Rituximab and intravenous immunoglobulin (IVIG) for the management of acquired factor VIII inhibitor in multiple myeloma: case report and review of literature.

Acquired factor VIII inhibitor (AFI) is a rare disorder and is even more uncommon in multiple myeloma patients, with only five cases reported in literature. Solid and hematologic malignancies, autoimmune conditions, drugs, and infections are the conditions commonly associated with the development of this condition, with mucocutaneous bleeding being the most common presenting sign. Diagnosis is usually made with the laboratory finding of an elevated partial thromboplastin time aPTT that cannot be corrected by plasma mixing, and further confirmed by low factor VIII activity/antigen levels along with elevated factor VIII inhibitor levels using the Bethesda assay. Treatment is usually based on the clinical picture with factor VIII inhibitor bypass activity (FEIBA) and recombinant factor VIIa (rFVIIa) employed to control acute bleeding; steroids and cyclophosphamide to suppress the inhibitor with Rituximab, in combination with other immunosuppressants in cases not suitable for steroids, and finally wherever possible, to remove the offending drug or control the underlying pathology that might predispose to the development of this condition. This case report highlights the successful management of a myeloma patient who presented with life-threatening hemorrhagic pericardial effusion and hemarthrosis. The patient was treated with FEIBA to control the acute bleeding and then received Rituximab in combination with intravenous immunoglobulin to suppress the AFI.