Anemia Lecture Flashcards
Acute anemia increase in RBC production
3x within 7-10 days
Chronic anemia increase in RBC production
6x - 8x
Average adult blood volume
5 L total = 3 L plasma + 2 L blood cells
Hb
Hemoglobin concentration (g/L)
Hematocrit
Packed red cell volume (%)
MCV
- Mean corpuscular volume
- Average size of a RBC
MCH
- Mean corpuscular hemoglobin
- Average amount/mass of Hb in a RBC
- = Hb/RBC count
RDW
- Red cell distribution width
- Coefficient of variation of RBC volume, variation in cell size
MCHC
- Mean corpuscular hemoglobin concentration
- Proportion of each red cell taken up by Hb (%)
Microcytic anemia
Decreased MCV, MCH, MCHC
Normocytic anemia
Normal MCV, MCH, MCHC
Macrocytic anemia
- Increased MCV
- Variable MCH and MCHC
Transferrin saturation
TRF = Concentration Fe / TIBC
Megaloblastic anemia and folate
Folate treatment partially corrects B12 deficiency but does NOT affect neurologic defecits
Production deficit anemias include
- Aplastic anemia
- Pure red cell aplasia → Diamond - Blackfan syndrome
Aplastic anemia
Acquired causes:
- Viral infections: hepatitis, EBV, HIV, parvovirus
- MOST COMMON CAUSES: autoimmune suppression by a T cell mediated mechanism
Hereditary causes - FANCONI’S ANEMIA:
- AR
- Defects in DNA REPAIR MECHANISM = chromosomal instability
- Congenital anomalies (hypoplastic radii, thumbs and organs)
- May be pre-malignant: evolves into myelodysplasia, AML, CML
Pure red cell aplasia
- Autoimmune disease mediated by T lymphocytes of IgG antibody VS red cell precursors
- Associated with: SLE, CLL, lymphomas, THYMOMAS
- Diamond-Blackfan syndrome
- Drugs: phenytoin, azathioprine, isoniazid
Sideroblastic anemia - nutritional deficiency
Pyridoxine (B6) and copper
Hemolytic anemia
ACUTE SYMPTOMS: fatigue, fever, pallor, jaundice, LOW BACK PAIN, splenomegaly, CONGESTIVE HEART FAILURE
CHRONIC SYMPTOMS: acute + gallstones, abnormal bone growth, fractures
LAB FINDINGS:
- ↑ unconjugated bilirubin
- ↓ serum haptoglobin concentration (which take up free Hb)
- ↑ serum LDH (RBC enzyme release
- Reticulocytosis
INTRAVASCULAR HEMOLYSIS:
- Free hemoglobin released → haptoglobin released: excessive free Hb = hemoglobinuria and hemoglobinsiderinuria; EXPECT ↓ SERUM HAPTOGLOBIN CONCENTRATION
Beta thalassemia VS Iron deficiency anemia
- Iron therapy improves iron deficiency anemia, worsens beta thalassemia
- Increased or normal serum iron and bone marrow iron in thalassemia
Hereditary spherocytosis treatment
Treat with FOLIC acid supplements or SPLENECTOMY
G6PD deficiency smears between attacks
Between attacks peripheral smears are normal
WAHA and disease
WAHA may antedate the onset of disease by months or years
CAD causes
ACUTE: associated with atypical pneumonia (against big I) and infectious mononucleosis (against little i)
CHRONIC: due to lymphoid malignancy or idiopathic, may be unremitting
Paroxysmal cold hemoglobinuria
- IgG autoantibody (Donath-Landsteiner Ab) = biphasic hemolysis
- AT LOW TEMPS binds to cells without causing hemolysis
- WARMING binds complement → intravascular hemolysis, hemoglobinuria
- No jaundice or splenomegaly
Test for Donath-Landsteiner Ab → differentiates PCH from CAD
- Mix patients serum (with antibody) with test RBCs
- First chill them then warm them to 38C
- Lysis of RBCs indicates PCH
Test for hemolytic transfusion reaction
Coombs test
Microangiopathic hemolytic anemias
Due to abrnomalities in microcirculation → fibrin deposition and vessel narrowing
- DIC
- HUS
- Thrombotic-thrombocytopenia purpura (TTP)
- Preeclampsia, HELLP syndrome (Hemolysis, Elevated Liver enzymes, Low Platelets)
Paroxysal nocturnal hemoglobinuria
- CD59 (MIRL, membrane inhibitor of reactive lysis) and CD55 (DAF) need GPI membrane
- Can evolve into: aplastic anemia, myelodysplasia, AML
- TREATMENT: iron supplement, prednisone, BM transplant
Mechanical and physical factors that cause nonimmune hemolytic anemia
- Prosthetic heart valces
- BURN INJURY: microspherocytes, barbell shapes, rod shapes
- MARCH HEMOGLOBINURIA: marching, marathon running, drum beating; hemoglobinuria after exercise; normal peripheral blood smear; anemia is rare in these individuals
