Clin Chem Exam 2 Porphyrins, Lead And Iron Clin Chem

Front 1

Body Iron regulation (absorbance of iron into gut) is monitered by...

Back 1

negative feedback with hepcidin

Front 2

The three most commonly look at lab assessments of iron are?

Back 2

Hgb, MCV, and RDW

Front 3

A ____ MCV together with an ______ RDW is strongly suggestive of ______

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Low; increased; iron deficiency

Front 4

When you have a strongly suggestive iron deficiency along with an increased erythrocyte porphyrin, it can be considered

Back 4

diagnostic of an iron deficiency

Front 5

What is the gold standard for storage iron assessment

Back 5

Bone marrow examination

Front 6

Name the 5 tests for Iron assessment other than Bone marrow examination

Back 6

1.serum iron
2.serum transferrin
3.transferrin receptor(TfR)
4.Iron-binding capacity
5.ferritin

Front 7

Sensisitve to the stage of mild iron deficiency; levels decrease after body stores are fully depleted but before Hgb levels droup; level are transiently increased after oral iron ingestion

Back 7

Serum Iron (SI)

Front 8

Serum/plasma iron >3500 ug/L (350 ug/dL) idicates

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significant exposure or overdose of iron

Front 9

A glycoprotein that binds iron very tightly but reversibly

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transferrin

Front 10

When transferrin in not bound to iron, it is known as

Back 10

apo-transferrin

Front 11

Circulation form of iron; increased in iron deficiency

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serum Transferrin (Tf)

Front 12

_____ umol of transferrin bind to ____ umol of iron

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2;1

Front 13

the ratio of serum iron to iron binding capacity; the most accurate indicator of iron supply to the bone marrow

Back 13

Transferrin saturation (TS)

Front 14

Iron deficiency is seen when % saturatioin is...

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<10-12%

Front 15

Whats the percent saturation if you have 9 transferritin molecules and 13 Fe3+ molecules what is percent saturation?

Back 15

72%

Front 16

Determines cells need for iron, this circulating form of iron is proportional to rate of erythropoeisis, becomes elevated in iron deficiency

Back 16

sTfR serum transferrin

Front 17

sTfR is used for differntial diagnosis of what two microcytic anemias?

Back 17

iron deficiency from anemia of chronic disease

Front 18

explain the transferrin cycle in transferritin receptor

Back 18

transferrin bind to cell and enters cell, Fe released in cell, apo- protein released out of cell

Front 19

storage form of iron

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serum ferritin (SF)

Front 20

1ug/L of serum ferritin binds to corresponds to what?

Back 20

8-10 mg of storage iron

Front 21

What are the levels for iron deficiency in serum ferritin?

Back 21

<12ug/L for adults
<6 for children and <12 ug/L in babies

Front 22

Serum ferritin acts as an acute phase reactant how?

Back 22

upon inflimmation, the acute ferritin levels will change (increase or decrease)

Front 23

what is the R/F ratio?

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serum transferritin receptor/ serum ferritin (receptor to serum ferritin ratio)

Front 24

used to provide an estimate of iron stores; this ratio is affected by inflammatory processes

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R/F ratio

Front 25

in the R/F ratio, which is not affected by oral contraceptives or iron intake?

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sTfR

Front 26

When is the best time to collect an iron specimen?

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morning

Front 27

Iron has a _______ variation
values are normal_______
values are low ________

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diurnal; in the am; in the pm

Front 28

Why can't you have a hemolyzed sample in an iron assessment?

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all the iron in the Hgb is released into the plasma

Front 29

What are different methods for measuring TIBC?

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1. saturate all binding sites with excess Fe3+
2. bind Fe3+ to free sites
3. remove Fe3+ left in serum, measure per iron method

Front 30

how do you calculate unbound IBC?

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unbound IBC= TIBC- serum Fe

Front 31

formula for % saturation

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(serum iron/ TIBC) x100

Front 32

name different ferritin assays (5)

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Immunoturbideimetric assay
electochemiluminescence immunoassay
immunoradiometric assay
radioimmunoassay
enzyme-linked immunosobenst assays

Front 33

immunological methods are used in what assay

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transferrin

Front 34

immunoenzymometric assay and sensitive monoclonal ELISA techniques are used in

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sTfR assays

Front 35

Blocks heme synthesis pathway in 3 spots

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Lead poisoning

Front 36

What are collection requirements when testing for lead?

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lead free needle for collection, collected in a royal blue top tube,EDTA is common anticoagulant used, capillary blood not recommended

Front 37

What is best for detection of lead exposure?

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Whole blood lead measurement

Front 38

What are the levels for iron testing in whole blood?

