Week 1 Flashcards
(224 cards)
1
Q
adult blood volumnes
A
male = 5-6L, female = 4-5L
– be careful taking blood from newborns. duh.
2
Q
hematocrit
A
% of blood volume that is RBCs
3
Q
plasma vs serum
A
serum = plasma without clotting factors.
get serum by letting blood stand and clot, and spinning it down. serum used for most metabolic panels
4
Q
blue-top tube
A
blood anti-coagulated with Na-Citrate.
used to measure functionality of coagulation cascade in plasma
PT (prothrombin time)
PPT (partial thromboplastin time)
5
Q
purple-top tube
A
blood anti-coagulated with Na-EDTA
used to assess cells in the blood - RBCs, WBCs, platelets
6
Q
Problems with CBC
A
Costs a lot, not always recommended. not recommended for healthy or mildly ill patients - will find things abnormal by chance - need to know what you’re looking for before ordering one.
7
Q
when to order CBC
A
for patients for which you suspect anemia (low RBC), thrombocytopenia (low platelet), leukopenia (low WBC), serious infection (not specific) or systemic inflammatory disease
8
Q
differential tree for anemia
A
- high/low reticulocyte (bone marrow production)
2. if low, MCV, if high, look for bleeding or hemolysis
9
Q
WBC components (percentages) in peripheral blood
A
neutrophils (40-75) eosinophils (1-6) basophil (<1) monocytes (2-10) lymphocytes (20-50- B and T cells)
10
Q
what cells come from myeloid progenitor
A
erythrocytes, platelets (from megakaryocyte), macrophages (from monocytes), neutrophils, mast cells, and eosinophils
11
Q
which cells come from lymphoid progenitor
A
plasma cell (activated B cell), T cell, NK cells
12
Q
where do certain WBCs differentiate/ become activated
A
B/T/NK get activated in lymphoid tissue and then migrate to peripheral tissues/inflammatory sites
Macrophages get activated in a tissue specific fashion
13
Q
macrophage morphology and function
A
look different in different tissues.
hallmark features: big cells, lots of cytoplasm
function: phagocytose particles, make cytokines, present antigens to immune cells
14
Q
dendritic cell morphology and function
A
related to macrophages, present in tissues.
interact with immune cells, make cytokines
15
Q
neutrophil morphology and function
A
moslty in blood
have 3 kinds of granules
last 1-4 days
polynucleated lobes, purplish granules
can migrate to tissue and phagocytose
16
Q
eosinophil morphology and function
A
look like neutrophil, but only have two lobes, and have denser coarser granules - pink staining.
circulate in blood, migrate to tissue, excrete granular content to mediate inflammatory response
17
Q
basophils morphology and function
A
very rare. can’t see nucleus because of basophilic granules.
circulate in blood. mediate allergic inflammatory responses. granules similar to mast cells
18
Q
mast cell morphology and function
A
basophilic granuels , reside in tissue.
mediate allergic response
19
Q
lymphocyte morphology and function
A
small, have little cytoplasm and large nucleus. RBC diameter similar to nucleus in lymphocyte
immune response
NK and cytotoxic T cells have more cytoplasm and have small granules
20
Q
monocyte morphology and function
A
kidney bean shaped nucleus, large, in blood.
21
Q
CD nomenclature
A
“cluster of differentiation”
number proteins on cells - protein expression varies depending on cell and stage of differentiation
22
Q
What protein is expressed on all mature T cells
A
CD3
23
Q
what proteins are expressed by helper T cells
A
CD3 and CD4
24
Q
what proteins are expressed by cytotoxic T cells
A
CD3 and CD8
25
what proteins are expressed by all B cells
CD19 (are CD3 negative)
26
what proteins are expressed by all NK cells
CD16/56 (are CD3 negative)
27
blood constitutes what percentage of total body weight
7-8%
28
examples of molecules in colloidal disperion
albumin, fibrinogen, globulin
29
size and notable features of RBCs
7.5 micrometers +/- 1.5 micrometer
takes of giemsa
average lifespan is 100-120 days, high turnover
have tubules, lose mitochondria, have central hemoglobin (33% solution- almost saturated)
use glucose, contain vitamins and bicarb
plasma membrane of RBCs have mostly lipid, then protein, then carbs. the ABO blood groups are 8% of the glycocalyx on surface
30
function of RBC
3 Cs
carry respiratory gasses
carry antigenic determinants
contain hemoglobin as buffer
31
changes in RBC count
increases (leukocytosis) NORMALLY during exercise, high altitude, pregnancy, dehydration and in neonates
increases ABNORMALLY during heart failure, hypoxia, and polycythemia vera
decreases (leukopenia) are ALWAYS PATHOLOGICAL - due to anemia (hemorrhage, destruction of bone marrow, iron deficiency)
32
change in RBC morphology
sickle cell
33
granular vs agranular leukocytes
granular (AKA polymorphonuclear PMN cells) (neutrophils, eosinophils, basophils)
agruanular (lymphocytes, monocytes - have lysosomes)
34
normal hematocrit
40-45% (RBC percentage)
35
different parts of platelets
hyalomere and granulomere
36
von willebrand factor
contained in membrane bound bodies in endothelium .
