A case of a patient with neuromyelitis optica spectrum disorder with hypogammaglobulinemia managed with immunoglobulin and zilucoplan

There are currently four FDA approved medications for the treatment of neuromyelitis optica spectrum disorder (NMOSD) in the United States. Each of these medications is formulated as a monoclonal antibody. While these novel treatments have greatly advanced the prevention of relapses in NMOSD, they can unfortunately be cleared by immunoglobulin or plasma exchange (PLEX). Given the high prevalence of hypogammaglobulinemia with extended use of B-cell depletion therapites, and rituximab in particular, this can present a treatment dilemma when attempting to correct and treat this immunodeficiency in NMOSD patients requiring continued maintenance therapy for relapse prevention. Here we detail a case of an NMOSD patient with severe hypogammaglobulinemia resulting from previous long-term rituximab use and how this was treated with supplemental immunoglobulin in conjunction with zilucoplan for relapse prevention.