Searching for New Biomarkers to Assess COVID-19 Patients: A Pilot Study

During the initial diagnosis of urgent medical conditions, which include acute infectious diseases, it is important to assess the severity of the patient's clinical state as quickly as possible. Unlike individual biochemical or physiological indicators, derived indices make it possible to better characterize a complex syndrome as a set of symptoms, and therefore quickly take a set of adequate measures. Recently, we reported on novel diagnostic indices containing butyrylcholinesterase (BChE) activity, which is decreased in COVID-19 patients. Also, in these patients, the secretion of von Willebrand factor (vWF) increases, which leads to thrombosis in the microvascular bed. The objective of this study was the determination of the concentration and activity of vWF in patients with COVID-19, and the search for new diagnostic indices. One of the main objectives was to compare the prognostic values of some individual and newly derived indices. Patients with COVID-19 were retrospectively divided into two groups: survivors (n = 77) and deceased (n = 24). According to clinical symptoms and computed tomography (CT) results, the course of disease was predominantly moderate in severity. The first blood sample (first point) was taken upon admission to the hospital, the second sample (second point)-within 4-6 days after admission. Along with the standard spectrum of biochemical indicators, BChE activity (BChEa or BChEb for acetylthiocholin or butyrylthiocholin, respectively), malondialdehyde (MDA), and vWF analysis (its antigen level, AGFW, and its activity, ActWF) were determined and new diagnostic indices were derived. The pooled sensitivity, specificity, and area under the receiver operating curve (AUC), as well as Likelihood ratio (LR) and Odds ratio (OR) were calculated. The level of vWF antigen in the deceased group was 1.5-fold higher than the level in the group of survivors. Indices that include vWF antigen levels are superior to indices using vWF activity. It was found that the index [Urea] × [AGWF] × 1000/(BChEb × [ALB]) had the best discriminatory power to predict COVID-19 mortality (AUC = 0.91 [0.83, 1.00], p < 0.0001; OR = 72.0 [7.5, 689], p = 0.0002). In addition, [Urea] × 1000/(BChEb × [ALB]) was a good predictor of mortality (AUC = 0.95 [0.89, 1.00], p < 0.0001; OR = 31.5 [3.4, 293], p = 0.0024). The index [Urea] × [AGWF] × 1000/(BChEb × [ALB]) was the best predictor of mortality associated with COVID-19 infection, followed by [Urea] × 1000/(BChEb × [ALB]). After validation in a subsequent cohort, these two indices could be recommended for diagnostic laboratories.

Predictive value of von Willebrand factor for venous thrombosis in patients with chronic heart failure complicated with atrial fibrillation after anticoagulant therapy

BACKGROUND

We investigated the value of von Willebrand factor (vWF) in predicting venous thrombosis in patients with chronic heart failure complicated with atrial fibrillation after anticoagulation therapy.

METHODS

Totally, 126 patients with chronic heart failure complicated with atrial fibrillation who were treated with anticoagulant therapy and 60 healthy individuals were enrolled. One year after anticoagulant therapy, venous thrombosis occurred in 19 patients. Clinical data of patients were collected. The plasma vWF activity was detected and compared. The logistic regression analysis was used to analyze the influencing factors of vWF. ROC curve was used to evaluate the predictive value of plasma vWF.

RESULTS

Plasma vWF activity was significantly higher in patients with heart failure and atrial fibrillation than control subjects (P < 0.01). The vWF activity in patients with venous thrombosis was significantly higher than that in patients without venous thrombosis (P < 0.01). ROC curve analysis showed that the cut-off value of vWF activity for venous thrombosis within one year after anticoagulant therapy was 267.5%, and the AUC was 0.742 (95% CI: 0.764-0.921, P < 0.05). The sensitivity was 80.0%, and the specificity was 63.6%. Factors of diabetes, myocardial ischemia, old myocardial infarction, and lower extremity atherosclerosis, but not sex, age, coronary heart disease, hypertension, and cardiac function, had significant effect on vWF activity (P < 0.05). Logistic regression analysis showed that vWF activity was significantly related with atherosclerosis of lower limbs and old myocardial infarction, but not significantly related with diabetes and myocardial ischemia. The risk of venous thrombosis in patients with vWF activity greater than 267.5% was 10.667 times higher than that in patients with vWF activity less than 267.5% (P < 0.05).

CONCLUSION

The vWF activity greater than 267.5% has clinical predictive value for the risk of lower extremity venous thrombosis in patients with chronic heart failure complicated with atrial fibrillation within 1 year of anticoagulant therapy.