Aquaporin-4 (AQP4) antibody-positive neuromyelitis optica spectrum disorder (NMOSD) complicated with acute pancreatitis: A case report

RATIONALE: Neuromyelitis optica spectrum disorders (NMOSD) is an autoimmune-mediated central nervous system (CNS) inflammatory demyelinating disease characterized by 6 major clinical syndromes, including myelitis, optic neuritis, area postrema syndrome, symptomatic cerebral syndrome, brainstem syndromes, and acute diencephalic clinical syndrome. PATIENT CONCERNS: A 32-year-old female, complaining of numbness in her right limb for 1 month, was diagnosed with aquaporin-4 antibody (AQP4-IgG)-positive NMOSD. She developed acute pancreatitis (AP) during disease relapse, representing a rare extra-neurological manifestation of NMOSD. DIAGNOSES: Spinal contrast-enhanced magnetic resonance imaging scan indicated hyperintense lesions on the T2-weighted sequence in the spinal cord at C2/C4 at the initial onset and extending from C2 to C6 vertebral levels at the recurrence of the disease. Serological profiling demonstrated a significant rise in AQP4-IgG titers (from 1:100 to 1:1000). During the recurrence of NMOSD, the patient manifested acute gastrointestinal symptoms, including severe epigastric pain with emesis. Laboratory tests revealed profound hyperamylasemia (amylase, 2293.8 U/L; pancreatic amylase, 1843.6 U/L). Abdominal computed tomography scan demonstrated definitive signs of AP, confirming the diagnosis. INTERVENTIONS: She received methylprednisolone and mycophenolate mofetil for NMOSD treatment. When AP occurred, she was placed on nil per os status and treated with gabexate and esomeprazole. OUTCOMES: The patient was discharged with relief of neurological dysfunction symptoms and maintained on nasojejunal tube feeding for nutritional support. Three months after discharge, clinical assessment revealed stable myelitis symptoms. There was no evidence of pancreatitis recurrence during the follow-up period. LESSONS: This case suggests that AQP4-IgG-mediated immune damage may not be confined to the CNS. There may be a possible association between NMOSD and AP in the pathophysiological mechanisms. AP may be a rare extra-CNS complication of NMOSD. Our case expands the spectrum of potential systemic complications in NMOSD, highlighting the need for increased clinical vigilance.