Neurologic Autoimmunity in the Immunodeficient: A Case of Neuromyelitis Optica Developing in an Individual with Common Variable Immunodeficiency
Monica Solorio1, Evan Luxenberg2, Kathleen Munger3, Andrew Ayers4, Yujie Wang2
1University of Washington School of Medicine, 2University of Washington, Department of Neurology, 3Multicare Health System, 4University of Washington, Medicine, Division of Allergy & Infectious Diseases
Objective:
Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing CNS autoimmune disorder most commonly characterized by longitudinally extensive transverse myelitis (LETM) and/or optic neuritis (ON). Common variable immunodeficiency (CVID) is the most common clinically significant primary immunodeficiency, characterized by immune dysregulation and decreased immunoglobulin production. Autoimmunity is common in CVID, however neurologic autoimmunity is exceedingly rare and co-occurrence with NMOSD has not been previously described.

Background:
We present the case of a 62-year-old man with CVID who presented with LETM and was subsequently diagnosed with NMOSD.  
Design/Methods:
NA
Results:
Our patient had been treated with intravenous immunoglobulin therapy for CVID for 5 years when he presented with subacute onset of ascending paraparesis, sensory loss, and urinary retention. MRI identified LETM from C3 to T9. Anti-aquaporin 4 (AQP4) serology was markedly elevated at a titer of >1:100,000. He responded well to immunotherapy.
Conclusions:
Autoimmunity in CVID is thought to be from loss of regulatory T cell function as well as increased peripheral plasmablasts. We highlight the importance of considering autoimmune CNS diseases in primary immunodeficiencies as well as review possible pathophysiology of neurologic autoimmunity in CVID. 
10.1212/WNL.0000000000205728