.011), INR (AUC = 0.630, p = 0.022), and TT (AUC = 0.617, p = 0.038) could distinguish HT from HE, although no significant difference was observed between the ROC curves.

CONCLUSIONS

D-dimer is useful in distinguishing HE from HB. Moreover, D-dimer, INR, and TT are useful in distinguishing HE from HT. Our findings provide a theoretical basis for future research in this area.

Using three external quality assurance schemes to achieve equivalent international normalized ratio results in primary and secondary healthcare

OBJECTIVES

Accurate prothrombin time international normalized ratio (INR) results are essential for safe anticoagulation treatment. Patients are treated both in primary and secondary healthcare, therefore equivalence of INR results from point-of-care (POC) and hospital measurement procedures (MPs) are important. It is not possible to evaluate this equivalence in traditional external quality assessment (EQA). The aim of this paper is to describe a special quality assurance system consisting of three different EQA schemes to monitor the harmonization of INR results in Norway.

METHODS

The EQA scheme for hospital laboratories uses commutable control materials and evaluates participant performance and the equivalence of hospital MPs. The EQA scheme for primary healthcare laboratories uses non-commutable control materials and evaluates participant performance. A third EQA scheme for selected primary healthcare laboratories uses native patient split samples and evaluates the equivalence between POC and hospital MPs.

RESULTS

The relationship between the three EQA schemes is presented. The split sample EQA scheme provides a link between the hospital scheme and the scheme for primary healthcare. Results from 2017 to 2022 are presented for all three schemes. When aberrant EQA results occur Noklus takes actions to be able to have a sustainable equivalence between INR results.

CONCLUSIONS

All three EQA schemes are important for monitoring the harmonization of INR results in Norway. This quality assurance system, including help and guidance of the participants, will reduce the risk of harm to patients due to non-equivalence of results from different MPs.

Preoperative coagulation screening tests in pediatric patients: Clinical relevance and hemorrhagic outcomes of abnormal results

PURPOSE

Coagulation screening tests in children are still frequently performed in many countries to evaluate bleeding risk. The aim of this study was to assess the management of unexpected prolongations of the activated partial thromboplastin time (APTT) and prothrombine time (PT) in children prior to elective surgery, and the perioperative hemorrhagic outcomes.

METHODS

Children with prolonged APTT and/or PT who attended a preoperative anesthesia consultation from January 2013 to December 2018 were included. Patients were grouped according to whether they were referred to a Hematologist or were scheduled to undergo surgery without further investigation. The primary endpoint was to compare perioperative bleeding complications.

RESULTS

1835 children were screened for eligibility. 102 presented abnormal results (5.6%). Of them, 45% were referred to a Hematologist. Significant bleeding disorders were associated with a positive bleeding history, odds ratio of 51 (95% CI 4.8-538.5, P=.0011). No difference in perioperative hemorrhagic outcomes were found between the groups. An additional cost of 181 euros per patient and a preoperative median delay of 43 days was observed in patients referred to Hematology.

CONCLUSIONS

Our results suggest that hematology referral has limited value in asymptomatic children with a prolonged APTT and/or PT. Hemorrhagic complications were similar among patients referred and not referred to Hematology. A positive personal or family bleeding history can help identify patients with a higher bleeding risk, thus it should guide the need for coagulation testing and hematology referral. Further efforts should be made to standardize preoperative bleeding assessments tools in children.

Prognostic Values of Prothrombin Time and Inflammation-Related Parameter in Acute Ischemic Stroke Patients After Intravenous Thrombolysis with rt-PA

