Assessment of oxidative/nitrative modifications of plasma proteins, selected ROTEM parameters and kinetics of fibrinogen polymerization in patients with multiple myeloma at diagnosis

Patients with multiple myeloma (MM) are at increased risk of thrombosis. Growing evidence indicates that oxidative and nitrative modifications of proteins, including fibrinogen, may lead to changes in hemostasis. The study compares samples from patients with MM at diagnosis and healthy volunteers with regard to the oxidative/nitrative modifications of proteins, ROTEM and thrombin-catalyzed fibrin polymerization. The content of carbonyl groups in plasma proteins of patients with MM was significantly higher than in controls (2.981 vs. 1.807 nmol/mg of protein, p = 0.005), while no differences were seen in the concentrations of nitrated proteins. Maximum clot firmness readings were significantly higher in the samples of patients than in controls according to FIBTEM test (23.5 vs. 15 mm, p = 0.006). The lag time of the fibrin polymerization process and the velocity of clot lysis (V-Lys) were found to be significantly higher in the group of MM patients than controls. In contrast, no marked differences were identified between studied groups in reference to maximal velocity of fibrin polymerization process (V-max), maximal absorbance (A(max)) and plasmin amidolytic activity values. In conclusion, our study demonstrates that at the time of diagnosis, patients with MM demonstrated greater oxidative stress than healthy volunteers, which is reflected in a higher amount of carbonylated proteins. Some prothrombotic features found in ROTEM tests in MM patients were not confirmed by turbidimetry.