THROMBOSES IN CHILDREN WITH ACUTE LYMPHOB LASTIC-LEUKEMIA TREATED WITH THE COALL-PROTOCOLL

To see whether the clinical manifestation of thrombotic events or hemo rrhagic infarctions appears as a relevant problem when treating childr en with acute lymphoblastic leukemia (ALL) concerning the COALL therap y-protocoll, we started an inquiry of the participating hospitals. The mentioned protocoll was designed by the German Society for Pediatric Oncology and Hematology to treat ALL in childhood. All participants ga ve us information about the treatment period from January 1989 to Dece mber 1992. In 6 from 286 treated patients a thromboses appeared in cli nical terms. None of them was connected with a lethal outcome. There w as no observation of a hemorrhagic infarction. The overall thromboses frequency was 2.1%. In 1.4% patients ''symptomatic'' thrombosis develo ped close to a continious venous catheter, which can be considered as a thrombogene risk factor. About 0.6% (2/286) of the patients develope d the thrombotic events without another risk factor. They can be regar ded as ''idiopathic''. 1/2 idiopathic thromboses led to a life threate ning situation. There are two important factors that can enhance throm boses: 1) the therapy period, especially induction therapy and applica tion of asparaginase and 2) a continious venous catheter. The fact tha t asparaginase is not used during the induction therapy is a character istic of the COALL protocoll. It seems to be useful to differentiate b etween ''idiopathic'' and ''symptomatic'' thrombotic events, because ' 'symptomatic'' thromboses appear also in non-leukemic diseases quite f requently.