Mielitis longitudinal extensa de presentación muy tardía: Una entidad del espectro de la neuromielitis óptica / Extensive longitudinal myelitis of very late presentation. An entity of the spectrum of optic neuromyelitis

Las enfermedades del espectro neuromielitis óptica son trastornos inflamatorios del sistema nervioso central caracterizados por una grave desmielinización y daño axonal inmunomediado que afecta principalmente a los nervios ópticos y médula espinal. Suelen presentars e en edades tempranas, aunque existen algunas comunicaciones en la literatura de pacientes con presentaciones tardías. Presentamos el caso de una mujer de 78 años que consultó por un cuadro de paraparesia grave, trastornos sensitivos y retención urinaria. Se realizó una resonancia magnética de columna cervicodorsal que evidenció una lesión medular longitudinal extensa. Se descartaron otras causas secundarias, basadas en la clínica y en resultados de laboratorio. El dosaje de anticuerpos anti-acuaporina 4 resultó positivo. Se indicó tratamiento con glucocorticoides a altas dosis y plasmaféresis, y mantenimiento con rituximab, obteniendo escasa respuesta clínica. En pacientes con lesiones medulares extensas se deben contemplar múltiples diagnósticos diferenciales según la presentación clínica, hallazgos mediante estudios por imágenes y epidemiología. Asimismo, debe incluir la búsqueda de anticuerpos anti-acuaporina 4 y contra la glicoproteína de la mielina del oligodendrocito, ya que el pronóstico funcional de estos pacientes suele ser desfavorable debido al gran componente destructivo de las lesiones. En consecuencia, el tratamiento temprano es fundamental a fin de limitar el daño agudo y prevenir futuras recaídas, lo cual es especialmente importante en presentaciones tardías de esta entidad debido a la escasa reserva funcional y baja capacidad de remielinización.

Optic neuromyelitis spectrum diseases are inflammatory disorders of the central nervous system characterized by severe demyelination and immunomediated axonal damage that mainly affects the optic nerves and spinal cord. They usually appear at an early age, although there are some reports in the literature of patients with late presentations. We present the case of a 78-year-old woman who consulted for severe paraparesis, sensory disorders, and urinary retention. An MRI of the cervicodorsal spine was performed, showing extensive longitudinal spinal injury. Secondary causes based on clinical observations and laboratory studies were ruled out. The dosage of anti-aquaporin 4 antibodies was positive. Acute treatment with high-dose glucocorticoids and plasmapheresis was indicated, and maintenance with rituximab, obtaining little clinical response. In patients with extensive spinal injuries, multiple differential diagnoses should be considered according to the clinical presentation, findings through imaging studies and epidemiology. Likewise, it should include the search for anti-aquaporin 4 antibodies and against the oligodendrocyte myelin glycoprotein, since the functional prognosis of these patients is usually unfavourable due to the large destructive component of the lesions. Consequently, early treatment is essential in order to limit acute damage and prevent future relapses, which is especially important in late presentations of this entity due to the low functional reserve and low remyelination capacity.

Clinical Usefulness of Cell-based Indirect Immunofluorescence Assay for the Detection of Aquaporin-4 Antibodies in Neuromyelitis Optica Spectrum Disorder

BACKGROUND: The presence of antibodies to aquaporin-4 (AQP4) has been identified as a key characteristic of neuromyelitis optica spectrum disorder (NMOSD), an autoimmune inflammatory demyelinating central nervous system (CNS) disorder. We evaluated the performance of a cell-based indirect immunofluorescence assay (CIIFA) for detecting AQP4 antibodies using antigen prepared with a recombinant AQP4 peptide transfection technique and assessed the usefulness of CIIFA for diagnosis of NMOSD in routine clinical practice. METHODS: Forty-six serum samples from 36 patients as a comparison set and another 101 patients enrolled consecutively from a neurology clinic were included. CIIFA and fluorescence immunoprecipitation assays (FIPA) were performed. CIIFA was performed at 2 different institutions for comparison purposes. RESULTS: CIIFA and FIPA sensitivity in the comparison set was 86% and 79% in neuromyelitis optica (NMO) patients and 55% and 36% in high-risk NMO patients, respectively. The semiquantitative titer measured by CIIFA correlated well with the arbitrary unit (fluorescence units [FU]) derived from FIPA (r=0.66). Titers measured by CIIFA and FIPA were elevated in NMO patients compared to high-risk NMO patients (1:240 vs. 1:180 and 8,390 vs. 4,059 FU, respectively). The frequency of AQP4 antibody detection by CIIFA in 101 consecutively enrolled patients was 100% in NMO and 23% in high-risk NMO patients, while only 4.6% in control patients, including those with multiple sclerosis. CONCLUSIONS: Detection of AQP4 antibodies by CIIFA provides sensitive and highly specific diagnostic information for NMO and high-risk NMO patients, which can be used to differentiate these conditions from other demyelinating CNS diseases.

Clinical Usefulness of Cell-based Indirect Immunofluorescence Assay for the Detection of Aquaporin-4 Antibodies in Neuromyelitis Optica Spectrum Disorder

BACKGROUND: The presence of antibodies to aquaporin-4 (AQP4) has been identified as a key characteristic of neuromyelitis optica spectrum disorder (NMOSD), an autoimmune inflammatory demyelinating central nervous system (CNS) disorder. We evaluated the performance of a cell-based indirect immunofluorescence assay (CIIFA) for detecting AQP4 antibodies using antigen prepared with a recombinant AQP4 peptide transfection technique and assessed the usefulness of CIIFA for diagnosis of NMOSD in routine clinical practice. METHODS: Forty-six serum samples from 36 patients as a comparison set and another 101 patients enrolled consecutively from a neurology clinic were included. CIIFA and fluorescence immunoprecipitation assays (FIPA) were performed. CIIFA was performed at 2 different institutions for comparison purposes. RESULTS: CIIFA and FIPA sensitivity in the comparison set was 86% and 79% in neuromyelitis optica (NMO) patients and 55% and 36% in high-risk NMO patients, respectively. The semiquantitative titer measured by CIIFA correlated well with the arbitrary unit (fluorescence units [FU]) derived from FIPA (r=0.66). Titers measured by CIIFA and FIPA were elevated in NMO patients compared to high-risk NMO patients (1:240 vs. 1:180 and 8,390 vs. 4,059 FU, respectively). The frequency of AQP4 antibody detection by CIIFA in 101 consecutively enrolled patients was 100% in NMO and 23% in high-risk NMO patients, while only 4.6% in control patients, including those with multiple sclerosis. CONCLUSIONS: Detection of AQP4 antibodies by CIIFA provides sensitive and highly specific diagnostic information for NMO and high-risk NMO patients, which can be used to differentiate these conditions from other demyelinating CNS diseases.