Activated protein C and free protein S in patients with mild to moderate bleeding disorders

BACKGROUND

Underlying mechanisms for bleeding and impaired thrombin generation (TG) and plasma clot formation (PCF) in patients with mild to moderate bleeding disorders (MBDs) are still to be elucidated, especially in bleeding disorder of unknown cause (BDUC). The role of the natural anticoagulants activated protein C (APC) and free protein S (PS) has not yet been investigated in this patient population.

AIMS

To analyze antigen levels of APC and PS in patients with MBDs and BDUC and investigate associations to clinical bleeding phenotype and severity as well as and hemostatic capacity.

METHODS

Antigen levels of APC and free PS were measured in 262 patients from the Vienna Bleeding Biobank (VIBB), a single-center cohort study, by ELISA and compared to 61 healthy controls (HC).

RESULTS

Antigen levels of APC were higher in MBD patients than in HC when adjusted for age, sex and BMI (median (IQR) 33.1 (20.6-52.6) and 28.6 (16.4-47.2) ng/mL). This was most pronounced in patients with BDUC (35.3 (21.7-54.3) ng/mL). No differences in PS antigen levels between patients and HC were seen overall, or according to specific diagnoses. Further, no association between APC or PS and bleeding severity or global tests of hemostasis or TG were identified, while paradoxically APC weakly correlated with shorter lag time and time to peak of PCF in BDUC.

CONCLUSION

Our data demonstrate increased antigen levels of APC in BDUC, which might contribute to the bleeding tendency in some patients and could be a future therapeutic target in BDUC.

Predictors of stroke outcome: the role of hemorheology, natural anticoagulants, and serum albumin

BACKGROUND

The early hours after an acute stroke are crucial; early accurate prediction of outcome in stroke patients can help health system providers and families to choose appropriate lines of management and plan for the future. The aim of this work is to assess the role of hemorheological parameters (such as blood viscosity, hematocrit, platelet aggregation, and leukocyte count), protein C, protein S, antithrombin III, and serum albumin as predictors of stroke outcome.

METHODS

Thirty subjects, 20 patients with acute ischemic stroke within 24 h from the onset and 10 normal subjects, were included in this case control study. Clinical, functional, and radiological evaluation was done for the patients, and all patients and control were subjected to routine laboratory tests and assessment of blood viscosity, hematocrit level, platelet aggregation, protein C, protein S, and antithrombin III.

RESULTS

Platelet aggregation was significantly higher and serum albumin was significantly lower in stroke patients compared to control (p value = 0.000 and 0.039) respectively. On comparing between patient with good and poor outcome, good outcome was associated with increased serum albumin level at admission (p value = 0.03) respectively. A significant negative correlation was found between total leukocyte count, hematocrit value, and stroke outcome (p value = 0.015 and 0.013) respectively. Only albumin was found to be a significant predictor for outcome by linear regression analysis.

CONCLUSION

Serum albumin, hematocrit level, and total leukocyte count at the time of presentation of ischemic stroke are useful markers for stroke outcome.