Renal thromboembolism during treatment with recombinant activated factor VII (rFVIIa) in a child with hemophilia B with factor IX inhibitors

BACKGROUND Serious thromboembolic events connected with rFVIIa therapy in hemophilia patients are rare. Only three cases are reported in children, all of them with hemophilia A. CASE PRESENTATION We present unique case of patient with hemophilia B and high titer inhibitors to coagulation FIX, who developed severe renal damage due to thromboembolic event during rFVIIa therapy, associated with unsuspected renovascular anomalies. CONCLUSION Caution is necessary if hematuria B requires administration of rFVIIa. US color doppler renal imaging before and after drug administration should be sufficient as an early warning.