In previous studies, prothrombin time (PT), systemic inflammation response index (SIRI) and systemic immune inflammation Index (SII) levels might be the prognostic factors for patients with ischemic stroke. However, the association between these coagulation and inflammation biomarkers and prognosis in patients with acute ischemic stroke (AIS) who undergo intravenous thrombolysis (IVT) with recombinant tissue plasminogen activator (rt-PA) remains unclear and needs further study. Thus, this study aimed to investigate the relationship between these biomarkers and clinical prognosis after IVT in AIS patients. We included patients at the Hebei general hospital diagnosed with AIS who received standard-dose IVT with rt-PA from September 2017 to August 2022. Demographic information, vascular risk factors, laboratory test results, and other stroke-related data were collected for analysis. Clinical outcomes included short-term outcome at 24 h and functional outcome at 3 months. We enrolled 281 patients in this study. In total, 16 patients had END within 24 h, and 106 patients had an unfavorable outcome at the 3-month visit. In the multivariate analysis, PT level (OR = 1.833; 95% CI: 1.161-2.893; P = 0.009), SIRI level (OR = 2.166; 95% CI: 1.014-4.629; P = 0.046) and SII level (OR = 1.002; 95% CI: 1.000-1.003; P = 0.021) were independently associated with 3-month poor outcome in AIS patients with IVT. In conclusion, the higher PT, SIRI and SII levels were independently associated with poor prognosis in AIS patients after IVT. Additionally, PT, SIRI and SII all can be novel short-term prognostic biomarkers for AIS patients treated with IVT.

Is there a circannual variation in the anticoagulation control of warfarin?

BACKGROUND

The literature regarding the seasonal variation in the therapeutic response to warfarin is somewhat contradictory, with several discrepancies. We assessed the influence of seasons on various pharmacodynamic indices of warfarin.

METHODS

A retrospective study was carried out in adults receiving warfarin for at least 6 months. Details of their demographic characteristics, duration and dose of warfarin therapy and values of prothrombin time international normalised ratio (PT-INR) were retrieved. Standard definitions were followed for defining various seasons, time in therapeutic range (TTR), log-INR variability and warfarin sensitivity index (WSI). National Institute for Health and Care Excellence (NICE) criteria were used for defining TTR into good (≥65%) and poor (<65%) anticoagulation control.

RESULTS

Two hundred and four patients were recruited. Only a subtle statistically significant difference was observed between the numbers of patients in the various PT-INR categories. However, no significant intra-individual differences were observed in mean TTR. Similarly, the proportion of patients with poor anticoagulation control, high INR variability and high WSI was not significantly different between summer, transition period 1, winter and transition period 2.

CONCLUSION

No clinically significant seasonal variations were observed in the therapeutic response to warfarin.

Triazol-1-yl Benzamides Promote Anticoagulant Activity via Inhibition of Factor XIIa

BACKGROUND

Human factor XIIa (FXIIa) is a plasma serine protease that plays a significant role in several physiological and pathological processes. Animal models have revealed an important contribution of FXIIa to thromboembolic diseases. Remarkably, animals and patients with FXII deficiency appear to have normal hemostasis. Thus, FXIIa inhibition may serve as a promising therapeutic strategy to attain safer and more effective anticoagulation. Very few small molecule inhibitors of FXIIa have been reported. We synthesized and investigated a focused library of triazol-1-yl benzamide derivatives for FXIIa inhibition.

METHODS

We chemically synthesized, characterized, and investigated a focused library of triazol- 1-yl benzamide derivatives for FXIIa inhibition. Using a standardized chromogenic substrate hydrolysis assay, the derivatives were evaluated for inhibiting human FXIIa. Their selectivity over other clotting factors was also evaluated using the corresponding substrate hydrolysis assays. The best inhibitor affinity to FXIIa was also determined using fluorescence spectroscopy. Effects on the clotting times (prothrombin time (PT) and activated partial thromboplastin time (APTT)) of human plasma were also studied.

RESULTS

We identified a specific derivative (1) as the most potent inhibitor in this series. The inhibitor exhibited nanomolar binding affinity to FXIIa. It also exhibited significant selectivity against several serine proteases. It also selectively doubled the activated partial thromboplastin time of human plasma.

CONCLUSION

Overall, this work puts forward inhibitor 1 as a potent and selective inhibitor of FXIIa for further development as an anticoagulant.

