Hematology & Immunology Flashcards
What does a positive Direct Coombs test indicate?
Autoimmune hemolytic anemia (antibodies bound to RBCs).
1️⃣ Autoimmune Hemolytic Anemia (AIHA)
Warm AIHA (IgG-mediated) → SLE, CLL, drugs (penicillin, methyldopa)
Cold AIHA (IgM-mediated) → Mycoplasma pneumoniae, EBV (mono), Waldenström’s macroglobulinemia
2️⃣ Hemolytic Disease of the Newborn (HDN)
Rh incompatibility (Mom Rh-, Baby Rh+)
3️⃣ Drug-Induced Hemolysis
Drugs like penicillin, cephalosporins, methyldopa can trigger immune destruction of RBCs.
4️⃣ Hemolytic Transfusion Reaction
Mismatched blood transfusion → RBC destruction
What does a positive Indirect Coombs test indicate?
Antibodies in the serum (e.g., Rh incompatibility in newborns).
Blood typing, Rh screening (pregnancy), transfusion compatibility
What is the gold standard test for diagnosing sickle cell disease?
Hemoglobin electrophoresis (shows HbS).
What do you see on a blood smear in G6PD deficiency?
Bite cells & Heinz bodies (due to oxidative stress).
What triggers hemolysis in G6PD deficiency?
Fava beans, infections, sulfa drugs, antimalarials.
What is the most common cause of isolated thrombocytopenia in an otherwise healthy patient?
Immune Thrombocytopenic Purpura (ITP).
What’s the classic pentad for Thrombotic Thrombocytopenic Purpura (TTP)?
FAT RN
- Fever
- Anemia (microangiopathic hemolytic)
- Thrombocytopenia
- Renal failure
- Neurologic symptoms
What is the treatment for TTP?
Plasma exchange (PLEX) – DO NOT give platelets!
What’s the most common inherited hypercoagulable disorder?
Factor V Leiden mutation.
Which coagulation factors does Warfarin inhibit?
1972 – Factors II, VII, IX, X (plus protein C & S).
What lab value is prolonged with heparin therapy?
aPTT (Intrinsic pathway).
What is the reversal agent for heparin toxicity?
Protamine sulfate.
What is the reversal agent for Warfarin overdose?
Vitamin K + FFP (for rapid reversal).
What lymphoma presents with Reed-Sternberg cells?
Hodgkin’s Lymphoma.
What’s the key difference in presentation between Hodgkin’s and Non-Hodgkin’s Lymphoma?
Hodgkin’s: Localized, orderly spread, B symptoms (fever, night sweats, weight loss).
Non-Hodgkin’s: Widespread, extranodal involvement, unpredictable spread.
What leukemia is associated with Auer rods?
Acute Myeloid Leukemia (AML).
What leukemia is known as ‘the leukemia of the elderly’ and often found incidentally?
Chronic Lymphocytic Leukemia (CLL).
What condition is associated with painless lymphadenopathy and B symptoms?
Lymphoma.
What condition is associated with punched-out bone lesions, hypercalcemia, M-spike, and Bence Jones proteins?
Multiple Myeloma.
What condition is characterized by bleeding after surgery, ↑ PTT, normal PT, normal platelet count?
Hemophilia A/B.
What condition has ↑ bleeding time, normal platelet count, and responds to Desmopressin (DDAVP)?
Von Willebrand Disease.
What’s the most common cause of microcytic anemia?
Iron deficiency anemia (due to blood loss or poor intake).
What lab values help differentiate iron deficiency anemia from thalassemia?
Iron deficiency anemia: ↓ Ferritin, ↑ TIBC, ↓ Serum Iron
Thalassemia: Normal or ↑ Ferritin, Normal or ↓ TIBC, Normal or ↑ Serum Iron
