[Anti-PF4 antibodies and thrombophlebitis in a child with cerebral venous thrombosis]

We report the case of a 13-year-old girl, with a cerebral venous thrombosis treated initially by heparin. In front of this early thrombocytopenia, in spite of the absence of preliminary treatment by heparin, the "heparin-dependent" anti-PF4 antibodies ELISA assay was realized and turned out to be strongly positive. In spite of the negativity of the specific functional tests, the heparinotherapy was substituted by a treatment by danaparoïd of sodium, allowing a clinico-biological improvement. Because of the low score of HIT imputability, we realized a specific antibodies anti-PF4 alone assay which was strongly positive. This specific positivity probably explains the positivity of the antibodies anti PF4 "heparin-dependent" assay. The originality of this case lies in the young age of the patient and in the probably pathogenic character of these unusual antibodies, in addition markers of an auto-immune disease.