High level of anticardiolipin antibodies is an unusual finding in an unselected stroke population

Anticardiolipin antibodies (ACA) were analysed in 502 consecutive patients admitted to our stroke unit Elevated ACA levels ≥11 units) were found in 20 of 396 patients (5%) with ischemic stroke and TIA, in none of 42 patients with cerebral haematomas and in five of 64 patients (8%) with other diagnoses than stroke. There were no statistically significant differences in occurrence of ACA in these groups. Markedly elevated ACA levels (> 20 units) were found in nine of the 396 patients (2%) with TIA/ischemic stroke. The frequency of ACA was higher in the age group 40-50 years (15%) than in the age group 50-90 years (3.6-6.0%). Re-examination in 18 of the 20 patients with ischemic stroke and elevated ACA levels after 26-395 days (mean 100 days) showed that in 10 patients ACA levels were lower (difference ≥ 6 units = 2 SD), compared to the initial value, whereas eight patients had unchanged ACA levels. The occurrence of previous deep venous thrombosis was significantly more common in patients with elevated ACA levels, otherwise there were no differences concerning earlier stroke, risk factor analysis or other laboratory parameters between patients with and without elevated ACA levels. In conclusion, we found elevated ACA levels in patients with ischemic stroke at a rather low prevalence as compared to most previous studies. The clinical relevance of ACA is uncertain, especially in patients with multiple risk factors. We recommend screening for ACA only in stroke patients < 50 years of age, or when the antiphospholipid syndrome is suspected.