Antiphospholipid antibodies in children.

Sera from children (n = 173) were tested for antiphospholipid antibodies (aPL) using an enzyme immunoassay detecting IgG anti-cardiolipin antibodies (GPL). Sera from adults (n = 100) were also tested. GPL were detected more frequently and at higher levels in children than in adults. Eighty-two per cent of the children and 27% of the adults tested positive (> or = 10 GPL Uml-1) for aPL (p < 0.001). Values of 45 GPLUml-1 or higher were detected in about 5% of the children, and 25 GPLUml-1 or higher in about 5% of the adults. Normal values should be adjusted accordingly.