Neurofilament light chain in the assessment of patients with multiple sclerosis / Neurofilamento de cadeia leve na avaliação de pacientes com esclerose múltipla

ABSTRACT Multiple sclerosis (MS) is an autoimmune, inflammatory, and degenerative disease of the central nervous system. Axonal degeneration is triggered by inflammation and is the pathological substrate of progressive disability in patients with MS. Therapeutic interventions can reduce inflammatory activity, thus delaying neurodegeneration and the progression of disability. Disease activity and neurodegeneration are assessed mainly through clinical evaluation and magnetic resonance imaging. These measures lack sensitivity and accuracy, so new biomarkers are necessary. Several markers have been studied and to date the most promising is neurofilament light (NfL), a component of the axonal cytoskeleton, which is released into cerebrospinal fluid (CSF) following axonal damage. In the present study, we review the current knowledge about CSF NfL determination in MS, clinically isolated syndrome, and radiologically isolated syndrome, and critically discuss how CSF NfL measurement may contribute to therapeutic decision-making in these patients.

RESUMO A esclerose múltipla (EM) é uma doença autoimune, inflamatória e degenerativa do sistema nervoso central. A degeneração axonal é deflagrada pelo processo inflamatório e é o substrato patológico da incapacidade na EM. As intervenções terapêuticas reduzem a inflamação retardando a neurodegeneração e a progressão da incapacidade. A neurodegeneração é avaliada pelo quadro clínico e pela ressonância magnética. Estas mensurações não suficientemente acuradas, havendo necessidade de novos biomarcadores. Diversos biomarcadores têm sido estudados e, até o presente, o mais promissor é o neurofilamento de cadeia leve (NfL). O mesmo é um componente do citoesqueleto que é liberado no líquido cefalorraquidiano após injúria axonal. No presente estudo nós revisamos o conhecimento atual acerca do NfL na EM, síndrome clinica isolada e síndrome radiológica isolada, discutindo criticamente como a determinação deste biomarcador pode contribuir na tomada de decisões clínicas.

Oligoclonal bands in the cerebrospinal fluid and increased brain atrophy in early stages of relapsing-remitting multiple sclerosis / Bandas oligoclonales en líquido cefalorraquídeo y incremento de la atrofia cerebral en estadios tempranos de pacientes con esclerosis múltiple forma recaída-remisión

OBJECTIVE: To determine if the presence of oligoclonal bands (OB) at early stages of multiple sclerosis was associated with higher brain atrophy, when compared with patients without OB. METHODS: Relapsing-remitting multiple sclerosis (RRMS) patients with less than two years of disease onset and OB detection in cerebrospinal fluid (CSF) were included. SIENAX was used for total brain volume (TBV), gray matter volume (GMV), and white matter volume (WMV). RESULTS: Forty patients were included, 29 had positive IgG-OB. No differences were found between positive and negative patients in gender, expanded disability status scale (EDSS), treatment received, and T2/T1 lesion load. TBV in positive IgG-OB patients was 1.5 mm³ x 10(6) compared with 1.64 mm³ x 10(6) in the negative ones (p=0.02). GMV was 0.51 mm³ x 10(6) in positive IgG-OB compared with 0.62 mm³ x 10(6) in negative ones (p=0.002). No differences in WMV (p=0.09) were seen. CONCLUSIONS: IgG-OB in the CSF was related to neurodegeneration magnetic resonance (MR) markers in early RRMS.

OBJETIVO: Evaluar si la presencia de bandas oligoclonales (BO) en líquido cefalorraquídeo (LCR) de pacientes con esclerosis múltiple recaídaremisión (EMRR) se asociaba con mayor atrofia cerebral al inicio de la enfermedad. MÉTODOS: Pacientes con EMRR con menos que dos años del inicio de la enfermedad y en quiénes se realizó la búsqueda de IgG-BO en LCR fueron incluidos. SIENAX fue usado para la medición del volumen cerebral total (VCT), volumen de substancia gris (VSG) y volumen de sustancia blanca (VSB). RESULTADOS: Cuarenta pacientes fueron incluidos, 29 tenían IgG-BO positivo. No fueron encontradas diferencias entre pacientes positivos y negativos en: género, expanded disability status scale (EDSS), tratamiento recibido y carga lesional en resonancia magnética. El VCT en pacientes IgG-BO positivos fue de 1,5 mm³ x 10(6) versus 1,64 mm³ x 10(6) en BO negativo (p=0,02). El VSG fue 0,51 mm³ x 10(6) BO positivo versus 0,62 mm³ x 10(6) BO negativo (p=0,002). No fueron encontradas diferencias en VSB (p=0,09). CONCLUSIONES: La presencia de IgG-BO en el LCR se asoció con signos de neurodegeneración temprana en este estudio.