| clotting factor in large vessels
37
Functions of endothelium - 7 functions
1. selective permeability (diffusion, active transport, pinocytosis, coated pits, fenestration)
2. thrombosis control (anti-thrombogenics and coagulants)
3. pro-thrombogenics - clotting
4. BP regulation - vasoconstrictors, vaso dilators
5. modulation of immune and inflammatory response - leukocyte adhesion, interleukins for migration
6. hormonal regulatory factors (GFs, IFs, ACE - angiotensin 1->2, inactivators)
7. lipoprotein oxidation (LDLs, VLDLs, cholesterol are oxidized by free radicals and make foam cells - plaque formation)
38
layers of vessels
1. tunica intima (endothelium)
2. tunica media (concentric smooth muscle - more in arteries)
3. tunica adventitia (longitudinal CT - more in veins)
39
properties of lymphatic vessels
- used for big particles (both good and bad)
- able to distinguish good and bad
- large openings, irregular outlines, with anchoring fibers
- large vessels have valves
40
connection between lymph and circulatory system
thoracic duct, right lymphatic duct - lymph collects and drains into venous system (subclavian vein)
41
spleen functions
1. hemopoietic - destruction of RBCs and retrieval of iron from hemoglobin
2. immune function
42
spleen histology (pulp)
1. red pulp - RBC (vascularized pulp peripheral to PALS)
2. white pulp - immune (contains T and B cells, responds to antigens, forms PALS around arteries - activated has lighter crown and darker mantle)
43
capsule and trabeculae
trabeculae is capsule invaginations - inner structure
44
rapid and slow route in splenic capillary beds - red pulp
1. rapid route - not found in humans -- closed circulation - straight through
2. slow route - sinusoids with fenestrations, into cords of bilroth (you get picked up back into sinus if you're a healthy RBC, if you're not, you don't go back into circulation)
45
3 functions of hemoglobin
1. oxygen binds to heme (Fe2+)
2. CO2 binds N-terminal amine group of 4 globin subunits forming carbamino group
3. hemoglobin acts as pH buffer by transporting H+ via histidine
46
exchange of gasses via hemoglobin - step by step (5 steps)
1. in lungs, pO2 is high, so O2 passes into RBC, binding to deoxy-Hb, making oxy-Hb
2. oxy-Hb is a stronger acid than deoxy-Hb and it gives up H+, shifting equilibrium between bicar and carbonic acid toward carbonic acid
3. carbonic acid dissociates into CO2 and water - catalyzed by carbonic anhydrase
4. low pCO2 drives CO2 out of RBC and into lung
5. bicarb/chloride antiport transports bicarb out and chloride in (maintain ionic balance and make sure no lysis happens - chloride shift)
47
3 basic classification of a anemias
1. normocytic normochromic anemia - normal size normal appearance, low hematocrit (<40%) can come from hemolytic anemia (can occur due to loss of pyruvate kinase) and blood loss.
2. microcytic hypochromic anemia - small size and under colored - low to normal hematocrit, less hemoglobin or heme synthesis occuring
3. macrocytic normochromic anemia (megaloblastic) - inhibited cell division - seen because of folate/vit B12 deficiency
48
from pleuripotent stem cell to RBC
1. pleuripotent stem cell
2. unipotent stem cell
3. proerythroblast (large neucleus)
4. early normoblast (basophilic, start heme synthesis)
5. intermediate normoblast - getting smaller
6. last normoblast (orthochromic) - even smaller - nucleus get extruded
7. reticulocyte (no nucleus, but ribosomes form heme synthesis)
8. erythrocyte RBC
takes several days - if this is blocked, by a week you'll have lost 0.8 x 7 = 5.5% loss
49
B12 and folate and anemia
megaloblatic/
pernicious anemia: loss of gastric parietal cells (bariatric sx, cancer, autoimmune) or deficiency of IF -- causes megaloblastic anemia (don't have enough folate/B12 to divide, so get large but can't divide)
50
iron deficiency and anemia
microcytic hypochromatic anemia (pinker, smaller)
| used in hemoglobin (65% of total body iron is in hemoglobin)
51
lead and heme synthesis
glycine + succinyl-coA --> 5-ALA (Rate limiting). enzyme for this step is 5-ALA synthase which is sensitive to lead.
ferrochelatase, which inserts Fe2+ into heme structure is also sensitive to lead.
52
porphobilinogen
build up causes pain and neurological issues. 2 ALA come together via 5-ALA dehydratase to form porphobilinogen
53
porphyria
caused by defective enzymes in heme biosynthesis - different kinds dependent on enzymes
54
deficiency in UP3 decarboxylase causes
cutanea tarda (Can be acquired - don't need family history)
55
acute porphyria
includes acute intermittent, variegate, and herediatry corproporphyria
is episodic
see:
abdominal pian, purple splotches, red urine, muscle weakeness, psychotic episodes, anxiety, schizophrenia - king george 3
can prevent acute attack - by hemin
56
chronic porphyria
includes congenital erythropoietic porphyria, porhyria cutanea tarda, veriegate porphyria
long term stable
dermatological issues (light sensitivity, blistering, sloughing) - werewolf syndrome, body hair, vampire syndrome, red gums, stained teeth, light sensitivity
57
globin genes and order of expression
alpha gene found on chromosome 16, beta on chromosome 11
From left to right:
(chrom 16) zeta (fetal), alpha 2, alpha 1
(chrom 11) epsilon (fetal), gamma G, gamma A, delta, beta
58
mutations in alpha or beta globin is more dangerous
alpha, because beta has a lot more regulation and complexity and options (locus of control region for beta is extensive)
59
what causes beta thalassemia
point mutation in globin gene intron yielding alternate splice site - adds 21 nucleotides = in frame 7 AA shift
yeilds hemeoglobin that acts more like myoglobin and doesn't like to give up oxygen
60
developmental heme switching
in fetus, epsilon and zeta (from yolk sac) are first to decrease, as alpha and gamma rise in the liver. beta starts to rise slowly and at around 7 weeks, the gamma/beta ratio is about half/half. bone marrow is taking over. delta rises slowly.
