Comparison of different activators of coagulation by turbidity analysis of hereditary dysfibrinogenemia and controls

Association of prothrombin time, thrombin time and activated partial thromboplastin time levels with preeclampsia: a systematic review and meta-analysis

BACKGROUND

Preeclampsia (PE), an obstetric disorder, remains one of the leading causes of maternal and infant mortality worldwide. In individuals with PE, the coagulation-fibrinolytic system is believed to be among the most significantly impacted systems due to maternal inflammatory responses and immune dysfunction. Therefore, this systematic review and meta-analysis aimed to assess the association of prothrombin time (PT), thrombin time (TT) and activated partial thromboplastin time (APTT) levels with preeclampsia.

METHODS

This systematic review and meta-analysis was conducted in accordance with the PRISMA guidelines. Articles relevant to the study, published from July 26, 2013, to July 26, 2023, were systematically searched across various databases including PubMed, Scopus, Embase, and Hinari. The methodological quality of the articles was evaluated using the Joanna Briggs Institute critical appraisal checklist. Utilizing Stata version 14.0, a random-effects model was employed to estimate the pooled standardized mean difference (SMD) along with the respective 95% CIs. The I2 statistics and Cochrane Q test were utilized to assess heterogeneity, while subgroup analyses were performed to explore its sources. Furthermore, Egger's regression test and funnel plot were employed to assess publication bias among the included studies.

RESULTS

A total of 30 articles, involving 5,964 individuals (2,883 with PE and 3,081 as normotensive pregnant mothers), were included in this study. The overall pooled SMD for PT, APTT, and TT between PE and normotensive pregnant mothers were 0.97 (95% CI: 0.65-1.29, p < 0.001), 1.05 (95% CI: 0.74-1.36, p < 0.001), and 0.30 (95% CI: -0.08-0.69, p = 0.11), respectively. The pooled SMD indicates a significant increase in PT and APTT levels among PE patients compared to normotensive pregnant mothers, while the increase in TT levels among PE patients was not statistically significant.

CONCLUSIONS

The meta-analysis underscores the association between PE and prolonged PT and APTT. This suggests that evaluating coagulation parameters like PT, APTT, and TT in pregnant women could offer easily accessible and cost-effective clinical indicators for assessing PE. However, multicenter longitudinal studies are needed to evaluate their effectiveness across various gestational weeks of pregnancy.

Pharmacodynamics Monitoring of Emicizumab in Patients with Hemophilia A

BACKGROUND

 Emicizumab is a bispecific antibody mimicking coagulation factor VIII (FVIII) employed to treat patients with hemophilia A (PwHA) regardless of FVIII inhibitor status. The identification of biological markers reflecting the hemostatic competence of patients under emicizumab therapy would have a great clinical value. Unfortunately, emicizumab over-corrects standard coagulation assays, precluding their use for evaluating the hemostatic correction achieved in vivo. Here, we investigated whether global coagulation assays (GCA) would allow monitoring the biological response to non-factor replacement therapy with emicizumab.

MATERIALS AND METHODS

 Six adults PwHA received a weekly dose of emicizumab of 3 mg/kg during weeks (W) 1 4 and 1.5 mg/kg from W5 onwards. Response to treatment was monitored weekly by emicizumab plasma concentration, thrombin generation (TG), and fibrin clot formation (FCF) and structure. TG and FCF results were compared to patient baseline, FVIII replacement, and healthy donors.

RESULTS

 TG and FCF significantly increased in PwHA after the loading period, reaching a plateau that lasted until the end of monitoring. Similarly, fibrin clot network became denser with thinner fibrin fibers. However, TG contrary to FCF remained at the lower limits of reference values. Remarkably, despite having similar plateau concentrations of emicizumab some patients showed markedly different degrees of TG and FCF improvement.

CONCLUSION

 Our study enriches the knowledge on the use of GCA to monitor non-factor replacement therapy, indicating that TG and FCF could act as direct markers of emicizumab biological activity. GCA allow to capture and visualize the individually variable response to emicizumab, leading a step forward to the personalization of patient treatment.

Development and validation for multifactor prediction model of sudden sensorineural hearing loss

Background

Sudden sensorineural hearing loss (SSNHL) is a global problem threatening human health. Early and rapid diagnosis contributes to effective treatment. However, there is a lack of effective SSNHL prediction models.

Methods

A retrospective study of SSNHL patients from Fujian Geriatric Hospital (the development cohort with 77 participants) was conducted and data from First Hospital of Putian City (the validation cohort with 57 participants) from January 2018 to December 2021 were validated. Basic characteristics and the results of the conventional coagulation test (CCT) and the blood routine test (BRT) were then evaluated. Binary logistic regression was used to develop a prediction model to identify variables significantly associated with SSNHL, which were then included in the nomogram. The discrimination and calibration ability of the nomogram was evaluated by receiver operating characteristic (ROC), calibration plot, and decision curve analysis both in the development and validation cohorts. Delong's test was used to calculate the difference in ROC curves between the two cohorts.

