Utility of osteopontin in cerebrospinal fluid as a diagnostic marker for neuropsychiatric systemic lupus erythematosus
The whole protein of osteopontin (OPN full) and its cleaved form (OPN N half) are involved in the immune response and the migration of immune cells to an inflammatory lesion. We have reported that serum OPN full and urine OPN N half are elevated in lupus nephritis (LN) Neuropsychiatric systemic lupus erythematosus (NPSLE) is a refractory complication of SLE. To investigate whether OPN full and OPN N half could serve as diagnostic markers for NPSLE, and to elucidate their role in NPSLE pathogenesis, the concentrations of OPN full and OPN N half in cerebrospinal fluid (CSF) were measured in NPSLE and non NPSLE patients. We found that the concentration of OPN full in the CSF was significantly higher in NPSLE than in non NPSLE, and it decreased after treatment. When the cutoff value of OPN full in CSF was set to 963.4 ng/ml, the sensitivity and specificity for the diagnosis of NPSLE were 70% and 100% respectively. The correlation analysis of OPN full, OPN N half and various cytokines/chemokines suggested that the cytokines/chemokines could be divided into two clusters: cluster A, which contains OPN full and cluster B, which contains interleukin 6. OPN full in CSF could be a novel diagnostic marker for NPSLE.
Lupus