A 30-year-old woman is described with both a cerebral venous thrombosi
s and a deep vein thrombosis of her leg in association with an exacerb
ation of her ulcerative colitis. Laboratory investigations revealed a
transient functional APC resistance, without Factor V mutation, and a
mild hyperhomocysteinaemia. After colectomy the APC ratio was normal.
These findings may form a partial explanation of the thrombophilia see
n in some patients with active ulcerative colitis.