HGB-op Anemia pt2 Flashcards
Describe Hgb structure
2 alpha 2 beta chains
4 hemes (Fe+2) protoprohyrin ring
two pairs of globin chains
4 hemes - 4 chains = Hgb
What is a Hgb-op
defective animo acid sequence (exchange/deletion)
What is a thalassemia
depressed production of globin chains
What are the Adult Hgbs?
Hgb A (2a,2b)
Hgb H2 (2a,2d)
Hgb F (2a,2g)
Describe Hgb S
Nationalities
What defect
What happens to Hgb S
___ transforms to ____
Shape?
Occulde?
most common in african/middle east/greek
B chain defect
Hgb deoxynagated
B6 GLU - VALINE
Hgb S less soluble/sickles
Occlude microvasc - infarction
What are some promoters of sickling?
Hypoxia
Low pH
Dec affinity for O2
What are the two types of sickling
Who is it not found in and why?
resversable/irreversable
Not found in children until 6mos of age (Due to HgbF being predominant/no B chains)
Describe sickle cell crisis
VOC (vasc-occul-crisis)
Inflammation - over expressed P-Selectin (adhesion mediator )on endothelial cells
Cellular clusters
Infarctions and Inc infections
COMMON CAUSE OF DEATH IN KIDS
Describe Hem. crisis in sickle cell crisises
short Rbc life
decreased Hgb/Hct
jaundice
Describe Aplastic crisis
Bm suppressed
unable to compensate
Describe sequestration
massive pooling of rbcs in spleen
Describe sickle cell anemia (Homozygous)
cell populations
shift?
BM
Hgbs present?
norm/norm/micro/hypo
sickle cells/targets
Nrbc/Stippling
NEUTROPHILIA (SHIFT)
thrombocytosis/erythrohyperplasia
HGB S
incr Hgb F
NO HGB A (no B chains)
Tube sol +
Describe sickle cell trait Heterozygous
symptoms?
cells?
Hgb ranges?
generally asympt
occ. sickling with extreme hypoxia
normal rbc morphology
Tube sol +
20-40% Hgb S
>60% Hgb A
norm HgbA2/HgbF
Describe Hgb C
Homozygous vs hetero
2nd most common in US
B chain defect
B6 GLU - LYSINE
Crystal cells
Homo: hemolytic anemia
micro/hypo
envelope cells
Hetero: Aysmptom
Describe Hgb SC
most common…
diff what?
population?
disease states?
hgb?
most common double hetero Hgb structure
diff amino acid substance on each of 2 globin chains
25% west africa
Tube sol +
Mild sickle cell disease
vaso-occlu less common
NO HGB A
Mild/mod anemia
Describe Hgb tube sol (sickle dex)
Reagents:
Principle
reagents: saponin - lyse rbc/create hgb
Sodium hydrosulfate - reducer
buffers
Hgb S is reduced (deoxy) crystalizes and creates cloud of suspension, normal Hgb clear
Causes of False + in Hgb tube sol
Flase -?
+ - hyperproteinemia
hyperlipidemia
polycy
Hgb-c/hgb BARTS
- anemia <7mg hgb
low Hgb S conc
Rgt deterioration
What MUST you confirm these with?
Hgb electrophoresis
Breifly describe Hgb electrophoresis
Strip is made of?
pH?
hgb have charges/pH of medium affects this
they migrate at specific rates/helps distinguish
strip (cellulose acetate)
pH (8.4-8.6)
T/F all Hgb that have abnormal patterns in Alkaline pH do not need to be electrophoresised at Acid pH?
false they do need to be electrophoresed at acidic pH with a CITRIC AGAR
Describe newborn hgb-op screening
all 50 states
must use IEF on dried blood
HPLL
molecular DNA based - most effective when targeted to mutation
List some other abnormal Hgb
Hgb D
Hgb G
Hgb O - arab
D-punjab
C-harlem
most have increased O2 affinity
Describe Hgb E
B chain defect
resembles Thal
30% southeast asians
mild anemia/micro/target
Describe Hgb M (unstable Hgb)
amino acid substitue in alpha or beta chain
iron not able to be oxidized, prevents O2 binding (-OH in place)
Pt have Metheme (Fe+3)
unable to carry O2
sample brown
HEINZE bodies
