Impact of Rituximab on relapse rate and disability in an Ecuadorian cohort of patients with neuromyelitis optica spectrum disorders.

BACKGROUND: Neuromyelitis Optica Spectrum Disorder (NMOSD) is a severe inflammatory demyelinating disease of the central nervous system that often causes disability. Based on evidence from prospective and retrospective studies, Rituximab (RTX) has been used as the first-line of therapy in NMOSD. Nevertheless, evidence of the impact of RTX on relapse rate and disability in Ecuadorian patients with NMOSD is lacking. OBJECTIVE: To evaluate the impact of RTX in an Ecuadorian cohort of patients with NMOSD. MATERIALS AND METHODS: A retrospective study was conducted in a cohort of patients with NMOSD who received treatment with RTX in a third-level hospital in Quito, Ecuador. Digital medical records of NMOSD patients were reviewed to attain sociodemographic data, disease characteristics, and treatment with RTX. The annualized relapse rate ARR, as well as the degree of disability measured through the expanded disability scale (EDSS), was established before and after treatment. RESULTS: Twenty-three patients with NMOSD treated with RTX were included, the mean age of onset of the disease was 37.2 years (range, 13-64.5). The average duration of disease was 8.5 years (range, 1.3-34.4). Positivity for antibodies against aquaporin-4 (AQP4-IgG) was identified in 78% of the patients. The mean duration of the treatment with RTX was 40 months (range, 12-61). After the RTX therapy, the number of relapses was reduced in 91% (21/23) of cases. The annualized relapsed rate (ARR) was reduced with RTX from 1.89 to 0.12 (p <0.001). The mean EDSS was also reduced from 4.8 to 3.9 (p = 0.014). In all patients, the mean EDSS was reduced or stabilized with RTX. Overall, the drug was well tolerated, the most frequent adverse events were infections which were present in 65.2% of cases. CONCLUSIONS: Though with the limitations of and observational study, our data support RTX effectiveness and safety in an Ecuadorian cohort of patients with NMOSD.

Factores pronósticos de la Esclerosis Múltiple / Prognostic factors in Multiple Sclerosis

Resumen La Esclerosis Múltiple es una enfermedad inflamatoria y degenerativa del Sistema Nervioso Central que afecta a la población adulta joven. La prevalencia de esta entidad es heterogénea en el mundo y baja en el Ecuador. El diagnóstico se basa en los criterios de McDonald 2017. Una vez que el diagnóstico se ha establecido, es necesario determinar si los pacientes tienen factores de mal pronóstico los cuales van a generar un impacto en el tipo de tratamiento a elegir. Al momento, se han estudiado factores pronósticos epidemiológicos, clínicos, biomoleculares y de imagen los cuales nos permiten predecir si la enfermedad tiene un comportamiento agresivo o por el contrario un curso benigno. El número de lesiones en las imágenes de resonancia magnética cerebral, la presencia de lesiones en tronco encefálico y médula espinal son los factores que han demostrado tener un impacto en la progresión de discapacidad. La presencia de bandas oligoclonales en el líquido cefalorraquídeo tiene un rol fundamental en la conversión de un síndrome clínico aislado en esclerosis múltiple clínicamente establecida. Los niveles bajos de vitamina D ha demostrado estar asociado con mal pronóstico pero su aplicabilidad en países como el Ecuador es aún tema de investigación.

Abstract Multiple sclerosis is an inflammatory and degenerative disease of the central nervous system which affects young adults. The prevalence of multiple sclerosis in the world is heterogeneous and is low in Ecuador. The diagnosis is based on the McDonald 2017 criteria. Once the diagnosis has been made, it is necessary that any negative factors which will impact the type of treatment used be identified. At this time, factors such as epidemiological, clinical, biomolecular, and magnetic resonance images, which will allow us to identify if the case is aggressive or benign, are studied. The number of lesions shown in a brain MRI, the presence of lesions in the brain stem and spinal cord are factors which have been demonstrated to have an impact on the progression of disability. The presence of oligoclonal bands in the cerebrospinal fluid has a fundamental role in the conversion of an isolated clinical syndrome to multiple sclerosis. Low levels of vitamin D have been associated with a negative prognosis, however how important vitamin D is in the prognosis of MS in countries such as Ecuador is still an area to be studied.