Lab Exam 2 Flashcards
stains used for retic ct
what shows up in retics?
supravital stain
new methylene blue
brilliant cresyl blue
crystal violet
reticulum
usually retics lose their reticulum within —– hours of leaving the BM
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retic RR
adult
baby
adult —0.5-2.0%
baby —2.5-6.5%
absolute retic calc
absolute = %retics(RBC)
sudden retic increase 3-4 days after acute hemorrhage
retic shower
very high glucose can affect…
appearance of reticulum in retics
methylene blue will also stain…
HJ bodies
heinz bodies
how to count retics
- 100x
- miller ocular
- all RBCs in small square
- all retics in large square
- exactly consecutive fields
- stop when you reach 112 RBCs
- count 2 smears
47 retics = ——-% retics
4.7%
corrected retic takes into account that…
retics being released are sent into a smaller pool of blood in states of anemia
corrected retic calc
corrected retic = retic%(Hct/45)
normal Hct may also be taken from a table of norms
RPI calc
RPI = corrected retic/maturation time
maturation time from table
RPI takes into account that…
BM is releasing more retics than normal during anemia, and they take longer to mature in PB than normal retics, falsely elevating count
immature retic fraction (IRF) is used…
in place of RPI when performed on autoanalyzer
↑ IRF indicates…
may make ———- unnecessary
adequate BM response to anemia
cell recovery
transfusion
RET-He or CHr indicates…
equivalent to —– in RBCs
Hgb content of retics
MCH
hemoglobins migrate toward the ——
anode (+)
the most ———- charged hgbs are “fast”
negatively
controls the pH and carries the Hgbs through the gel medium
buffer
precipitates the Hgb into the gel to immobilize and prevent diffusion of bands
acid alcohol
allows visualization and densitometric scanning
stain
“fixes” stain to Hgb bands and washes stain from background
acetic acid
Hgb electro preferred sample
EDTA WB
alkaline gel and pH
cellulose acetate
8.4
acid gel and pH
citrate agar
6.0-6.2
if Hgbs cannot be fully identified with alkaline and acid gels, use ———- to ID
isoelectric focusing
uses gels with a pH gradient, and each Hgb migrates to point where pH is equal to pI
isoelectric focusing
alkaline gel buffer and stain
B2 buffer
blue stain
acid gel buffer and stain
maleic acid buffer
violet stain
A >97%
A2 1.5-3%
F <1%
normal
S 90%
F 10%
slight A2
no A
sickle cell disease
A 60%
S 40%
sickle cell trait
C 95%
F 5%
Hgb C disease
A 60%
C 40%
Hgb C trait
S 50%
C 50%
S/C disease
A most
A2 3.5-7%
F minor component
β thal minor
F 90%
A2 10%
A minor component
β thal major
alkaline gel migration pattern
+
A
F
SDGL
CEOA2
=
acid gel migration pattern
+
C
S
AA2
F
=
not recommended to quantitate by scanning
A2
F
column chromatography instead
column chromatography procedure
- column has resin full of + charged molecules
- buffer and pH levels are controlled to cause different Hgbs to bind to resin
- elution buffer is added to remove Hgb A2, and other Hgb are retained
- absorbance of A2 eluate fraction and total Hgb are read, and A2 is expressed as a percent
cause increased osmotic fragility
spherocytes
burn patients
AIHA
cause decreased osmotic fragility
target cells
sickle cells
hypochromic cells
thalassemia
preferred osmotic fragility specimen
Na heparin
osmotic fragility % hemolysis calc
% hemolysis = (ODx - OD.85)(100)/(OD0) - (OD.85)
control OF patient should start hemolysis around —–% and end around —–%
0.45
0.35
elongated crystals of polymerized Hgb S
tactoids
causes for crises in sickle trait pts
- respiratory infection
- anesthetsia
- extreme exercise
- congestive heart failure
preferred sickle solubility sample
EDTA WB
sickle solubility reagent
Na hydrosulfite/Na dithionite
sickle solubility test has —–% HgbS sensitivty
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other sicklings Hgbs detected by solubility test
- Hgb C Harlem
- Hgb C Georgetown
- Hgb Memphis
- Hgb Bart
sickle solubility false +
too many RBCs
↑ Hct
↑ protein
sickle solubility false =
Hgb S <10%
multiple transfusions
newborns
QC requirements for sickle solubility
- room temp reagent
- pos and neg controls
- correction of sample volume based on Hgb
preferred KB sample
EDTA WB
negative control for KB is…
normal male blood
positive controls for KB
1:10 and 1:20 cord blood + adult blood
in the KB test, cells are exposed to ——— which destroys Hgb A and leaves Hgb F
acid buffer
standard ESR method
Westergren method
2 forces at work during ESR test
- downward force of the RBCs
- retarding force of the plasma
3 stages of settling in ESR
- Initial aggregation (10 min)—rouleaux occurs
- Fast, constant settling (40 min)
- Final packing (10 min)—sedimentation slows
plasma factors that ↑ ESR
- ↑ fibrinogen
- ↑ alpha and gamma globulins (↓ zeta potential of RBCs)
plasma factors that ↓ ESR
- extreme increase in plasma viscosity
RBC factors that ↑ ESR
- anemia
- microcytes
RBC factors that ↓ ESR
- high RBC count
- irregular shape (sickle, spherocyte)
- macrocytes
preferred ESR specimen
EDTA or Na citrate WB
tube additive that falsely ↑ ESR
heparin
ESR specimen stability
12 hours refrigerated
8 hours room temp
ESR RR
male: 0-15 mm
female: 0-20 mm
chief value of ESR (2)
- differentiate among diseases with similar sx
- indicates extend of inflammatory response
how does temp affect ESR?
↑ temp (>27°) falsely ↑ ESR
examples of ESR used in differential dx
- bacterial infection, but not viral infection, ↑ ESR
- MI with angina, but not angina without MI, ↑ ESR
- RA, but not osteoarthritis, ↑ ESR
peak mono age
14-24
EBV transmission
infected saliva
EBV infects…
protection mediated by…
B-cells, oropharynx, cervix
T-cells
at risk for serious complications from EBV (eg B-cell tumors)
immunocompromised (AIDS, transplant)
EBV sx
- fever
- pharyngitis
- lymphadenopathy
- lethargy
- h/a
- nausea
- anoxia
- severe: splenomegaly, hepatomegaly, jaundice
complications of EBV
- hepatitis
- AIHA (anti-i cold agglutinin)
- ↓ platelets
- agranulocytosis
- aplastic anemia (rare)
EBV lab findings
- ↑ WBC (12-25) with absolute lymphocytosis
- > 20% atypical lymphs
- occasional immunoblasts, plasma cells
- slight ↓ platelet
other causes of mono-like illnesses
- CMV
- toxoplasma
- viral hepatitis
rapid mono test is for the ——– Ab
heterophile
reacts with Ag common to multiple species
heterophile Ab
rapid mono test detects…
heterophile Ab which agglutinates sheep, horse or bovine RBCs
limitations of rapid mono test
false negative results in 10-20% of adults, 50% children <4yo
reflex test for rapid mono
if negative, do EBV serologies or repeat in 1 week if sx persist
disadvantages of EBV serologies
- more expensive
- take longer
Ab detected in EBV serology tests
- VCA-IgM
- VCA-IgG
- EBNA
- EBVEA
when does EBNA rise?
early convalescent period (recovery) and persists along with IgG
VCA
viral capsid antigen
(EBV)