Microcytic, Hypochromic Anemias Flashcards
Anemia Definition
What is it correlated with?
deficiency of oxygen delivery to the tissues / healthy red blood cells
Low RBC Count
Low hematocrit
Low Hemoglobin
Anemia is classified by:
Physiology
- symptoms, bone marrow response
Morphology
- visual interpretation of peripheral smear
- RBC indices: MCV, MCHC, MCH
Microcytic, hypochromic anemias definition
group of red cell disorders that involve a defect in hemoglobin synthesis and can produce RBCs that are:
Microcytic: < 6 um
(often MCV <80fL
Hypochromic = CAP >3 um
(often MCHC <32%)
Deficiency of iron
IDA - iron deficiency anemia
- Majority
- Most common anemia
Abnormal utilization of iron
- Anemia of chronic disease
- Sideroblastic Anemia
Abnormal heme synthesis
Poryphyrias
Abnormal globin chain synthesis
Thalassemia
Iron (Fe)
Iron is essential for life
- makes hemoglobin
- essential mineral our body needs
Iron can be classified in two categories
Heme iron
Non heme iron
Heme iron
complexed into a porphyrin ring to form heme ring of hemoglobin
non-heme iron
- Any iron outside of hemoglobin
- **Transfer and storage compounds **
- RBC inclusions
Examples of non-heme iron; transfer and storage compounds
Transferrin
Ferritin
Hemosiderin
Transferrin
CARRIER protein
- carrier protein for serum iron
- composed of beta globulin
- made in the liver
Ferritin
STORAGE
- Water soluble
- Storage pools of bone marrow and liver
- Easily mobilized
- Serum Ferritin - proportional to iron stores in liver and BM
Hemosiderin (harder to access)
STORAGE
- Water insoluble
- lysosomal membranes of macrophages (where they are stored)
- Precipitated aggregates of ferritin
- Long term-storage (last resort)
Ferritin vs Hemosiderin
Hemosiderin has an extra phosphate
Non heme iron in RBC
inclusions terminology
- Wright stained - pappenheimer bodies
- Prussian blue (iron stain) - siderotic granules
Cell terminology
- nulceated RBC - Sideroblasts
- Non-nucleated RBC - siderocytes
wright stained RBC
pappenheimer bodies
Prussian blue (iron stain)
Siderotic granules
Nucleated RBC
sideroblasts
non-Nucleated RBC
Siderocytes
Iron absorption pathway
Iron in diet (Fe3+ and Fe2+)
Stomach (acidic pH)
Reduced to Fe2+
Intestines
Absorbed (Duodenum/Jejunum)
Blood (converted back to Fe3+)
Binds to Transferrin (carrier protein)
BM & Liver for storage (Ferritin)
Iron is absorbed in
Duodenum/Jejunum which components of the small intestine
Iron Sources
Meats (muscles)
Organ meats
Wheat Germ
Brewer’s yeast
Certain legumes
Milk/formula
Green veggies
Green veggies (vitamin C and fructose)
enhance iron absorption
Iron Minimal Daily Requirement (MDR)
Iron - loss of 1% of RBCs/day that must be replenished
Most (95% in adults) iron comes from recycling senescent (old) RBCs. – Remaining approx. 5% needs to come from diet
Additional Loss of iron: Normal conditions
- sweating, stool. menstruation
Serum Iron (Analysis)
Transferrin - bound Iron
Normal Range: 50-150 ug/dL
TIBC - Total Iron Binding Capacity (analysis)
Availability of iron binding sites on Transferrin
Normal Range: 250-450 ug/dL
Transferrin % Saturation
Amount of iron bound in plasma/serum
Normal Range: 20-50%
Serum Ferritin
Proportional to amount of iron stored (Liver and BM - Acute phase reactant)
Normal Range Male: 20-250 ug/dL
Normal Range Female: 10-120 ug/dL
IDA - Most common anemia
State in which body iron stores are depleted
IDA causes
Blood loss (most common cause in western world)
- Menstruation in females
- GI bleed in Males
Dietary insufficiency
- Increased need - pregnancy /infants
- lack in diet (3rd world)
Absorption issue
- Malabsorption - lack of gastric acids (gastrectomy, gastic bypass), or problem at absorption site (IBS, Celiac Disease)
Many more
IDA stage 1
Iron Depletion
- Iron stores in the bone marrow are depleted (low ferritin)
- our body compensated by increasing mucosal absorption of iron and producing more transferrin (increased TIBC)
- CBC and RBC morphology = normal
- Completely asymptomatic
IDA stage 2
Iron Deficient Erythropoiesis
- Plasma iron level drops (low serum iron)
- CBC (Hgb and Hct) low – more microcytic and hypochromic
- RBC Morphology = slightly presentation of microcytic hypochromia
IDA stage 3
Iron Deficiency Anemia
- RBCs are severely deficient in iron
- Hemoglobin formation is delayed
- CBC (Hgb and Hct) marked Low
- less O2 delivery to cells
- EPO levels increase
- Overt symptoms - RBC morphology = microcytic, hypochromic RBCs
- possible to see reticulocytes, target cells and elliptocytes
IDA clinical features
Typical symptoms
Typical Symptoms:
- Fatigue/Lethargy
- Pallor
- Vertigo
- Dyspnea
- Cold Intolerance
IDA clinical features
Miscellaneous Symptoms
Pica
- Pagophagia
- Geophagia
Koilonychia
Pica
abnormal cravings
Pagophagia
craving for ice
Geophagia
Craving for dirt, clay
Koilonychia
spoon nails
Microcytic, Hypochromic RBC
IDA Lab Findings - Peripheral Smear
Microcytic, Hypochromic RBCs
(large central pallor)
Mild to moderate anisopokilocytosis (variation in size/shape)
Additional Possibilities:
- slight reticulocytosis (polychromasia) - accelerated erythropoiesis
- target cells
-Elliptocytes
IDA Lab Findings - Iron Studies
Low serum ferritin (FOUND IN ALL IDA STAGES)
High TIBC
Low Serum Iron
Low % Transferrin Saturation
LOW serum ferritin
FOUND IN ALL IDA STAGES
IDA lab findings - Bone Marrow
Usually not indicated for testing
Mild to moderate erythroid hyperplasia. low M:E
Poorly hemoglobinized pre-cursors with scanty cytoplasm
Hemosiderin absent
IDA bone marrow
IDA treatment
Iron supplements
- oral tables or drops (infants/children)
- infusions (absorption issue)
Severe cases ( significantly low hemoglobin)
- transfusion
