Acquired factor V deficiency in a patient with myeloma and amyloidosis.

INTRODUCTION

We describe our experience with managing an unusual case of acquired Factor V deficiency (aFVd) in a myeloma patient with demonstrated amyloidosis.

METHODS

Following diagnosis, records of previous investigations were sought. Specific clotting factors and inhibitors were tested. The clinical progress and treatment response measured by serial factor V levels and coagulation parameters was then prospectively tracked.

RESULTS

A 57 year-old woman presented with spontaneous right knee haemarthrosis in association with bilateral symmetrical polyneuropathy and proteinuria. Coagulation screen showed prolongation of both PT (18.6 s, normal range [9.9-11.4 s]) and aPTT (41.4 s, normal range [25.7-32.9 s]), which were both fully correctable following a mixing study. Liver function, fibrinogen, clotting factor II/VIII/X assays and disseminated intravascular coagulopathy screen was normal. FV level was reduced (19%, normal range [70-170%]). Inhibitor titer was undetectable. Congenital FVd was excluded as her previous coagulation screen was normal. Bone marrow investigation performed for suspected underlying plasma cell dyscrasia showed 60% neoplastic plasma cells. Congo red staining was positive for amyloid within vascular walls of the marrow trephine. She was diagnosed with light chain myeloma and aFVd. She received Bortezomib/Cyclophosphamide/Dexamethasone (VCD) chemotherapy. After one cycle of VCD, serum kappa free light chain (SFLC) was reduced from 6951 mg/L to 3354 mg/L with serial measurements of FV levels showing increment to 76% and normalization of PT/aPTT.

CONCLUSION

Plasma cell dyscrasia with amyloidosis should be sought as a cause for aFVD, in particular one where bleeding manifestation is profound even with the absence of demonstrable inhibitors.