Neurofilament light is a biomarker of brain involvement in lupus and primary Sjögren's syndrome.

Background: To test the hypothesis that neurofilament light (NfL) in CSF is a biomarker of CNS involvement in patients with systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (pSS), we measured NfL in CSF from 52 patients with lupus and 54 with pSS and explored associations with clinical, structural, immunological and biochemical abnormalities.

Methods: In CSF, we measured NfL, anti-P antibodies, protein S100B and TWEAK by ELISA and anti-NR2 antibodies by electrochemiluminescence. Anti-phospholipid antibodies and routine immunological tests were performed in blood.

Memory dysfunction in primary Sjögren's syndrome is associated with anti-NR2 antibodies.

Objective: Our understanding of the etiology and pathogenesis of neuropsychiatric involvement in primary Sjögren's syndrome (SS) is incomplete. In systemic lupus erythematosus, it has been reported that antibodies directed against N-methyl-D-aspartate receptor subtype NR2 (anti-NR2) interfere with memory and learning function, as well as mood. This has not been investigated in primary SS; however, the present study was undertaken to advance our understanding of neuropsychiatric involvement in this disease.