61
HbA1 (AKA HbA) contains which types of globin
2alpha2beta
62
HbA2 contains which types of globin
2alpha2delta
63
HbF contains which types of globin
2alpha2gamma
64
heme binding pocket contains
hydrophobic cleft and two central histidines:
| proximal histidine binds covalently to Fe2+ and other protects the oxygen binding site (distal)
65
pO2 in muscle vs lung
muscle - 26-30torr
lung - 100-110torr
hemoglobin will give up oxygen that it gets in the lung in the muscle.
in muscle, hemoglobin is more stable as deoxygenated than oxygenated. myoglobin is more stable in oxygenated
66
cooperative interactions
subunit-subunit interactions
in deoxy, once the 1st O2 binds, the rest bind (distal histidine gets out of the way because of the binding of the first O2 and the conformational change)
in oxy, once the 1st O2 leaves, the rest leave (distal sweeps the O2s out of the way)
67
how many salt bridges in deoxy-form (T) of hemoglobin
8
68
how many salt bridges in oxy-form (R) of hemoglobin
6
69
heme metabolism and carbon monoxide
1. hemoglobin -> globin and hemin
2. hemin -> biliverdin and CO (from non-polar side of hemin) (via heme oxygenase)
3. biliverdin -> bilirubin (via bilverdin reductase)
bilirubin has free rotation - clamps down on itslef - not soluble.
4. in liver, bilirubin is modified by adding 2 glucuronic acids to make it soluble so it can be lot in the bile
70
How can Hb be forced to deliver more O2 to metabolically active peripheral tissues
increase the number of deoxy stabilizing salt bridges
71
bohr effect
increasing pCO2 and number of protons drives oxygen binding curve
H+ adds to histidine, establishing new salt bridge on each Beta -- now at 10 salt bridges
CO2 binds amino terminal end of beta-globin making carbamate on each subunit making 4 additional salt links -- now at 14 salt bridges
so, in acidic environment (lactic acidosis), you give off a lot of O2 and pick up CO2
72
chloride shift
as CO2 increases, HCO3- will flow out of cell into circulation, when that negative charge leaves, you create electrical gradient, so Cl- comes in. Cl- level in circulatory system drops.
H+ binds to heme stabilizing deoxy confirmation to give off O2
73
Rapoport-Leubering Shunt
in H+ conditions, H+ activates mutase which takes 1,3 BPG to 2,3 BPG and then back to 3-PGA by phosphatase
2,3 BPG gets into central pore of hemoglobin, stabilizing the deoxy conformation by adding 6 additional salt-bridges between beta-subunits -- now have 18-20 salt bridges stabilizing the deoxy unit - forces all O2 off the hemoglobin
74
3 metabolic pathways in RBC
1. glycolysis
2. HMP shunt
3. rapoport-leubering shunt
75
difference between fetal hemoglobin HbF and maternal HbA
fetal hemoglobin misses a histidine, so you have 2 fewer salt bridges - so deoxy form in mom is more stable - mom gives off O2 to fetus.
76
if you have a problem with Beta subunit, how does your body react
can induce expression of gamma and delta
77
sickle cell
position 6 on Beta chain, point mutation takes glutamic acid off the surface of heme, which was making it soluble - shell of hydration. without it, the heme sticks together. in deoxy states, heme can precipitate out of solution.
so for people with trait, don't exert, don't go to high altitudes
78
HbC
lysine replaces glutamic acid instead of valine.
lysine is positive - still has shell of hydration. for heterozygote, one is normal one is lysine - you get electrostatic interaction - make salt bridges, make heme to clump up - doesn't spindle.
79
MetHb
1-2% normally is MetHb. Hb-O2 gets converted to Met-Hb and releases O2 radical. SOD takes care of radical, but at high levels can cause damage.
Met Hb doesn't bind O2 - changes blood to blue-chocolate blood. Met Hb reductase uses cytochrome (uses NADH from glycolysis).
in cyanide poisioning, give amyl nitrite you get Met-Hb and then remove by nitrite and thiosulfate.... or just use B12
80
issue with RBC lysis
RBCs lyse and release hemoglobin, hemoglobin is right at the threshold for kidney filtration and ends up clogging it leading to kidney failure.
Normally, to prevent this, hemoglobin gets complexed with HAPTOGLOBIN which is synthesized by the liver, and the complex is large enough that it doesn't damage the kidney, and gets targeted to spleen/liver for metabolism.
when lysis happens free heme is also picked up by HEMOPEXIN, to prevent clearance from kidney and to recycle iron. hemes create free radicals.
81
Hemoglobin is broken down into ___
1. iron
2. bilirubin (heme)
3. globin (re-enters amino acid pool)
82
jaundice
AKA ICTERUS
excessive RBC turnover, hemolytic anemias, bile blockage, liver disease (blocked glucuronylation) all lead to buildup of insoluble bilirubin - accumulate in whites of eyes and fatty tissues under skin -- leading to yellow coloration.
