Use of point-of-care testing for plasma therapy

Design and Quantitative Analysis of Cancer Detection System Based on Fluorescence Immune Analysis

Human blood is an important medical detection index. With the development in clinical medical detection instruments and detection technology, the requirements for detection accuracy and efficiency have been gradually improved. Fluorescent immunochromatography is a new detection technique. It has the characteristics of high efficiency, convenience, no pollution, and wide detection range. Human blood can be detected quickly using fluorescent immunochromatography. At present, it has received great attention from the field of clinical testing. In this paper, a set of fluorescent immunochromatographic analyzer has been designed. It is mainly based on the principle of fluorescence immunochromatography. A new method of signal analysis and system design for fluorescent immunochromatography analyzer is proposed. By using the improved threshold function denoising algorithm, the quantitative detection of fluorescent immunochromatographic strip is realized. The concentration of pathogenic factors (cancer cells) in human serum can be measured conveniently and accurately. The system integrates many peripheral modules, including fluorescence signal acquisition, fluorescence signal processing, quantitative curve fitting, and test results. In this paper, the quantitative detection experiments of the system are carried out in three aspects: linearity, repeatability, and sensitivity. The experimental results show that the linear correlation coefficient is up to 0.9976, and the limit of detection is up to 0.05 ng/ml. The requirements of the system are satisfied. The system performance is good, and the quantitative result is accurate. Therefore, the establishment of a fluorescence analysis system is of great significance.

Diagnostic performance of prothrombin time point-of-care to detect acute traumatic coagulopathy on admission: experience of 522 cases in trauma center

BACKGROUND

Early identification of acute traumatic coagulopathy is a key challenge during initial management to determine whether to initiate early hemostatic support. We assessed the performance of prothrombin time (PT) at point-of-care in trauma patients to detect moderate and severe coagulopathy on admission.

STUDY DESIGN AND METHODS

All admitted consecutive trauma patients were analyzed retrospectively between April 2014 and July 2015. PT was measured on admission with both a PT point-of-care device (PTr-CGK) and a standard coagulation test (PTr-STD). The results for PTr-CGK and PTr-STD were compared using analysis of agreement, precision, and accuracy. The diagnostic performance of PTr-CGK to predict coagulopathy was established by analysis of receiver operating characteristic curves. The predictive performance of different thresholds and risk factors for misclassification were also studied.

RESULTS

Over a 16-month period, 522 patients were included. PTr-CGK estimated PTr-STD with a bias of 0.00 (95% confidence interval [CI], -0.48 to 0.50) and a precision of 0.25. The optimal threshold was 1.4 to predict severe coagulopathy (sensitivity 81% [95% CI, 68%-94%], negative predictive value 98% [95% CI, 97%-99%]), and 1.2 for moderate coagulopathy (sensitivity 80% [95% CI, 72%-88%], negative predictive value 94% [95% CI, 91%-96%]). A low PTr-CGK in the presence of severity criteria (Injury Severity Score ≥ 16, Trauma Associated Severe Hemorrhage score ≥ 12, hemoglobin level < 7 g/dL, fibrinogen level < 2 g/L, base deficit ≥ 6 mmol/L) was strongly associated with a false-negative risk.

CONCLUSIONS

The PT point-of-care device is reliable and accurate for the early identification of coagulopathic trauma patients.

Managing target-specific oral anticoagulant associated bleeding including an update on pharmacological reversal agents

Target-specific oral anticoagulants (TSOACs) dabigatran, rivaroxaban and apixaban are approved for the prevention and treatment of thromboembolism in several clinical settings. Bleeding is the major complication of anticoagulant therapy, including TSOACs, and anticoagulant reversal strategies are highly desired for the management of anticoagulant-associated major bleeding in addition to maximum supportive care and procedural/surgical intervention. Unlike VKAs for which vitamin K and coagulation factor replacement with prothrombin complex concentrate (PCC) can restore hemostasis, there are no clinically available agents proven to reverse TSOAC anticoagulant effect and ameliorate TSOAC-related major bleeding. This narrative review critically evaluates the evidence for TSOAC reversal using non-specific reversal agents PCC, activated PCC (APCC) and recombinant activated factor VII (rVIIa) which have been assessed primarily using in vitro experiments, animal models and healthy human volunteers. Aripazine is a novel agent undergoing clinical development for non-specific anticoagulant reversal, including TSOACs. Data are presented regarding specific reversal agents idarucizumab (dabigatran) and andexanet alfa (oral factor Xa inhibitors) currently being evaluated in clinical trials. A practical approach to management of patients with TSOAC-associated bleeding is also provided. There is an urgent need for clinical studies that evaluate the efficacy and safety of reversal strategies for TSOAC-related major bleeding with assessment of clinical outcomes such as bleeding and mortality.

