Pilot Study of alpha1-antitrypsin to Treat Neuromyelitis Optica Relapses

Inclusion Criteria: * Provide written informed consent. * Age ≥18 and ≤ 75 years. * Diagnosis of NMO or NMO spectrum disorder (NMOSD). The diagnosis of NMO will conform to the 2006 Wingerchuk criteria.1, 2 The diagnosis of NMOSD will include patients with relapsing optic neuritis and aquaporin-4 antibody (AQP4) seropositivity or patients with relapsing longitudinally extensive transverse myelitis and AQP4 seropositivity.2-5 NMO and NMOSD will be collectively referred to as NMO. * AQP4-antibody positivity. * Present with an acute NMO attack (see definition below). * Patients must not have a history of clinically significant infusion reactions with administration of biologic agents. * If on chronic treatment for NMO, treatment was initiated at least 3 months earlier and medication dose is stable. Additional restrictions will be placed on changes in concomitant symptomatic medications. * A female subject of childbearing potential must have a negative serum pregnancy test at the screening visit and agree to use a medically reliable method of contraception (e.g., barrier with either spermicide or hormonal contraception) until study completion. * Agree to answer the questions on the Columbia Suicide Severity Rating Scale at each specified visit. Exclusion Criteria: * A woman who is pregnant, breastfeeding, or planning pregnancy. * If the patient is enrolled in any other experimental trial or on other experimental therapy. * If the patient has a known IgA deficiency with IgA-antibodies. * Any medical condition or clinically significant laboratory abnormality that in the Investigator's judgment may affect the patient's ability to safely complete the study. Acute attack: * The occurrence of new or worsening neurological symptoms consistent with optic neuritis, transverse myelitis, or a brain lesion that develop acutely (i.e., patients must present within 7 days of symptom onset). * The symptoms must persist for at least 48 hours, are not attributable to confounding clinical factors (e.g., fever, infection, injury, adverse reactions to concomitant medications). * The symptoms must be accompanied by sensory, motor or visual acuity objective deficits, which must be verified by the examining physician. * A single episode of a paroxysmal symptom (e.g., tonic spasm) is not a relapse; however, the new onset of multiple occurrences of a paroxysmal symptom over at least 48 hours can be a relapse if accompanied by a new, corresponding objective deficit. * Sensory symptoms with no change on clinical examination, fatigue, mood change, or bladder or bowel urgency or incontinence will not be sufficient to establish a relapse.