Anemia Flashcards
microcytic anemias
- MCV < 80fl
- iron deficiency//chronic disease, thalassemia
normocytic anemias
- 80 < MCV < 100fl
- chronic disease, bone marrow, hemolytic anemia
macrocytic anemia
- MCV > 100fl
- B12 deficiency, folate deficiency, megaloblastic, liver disease
MCHC
mean corpuscular hemoglobin concentration = hemoglobin concentration/hematocrit –> normal = 32-36 g/dL
MCV
mean corpuscular volume
Iron deficiency anemia epidemiology
most common anemia; f>m
Iron deficiency anemia causes
lack of available iron limits hemoglobin synthesis:
- insufficient intake
- GI bleed
- menstrual loss
Iron deficiency anemia ID
microcytic anemia, decreased serum iron/ferritin/transferrin, increased total iron-binding capacity (TIBC)
Anemia of chronic disease ID
IL6 -> hepcidin excess -> iron retained in macrophages -> EPO restricted by iron
Pernicious Anemia
- autoimmune gastric atrophy -> reduced intrinsic factor production -> reduced B12 production -> defective nuclear maturation/DNA synthesis -> anemia/low reticulocytes • ID: macrocytic anemia, reduced reticulocyte index, abnormal Schilling test, low serum B12 or folate
Schillings test
staged radiolabeled B12 to track renal excretion -> increased urinary output diagnosis pernicious –> distinguishes between various causes of low if
Aplastic Anemia/Bone marrow failure
• severe normocytic anemia • idiopathic or secondary to medications, toxins, or infections
Hemolytic anemia
results from RBC destruction –> initial reticulocytosis but ultimately results in anemia
Hemolytic anemia - intravascular hemolysis ID
- low haptoglobin
- high hemoglobin
- hemoglobinuria
in addition to normal hemolytic anemia
- increased LDH
- increased bilirubin
- increased reticulocytes
Hemolytic anemia - extravascular hemolysis ID
- increased LDH
- increased bilirubin
- increased reticulocytes
Hemolytic anemia - Hereditary spherocytosis
- autosomal dominant defect of spectrin/ankyrin –> reduces RBC deformability –> splenic mediated hemolysis
- Epi: Northern europe
- ID: range of splenomegaly spherocytes, reticulocytosis, elevated MCHC, increased osmotic fragility, negative DAT
- Tx: splenectomy
Hemolytic anemia - Hereditary elliptocytosis
- autosomal dominant defect of structural proteins –> reduces resistance to shear –> mostly asymptomatic
- ID: African/Med elliptocytes, normal osmotic fragility