Microparticle profile and procoagulant activity of fresh-frozen plasma is affected by whole blood leukoreduction rather than 24-hour room temperature hold

BACKGROUND

Microparticles (MPs) are small phospholipid-containing vesicles that have procoagulant properties. MPs are thought to contribute to the hemostatic potential of plasma. This study investigated the effects of whole blood (WB) hold time and leukoreduction (LR) on the MP profile and hemostatic potential of fresh-frozen plasma (FFP).

STUDY DESIGN AND METHODS

WB units (n=12) from healthy donors were divided into two pairs and each pair was held at 20 to 24°C for 6 or 24 hours. At the designated hold time, 1 unit from the pair was LR while the other unit was not LR. FFP was prepared by standard procedures, aliquoted, and frozen. The MP content was determined by flow cytometry using an absolute count assay and specific labels for red blood cells (CD235a), platelets (CD41), and phosphatidylserine (PS). The hemostatic potential was determined by thrombelastography (TEG) and coagulation factor assays.

RESULTS

Compared to non-LR-FFP, LR-FFP had significantly lower numbers of MPs, particularly CD41+ MPs and PS-positive MPs (p<0.03). LR-FFP, compared to non-LR-FFP, had a slower clot formation time (p=0.002); lower clot strength (p<0.001); and lower Factor (F)VIII, FXII, and fibrinogen levels (p<0.01). With longer WB hold time, the TEG profile was unchanged, although FVIII levels were decreased as expected (p<0.01). On average FFP units met quality requirements.

CONCLUSION

LR of WB resulted in lower hemostatic potential of FFP in conjunction with depletion of MPs and coagulation factors. Longer WB hold time did not significantly affect the hemostatic potential of FFP as measured by TEG. Acceptable hemostatic quality was maintained for all FFP processing conditions studied.

Reversal of target-specific oral anticoagulants

The target-specific oral anticoagulants represent the first new oral anti-thrombotic therapy in over 50 years and have the potential to make therapy easier and hence more accessible to many patients. Like any new therapy, the potential benefits must be weighed against the potential challenges and one of the most concerning aspects of the new target-specific oral anticoagulants is the lack of a proven method to reverse their effect. Unlike the vitamin K antagonist, i.e. warfarin, there is no specific antidote for these medications. This paper will review the limited data on the use of non-specific therapies to reverse anticoagulation for the new agents. We hope to prepare clinicians who are faced with a patient who has serious bleeding or needs emergent surgery while taking dabigatran, rivaroxaban or apixaban.

Reversal of novel oral anticoagulants in patients with major bleeding

Novel oral anticoagulants (NOACs) that directly inhibit thrombin (dabigatran) or factor Xa (rivaroxaban, apixaban, edoxaban) are effective therapies for the prevention and treatment of thromboembolism with reduced bleeding complications compared with warfarin for some indications. However, specific antidotes to reverse the anticoagulant activity of NOACs in the event of major bleeding are not available. Evidence supporting non-specific prohemostatic therapies (prothrombin complex concentrate [PCC], activated prothrombin complex concentrate [aPCC], recombinant factor VIIa) in this setting is limited to healthy human volunteers, animal models, and in vitro studies. Clinical outcome data are lacking. Administration of PCC or aPCC may be considered in addition to supportive measures for patients with severe or life-threatening bleeding. Clinical studies are needed to establish the efficacy and safety of these treatments. Target-specific antidotes are in development and hold promise for NOAC reversal, but require further investigation.