Fatal anti-aquaporin-4 seropositive neuromyelitis optica spectrum disorder in tuberculosis

BACKGROUND Neuromyelitis optica (NMO) is an autoimmune inflammatory condition of the central nervous system that is characterized by circulating anti-aquaporin-4 antibodies, transverse myelitis and optic neuritis. NMO spectrum disorders are rarely reported in patients with active pulmonary tuberculosis (TB). We report a fatal case of anti-aquaporin-4 antibody positive NMO spectrum disorder in a patient who was receiving treatment for pulmonary tuberculosis. CASE PRESENTATION A previously healthy 42-year-old Chinese man was diagnosed with smear positive pulmonary tuberculosis. After one month of anti-tuberculosis treatment, he presented with acute generalized weakness and rapid neurological deterioration. Spinal imaging and anti-aquaporin-4 antibody positivity established a diagnosis of neuromyelitis optica spectrum disorder. CONCLUSION This is the first reported case of anti-aquaporin-4 antibody-positive NMO spectrum disorder in a patient with active tuberculosis. It shows the usefulness of testing for anti-aquaporin-4 antibodies while evaluating neurological deterioration in patients with tuberculosis. The literature on the rare association between NMO spectrum disorders and TB is reviewed.