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<10 mcg/dL normal in adults
>30 mcg/dL in adults indicates significant exposure

Front 39

-not sensitive indicators of low level lead (<35 mcg/dL)
-should not be used as screeing test to detect lead- exposed children
valuable test as a screening test for iron deficiency and for management and follow up care of children with confirmed elevated blood lead leavels

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Free erythrocyte protoporphyrin assay levels(EPP)

Front 40

BLL-EP pairs useful in follwing long term trends in lead absorption and in evaluating the question of internal redistribution of lead after______________

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chelation therapy

Front 41

-considered a supplemental lead test
-not specific due to iron deficiency and anemia of chronic disease
-sensitivity limits of 25 mcg/dL

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zinc protoporphyrin (ZPP)

Front 42

Free erythrocyte protoporphyrin chelates ____ and forms ____________

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zinc; zinc protoporphyrin

Front 43

The level of zinc protoporphyrin in the RBC is directly related to?

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the level of lead in blood

Front 44

Cutaneous erythropeitic porphyria is commonly known as

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werewolf syndrome

Front 45

-Only cure is bone marrow
-symptoms include blackening of teeth, spleen liver and heart damage
-treatment without bone marrow includes blood transfusions every three weeks for the rest of life

Back 45

congenital erythropoietic porphyria (CEP)

Front 46

In cutaneous erythropoietic porphyria symptoms include

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brown teeth, thickening of the forehead, jaw, lips, and cheeks, bone fragmentation, extreme hair grouth over entire body, delayed learning

Front 47

cyclic compounds formed by methylene linkage of 4 pyrole rings

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porphyrins

Front 48

Three porphyrins of clinical significance are

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uroporphyrin, coporphyrin, protophyrin

Front 49

-Pyrroles nuclei substitution by carboxyl groups alter the solubility
-deposit in the skin injured when exposed to UV light

Back 49

Chemical properties of porphyrins

Front 50

porphyrins that are soluble in water and cause late bullous lesions

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Uroporphyrin and coproporphyrins

Front 51

this porphyrin is soluble in lipids and insoluble in water. concentrates are more in cellular membranes, inflammatory reactions with burning sensations after exposure to sunlight

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Protoporphyrin

Front 52

_______ is eliminated through urine
_______ is eliminated through in feces
_______ is eliminated through both methods

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uroporphyrin; protoporphyrin; coproporphyrin

Front 53

Porphyrin diseases are divided into what three categories?

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pophyrinuria, porphyrinemia, porphyrias

Front 54

moderate increase in urine coproporphyrin production

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porphyrinuria

Front 55

increase in protoporphyrin concentration in RBCs

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porphyrinemia

Front 56

abnormal porphyrin metabolism and an overproduction or accumulation of heme precursors in body

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porphyrias

Front 57

porphyrinuria is caused by (4)

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liver damage, accelerated erythropoiesis, infection, lead intoxication

Front 58

porphyrinemia is caused by (4)

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iron deficiency, impaired iron absorption, chronic infection, lead intoxication

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-Inherited or acquired disorder
-results in abnormal porphyrin metabolism and an overproduction of heme precursors
-common feature is the excess accumulation of porphyrins or porphyrin precursors in the body

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Porphyria

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-acquired caused by liver disease or toxicity from heavy metals or drugs
-inherited is result of a deficiency of an enzyme in heme synthesis pathway

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porphyria inherited or acquired disorders

Front 61

Hepactic porphyria is a defect in...

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the porphyrin metabolism in liver

Front 62

erythropoietic porphyria is defect in...

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blood producing tissues (bone marrow)

Front 63

porphyria characterized by skin manifestations

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cutaneous porphyria

Front 64

porphyria characterized by sudden attacks of pain and other nuerological symptoms

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acute porphyria

Front 65

-hereditary defect of hepatic prophobilinogen deaminase (PBG-D)
-high deltaALA in urine
- high porphobilinogen in urine

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AIP (acute intermittent porphyria)

Front 66

-also known as Gunther's disease
-defect in uroporphyrinogen III cosynthase
-urine a port wine color
-High ALA
-high uro and coproporophyrinogen

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CEP (congenital erythropoietic porphyria)

Front 67

-20-30% decrease in ferrochelatase
-protoporphyrin accumulates in the bone marrow, red blood cells
-no excess porphyrins in urine

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EPP (erythropoietic protoporphyria)

Front 68

-dark red or purple color
-oxidized by light
-flouresce in organic solutions under UV light

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properties of porphyrins in urine

Front 69

-Most commonly used test for measurement of porphobilinogen
- uses Ehrlich's reagent

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Watson-Schwartz test

Front 70

What reaction takes place in the watson- schwartz test

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p-dimethylaminobenzaldehyde (PBG)+ehrlich's---> red color

Front 71

-flouresce principle
-add amyl alcohol, etherl ether and glacial acetic acid
-shake, allow to seperate
-upper, organic layer will flourescence if porphyrins are present

Back 71

porphyrin test

Front 72

-Not a very sensitive test, but used for kids in lead poisoning
- reference values 20-80 ug/dL RBC

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Hematofluorometer