Evaluation of Cerebrospinal Fluid for the Presence of Anticardiolipin Antibodies (aCL) in NP-SLE Patients

Many neurological or psychiatric manifestations of SLE (NP-SLE) are related to the presence of anticardiolipin antibodies (aCL) in the patient’s sera. The aim of this study was to evaluate the presence of aCL in cerebrospinal fluid (CSF) in SLE patients with NP features. Fifteen SLE patients were studied, all with NP features. CSF was evaluated for intrathecal IgG synthesis, oligoclonal IgG, and blood–brain barrier impairment. Sera and CSF were tested by ELISA for the presence of aCL-IgG and aCL-IgM with and without β₂ glycoprotein (β₂ GPI) cofactor. CSF and sera of 50 low back pain patients served as controls. Six patients were aCL(+) and nine aCL(–). In all patients the general CSF examination was normal. In all patients the value of indices of intrathecal IgG synthesis were normal but oligoclonal protein was present in the CSF of three patients. In none of the patients was the blood–brain barrier impaired. Neither aCL-IgG nor aCL-IgM was detected in the CSF of any NP-SLE patient. Mean levels of aCL in patients without cofactor β₂ GPI and with cofactor were as follows: for IgG class 0.005 and 0.057 OD (negative); for IgM class 0.004 and 0.024 OD (negative). We could not detect aCL in the CSF of patients with NP-SLE, even if sera were positive for aCL. Received: 6 July 1999 / Accepted: 18 January 2000