Raised CSF levels of soluble adhesion molecules across the clinical spectrum of multiple sclerosis

Endothelial activation is considered an important step in multiple sclerosis (MS) lesion formation, elevated cerebrospinal fluid (CSF) and serum levels of certain adhesion molecules being associated with varying stages of disease activity and clinical course. CSF and serum sVCAM-1, sICAM-1, sE-selectin and sL-selectin were measured by ELISA in 16 primary progressive (PPMS), 16 secondary progressive (SPMS) and 43 relapsing-remitting MS patients (RRMS) and compared with 20 inflammatory (IND) and 46 non-inflammatory neurological disease (NIND) controls. CSF sVCAM-1 and sICAM-1 were increased in all MS groups vs. NIND with no significant differences between the MS groups. CSF sE-selectin (p = 0.007) and the sE-selectin index (p = 0.01) were elevated in PPMS vs. RRMS in relapse, whilst serum sE-selectin was significantly raised in PPMS compared to RRMS in remission (p = 0.005), RRMS in relapse (p = 0.004), NIND (p = 0.03) and IND (p = 0.05). Adhesion molecule levels in both progressive MS groups were similar. These results provide evidence for a distinct inflammatory component in PPMS and for immunological heterogeneity between the clinical subgroups of MS.