Results

Thrombin time (TT), red blood cell (RBC), and granulocyte-lymphocyte ratio (GLR) were found to be associated with the diagnosis of SSNHL. A prediction nomogram was constructed using these three predictors. The AUC in the development and validation cohorts was 0.871 (95% CI: 0.789-0.953) and 0.759 (95% CI: 0.635-0.883), respectively. Delong's test showed no significant difference in the ROC curves between the two groups (D = 1.482, p = 0.141).

Conclusion

In this study, a multifactor prediction model for SSNHL was established and validated. The factors included in the model could be easily and quickly accessed, which could help physicians make early diagnosis and clinical treatment decisions.

Physiological correction of hereditary mild hypofibrinogenemia during pregnancy

INTRODUCTION

Hereditary hypofibrinogenemia is a rare fibrinogen disorder characterised by decreased levels of fibrinogen. Pregnant women with hypofibrinogenemia are at risk of adverse obstetrical outcomes, depending on the fibrinogen level.

AIM

We investigated how the physiological changes of hemostasis throughout the pregnancy impact the hemostatic balance in a woman with hereditary mild hypofibrinogenemia.

METHODS

Fibrin clot properties were analyzed by turbidimetry and scanning electron microscopy, clot weight and red blood cells retention were measured by whole clot contraction, and in vitro thrombin generation was assessed by calibrated automated thrombogram and ex vivo by TAT.

RESULTS

Throughout the pregnancy, the fibrinogen levels increased reaching normal values in the third trimester (activity 3.1 g/L, antigen 3.2 g/L). In parallel, the fibrin polymerisation increased, the fibrinolysis decreased, the fibrin clot network became denser with thicker fibrin fibers, and the fibrin clot weight and red blood cells retention increased, reaching control's value at the third trimester. Similarly, in vitro and ex vitro thrombin generation increased, reaching maximum values at the delivery.

CONCLUSION

In this case of hereditary mild hypofibrinogenemia we observed a physiological increase of fibrinogen and thrombin generation. Future studies should focus on moderate and severe hypofibrinogenemia, to assess fibrinogen variation and the overall impact of increased TG on the hemostasis balance.

Impact of fibrinogen infusion on thrombin generation and fibrin clot structure in patients with inherited afibrinogenemia

INTRODUCTION

Inherited afibrinogenemia is a very rare disease characterized by complete absence of fibrinogen in the circulation and an increased risk in both thrombosis and bleeding. Infusion of fibrinogen concentrate (FC) is the main approach for prevention and management of bleeding; however, it has been reported to carry a thrombotic risk.

METHODS

We investigated the impact of a standard dose (40-100 mg/kg) of FC infusion on the thrombin generation (TG) parameters and the fibrin clot structure formed in plasma samples of patients with afibrinogenemia. Blood samples were collected from 20 patients before (T0) and 1 hour after infusion of FC (T1). TG was studied with Calibrated Automated Thrombography. Fibrin clot structure was assessed with turbidimetry and scanning electron microscopy (SEM).

RESULTS

FC infusions (mean Clauss fibrinogen plasma level 1.21 g/L at T1) led to a statistically significant increase in endogenous thrombin potentials (ETP) (p<0.0001) and thrombin peaks (p=0.02). Nevertheless, when compared to healthy controls, patients' T1 lag times were longer (p=0.002), ETP values were lower (p=0.0003), and thrombin peaks were lower (p<00001). All fibrin polymerization parameters (turbidimetry) obtained at T1 were comparable to those of patients with inherited hypofibrinogenemia matched for fibrinogen plasma levels.

CONCLUSIONS

In summary, fibrinogen infusion with a standard dose of FC increased but did not correct TG and led to formation of fibrin clots similar to those of patients with hypofibrinogenemia. All in all, our results do not support to biological evidence of hypercoagulability induced by FC in patients with afibrinogenemia.

The Reevaluation of Thrombin Time Using a Clot Waveform Analysis

Object: Although thrombin burst has attracted attention as a physiological coagulation mechanism, clinical evidence from a routine assay for it is scarce. This mechanism was therefore evaluated by a clot waveform analysis (CWA) to assess the thrombin time (TT). Material and Methods: The TT with a low concentration of thrombin was evaluated using a CWA. We evaluated the CWA-TT of plasma deficient in various clotting factors, calibration plasma, platelet-poor plasma (PPP), and platelet-rich plasma (PRP) obtained from healthy volunteers, patients with thrombocytopenia, and patients with malignant disease. Results: Although the TT-CWA of calibration plasma was able to be evaluated with 0.01 IU/mL of thrombin, that of FVIII-deficient plasma could not be evaluated. The peak time of CWA-TT was significantly longer, and the peak height significantly lower, in various deficient plasma, especially in FVIII-deficient plasma compared to calibration plasma. The second peak of the first derivative (1st DP-2) was detected in PPP from healthy volunteers, and was shorter and higher in PRP than in PPP. The 1st DP-2 was not detected in PPP from patients with thrombocytopenia, and the 1st DP-2 in PRP was significantly lower in patients with thrombocytopenia and significantly higher in patients with malignant disease than in healthy volunteers. Conclusion: The CWA-TT became abnormal in plasma deficient in various clotting factors, and was significantly affected by platelets, suggesting that the CWA-TT may be a useful test for hemostatic abnormalities.