A longitudinal study of anticardiolipin antibody levels and cognitive functioning in systemic lupus erythematosus

Objective. To determine the relationship between persistently raised antica rdiolipin antibody (aCL) levels and neuropsychological performance in patie nts with systemic lupus erythematosus (SLE). Methods. Forty-five patients with SLE underwent a detailed neuropsychologic al assessment on 2 occasions 12-18 months apart. Serum samples stored since the time of previous assessments as well as samples obtained 6 months to 2 years before the first neuropsychological assessment were tested for IgG a CL levels. Patients were divided into 4 groups according to the number of t imes their aCL levels were elevated (never, once, twice, 3 times). A wide-r anging battery of new neuropsychological tests was utilized, and the result s were compared with double-stranded DNA (dsDNA) antibody levels, C3 levels , and results of magnetic resonance imaging (MRI). Results. Analysis of variance revealed that the group with persistently ele vated aCL levels performed less well than the other groups. At the first ne uropsychological assessment, poorer performance by this group was noted for letter cancellation (P = 0.02), trail making task B (P = 0.04), and digit span (P = 0.03). At the second assessment, letter cancellation (P = 0.01), trail making task A (P = 0.03), trail making task B (P = 0.01), word fluenc y (P = 0.01), and reaction time (P = 0.05) were impaired. In contrast, no s ignificant differences in neuropsychological test results were identified w ith respect to DNA antibody or C3 levels. MRT abnormalities were associated with both persistent elevation of aCL levels and low C3 levels. Conclusion. Levels of IgG aCL that were persistently elevated over a 2-3-ye ar period (as opposed to never or occasionally elevated) were associated wi th significantly poorer performance in cognitive function by patients with SLE. Tasks requiring speed of attention and concentration appear to be part icularly affected.