Summary
To date very few studies that analyze the prevalence of anticardiolipin antibodies
(ACA) in healthy subjects have been reported. No data based on a systematic analysis
of normal subjects with positive ACA is available. The aim of the present study was
to evaluate the prevalance of ACA, its clinical significance and relationship to the
lupus anticoagulant (LA) and other autoimmune parameters in an apparently healthy
population. 552 normal blood donors from a blood bank were randomly selected. ACA
positive donors who consented were monitored over a period of twelve months and tested
every three months. ACA (IgG and IgM isotypes) were quantitated by enzyme linked immunoassay
(ELISA). The prevalance for IgG ACA in our donor population was estimated to be 6.5%,
and 9.4% for IgM ACA, which is similar to the one previously reported for IgG and
slightly higher for IgM. It is worth noting that in our study ACA positive donors
exhibited a progressive negativization. Eight donors with IgG ACA and seven with IgM
ACA remained positive for nine months. Five donors with IgG ACA and four with IgM
ACA had family history of thromboembolic disease. One donor with IgG ACA and two with
IgM ACA had had unexplained miscarriages in the past. We did not find any relationship
between ACA and LA, nor between ACA positivity and the clinical and laboratory data
studied. Pseudopositivity for lues was not found. No thrombotic event occurred in
donors that were positive for ACA during the 12-month follow-up.
