Retics and Erythrocytes Flashcards
rarely done because of its inaccuracy and questionable necessity.
Manual RBC count
people living at a HIGHER ALTITUDE
RBC count, hemoglobin and hematocrit values are ELEVATED
Glucose penetrates the red blood cell with no energy expenditure
via
CLUT-1
ATP uses for RBC
1) maintenance of shape & deformability
2) energy for active transport of cations
3) monitoring/modulating amount of 2,3-BPG generated
product of EMP
2 ATP molecules
Most common enzyme deficiency of the EMP and most common form of HNSHA
Pyruvate kinase (PK) deficiency
screenig for PK def.
Autohemolysis test
confirmatory for PK def
Quantitative PK assay
Recommended screening test for PK deficiency
PK fluorescent spot test
prevent oxidation of globin
HMS
Aerobic glycolysis
HMS
HMS aka
Pentose Phosphate pathway
Most common enzyme deficiency in the pentose phosphate pathway
Glucose-6-phosphate dehydrogenase (G6PD) deficiency
most
common RBC enzyme defect
Glucose-6-phosphate dehydrogenase (G6PD) deficiency
Possible PBS findings in G6PD def include
heinz bodies
bite cells
favism is seen in what type of G6PD def.
Type II
G6PD-Mediterranean variant
Type II G6PD def
drugs, chemicals and food that may cause hemolysis in G6PD deficiency patients (MUST BE AVOIDED):
- Fava beans
- Red wine
Legumes (ex.: garbanzos, kadyos, munggo) - Blueberry
- Soya food (ex.: taho, tokwa, soy sauce)
- Ampalaya
-Naphthalene (mothballs)
cytochrome b5 reductase
Methemoglobin Reductase Pathway
Methemoglobin Reductase Pathway function
maintains the iron in the heme in its reduced state
Rapoport-Luebering Shun function
for production of 2,3-BPG
2,3-BPG function
binds to hgb and decreases the oxygen affinity of Hgb
affinity of hemoglobin for oxygen is dependent on 5 factors:
pH
o Partial pressure of carbon dioxide
o Concentration of 2,3-bisphosphoglycerate (2,3-BPG)
o Temperature
o Presence of other hemoglobin species that are nonfunctional
Shift to the left
increased affinity to O2 and pH
Shift to the right
decrease affinity to O2 and pH
a shift in the curve due to an alteration
in pH , effect of hydrogen ions
▪Bohr effect:
-depicts the occurrence by which the
binding of O2 to the hemoglobin
promotes the release of CO2
▪Haldane effect:
RETICULOCYTE
immature, non-nucleated RBC which contains > 2 blue-stained, granulofilamentous materials
production of reticulocytes
50 x 109/L/day
normal maturation time for reticulocytes in blood:
1 day
RETICULOCYTE COUNT
a measure of EFFECTIVE ERYTHROPOIESIS
reticulocyte range
Adults: 0.5 to 1 .5%
Newborns: 1 .8 to 5.8%
Increased (↑) reticulocyte counts
polychromasia / polychromatophilia
first sign of accelerated erythropoiesis
polychromasia / polychromatophilia
used for counting retics
Miller disk/calibrated miller disk
stains for retics
supravital
1) NMB
2) BCB
more preferred supravital stain for retics
NMB
NMB contains
Sodium oxalate =prevent coag.
Sodium Chloride = provides isotonicity
BCB contains
Sodium citrate + sodium chloride
LARGE (A) square
counting retics
smal square (B)
RBC counting
square B ____ of square
1/9
After combining supravital stain and blood for retic count, next step is
allow to incubate at room temperature
for 3 to 10 minutes.
how many RBCs counted in routine LM mtd in retic count
1000 RBCs OIO
*retics included in total RBC count
CALIBRATED MILLER DISK METHOD , # of RBCs counted
minimum of 112 RBCs in small square (B)
CALIBRATED MILLER DISK METHOD Formula
Retics(%) = Total retics in Square A /
(Total RBCs in Square B x 9) x 100
Most rapid, accurate, and precise method for reticulocyte count
flow cytometry
flow cytometry uses ___ for counting retics
optical scatter or fluorescence
example of machine using flow cytometry for retcis
Sysmex R-3500
a supravital fluorescent dye for retics in Sysmex R-3500
Auramine O
sum of the middle-fluorescence and high-fluorescence ratios
Immature Reticulocyte Fraction (IRF)
Immature Reticulocyte Fraction (IRF) is used as
an early indication of erythropoiesis
ic, the proportion of dye to blood should be adjusted accordingly in retic count if the px is
anemic or polycythemic
Actual number of reticulocytes in 1 liter of whole blood
ABSOLUTE RETICULOCYTE COUNT
ARC formula
ARC = [reticulocytes (%) x RBC count (x1012/L) /
100 ] x 1000
ARC ref. range
25 - 75 x 10^9/L
Poor Man’s Bone Marrow Aspirate /
Reticulocyte Index, /
Hematocrit Correction
CORRECTED RETICULOCYTE COUNT
RETICULOCYTE PRODUCTION INDEX
provides a further refinement of the CRC
-A general indicator of the rate of erythrocyte production increase above normal in anemias
shift correctio
RPI
shift correctioN
RPI
