The predictive value of CSF multiple assay in multiple sclerosis: A single center experience

Multiple sclerosis (MS) is a chronic, immune-mediated, inflammatory, neurodegenerative disorder. Many studies are investigating the potential role of body fluid biomarkers as prognostic factors for early identification of patients presenting with clinical isolated syndrome (CIS) at high risk for conversion to MS or to recognize RRMS patients at high risk for progression.

To evaluate the correlation between levels of BAFF, chitinase 3-like 1 (CHI3L1), sCD163, Osteopontin (OPN), both on serum and cerebral spinal fluid (CSF), and the disease activity and progression. We also want to explore a possible relationship between serological and CSF biomarker's levels.

We enrolled 82 patients between June 2014 and June 2016. Seventy-one received a diagnosis of demyelinating disease of CNS (46 RRMS and 25 CIS), while 11 were affected by other neurological diseases. All patients underwent a neural axis MRI, lumbar puncture and blood samples. Levels of BAFF, CHI3L1, sCD163, OPN on serum and CSF were analyzed by Luminex xMAP system, with a kit 11-plex ad hoc.

The CSF CHI3L1, sCD163 and OPN levels were significantly higher in MS patients than in controls. We did not find significant differences in serum CHI3L1, sCD163 and OPN levels, nor CSF or serum BAFF levels between patient and control groups. We found significantly higher CSF level of sCD163 and CHI3L1 in all patients' subgroups compared with controls, while OPN was higher in CIS and RR subgroups. We did not find significant differences for serum and CSF levels of all the markers between patients with or without clinical or radiological disease activity. CSF sCD163 and CHI3L1 levels was significant higher in CIS patients who converted to MS (p < 0.05). Using ROC curve analysis, CSF sCD163 resulted the best predictive factor. CSF CHI3L1 and OPN levels resulted useful independent predictors too. Combined ROCs of those three analytes demonstrated a better predictive value, with sCD163 and CHI3L1 resulting as the best combination.

CSF sCD163 CHI3L1 and OPN levels were higher in MS patients whereas serum CHI3L1, sCD163 and OPN levels did not show differences compared with controls. This finding confirms the high CSF specificity with regards to the analysis of processes, inflammatory and non-inflammatory, that occur within the CNS.