Cerebrospinal fluid immunoglobulins and neuronal antibodies in neuropsychiatric systemic lupus erythematosus and related conditions.

Neuronal antibodies found in the cerebrospinal fluid (CSF) of patients with systemic lupus erythematosus (SLE) may be locally produced, or may enter through a damaged blood-brain barrier. We measured CSF serum/albumin and IgG ratios, oligoclonal banding, and paired CSF/serum neuronal antibody in 36 patients and 98 controls. Only 14% of SLE CSF contained neuronal antibodies; 80% of these had clinically overt neuropsychiatric manifestations. None of 73 patients with noninflammatory central nervous system (CNS) disease had CSF-neuronal antibodies, compared with 8/61 with SLE or related inflammatory CNS disorders (p less than .001). In SLE, CSF neuronal antibodies were accompanied by high titer serum neuronal antibodies (p less than 0.03) or abnormal Q-albumin and occurred only when serum neuronal antibodies were present. CSF-neuronal antibodies appear to be related to immune-inflammatory CNS disease, especially SLE, and may traverse a damaged blood-brain barrier.