[Comparison of four-coagulation-tests values in normal pregnant women during early and late pregnancy and the influence of age]

Objective: To explore and compare the reference ranges of four coagulation tests in normal pregnant women during early and late pregnancy and the influence of age. Methods: Values of four coagulation tests from 4 974 pregnant women, who gave single birth at Peking University First Hospital, Obstetrics and Gynecology Hospital of Fudan University, West China Second University Hospital, Peking University Third Hospital and Shengjing Hospital of China Medical University from February 2017 to July 2020, were measured and analyzed in this study, including prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (Fib) and thrombin time (TT). The four normal reference ranges of coagulation during early and late pregnancy phases were expressed as P_2.5-P_97.5. The difference of two pregnancy phases was compared by non-parametric test of two related samples. And the difference between pregnant women of advanced and non-advanced age in the same pregnancy phase was compared by independent sample non-parametric test. Chi-square test was used to compare the incidence of pregnancy complications in different coagulation reference ranges. Results: The reference ranges of PT of normal pregnant women's early and late pregnancy were 10.0-13.9 s and 9.6-12.3 s, the reference ranges of APTT were 22.6-35.3 s and 22.4-30.9 s, the reference ranges of Fib were 2.4-5.0 g/L and 3.0-5.7 g/L, the reference ranges of TT were 12.0-19.0 s and 11.5-18.4 s. Compared with early pregnancy, PT, APTT and TT shortened significantly, while the Fib significantly increased in late pregnancy (all P<0.001). PT, APTT and TT of advanced and non-advanced age pregnant women were significantly different (all P<0.01). Compared with the ranges of non-pregnant population, more pregnant women were included in the normal pregnant reference ranges of PT in early pregnancy and APTT in the early and late pregnancy, while the incidence of pregnancy complications had no significant differences (all P>0.05). The incidence of fetal distress was higher and the incidence of preterm birth was lower in the reference range of PT in late pregnancy. The incidence of gestational diabetes mellitus was higher in the early and late gestational Fib reference ranges, and the incidence of hypertensive disorders in pregnancy was higher in the late gestational Fib reference range (all P<0.05). Conclusions: The coagulation function of pregnant women increases significantly with the growth of pregnancy, and there is a significant difference between advanced significantly and non-advanced age pregnant women. The recommended ranges of normal pregnant women's early and late pregnancy PT are 10.0-13.9 s and 9.6-12.3 s, the recommended ranges of APTT are 22.6-35.3 s and 22.4-30.9 s, the recommended ranges of TT are 12.0-19.0 s and 11.5-18.4 s. The appropriate ranges of normal pregnant women's early and late pregnancy Fib still need further exploration.

Development of a paper-based lateral flow prothrombin assay

Disorders of haemostasis result in both excessive bleeding and clotting and are a major global cause of morbidity and mortality, particularly in the developing world. A small number of simple tests can be used to screen and monitor for such dysfunctions, one of which is the prothrombin time (PT) test and associated International Normalisation Ratio (INR). PT/INR is routine in hospital laboratories in developed countries, and can also be performed using point-of-care instruments. However, neither of these approaches is appropriate in low-resource settings. Significant interest has grown in paper-based devices to form the basis of simple and low-cost assays that may have the potential for application in such environments. This study describes the development of a simple, low-cost, paper-based lateral flow prothrombin assay. The assay employed wax printing on chromatography paper to define test channels, with deposition of thromboplastin reagent and calcium chloride onto the resulting strips. These were placed in a test housing and measurement of the flow rates of deposited plasma samples were performed in triplicate. The flow dynamics of the assay was optimised according to the type of paper substrate used, the nature and quantity of the thromboplastin reagent, the amount of calcium chloride required, and the volume of sample employed. An optimised assay configuration demonstrated a dynamic range of 6 mm between normal and factor-deficient plasmas. The assay showed good correlation with laboratory-based PT assay (Yumizen G200) in artificial plasmas in the 9.8 to 36 s range (r² = 0.8112). The assay also demonstrated good dynamic range and correlation in patient plasma samples in comparison with hospital PT, with a range of 9.8 to 45 s (r² = 0.7209).