Acquired SERPINC1/antithrombin deficiency during oral contraceptive consumption: a case report

SERPINC1 is a glycoprotein that regulates blood coagulation. SERPINC1 congenital or acquired deficiencies represent a significant risk factor for thromboembolic disease. SERPINC1 acquired defects are observed in very few cases and can occur in many clinical conditions such as treatment with L-asparaginase or oral contraceptive (particularly estrogen derivatives), but these conditions are not routinely investigated.

A 50-year-old Caucasian woman who took gestodene 75 µg/ethinylestradiol 20 µg as oral contraceptive, was sent to our thrombophilia clinic because, on thrombophilia testing, a reduction of SERPINC1 (74%) and a slight increase in circulating D-dimer and homocysteine were found. We investigated triggers of such SERPINC1 reduction, and identified gestodene 75 µg/ethinylestradiol 20 µg use as the most likely candidate. Two months after the discontinuation of the oral contraceptive, SERPINC1 value returned to normal (92%) and D-dimer and homocysteine were normalized.

Each patient has a different sensitivity to contraceptive use. Genetic (or epigenetic) regulation of anticoagulant proteins might account for a different rate of consumption of anticoagulant proteins as oral contraceptives and probably determine the susceptibility to thrombotic events.