biliverdin absorbs light - neonatal jaundice - light therapy prevents conversion of biliverdin to bilirubin which is insoluble (because babies don't have glucuronyosyltransferase). if not resolved, baby will have neurologic issues called KERNICTERUS
83
epo
erythrocytic growth factor - negative feedback like all the growth factors
mostly made in kidney, but can also be made by liver
epo producing cells have O2 sensors (not enough stimulates RBC production) - then downregulates neg feedback
84
bone marrow -
scaffolding for differentiation and regulation by cell-cell interactions - niche theory
85
niche theory
vascular niche
osteoblast niche
regulated by cytokines - tells cells to get out of niche and differentiate
provide backup supply
86
erythocytic lineage time to mature, #progeny, survival time
5 days
16 (4 divisions)
120 days
87
granulocytic lineage time to mature, #progeny, survival time
5 days (14 days to release)
16-32 (4-5 divisions)
1-4 days
88
megakaryocytic lineage time to mature, #progeny, survival time
5 days
hundreds (many fragmentations into platelets)
8-11 days ~ 10 days
89
which cells (what stage) can undergo mitosis
only 'blasts and pro' cytes
90
sites of hematopoesis from fetal to adult
yolk sac, then liver and spleen, bone marrow takes over by the time of birth.
adult (vertebral and pelvis (posterior iliac spine) first then sternum (can only do aspirate), then ribs) lymph nodes also.
long bones only active until puberty (anterior tibia)
less reserves in central bone as we age
spleen and liver have capacity to resume hematopoesis
91
what can you see/assess with aspirate smear
- ratio of M:E (normal is 3:1) granulocytes:erythocytes
- maturation of lineages
- low frequency elements (plasma, lymphocyte etc.)
- iron stores (not decalcified like for core)
- foreign cells (metastatic neoplasms)
- microorganisms
92
what stain do you use to see iron in aspirate smear
prussian blue
93
what do we look for/see in bone marrow core
- cellularity (~90% occupied by cells in children, ~30% in elderly - more fat in elderly)
- maturation of lineages (aspirate is better)
- fibrosis (only in core)
- foreign cells (better than aspirate)
- granulomas (only in core)
- microorganisms
- bone morphology
94
when do you do a bone marrow examination
not first - it's invasive
if you can't explain it with other non invasive tests
1. combination of anemia, neutropenia and/or thrombocytopenia
2. leukemia eval
3. metastatic neoplasms (staging)
4. search for infectious agents (mycobacteria or fungi)
95
definition of anemia
reduction of RBC mass, results in decreased ability to carry O2
96
variables that affect hematocrit, hemoglobin and RBC count
- gender (higher in men)
- age
- altitude (increased at high altitude)
- posture (prolonged bed rest decreases)
- stress, exercise (increased)
- dehydration (increases)
- overhydration (decreases)
97
pathophysiologic classification of anemia
- decreased RBC production (affecting stem cells or differentiating cells)
- increased RBC destruction (hemolytic)
- RBC loss (hemorrhage)
98
morphologic classification of anemia
big - macrocytic
normal - normocytic
small - microcytic
99
examples of decreased RBC production due to stem cell issues
1. aplastic anemia
2. pure red cell aplasia
3. myelodysplastic syndromes
4. anemia of renal failure
100
examples of decreased RBC production due to differentiating cell issues
```
impaired DNA synth
- B12 and folate
imparied hemoglobin synth
- iron deficiency
- thalassemia (globin chain defect)
- sideroblastic anema (heme synth defect)
multiple mechanisms
- anemia of chronic disease
- myelophthisic anemia - fibrosis
```
101
examples of anemia caused by increased RBC destruction
```
EXTRACORPUSCULAR
- immune-mediated
- non-immune-mediated
INTRACORPUSCULAR
- acquired
- inherited (RBC membrane defects, enzyme deficiencies, globin chain structural -sickle, or synthesis defects - thal)
```
102
examples of macrocytic anemia causes (2)
1. B12/folate deficiency
| 2. antineoplastic drugs
103
exaples of normocytic anemia causes (5)
1. aplastic anemia
2. anemia of chronic disease (some)
3. hemolytic anemia
4. myelophthisic anemia
5. acute blood loss
104
examples of microcytic anemia causes (4)
1. iron deficiency
2. thalassemia
3. sideroblastic anemia
4. anemia of chronic disease (some)
105
clinical general features of anemia (11)
```
tissue hypoxia and
compensatory mechanisms
1. fatigue
2. dyspnea on exertion
3. faintness
4. vertigo
5. angina pectoris
6. claudication
7. palpitations
8. pallor
9. hypotension
10. tachycardia
11. systolic murmur
```
106
clinical specific symptoms of anemia (7)
1. GI or GU bleed (iron def anemia)
2. PICA - eating clay or ice ( iron def anemia)
3. JAUNDICE (hemolytic)
4. DARK URINE (hemolytic)
5. NEURO (B12)
6. DRY ATROPHIC SKIN/NAILS (iron deficient)
7. RED SWOLLEN TONGUE (B12)
107
lab evaluation of anemia - step by step
ALWAYS DONE
1. hematocrit, hemoglobin, RBC CBC
2. RBC indices
3. peripheral smear eval
SOMETIMES DONE
4. reticulocyte count
SPECIALIZED
5. iron studies (microcytic)
6. B12/folate (macrocytic)
7. hemoglobin degradation products LDH (hemolytic)
8. other tests for hemolytic anemias
9. bone marrow
108
MCV
Mean corpusular volume
- measure of size
- lower in kids than adults
109
RDW
RBC distribution width
- measures how uniform the cell size is
- high in iron deficiency, not in thalassemia
110
MCH
Mean corpuscular hemoglobin
| - average hemoglobin content (parallels MCV and MCHC)
111
MCHC
mean corpuscular hemoglobin concentration
- concentration of hemoglobin in RBC
- often low in microcytic anemias
color - area of central pallor
112
polychromasia
larger and bluer - just released from bone marrow
113
poikilocytosis
