Differing coagulation profiles of patients with monoclonal gammopathy of undetermined significance and multiple myeloma.

The link between myeloma and thrombosis is well established. Monoclonal gammopathy of undetermined significance (MGUS) has also been associated with an increased risk of thrombosis. It was recently demonstrated that patients with myeloma display changes in thromboelastometry that may indicate a prothrombotic state. There is little data with regard to changes in thromboelastography in patients with myeloma or MGUS. The aim of this study was to investigate the differing coagulation profiles of patients of patients with myeloma and MGUS by means of conventional coagulation tests and thromboelastography. Blood was taken by direct venepuncture from patients with myeloma, MGUS and normal controls. Routine coagulation tests were performed in an accredited hospital laboratory. Thromboelastography (TEG(®)) was performed as per the manufacturer's protocol. Eight patients were recruited in each group. Patients with myeloma had a significantly lower mean haemoglobin level than patients with MGUS or normal controls (p < 0.001). Patients with myeloma had a significantly more prolonged mean prothrombin time than normal controls (p = 0.018) but not patients with MGUS. Patients with myeloma had significantly higher median D-dimer levels than normal controls (p = 0.025), as did patients with MGUS (p = 0.017). Patients with myeloma had a significantly higher mean factor VIII level than normal controls (p = 0.009) and there was a non-significant trend towards patients with MGUS having higher factor VIII levels than normal controls (p = 0.059). There was no significant difference in thromboelastographic parameters between the three groups. Patients with MGUS appear to have a distinct coagulation profile which is intermediate between patients with myeloma and normal controls.