A method of factor Xl-dependent blood coagulation enhancement in a subject in need of enhanced blood coagulation comprising administering a therapeutically effective amount of a composition comprising a non-anticoagulant sulfated polysaccharide (NASP) to the subject. A method of factor Xl-dependent blood coagulation enhancement in a subject in need of enhanced blood coagulation comprising: (i) selecting a subject that is not deficient for factor Xl and (ii) administering a therapeutically effective amount of a composition comprising a non-anticoagulant sulfated polysaccharide (NASP) to the subject, wherein the NASP enhances blood coagulation in a factor Xl-dependent manner. A method of identifying a non-anticoagulant sulfated polysaccharide (NASP) which is capable of enhancing blood coagulation in dependence on FXI, the method comprising: a) combining a blood or plasma sample comprising activation competent FXI with a composition comprising a sulfated polysaccharide and measuring the clotting or thrombin generation parameters of the blood or plasma sample b) combining a corresponding blood or plasma sample deficient in activation competent FXI with a composition comprising the sulfated polysaccharide and measuring the clotting or thrombin generation parameters of the blood or plasma sample and c) comparing the clotting or thrombin generation parameters of the blood or plasma samples as determined in steps (a) and (b) with each other, wherein a decrease in the clotting time of the blood sample or an increase in peak thrombin or decrease in peak time of the plasma sample comprising activation competent FXI compared to the clotting time of the blood sample or peak thrombin or peak time of the plasma sample deficient in activation competent FXI is indicative of a NASP which is capable of enhancing blood coagulation in dependence on FXI.Linvention concerne une méthode pour améliorer la coagulation sanguine en relation avec le facteur XI chez un sujet ayant besoin dune te
