Guillain-Barr Syndrome Caused by Cytomegalovirus after Multiple Myeloma Treatment

Both humoral and cell-mediated immunity of the patient affected by multiple myeloma (MM) are impaired; thus, infection is the main cause of the onset of symptoms and death caused by MM. Bortezomib is a first-line drug approved for patients with multiple myeloma (MM) and has significantly increased their overall survival. However, bortezomib-induced peripheral neuropathy (PN) remains a significant side effect that has led to its discontinuation in some patients. Guillain-Barre syndrome (GBS) is thought to be related to immune damage, and most patients have cytomegalovirus (CMV), Epstein-Barr virus (EBV), or mycoplasma infection before onset. Cases of GBS secondary to MM are rare.