A prospective analysis of cognitive function and anticardiolipin antibodies in systemic lupus erythematosus

Objective. To prospectively analyze the association between changes in cogn itive function and circulating anticardiolipin antibodies (aCL) over a peri od of 5 years in patients with systemic lupus erythematosus (SLE). Methods. Cognitive function was assessed in 51 unselected female SLE patien ts at baseline and after a mean follow up of 64.5 months (range 52-71 month s), using standardized tests of cognitive function, i.e., the Wechsler Adul t Intelligence Scale--Revised, the Wechsler Memory Scale--Revised, and the California Verbal Learning Test. Circulating IgG, IgA, and IgM aCL and anti -double-stranded DNA (anti-dsDNA) antibody levels were determined by enzyme -linked immunosorbent assay on 4-7 occasions over the same time period. Per sistent antibody reactivity was defined as levels more than 2 standard devi ations (moderately positive) and more than 5 standard deviations (highly po sitive) above the mean for normal controls over the duration of the study. Changes in overall cognitive performance and in raw scores on individual co gnitive tests were compared in patients who were persistently positive or n egative for aCL. Results. At baseline 11 patients (22%) were cognitively impaired, compared with 7 (14%) at followup. Between 16% and 37% of patients had persistently elevated aCL levels of different isotypes. There was no significant differe nce in the prevalence of overall cognitive impairment in patients who were persistently positive for aCL compared with those who were not. In contrast , over the period of study, patients who had persistent Ige aCL positivity had a reduction In psychomotor speed, and patients who had persistent IgA a CL positivity had a reduction in conceptual reasoning and executive ability . Similar associations with anti-dsDNA antibodies were not found. Conclusion. These results suggest that Ige and IgA aCL may be responsible f or long-term subtle deterioration in cognitive function in patients with SL E.