Micro & Macro Anemia Flashcards
Type of anemia when MCV<80 fL
Microcytic
Type of anemia when MCV>100 fL
Macrocytic
M:E ratio is __ in Microcytic anemia
DECREASED; erythroid hyperplasia due to EPO trying to compensate
Causes of IDA
Lack of iron during heme formation:
- Increased requirements (pregnancy, growth)
- Decreased intake (poor diet, malabsorption)
- Increased loss (hemorrhage)
Describe 3 stages of IDA
- Stored iron (ferritin) is accessed; normal blood results
- Stored and serum iron exhausted; iron studies all decreased, dual pop’n of micro/hypo and normo/normo
- IDA; iron studies decreased EXCEPT TIBC increased, low Hgb, MCV<80 fL, micro/hypo
Lab results for IDA (HGB, HCT, RBC, PBS, BM, Indices, WBC, PLT, RETIC, serum iron, serum ferritin TIBC, transferrin sat.)
HGB/ MCH/ MCHC: decreased
HCT: decreased
MCV: <80 fL
RBC: decreased
PBS: hypo/micro
BM: decreased iron stores (prussian-blue)
WBC: decreased M:E ratio
RETIC: decreased
PLT: normal
serum iron: decreased
serum ferritin: decreased
TIBC: INCREASED
transferrin sat: decreased
Cause of sideroblastic anemia
Decreased protoporphyrin production OR inability to
incorporate iron into heme:
- Enzyme deficiency (ALA synthase)
- Lead poisoning
- Drugs (chloramphenicol, chemotherapy)
Why are ringed sideroblasts seen in sideroblastic anemia ?
abnormal deposition of iron in mitochondria due to defective incorporation into heme
RDW is high or low for sideroblastic anemia; why ?
HIGH RDW; defective incorporation of iron leads to inconsistent RBCs (dimorphic)
Lab results for Sideroblastic anemia (RDW, HGB, HCT, RBC, PBS, BM, Indices, WBC, PLT, RETIC, serum iron, serum ferritin, TIBC, transferrin sat.)
RDW: HIGH
HGB/ MCH/MCHC: decreased
MCV: <80 fL
HCT: decreased
RBC: decreased
PBS: hypo/micro + normo/normo (DIMORPHIC)
BM: increased iron stores (prussian-blue), ringed sideroblasts
RETIC: decreased
serum iron: INCREASED
serum ferritin: INCREASED
TIBC: decreased
transferrin sat: INCREASED
Cause of Anemia of Chronic Infection
Underlying infection/ inflammation, autoimmune diseases, malignant neoplasms:
- Impaired iron kinetics: sequestered iron from pathogen
- Impaired erythropoiesis: inflammatory cytokines hinder action of EPO on HSC
- Decreased RBC survival: reticuloendothelial cells increase removal of RBCs with small defects
NOTE: reticuloendothelial cells descend from monocytes = phagocytes
Lab results for Anemia of Chronic Infection (CRP, HGB, HCT, RBC, PBS, BM, Indices, WBC, PLT, RETIC, serum iron, serum ferritin, TIBC, transferrin sat.)
CRP: INCREASED
HGB/MCH/MCHC: decreased
HCT: decreased
RBC: decreased
PBS: micro/hypo
BM: normal to increased iron stores (prussian-blue)
RETIC: decreased
serum iron: decreased
serum ferritin: increased
TIBC: decreased
transferrin sat: increased
General cause of megaloblastic anemia
- Impaired DNA synthesis
- vit B12 and folate deficiency
Pathophysiology of megaloblastic anemia
- lack of vit B12 = folate CANNOT donate a methyl group to uracil = NO thymine production
- DNA strand has gaps of where thymine should be = DNA development is delayed
Causes of vit B & folate deficiency
- Diet
- Malabsorption (surgical removal, inflammatory bowl, parasites)
- Increased requirement (pregnancy)
Megaloblastic anemia: CBC results (HGB, HCT, RBC, Indices, WBC, PLT, RETIC)
HGB: DECREASED
HCT: increased
RBC: decreased
MCV: increased
MCH: INCREASED
MCHC: NORMAL
WBC: HYPERSEG neuts
PLT: DECREASED
RETIC: DECREASED
Megaloblastic anemia: BM (M:E, iron stores, morph)
- M:E decreased; erythroid hyperplasia
- NORMAL iron stores
- nuclear-cytoplasm asynchrony
- enlarged precursors
Iron studies (serum iron, serum ferritin, TIBC, transferrin sat.) for both Megalo/Non-megaloblastic anemia
NORMAL iron studies in PBS
NOTE: BM may have increased iron stores
How is megaloblastic anemia differentiated from pernicious anemia ?
Patients with pernicious anemia will be DAT positive due to autoAb
Cause of pernicious anemia
- autoAb destroy parietal cells that produce Intrinsic Factor
- IF is required to absorb vit B12
2 types of pernicious anemia
Type I= competes for vit B12 binding site on IF
Type II= hinders IF by forming a complex
Causes of non-megaloblastic anemia
- liver disease
- chronic alcoholism
- bone marrow failure (aplastic anemia or MDS)
- post-splenectomy
Non-Megaloblastic Anemia: CBC results (HGB, HCT, RBC, Indices, WBC, PLT, RETIC)
HGB: DECREASED
HCT: increased
RBC: decreased
MCV: increased
MCH: INCREASED
MCHC: NORMAL
WBC: HYPERSEG neuts
PLT: DECREASED
RETIC: DECREASED