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 st udied, all with NP features. CSF was evaluated for intrathecal IgG synthesi s, oligoclonal IgG, and blood-brain barrier impairment. Sera and CSF were t ested by ELISA for the presence of aCL-IgG and aCL-IgM with and without bet a(2) glycoprotein (beta(2) GPI) cofactor. CSF and sera of 50 low back pain patients served as controls. Six patients were aCL(+) and nine aCL(-). In a ll patients the general CSF examination was normal. In all patients the val ue of indices of intrathecal IgG synthesis were normal but oligoclonal prot ein was present in the CSF of three patients. In none of the patients was t he blood-brain barrier impaired. Neither aCL-IgC nor aCL-IgM was detected i n the CSF of any NP-SLE patient. Mean levels of aCL in patients without cof actor beta(2) GPI and with cofactor were as follows: for IgG class 0.005 an d 0.057 OD (negative); for IgM class 0.004 and 0.024 OD (negative). We coul d not detect aCL in the CSF of patients with NP-SLE, even if sera were posi tive for aCL.