Determination of systemic inflammatory biomarkers in multiple sclerosis.

Background: Multiple sclerosis (MS) is one of the most common demyelinating diseases of the central nervous system. We aimed to investigate serum and cerebrospinal fluid levels of different laboratory inflammatory biomarkers in patients with MS. Methods: A total of 120 subjects participated in the study, 60 of whom were diagnosed with MS, 30 with the final diagnosis of non-inflammatory diseases of the central nervous system (CNS), and 30 healthy subjects representing the control group. Regarding the progression of radiological findings after 2 years from the initial diagnosis, the MS group was divided into stationary radiological findings (n=30) and radiologically proven disease progression (n=30). In all patients, we analyzed levels of laboratory inflammatory biomarkers: C reactive protein (CRP), Neutrophil-to-lymphocyte ratio (NLR), Growth differentiation factor 15 (GDF15) in serum samples, and neurofilaments (NFs) in cerebrospinal fluid (CSF). NFs and GDF15 were analyzed initially, while CRP and NLR values were analyzed initially and after two years. Results: We found statistically lower GDF15 values and initial CRP values in the MS group regarding the group with non-inflammatory diseases of the CNS (p<0.0001). On the other side, we determined a significant elevation of laboratory markers CRP and NLR, initially and after a two-year period, in the MS subgroup with the progression of magnetic resonance imaging (MRI) findings (p<0.0001 and p=0.050, respectively). Also, we found a positive correlation between CRP and NFs (r=0.243, p=0.04), as well as a positive correlation between CRP and GDF15 in patients with MS (r=0.769, p<0.0001). Conclusions: We found a significant elevation of laboratory markers of systemic inflammation, CRP, and NLR in MS patients who developed disease progression based on MRI findings. There is a need for further studies to validate current parameters to be considered as useful markers of MS activity and disability.