Match each patient's clinical presentation and advanced hemostatic laboratory findings with the correct underlying pathophysiological mechanism of their coagulation disorder.
- A 68-year-old female presents with spontaneous, extensive ecchymoses. Labs show an isolated prolonged aPTT. A 1:1 mixing study with normal plasma shows complete immediate correction, but the aPTT re-prolongs significantly after 2 hours of incubation at 37°C.Development of autoantibodies that exhibit time- and temperature-dependent inhibition of the intrinsic tenase complex.
- A 29-year-old female with a history of recurrent mid-trimester fetal loss presents with deep vein thrombosis. Labs show an isolated prolonged aPTT. A 1:1 mixing study demonstrates no correction of the aPTT immediately or after incubation.Presence of immunoglobulins that inhibit in vitro phospholipid-dependent coagulation but promote in vivo thrombosis.
- A 35-year-old asymptomatic male is evaluated prior to a tonsillectomy. Labs reveal an isolated prolonged aPTT. A 1:1 mixing study demonstrates complete correction of the aPTT immediately, and the correction is maintained after 2 hours of incubation.Autosomal recessive trait causing reduced synthesis of a zymogen that bridges the contact system to the amplification phase.
- A 22-year-old female presents with severe menorrhagia and borderline thrombocytopenia. Her PT and aPTT are normal. Platelet aggregometry demonstrates an enhanced aggregation response to low-dose ristocetin.Qualitative defect causing pathological hyper-affinity between a bridging glycoprotein and the platelet surface receptor.
Cevap
The correct pairings match the time-dependent inhibitor presentation with Acquired Hemophilia A, the immediate inhibitor presentation with Lupus Anticoagulant, the sustained correction presentation with Factor XI deficiency, and the enhanced low-dose ristocetin response with Type 2B von Willebrand disease.
Each advanced laboratory finding corresponds uniquely to a specific pathophysiological mechanism. Time-dependent mixing study correction failures are driven by Factor VIII autoantibodies. Immediate mixing study failures in pro-thrombotic patients are driven by antiphospholipid antibodies. Complete, sustained mixing study corrections represent true zymogen deficiencies. Enhanced low-dose ristocetin responses point directly to the hyper-affinity glycoprotein defect of Type 2B vWD.
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Anahtar Kavram
Interpretation of immediate vs. incubated mixing studies and platelet aggregometry to diagnose complex coagulopathies.