RBC Assessment In Anemia Flashcards
What hormone is principle in growth and maturation of erythroid cells?
erythropoietin
What produces erythropoietin and how is it regulated?
. Kidneys in response to tissue hypoxia
. Renal O2 levels regulate production
Erythropoiesis
. Multipotent stem cells mature into burst-forming units-erythroid (BFU-E)
. Single BFU-E produces colony of >1000 rbcs
. Blast cell maturation takes 3-5 rounds of cell division (cells become smaller each round)
Chromatin in immature blood cells
Delicate, fine, and speckled
What happens to chromatin in rbcs as they mature?
Become coarse, clumped, and compact
Effects of erythropoietin
. Binding + activating specific receptors on RBC progenitors in bone marrow to generate inc. BFU-E
. Signal transduction via erythropoietin receptor prevents apoptosis of erythroid cells to permit further proliferation and differentiation into mature rbcs
. Stimulate release of reticulocytes from marrow into circulation (reticulocytosis)
Reticulocytes
. Larger than rbcs from having ribosomes, mitochondria, and mRNA still
. Parts used to synthesize more Hb
Maturation time of reticulocytes
72 hours (48 in marrow, 24 in circulation)
Percentage of reticulocytes in normal blood
0.5-1.5%
Need what components to have effective erythropoietin effects?
. Responsive marrow
. 1+ kidney
. Adequate nutrition (adequate Hb synthesis and cell division)
Anemia condition or disease?
. Condition NOT DISEASE
Signs and symptoms of anemia
. Pallor skin/mucous membranes/nail beds
. Dizzy
. Ease of fatigue
red cell concentration and average number
. (RBC)
. Conc. Of erythrocytes in whole blood
. Avg: 5x10^6/uL
Hb concentration and average
. (HGB)
. Conc. Hb in whole blood
. Avg: 15gm/100mL
Hematocrit and average
. (HCT) or (PCV)
. Volume percentage of whole blood occupied by red cells
. Avg: 45%
Rule of 3 in CBC
. For healthy persons :
. RBC (millions) x3 = HGB (gm%)
. HGB (gm%) x3 = HCT (volume %)
What were corpuscular indices good for?
Assessing CBC of anemic individual and develop morphological classification of anemia
Mean corpuscular volume and reference range
. Volume of avg erythrocyte
. MCV = (HCT/RBC)x10
. 80-100 fl (normocytic RBCs)
Micro cystic RBC
MCV< 80fl
Macrocyclic RBCS
MCV> 100
Mean corpuscular Hb and reference range
. Quantity of Hb in avg erythrocyte
. MCH = (HGB/RBC)x10
. 26-32 pg range
Mean corpuscular Hb concentration and reference range
. Concentration of Hb in avg erythrocyte
. MCHC=(HGB/HCT)x100 OR (MCH/MCV)x100
. 31-37% (normochromic)
Hypochromic RBCs
MCHC<31
T/F MCHC cannot exceed reference range
T, conc. Is max that is soluble
Red cell distribution width and normal range
. RDW
. measure of variation in RBC volume
. Calculated as coefficient of variation for RBC size
. 11-15% range
RDW with anisocytosis and what is anisocytosis
. Increased
. Unusual cell size
RDW with poikilo-cytosis and what that is
. Increased
. Unusual cell shape
RDW with anemia
. Elevated when anemia is from nutritional deficiencies
Observed reticulocytes count and reference range
. OR
. % of erythrocytes that are reticulocytes
. OR = (# reticulocytes/# RBCs)x100
, index of production of mature RBCs by bone marrow
. 0.5-1.5% range
Calculation of corrected reticulocytes count
. (CR)
. Reticulocytes count adjusted to reflect what it would be for normal red cell conc. Of hematocrit
. CR = OR x patient’s HCT/ mean HCT
Mean HCT = 45%
OR in anemia
. Reticulocytes percentage not reflective of actual reticulocytes production because each reticulocytes is diluted into fewer mature RBCs
. Corrected by CR
When is Hb, HCT, and RBC count reduced?
. If red cell mass is decreased or plasma volume is increased
WHen is Hb, HCT, and RBC count increased?
. Plasma volume decreases (hemoconcentration)
Causes for impaired erythropoiesis
. Dec erythropoietin production
. Dec bone marrow mass
. Dec Hb synthesis
What is CR increased in anemia?
Premature red cell loss
If anemic and normal CR, what does that mean?
Impaired erythropoiesis
What does impaired Hb synthesis cause?
. Microcytic, hypochromic anemia
. Reduces production of erythrocytes decreases MCV and MHC of those made
Most common cause of impaired Hb synthesis?
Chronic Fe deficiency
How does impaired DNA synthesis effect RBC production?
. Insufficient DNA slows blasé cell division but not protein synthesis
. Resultant erythrocytes have more Hb (inc. MCH) but erthrocyte production dec.
. Results in macrocytosis from more proteins in cell
Common cause of impaired DNA synthesis of RBC DNA?
Vit. B12 or folate deficiency
How is anemia classified?
. By RBC morphology and pathogens is
HGB low means ____
Anemia is present
Type of anemia if CR high
Anemia due to premature RBC loss (RBC destruction or acute blood loss but normocytic, normochromic)
Type of anemia is CR is normal
Anemia. Due to insufficient RBC production
Anemia type if MCV is normal?
. Anemia due to loss of bone marrow stem cells or loss of bone marrow stimulation (insuff. Erythropoetin from kidney disease) or due to chronic disease
. Still normocytic, normochromic
Anemia type if MCV is high
Anemia from impaired DNA synthesis
. FOlate/B12 issue
. Macrocytic, normochromic
anemia type if MCV is low
Anemia due to impaired HGB synthesis (Fe deficiency, thalassemia)
. Microcytic, hypochromic
Common cause/mechanism for microcytic anemia
. Chronic GI blood loss, dietary deficiency, genetic Hb alteration
Common cause/mechanism of normocytic anemia
. Infection, inflammation, malignancy
. Premature RBC destruction or acute blood loss
. Anemia of inflammation (AOI) aka anemia of chronic disease
Macrocytic anemia common cause/mechanism
Malabsorption, inadequate diet, alcoholism
Anemia of inflammation
Associated w/ inflammation, malignancy, or infection
. Takes 1-3 months to develop
. Mild to moderate in severity (HCT 30-40%)
. Indices normocytic but microcytic under severe conditions
Factor deficiency anemia
. Commonly seen in popular due to Fe, vit. B12, or folate deficiency
How to confirm Fe deficiency
Specific testing for serum Fe levels
. Total iron binding capacity (TIBC), transferrin saturation, ferritin levels
B12 deficiency common symptoms
. Fatigue, pallor, 50% patients have glossitis and 45% neurological symptoms (diminished vibratory sensation and proprioception) that can be irreversible
B12 deficiency in elderly
. Clinical manifestation are subtle
. Insufficiency dietary intake and malabsorption
folate deficiency can result from _____
. Inadequate dietary intake, defective absorption, impaired utilization, or combo
Difference between folate deficiency and vit B12 deficiency
B12 has neuro issues and folate deficiency does not
Increase in homocysteine shows ____
Tissue folate deficiency
Normal methylmalonic acid level means ____
Folate deficiency, rise in MMA means vit. B12