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Zorluk: OrtaHematology and Oncology

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

Cevap

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.

Adım Adım Çözüm

1
Analyze the first presentation: fever, confusion, microangiopathic hemolytic anemia (schistocytes), and thrombocytopenia with normal coagulation studies.
Identifies Thrombotic Thrombocytopenic Purpura (TTP).
TTP classically presents with this pentad (or partial pentad) and is driven by ADAMTS13 deficiency.
2
Analyze the second presentation: isolated thrombocytopenia with large platelets and normal coagulation studies in an otherwise healthy young woman.
Identifies Immune Thrombocytopenia (ITP).
ITP is an autoimmune condition caused by anti-GpIIb/IIIa IgG antibodies.
3
Analyze the third presentation: hemolytic anemia with spherocytes and a positive direct antiglobulin test (DAT) in a patient with CLL.
Identifies Warm Autoimmune Hemolytic Anemia (AIHA).
Warm AIHA is mediated by IgG antibodies against RBC antigens and is frequently associated with CLL.
4
Analyze the fourth presentation: acute hemolytic anemia with bite cells following exposure to an oxidative stressor (sulfamethoxazole-trimethoprim).
Identifies Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency.
G6PD deficiency impairs the RBC's ability to produce NADPH, leading to oxidative damage when exposed to sulfa drugs.

Anahtar Kavram

The diagnosis of hematologic disorders requires integrating clinical findings, specific peripheral blood smear abnormalities, and an understanding of the underlying autoimmune or enzymatic pathophysiology.
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