variation in shape of RBC
114
Codocyte/target cell
darker in center
shaped like cup
too much membrane not enough cytoplasm
115
teardrop/dacryocytes
myelofibrosis
metastatic
myelophthisic
116
schistocytes/helmet cells
damaged in circulation
| fibrin in DIC causes slicing of cell
117
sickle/drepanocytes
sickle cell
118
ovalocytes/elliptocytes
rare
| hereditary ovalocytosis
119
spherocytes
bits and peices removed, form sphere
no area of central pallor
hereditary spherocytosis
autoimmune hemolytic anemia
120
burr cell/echinocytes
sometimes an artifact
| see with uremic patients
121
acanthocytes
thorn cells
122
reticulocyte count
% = raw retic % x (pt hematocrit/mean normal hematocrit)
123
TIBC
Total iron binding
capacity of serum to bind iron
reflection of serum transferrin levels
124
serum ferritin
how much iron is actually in storage
125
serum vit B12
for megaloblastic anemias, good reflection of vitb12 stores
126
serum and RBC folate
for megaloblastic anemia,
| serum is good measure, but labile. RB level better for total body stores, but subject to analytical problems
127
intrinsic factor blocking antibody
megaloblastic
| -proves cause of B12 deficiency
128
tests for patients with megaloblastic/macrocytic anemia
- serum vit B12
- serum folate
- IF blocking antibody
129
hemolytic anemia tests
- LDH
- and hemoglobin degradation product (high unconjugated bilirubin, hemosiderin, low haptoglobin etc., hemoglobin in urine)
130
coombs test
for autoimmune - antigolbuin, hemolytic anemia
131
3 layers of immune defense
1. barriers (skin, pH, enzymes)
2. innate (neutrophils, macrophages, dendritic cells, NK cells - specialized lymphocytes)
3. adaptive (T cells, B cell lymphocytes)
132
innate and adaptive immune response communication/feedback
innate positively regulates/feedsback on adaptive immunity, adaptive regulates innate - don't want ongoing damage due to inflammation. innate contains, adaptive clears
133
receptors for innate immunity arise from what?
germline - they're germline encoded - passed down from parents. are broadly specific (recognize broad molecular patterns associated with pathogens or tissue damage)
134
receptor for adaptive immunity arise from what?
NOT germline encoded - antigen receptors require somatic recombination during development
135
example of antimicrobial protein
defensins (seen in skin, gut, lungs, ENT) - can insert themselves into cell membrane of bacteria, fungi and some viruses (secretion can be induced by gut flora or epithelia or neutrophils)
136
microbial flora/ commensal bacteria role
1. competes with pathogenic bacteria
2. induces epithelial and immune cells in microenvironment to produce anti-microbial innate factors -- immune equilibrium
137
complement system - 3 pathways and 3 effects (include specific complement molecules associated with effects)
3 pathways:
1) classical (antigen:antibody)
2) lectin (lectin binds to pathogen)
3) alternative (pathogen surfaces)
C3 CONVERTASE goes from pathways to effects
All pathways result in
1) recruitment of inflammatory cells (Chemoattractants - also make BVs leaky "C5a, C3a")
2) opsonization of pathogens (coats to make cells recognizable to phagocytes) "C3b"
3) killing of pathogens by inducing pores within membrane of invading pathogens -- assembles a membrane-attack complex (MAC) to make pores - enough pores will degrade the integrity of pathogen membrane "C5b, C6, C7. C8. C9"
138
complement - lectin pathway
initiated by mannose binding lectin - interacts with mannose-containing carbohydrate present on pathogens
139
complement- alternative pathway
spontaneous activation at low levels, interacts with negatively charged features of pathogen cell walls
140
complement - classical pathway
activated by antibody-mediated recognition of antigen
141
How do innate immune cells sense changes in the microenvironment (5 ways)
1. Pattern Recognition Receptors (PAMPs, DAMPs)
2. Toll-like receptors
3. NOD-like receptors
4. Lectin receptors
5. scavenger receptors
142
PAMP
Pathogen-associated molecular pattern
- molecules associated with microbes - bacterial and fungal cell wall constituents, bacterial/viral nucleic acids, bacterial proteins (i.e., flagellin)
examples: peptidoglycans, lippopolysaccharides, flagellin, DNA/RNA
143
DAMP
Danger-associated molecular pattern
- molecules released by host cells when they're damaged or during necrosis (not by healthy or apoptotic cells). include uric acid, ATP, stress induced proteins (heat shock proteins), nuclear proteins (HMGB1)
- NOD and TLRs recognize both PAMPs and DAMPs
144
Consequences of pattern recognition receptor signaling
PRR signaling events stimulate macrophages and neutrophils to secrete lipid mediators of inflammation (PROSTOGLANDINS/LEUKOTRIENES), CHEMOKINES (IL-8 or CXCL8) and CYTOKINES (IL-1, IL-6 and TNF-alpha) which cause local inflammation that includes swelling, heat and redness and pain.
145
what is a consequence of swelling during local inflammation?
(increase in fluid bring in complement factors that kill invading organisms, and clotting factors that prevent organisms from spreading)
146
What does IL-1beta do (6 things)
pro-inflammatory cytokine
locally (lymphocyte/liver):
- enhances responses
- production of IL-6 --> acute-phase protein secretion
147
What does TNF-alpha do? (5)
pro-inflammatory cytokine
locally (works on vascular endothelium):
- increases vascular permeability, which leads to increased entry of IgG, complement, and cells to tissues and increased fluid drainage into lymph
- VCAM, E- and P- selectin expression
148
What does IL-6 do?
pro-inflammatory cytokine
locally (lymphocyte/liver):
- enhances responses
- induces acute-phase protein production
149
What does CXCL8 (IL-8) do?
