Increased osteopontin levels in the cerebrospinal fluid of patients with multiple sclerosis

Objective: To determine cerebrospinal fluid levels of osteopontin (OPN), a proinflammatory cytokine that was found to be overexpressed in multiple sclerosis lesions and increased in plasma during relapses and in secondary progressive multiple sclerosis. Design: Case series. Osteopontin, interleukin 12p40 (IL12p40), IL-10, and matrix metalloproteinase 9 were measured by enzyme-linked immunosorbent assay by an investigator unaware of the patients' diagnoses. Patients: Consecutive patients with multiple sclerosis (n=27), or other inflammatory (n=11) or noninflammatory (n=23) neurological diseases, undergoing lumbar puncture, were investigated. Results: Osteopontin was significantly elevated in the cerebrospinal fluid of patients with multiple sclerosis (mean [SD], 415 [186] ng/mL) and other inflammatory diseases (563 [411] ng/mL) compared with those with noninflammatory neurological diseases (286 [150] ng/mL). Cerebrospinal fluid OPN levels were slightly higher than plasma OPN levels. Cerebrospinal fluid OPN levels positively correlated with the ability to detect cerebrospinal fluid IL-12p40. Conclusion: Osteopontin in the cerebrospinal fluid may be, in part, of central nervous system origin, and may play an important role in central nervous system inflammation.