A 32-year-old primigravida at 34 weeks gestation presents with blood pressure of 158/106 mmHg, severe headache, and 4+ proteinuria. Platelet count is 82,000/μL, ALT 180 U/L, LDH 620 U/L, and the patient reports epigastric pain. Which of the following best describes the pathophysiology underlying the thrombocytopenia in this condition?
- A Consumptive coagulopathy from intravascular fibrin deposition causing platelet sequestration in microcirculation
- B Immune-mediated platelet destruction via anti-platelet IgG antibodies triggered by placental antigens
- C Platelet activation and aggregation at sites of endothelial damage with microvascular thrombus formation ✓
- D Bone marrow suppression secondary to elevated endothelin-1 levels reducing thrombopoietin receptor sensitivity
Explanation
HELLP syndrome thrombocytopenia results from platelet activation and aggregation at sites of endothelial injury — the hallmark of pre-eclampsia pathophysiology. Dysfunctional endothelium exposes subendothelial collagen and activates coagulation, causing platelets to aggregate and be consumed. This is distinct from consumptive DIC (option A) which has full coagulopathy with prolonged PT/aPTT; HELLP is primarily a microangiopathic process without classic DIC. Option B (immune ITP) is excluded by the clinical setting. Option D is fabricated; endothelin-1 is elevated in pre-eclampsia but does not suppress bone marrow thrombopoiesis.
Reference: Williams Obstetrics, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.