Clotting abnormalities in children during maintenance chemotherapy for acute lymphoblastic leukemia.

BACKGROUND

Many of the drugs used in the treatment of acute lymphoblastic leukemia in children may induce modifications in different organs and functions. Following the observation of a recurrent, mild delay in the prothrombin time in ALL children during maintenance chemotherapy, we explored the main parameters of the clotting function.

METHODS

17 children with acute lymphoblastic leukemia were studied during maintenance chemotherapy for clotting function screening evaluation; 15 healthy children, matched for age and sex, were used as controls.

RESULTS

A uniform pattern of slight prolongation of the prothrombin time with significantly reduced levels of factors VII, IX, and a trend toward reduced activity of factor X was observed in the absence of any demonstrable anticoagulant factor.

CONCLUSIONS

Antileukemic maintenance chemotherapy is associated with a subclinical modification of the clotting parameters that is not responsible for hemorrhagic diathesis. Long-term administration of anti-metabolites (6-mercaptopurine and methotrexate) could be responsible for this reversible impairment.