Multiple inhibitory effects associated with IgG kappa multiple myeloma.

REMOTTI L; INGRATTI M; SÁNCHEZ LUCEROS A; GROSSO S; MESCHENGIESER SS; BLANCO A; LAZZARI MA

Amsterdam

Congreso; XXIV Congress of the International Society on Thrombosis and Haemostasis; 2013

International Society on Thrombosis and Haemostasis

Background: Haemostatic alterations are often detected in patients with monoclonal gammopathies such as multiple myeloma (MM). They frequently show abnormal coagulation tests (thrombin times, fibrin degradation products (FDP), platelet aggregation, and bleeding time), due to the interference of the paraprotein present in their plasma. Aims: The aim of this report is to present the case of a patient with multiple myeloma whose prothrombin time (PT), activated partial thromboplastin time (APTT) and thrombin time (TT) were significantly prolonged and did not correct by mixing with normal plasma. Case Report: A 47-year-old man with IgG kappa multiple myeloma was referred to our institute, because he had had episodes of haematuria and epistaxis without previous history of bleeding in major surgeries. Results: Coagulation screening of plasma of patient showed prolonged APTT (ratio 4.6; RV: 0.87-1.13), PT (ratio 1.5; RV: 0.82-1.13) and TT (ratio 1.6; RV: 0.75-1.25), and slightly high fibrinogen clotting activity (430 mg/dL). Mixing tests did not correct neither the APTT (ICA 72; control lower than 10), the PT (1.31; control 1.19) or TT (1.38; control 1.1) suggesting an inhibitory effect on different coagulation pathways. FDP were negative. Screening (APTT and dRVVT) and confirmatory tests were performed showing results compatible with positive lupus anticoagulant like effect (LA-like). No time dependent inhibitory effect (characteristic of the anti FVIII inhibitors) was detected. Moreover, FVIII and IX coagulant activities were very low (2 UI/dL and 1.2 UI/dL respectively) probably due to the interference of LAlike effect and/or the paraprotein effect; an apparent activity increase was observed on progressive dilutions of sample plasma patient for both factors. Coagulation activity of the extrinsic pathway factors was normal except for FV (52 UI/dL). Mixing tests did not correct FV activity and no apparent activity increase was observed on progressive dilutions of sample of patient. These behaviour was compatible with a specific inhibitory effect on FV activity. In addition, the inhibitory effect on TT was normalized by progressive dilutions of patient?s plasma, suggesting an interference of the paraprotein on the polymerisation of fibrin. Conclusion: Interferences on coagulation tests due to the paraprotein effect have been previously described mainly on thrombin time; LAlike activity was also reported in multiple myeloma patients. Anti-FV autoantibodies have been identified rarely in patients with monoclonal gammopathies The results of the case presented here suggest multiple inhibitory effects. In addition to the interference on fibrin polymerization and LA-like activity, an inhibitory effect against FV was also detected; further studies are necessary in order to characterize this effect. None of them can be clearly associated with the clinical symptoms of the patient.