Fragoso-Loyo H et al. (2007) Interleukin-6 and chemokines in the neuropsychiatric manifestations of systemic lupus erythematosus. Arthritis Rheum 56: 1242–1250

Patients with systemic lupus erythematosus (SLE) can have a wide array of neuropsychiatric manifestations, but despite the high prevalence of these manifestations, an accurate indicator of central nervous system involvement in patients with SLE has not been identified. Cytokines and chemokines are associated with neuropsychiatric symptoms, and therefore a study has been carried out to elucidate the levels of inflammatory molecules in the cerebrospinal fluid (CSF) of patients with neuropsychiatric SLE.

The study included 42 patients with neuropsychiatric SLE, 6 patients with SLE and septic meningitis, 16 patients with SLE without neuropsychiatric symptoms, and 25 patients with nonautoimmune diseases without neuropsychiatric manifestations. CSF samples from all patients were analyzed using bead flow cytometry to detect levels of cytokines (IL-2, IL-4, IL-6, IL-10, TNF and IFNγ) and chemokines (CCL2, CCL5, CXCL8, CXCL9, and CXCL10). Thirty patients with neuropsychiatric SLE had a second CSF sample taken and analyzed 6 months after the first.

Patients with neuropsychiatric SLE had high levels of the type 2 T-helper lymphocyte cytokine IL-6 and of chemokines compared with patients with nonautoimmune diseases and patients with SLE without neuropsychiatric symptoms. Analysis of the second CSF sample in patients with neuropsychiatric SLE showed that all previously elevated levels of inflammatory molecules had decreased.

This study shows that IL-6 and chemokines seem to be accurate indicators of neurologic involvement in patients with SLE, although more details of the pathogenesis of neuropsychiatric SLE remain to be elucidated.