```
chemotactic factor recruits (works on phagocytes):
- neutrophils
- basophils
- T cells
to site of infection
```
150
What does IL-12 do?
pro-inflammatory cytokine (works on naive T cells)
- pro-inflammatory
- diverts immune response to T H1
- cytokine secretion
- NK activation
151
Toll-like Receptor (TLRs) - examples, signal transduction
family of PRRs that recognize microbial molecules
Some TLRs are plasma membrane bound, others are in endosomal compartments
TLR generate signal transduction cascate reulting in NF-kB dependent gene transcription - inducing production of pro-inflammatory cytokines (TNFalpha, IL-6, IL-12 etc.)
152
NOD-like receptors (example, issues)
located in cytoplasm - recognize microbial patterns and induce cells to produce cytokines (via NF-kB also)
- NOD defects seen in subset of Crohn's disease
153
Scavenger receptors
recognize phospholipids on microbial cell wall - promote phagocytosis and cytokine production
154
Myeloid innate immune cells
- macrophages
- dendritic cells
- neutrophils
- eosinophils
- basophils
- mast cells
155
Lymphoid innate immune cells
- NK cells
| - others that will be covered later...
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Macrophage effector functions (3)
- constitutively active, stay on site
- engulf and kill invading pathogens
- release lipid mediators of inflammation (prostaglandins and leukotrienes)
- release chemokines and cytokines to recruit leukocytes (first wave includes monocytes that differentiate into macrophages once in tissue, and phagocytic neutrophils PMNs) - high levels of cytokine release will cause sepsis
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M1 macrophages
"classically" activated macrophages - associated with Th1 type immune responses (IFNg pro-inflammatory) - in obsese adipose tissue
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M2 macrophages
associated with Th2 type immune responses (IL-4 allergic inflammation) -- wound healing, tissue repair, in lead adipose tissue
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mechanism of neutrophil recruitment to injury
neutrophils are continually produced by bone marrow and released by cytokines and chemokines
recruitment:
1) cytokines released by macrophages (TNF-alpha, IL-1) upregulate expression of ADHESION MOLECULES on BV endothelium. leukocytes become attached to selectins, integrins (bind to ICAM) cause leukocyte to stop rolling and adhere to endothelium.
2) integrins and chemokine receptors signal DIAPEDESIS (extravasation) into tissues
3) extravasated leukocytes respond to chemokine gradient (i.e. IL-8 and complement for neutrophils) via interaction with chemokine receptors --> leukocytes move toward injury which has high concetration of chemokines
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classes of adhesion molecules that regulate neutrophil recruitment
1. selectins (P and E selectin expression upregulated by addressins, expressed by neutrophil)
2. integrins
3. members of immunoglobulin supergene family - ICAM, VCAM
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Mechanism of neutrophil effector function
neutrophils express receptors that interact with microbial patterns and facilitate phagocytosis
reactive oxygen and nitrogen species are made by NADPH oxidase to destroy the endocytosed organisms - called RESPIRATORY/OXIDATIVE BURST
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Dendritic cells (where they are, what they do (3 things))
constituatively present in tissue and sense the microenvironment using pattern recognition receptors.
activation causes production of cytokines that promote INITIAL imflammatory immune response
migrate from tissue to lymph tissue - where they serve as antigen presenting cell for NAIVE T CELL ACTIVATION
respond to viral infection via PLASMACYTOID DENDRITIC CELLS
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plasmacytoid dendritic cell (function)
plumper in appearance. rare-ish. subset of dendritic cells produces TYPE 1 INTERFERONS (IFN-alpha, IFN-beta) in response to VIRAL INFECTIONS
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functions of type 1 interferons (3)
1) induce anti-viral state by bystander cells (stimulation of enzymes that block viral replication if bystander cell becomes infected)
2) activate virus infected cell to increase MHC class 1 proteins to promove interaction with cytotoxic T lymphocytes
3) activate NK cells to be more efficient at killing infected cells
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what is the role of NK cells in innate immunity? (2)
1) to recognize and kill pathogens residing in the cytoplasm of host cells - viruses especially via KAR and enzymes. --
macrophages release chemokines (from granules) that recruit circulating NK cells to infected tissues. keep the replication of viruses to minimum until adaptive immune responses are activated
2) NK cells also produce interferon gamma - regulate development of immune response
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NK cell receptors
NK cells recgonize infected host by using receptrs that notice changes in host cell surface proteins.
1) Killer Activating Receptors (KARs) recognie viral-associated molecules on surface as well as molecules indicative of cell stress
2) Killer Inhibitory Receptors (KIR) recognize MHC class 1 expression - does not kill normal cells, but may decrease during viral infection (so altered MHC will kill target cell)
167
NK mechanism of action
Once NK receptors are activated, cell resleases PERFORIN, GRANZYMES and GRANULYSIN which are stored in preformed granules - trigger caspases.
perforin forms pore in targe cell membrane
granzymes (trigger caspases) are released into cytopasm to initiate apoptosis. granulysin is antimicrobial and induces apoptosis
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how are NK and cytotoxic T cell actions different
similar mechanism and molecules, but NK cells don't express T cell antigen receptor
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NALPs
- NALPs (NOD-like receptor with pyrin-like domains) are important for IL-1beta (inflammasome activates caspase 1, which cleaves IL-1beta to be secreted). NALP associates with other molecules, forming macromolecular complex called INFLAMMASOME. - responds to microbe and DAMPs like URIC ACID IN GOUT.
