CCL18 plasma levels are increased in progressive MS patients and associated with MRI outcomes of tissue injury (P1.396)

Objective: To investigate correlations of C-C motif ligand 18 (CCL18) levels with clinical and MRI measures in multiple sclerosis (MS) patients.Background: CCL18 is a cytokine that may play a role in both humoral and cell-mediated immunity responses. Very limited information are available in relation to MS. CCL18 has been found highly expressed by foamy macrophages inside MS lesions together with other markers involved in anti-inflammatory processes.Design/Methods: CCL18 plasma levels were evaluated in 138 MS patients (85 relapsing-remitting-RRMS, 53 progressive-PMS) and in 42 age- and sex-matched healthy controls (HC) enrolled in the Cardiovascular, Genetic and Environmental (CEG) study in MS. Association of CCL18 levels with MRI outcomes of disease severity was performed. Partial correlation corrected for age and Mann–Whitney test were used, as appropriate.Results: Higher CCL18 plasma levels were found in PMS compared to RRMS (54.0±20.2 vs 48.1±29.8 ng/mL, p=0.014) and to HC (54.0±20.2 vs 43.5±19.3 ng/mL, p=0.01). Higher CCL18 levels in PMS, were associated with increased T2 lesion volume (LV) (p=0.006), T1-LV (p=0.001), lateral ventricular volume (p=0.032), and decreased grey matter (p=0.012) and cortical (p=0.03) volumes. No associations between CCL18 and lesion and brain volume outcomes were detected in RRMS patients.Conclusions: The study provides in-vivo evidence that CCL18 plasma levels are associated with more severe inflammatory and neurodegenerative MRI outcomes in progressive MS patients.