OBJECTIVES: Magnetic resonance imaging (MRI) of the brain and spinal cord is the 
gold standard for assessing disease activity in multiple sclerosis (MS). MRI is 
an excellent instrument for determination of accumulated damage to the brain and 
spinal cord, but tells us little about ongoing tissue damage. In this study, 
biomarkers of oligodendrocyte, axonal and astrocyte injury were related to MRI 
and clinical findings and used to assess tissue damage in MS.
MATERIALS AND METHODS: Cerebrospinal fluid from 44 patients with 
relapsing-remitting MS, 20 with secondary progressive MS and 15 controls were 
investigated with ELISA to determine levels of myelin basic protein (MBP), 
neurofilament light (NFL) and glial fibrillary acidic protein (GFAp). Patients 
underwent MRI of the brain and spinal cord, and gadolinium enhancing lesions, T1 
lesions and T2 lesions were counted.
RESULTS: Patients in clinical relapse and patients with nonsymptomatic 
gadolinium enhancing lesions had high levels of MBP and NFL, indicating ongoing 
damage to oligodendrocytes and axons. The level of MBP dropped quickly within a 
week from the onset of a relapse, whereas NFL remained elevated for several 
weeks and GFAp slowly rose during the course of a relapse. Relapsing-remitting 
MS patients without gadolinium enhancing lesions had values of MBP, NFL and GFAp 
similar to controls, while patients with secondary progressive disease had 
moderately increased values of all biomarkers.
CONCLUSIONS: Analysis of MBP, NFL and GFAp provides direct means to measure 
tissue damage and is a useful addition to our methods for evaluation of MS.