- familial periodic fever syndromes (familial mediterranean fever) mutations in pyrin
170
effect of inflammatory cytokines on liver
causes:
acute-phase proteins (c-reactive protein, mannose-binding lectin)
which in turn causes:
- activation of complement
- opsonization
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effect of inflammatory cytokines on bone marrow
causes:
neutrophil mobilization
which causes:
- phagocytosis
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effect of inflammatory cytokines on hypothalmus
causes
increased body temp
which causes:
decreased viral/bacterial replication
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effect of inflammatory cytokines on fat/muscle
causes:
protein/energy mobilization to increase body temp
which causes: decreased viral/bacterial replication
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2 examples of stimuli that regulate movement of dendritic cells into lymph nodes
- PAMP
| - chemokine
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someone with decreased beta-2 integrins (CD11a or LFA-1) would present with what?
increased circulating neutrophils - can't get into tissue - leukocytosis
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describe graph of immune response events after infection (levels of substances you would see in the blood)
1) pro-inflammatory cytokines are first (~2 days after infection) - IFN-alpha, beta (made by dendritic cells - IFN-1s), TNF-alpha, IL-12
2) NK mediated killing of affected cells - contain virus
3) T-cell (adaptive) mediated killing of infected cells - eliminate virus
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Step by step, what happens when you get a splinter
1. splinter happens, damages cells (releases DAMPS) introduces bacteria (microbial- associated microbial patterns - PAMPs)
2. constitutively resident macrophages and dendritic cells have pattern recognition receptors that respond to DAMPs and PAMPs
3. macrophages and dendritic cells are activated and produce cytokines and chemokines to recruit additional cells to contain infection
4. adaptive immunity comes later
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possibilities when you see microcytic anemia
1) iron deficiency
2) anemia of chronic disease
3) thalassemias (microcytosis out of proportion to hb/hematocrit)
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iron deficiency anemia initial differential (after obtaining CBC)
In CBC, when you see low Hct, RBC, Hb, MCHC, MCH and MCV, and high RDW and platelets, think iron deficiency.
Iron deficiency anemia is always due to an underlying cause:
1) suspect bleed (GI or GU bleed should always be suspected first in older man and post-menopausal woman)
2) decreased uptake (inadequate diet, gastric surgery - Fe absorbed in proximal jejunum, celiac disease, increased gastric pH, tannins in tea)
3) increased requirements - pregnancy, childhood
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clinical manifestations of iron deficiency
- symptoms of anemia (fatigue, shortness of breath, dizziness, palpitations)
- PICA - eating random shit (ice, clay, chalk)
- restless leg
- KOILONYCHIA - spooning of nails
- blood in stool (if GI bleed is cause) or urine (if GU bleed is cause)
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additional lab tests for iron deficiency anemia
```
- iron panel (serum iron, serum ferritin, TIBC, sTFR)
see:
- decreased serum iron
- decreased iron saturation
- decreased serum ferritin
- increased total iron-binding capacity
```
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treatment for iron deficiency anemia
treat underlying cause (malnutrition, GI bleed)
| - give oral supplements or parenteral if oral isn't tolerated
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macrocytic anemia subtype
megaloblastic (B12, folate)
| non-megaloblastic (alcohol, liver disease)
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B12 deficiency - classic findings
- megaloblastic anemia
- can see pancytopenia (anemia, leukopenia and thrombocytopenia)
- takes years to develop (as opposed to folate deficiencies which can develop quickly)
- neurological changes (myelopathy of posterior columns - vibration and position sense, of lateral columns - weakness, spacticity)
- low retic count
- hypersegmented neutrophils
- macro ovalocytes
- see high methylmalonyl coa and homocysteine
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causes of B12 deficiency
1. pernicious anemia (autoimmune, seen with other autoimmune defects, failure to secrete intrinsic factor because of antibody)
2. surgical (gastrectomy or gastric bypass, resection of terminal ileum)
3. zollinger-ellison syndrome - inactivation of pancreatic protease which impairs B12 binding to iF
4. pancreatic exocrine deficiency (enzymes)
5. blind loop syndrome (colonizing bacteria bind B12)
6. diphyllobothrium latum (worm that binds B12 and prevents absorption)
7. dietary (vegans)
186
treatment for B12 deficiency
intramuscular B12
oral B12
phrophylactic therapy for gastric/ileum resection
watch out for hypokalemia with treatment early on
187
folic acid deficiency - classic findings
- low serum folate
- low RBC folate
- elevated serum homocysteine level
188
folic acid deficiency - causes
- inadequate diet (mostly with elderly, poor and alcoholics)
- impaired absorption (due to sx)
- medications (anticonvulsants, contraceptives)
- increased requirements (pregnancy, chronic hemolytic anemia, exfoliative dermatitis)
189
anemia of chronic disease
- usually normocytic, can eventually become microcytic
- cytokine driven (iron unavailable - sequestered in macrophages)
-
190
cytokine role in anemia (epo, hepcidin etc.)
