REFRACTORY GUILLAIN-BARRÉ SYNDROME IN A PATIENT WITH ASYMPTOMATIC MULTIPLE MYELOMA SUCCESSFULLY TREATED WITH LOW-DOSE RITUXIMAB.

Despite being extremely rare, Guillain-Barré syndrome (GBS) has been recognized as a neurological complication of multiple myeloma, with variable responses to plasmapheresis (PEX), intravenous immunoglobulins (IVIG), and anti-myeloma therapies. In this paper, we report a case of a female patient with asymptomatic multiple myeloma (aMM) who initially presented as PEX- and IVIG-refractory GBS. After failure of PEX, IVIG, and anti-myeloma therapy (bortezomib, melphalan, and prednisone), the patient was eventually successfully treated with low-dose rituximab (100 mg/m week in four doses). To the best of our knowledge, this is the first case to report successful treatment of refractory GBS potentially associated to aMM with low-dose rituximab. Additional studies are needed to elucidate the pathophysiological processes and the interplay between the dysregulated immune response, monoclonal immunoglobulin (MG), and neural tissue damage in GBS patients. Also, the potential role of rituximab in the treatment of MG-associated GBS warrants further exploration.