SPP1 and myeloid sarcoma: To further elucidate the role of osteopontin in acute inflammatory MS activity, we explored the correlation between the relapse distance, expressed by the time interval elapsing between the last clinical relapse and the lumbar puncture (LP), and the CSF levels of osteopontin and a group of inflammatory cytokines and adipokines such as resistin, plasminogen activator inhibitor-1 (PAI-1), osteoprotegerin, IL-1β, IL-2, IL-6, IL-1 receptor antagonist (IL-1ra).