Match each patient's clinical presentation and peripheral blood smear findings to the most likely underlying pathophysiologic mechanism.
- A 42-year-old woman is evaluated in the emergency department for confusion and fever. Temperature is 38.4°C (101.1°F), blood pressure is 130/80 mm Hg, and pulse is 105/min. Physical exam shows scattered petechiae. Laboratory studies show hemoglobin 8.1 g/dL, platelets 14,000/mm³, normal PT and aPTT, elevated creatinine of 2.1 mg/dL, and numerous schistocytes on peripheral smear.Decreased ADAMTS13 protease activity resulting in uncleaved, ultra-large von Willebrand factor multimers
- A 28-year-old woman presents to the clinic with heavy menstrual bleeding and scattered ecchymoses over her lower extremities. Vitals are normal. Physical exam reveals no hepatosplenomegaly. Labs show hemoglobin 12.2 g/dL, platelets 18,000/mm³, normal PT and aPTT, and megathrombocytes on peripheral smear without other cytopenias.Formation of IgG autoantibodies directed against platelet membrane glycoproteins IIb/IIIa
- A 60-year-old man with a history of chronic lymphocytic leukemia presents to the clinic with progressive fatigue and scleral icterus. Vitals are normal. Labs show hemoglobin 7.4 g/dL, elevated reticulocytes (8%), elevated indirect bilirubin, spherocytes on smear, and a positive direct antiglobulin test.Production of IgG autoantibodies directed against red blood cell surface antigens causing extravascular hemolysis
- A 22-year-old man presents to the emergency department with sudden severe back pain and dark urine. He began taking sulfamethoxazole-trimethoprim two days ago for a skin infection. Vitals are normal. Labs show hemoglobin 8.5 g/dL, and peripheral smear reveals bite cells and Heinz bodies.Congenital deficiency of an enzyme required to generate NADPH and protect red blood cells from oxidative stress
Answer
The correct matches align classic hematologic presentations with their distinct pathophysiologies: TTP is due to ADAMTS13 deficiency, ITP is due to anti-platelet antibodies, Warm AIHA is due to anti-RBC antibodies, and G6PD deficiency limits protection against oxidative stress.
Each patient's clinical scenario and lab findings perfectly align with a specific hematologic mechanism. The TTP case matches ADAMTS13 deficiency; the ITP case matches anti-platelet antibodies; the AIHA case matches anti-RBC antibodies; and the drug-induced bite cell hemolysis matches G6PD deficiency.
Step-by-Step Solution
Key Concept
The diagnosis of hematologic disorders requires integrating clinical findings, specific peripheral blood smear abnormalities, and an understanding of the underlying autoimmune or enzymatic pathophysiology.
Estimated Time:2m 0s