Prompt Response and Long Term Remission of Refractory MGUS Related Acquired Hemophilia with Bortezomib

We describe a case of a 81 years old woman who was admitted in the neurology ward of a tertiary university referral hospital for the work-up of relapsing syncopal events. During her stay a spontaneous right elbow bleeding appeared and a coagulation factor determination showed a FVIII concentration < 1% . Acquired Haemophilia A (AHA) was suspected and methylprednisolone therapy was promptly started. As bleeding was continuing the patient received Prothrombine Concentrate and tranexamic acid. A Factor VIII-inhibitor with 65,75 Bethesda Units (BU) was detected. Three months of full treatment with corticoids, cyclophosphamide, immune-adsorption and high-dose FVIII infusion failed to achieve complete bleeding control and inhibitor elimination. After a IgA kappa Monoclonal Gammopathy of Undetermined Significance (MGUS) had been diagnosed, assuming that paraproteinemia can act as inhibitor, the patient was started on Bortezomib, a proteasome 26S inhibitor, employed in the care of Multiple Myeloma (MM). After two cycles the patient achieved complete remission without developing any side effects. This case suggests that Bortezomib could be a promising option in eradicating inhibitors in AHA in MGUS and MM patients.