?
cytokines:
suppress erythropoeisis and increase hepcidin production.
increased hepcidin increases iron sequenstration
renal failure decreases hepcidin excretion into urine, decreases epo
macrophages increase phagocytosis
191
causes of ACD
- acute/chronic infection (HIV, fungal, parasitic)
- malignancy
- autoimmune (lupus, inflammatory bowel disease)
- hospitalization
- end stage renal disease
192
RDW in iron deficiency vs ACD
high in iron deficiency, normal in ACD
193
platelet levels in iron deficiency vs ACD
can be normal to high in either
194
wbc count in iron deficinency vs ACD
Normal to high in ACD, normal in iron deficiency
195
treatment for ACD
treat underlying cause
transfuse
erythropoeitic stimulating agents
196
general lab characteristics of hemolytic anemia (from CBC, marrow, smear)
- high retic count (increased erythropoesis)
- increased degradation products (LDH, bilirubin)
- decreased haptoglobin
- erythroid hyperplasia in marrow (increased RBC precursors)
- polychromasia (blue-ish immature cells)
- immature nucleated RBCs
- schistocytes (microangiopathic)
- microspherocytes (AIHA)
197
clinical features (physical presentation) of hemolytic anemia (both intra and extravascular)
- general anemia symptoms
- jaundice
iF INTRAVASCULAR
- can see hemoglobinemia, hemoblobinuria, shock, DIC, hypotension, renal failure
IF EXTRAVASCULAR (TBCs destroyed in phagocytosis - can see with sickle cell)
- splenomeglay
- gall stones
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hereditary causes of hemolytic anemias (8)
- G6PD deficiency
- pyruvate kinase deficiency
- heridtary spherocytosis
- hereditary ovalocytosis
- sickle cell
- HbC
- HbE
- Thalassemia
199
acquired causes of hemolytic anemia
- immune hemolytic anemia (AIHA)
- mechanical (shear stress)
- microangiopathic (DIC, TTP)
- Infection (malaria, clostridium)
200
How to diagnose immune hemolytic anemia
Coombs test (direct tests for antigens on RBCs for IgG or complement)
WARM: IgG (spleen)
COLD: IgM - fixes complement (liver and spleen)
201
Warm AIHA - associated disorders
- idiopathic
- drugs (methyl dopa, penicillin)
- lymphoid malignancies
- autoimmune (SLE)
202
Cold AIHA - associated disorders
- idiopathic (cold agglutinin disease)
- lymphoid malignancies
- infections - ebstein barr, mycoplasma
203
AIHA clinicla presentation (6)
- anemia
- jaundice
- cardiopulmonary collapse
- hepatosplenomegaly
- thrombosis
- acrocyanosis (cold agglutinins)
204
Warm AIHA treatment
- treat underlying (discontinue drug if drug-induced)
- immune suppression to decrease antibody production
- splenectomy (warm) -site of destruction
205
Cold AIHA treatment
- treat underlying (EBV etc.)
- administer warmed RBCs
- plasma exchange if really severe
- avoid cold
206
G6PD deficiency anemia (genetics)
- x-linked disorder
- A form in african american men (milder)
- Mediterannean type more severe (even reticulocytes have low levels of G6PD)
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G6PD hemolytic triggers
- increased susceptibility to oxidative damage
- infection or medication (antimalarials, sulfonamides) cause oxidative stress to trigger anemia
- fava beans also increase oxidative stress
208
lab tests for G6PD hemolytic anemia
- Heinz bodies and bite cells
| - G6PD levels in older RBCs
209
hereditary spherocytosis (genetics)
- autosomal dominant
| - defective ankyrin protein
210
hereditary spherocytosis (clinical manifestations)
- chronic anemia
- splenomegaly
- gall stones
211
hereditary spherocytosis (lab tests)
- see spherocytes
- increased osmotic fragility
- hemolytic anemia findings (LDH, breakdown products, jaundice, high retic, low haptoglobin)
212
treatment for hereditary spherocytosis
- splenectomy in severe cases
213
2,3 BPG and oxygen shift
2,3, BPG decreases O2 affinity - right shift
214
alkylosis and oxygen shift
alkylosis causes increased O2 affinity - left shift
215
genetic differences between beta thal major, minor and intermedia
all beta thal has impaired beta chain synthesis
minor = heterozygote
major (B0) = homozygote
intermedia (B+) = homozygote but only impaired, not deleted
216
consequences of beta thal defects in beta thal major
alpha chain preceipitates cause:
1) ineffective erythropoesis
2) hemolysis
3) marrow expansion (in face - chipmunk)
4) extramedullary hematopoesis (spleen, spine)
5) high output congestive failure
217
electrophoresis and thalassemias (what can you use it for)
can determine the type of beta thalassemia (see if you have delta, beta or gamma) - alpha doesn't work - always the same percentage (have to use PCR or gene sequencing)
218
treatment for beta thal major
- transfusion (but be careful about iron overload)
- hydroxyurea (increases fetal hemoglobin)
- stem cell transplantation
219
what do you expect to see in a beta thal minor patient's CBC - RBC, Hgb, Hct, MCV
you would see a disproportionally high RBC to Hgb and Hct (could all be low, but RBC is less low). see low MCV (disproportionatly low as compared to Hct)
220
how many loci can have mutations in alpha thal
4 total. 1, 2 or 3 are viable with life, 4 isn't (Bart's Hydrops Fetalis - no functional alpha globin genes - all gamma, leads to eclampsia and stillbirth)
3 defects lead to hemoglobin H (beta chains combine with each other, causes serious fast hemolysis - need transfusion therapy)
221
sickle cell treatment
```
prophylactic antibiotics until age 5
pneumococcal vaccine for kids
hydroxyurea
oxygenation
transfusion (simple or exchange)
```
222
why do you get gall stones in sickle cell
you have increased red cell destruction, increased bilirubin - gall stones
223
why do you get necrosis of bone structure in sickle cell
can't get O2 to bone structure because of sickled shape
224
complications of sickle cell
- acute chest
- stroke in kids
- leg ulcers in adults
- seizures
- renal failure
- bone necrosis
