Anticardiolipin antibodies in normal subjects. Neuropsychological correlates and MRI findings.

BACKGROUND AND PURPOSE

Our aim was to assess the association of elevated anticardiolipin antibody (aCL) titers with silent brain damage and cognitive functioning in middle-aged and elderly normal subjects.

METHODS

We determined the IgM and IgG aCL titers from 233 randomly selected clinically normal participants of a population-based stroke prevention study (age range, 44 to 82 years). aCL titers were categorized into negative (0 to 10 U/L), low positive (10 to 20 U/L), and moderately high positive (> 20 U/L). All participants underwent 1.5-T MRI and demanding neuropsychological testing. Semiautomated measurements of the total white matter hyperintensity area and the size of ventricles and cortical sulci were conducted.

RESULTS

There were 180 subjects (77.3%) with negative, 35 (15.0%) with low positive, and 18 (7.7%) with moderately high positive aCL titers. The frequency and extent of focal and diffuse brain abnormalities were not related to the aCL status of those examined. However, subjects with positive aCL results performed worse than those with negative findings on almost all tests administered, and this effect was mainly IgG titer related. When an ANCOVA test and partial correlations to correct for slight group differences in age and for the presence of major vascular risk factors were used, values of P < .05 were noted on tests assessing mnemonic and visuopractical abilities.

CONCLUSION

Increased aCL titers in normal elderly persons may be associated with subtle neuropsychological dysfunction, but they do not appear to cause any morphological changes as demonstrated by MRI.