[Neuromyelitis optica spectrum disorder in a patient with human immunodeficiency virus].

Background: Neuromyelitis optica spectrum (NMO) is an autoimmune condition with preferential target at the optic nerves and spinal cord. Although HIV infection can also cause neuritis and myelitis, the entity of HIV related to NMO has recently been elucidated, however, little is known about the context of this disease. Objective: To describe the clinical characteristics, imaging, treatment, and functional prognosis in an HIV-positive patient who developed an episode of longitudinally extensive transverse myelitis (LETM) with positive anti-AQP4 antibodies. Clinic case: 36-year-old man with a history of HIV diagnosed in 2017, on antiretroviral treatment. On March 2021 he was admitted for study due to complete spinal cord syndrome, corroborating in MRI a longitudinally extensive lesion from T8-L1, with CSF with and AQP4 seropositivity, a diagnosis of NMO was integrated by Wingerchuk criteria and rituximab is started with symptomatic improvement, objectifying it with the Expanded Disability Status Scale (EDSS) from 4 to 1. Conclusion: NMO entity related to HIV is rare, this phenomenon being classically found at the time of diagnosis or after the start of treatment when the immune system is still capable of developing an exaggerated immune response, however in the case we report the debut of NMO occurred 3 years after diagnosis, contrasting with previously reported cases, so we suggest that some other mechanisms could be involved, such as altered regulation of B cells and a direct viral effect.