Blood was drawn by venipuncture at the time when hearing recovery was determined, which was at least 8 weeks after ISSHL to avoid acute phase reactions secondary to the acute event. Fibrinogen was measured in citrated plasma after centrifugation for 15 min at 2,500 g. The sample analysis was done within 1 h after venipuncture. DNA was extracted from EDTA-treated blood by a spin column procedure (Quiagen, Germany).
Fibrinogen was determined using the Multifibren U reagent (BCS analyzer; Dade Behring). The coagulation process was initiated by adding a large excess of thrombin to the plasma sample. The time until formation of a fibrin clot was measured. The fibrinogen concentration was then calculated from a standard curve prepared by measuring fibrinogen calibrators of a known concentration. All other routine measurements were performed as previously described [19] (link).
Fibrinogen was determined using the Multifibren U reagent (BCS analyzer; Dade Behring). The coagulation process was initiated by adding a large excess of thrombin to the plasma sample. The time until formation of a fibrin clot was measured. The fibrinogen concentration was then calculated from a standard curve prepared by measuring fibrinogen calibrators of a known concentration. All other routine measurements were performed as previously described [19] (link).