Effect of serum monoclonal protein concentration on haemostasis in patients with multiple myeloma.

Abnormalities in haemostasis are often detected in patients with multiple myeloma and the fundamental factors that lead to these abnormities are worthy of exploration. The objective of this study was to investigate bleeding diathesis and coagulopathy in different multiple myeloma types or stages and assess how paraprotein concentration contributes to differences in these conditions. Haemostasis screening tests and serum monoclonal protein (M protein) concentration were retrospectively analysed in 101 patients newly diagnosed with multiple myeloma from January 2012 to April 2014. No significant differences were found between bleeding diathesis and types or International Staging System (ISS) stages of multiple myeloma; however, prolonged thrombin time (TT) was found in most of patients (77.7%) and was positively related to light-chain concentration (P ≤ 0.01). Prolonged prothrombin time (PT) was more obvious in IgA and IgG-type multiple myeloma than in the light-chain type (P ≤ 0.01). With increased clinical staging, PT remarkably increased (P ≤ 0.01). M protein concentration was significantly higher in patients with prolonged PT than in those with normal PT (P ≤ 0.01). The D-dimer mean was significantly higher than normal (>0.5 μg/ml) (P ≤ 0.01). Fibrinogen was negatively related to M protein levels (P ≤ 0.01); however, there was no correlation between activated partial thromboplastin time (APTT) and multiple myeloma stages or types, M protein levels and serum light-chain concentration (P ≥ 0.05). Patients with light-chain type multiple myeloma were more likely to have prolonged TT than patients with other types. M protein levels had an obvious effect on PT. Prolonged PT was more common in IgA and IgG-type multiple myeloma. Abnormal haemostasis test results are not always accompanied by clinically apparent haemostatic complications.