[Therapy-refractory pelvic vein thrombosis in pregnancy as a sequela of protein S deficiency]

Area of Science:

• Hematology
• Genetics

Background:

• Protein S (PS) is a crucial cofactor for activated Protein C, mediating anticoagulation.
• PS deficiency, whether inherited or acquired, is linked to recurrent thromboembolic events.
• Physiological PS levels decrease during pregnancy, puerperium, and oral contraceptive use.

Observation:

• A 26-year-old pregnant woman (39 weeks gestation) presented with descending iliofemoral venous thrombosis.
• Initial venous thrombectomy with an arteriovenous fistula was followed by recurrent thrombosis postpartum.
• Repeat thrombectomy and lysis therapy failed to resolve subsequent recurrent thromboses.

Findings:

• Coagulation analysis revealed markedly reduced functional Protein S activity (34%), the sole pathological finding.
• The patient's mother has a 20-year history of recurrent thromboembolic complications managed with coumarin therapy.
• These factors strongly suggest an underlying inherited Protein S deficiency in the patient.

Implications:

• This case underscores the critical role of Protein S in preventing thrombosis, especially during pregnancy.
• Identifying inherited Protein S deficiency is vital for managing recurrent thromboembolic events.
• Early diagnosis and appropriate anticoagulation strategies are essential for patients with PS deficiency.