Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Clinical Chemistry 2 (CC2) > (P) Lec 3: Porphyrins (Part 2) > Flashcards

(P) Lec 3: Porphyrins (Part 2) Flashcards

1
Q
  • These are metabolic intermediates in the hemoglobin, myoglobin, and cytochrome synthesis
  • It produces a red-violet to red-brown color
  • These will not increase unless there is a problem with heme synthesis
A

Porphyrins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

This molecule is composed of heme and globin

A

Hemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q
  • This molecule is composed of iron and a protoporphyrin ring
  • This also incorporates into a protein (globin) to produce a biologically functional hemoprotein (hemoglobin)
A

Heme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Three Clinically Significant Forms of Porphyrins

  1. Found in urine and is most stable in water
  2. Found in urine, stool, and blood
  3. Found in stool
A
  1. Uroporphyrin
  2. Coproporphyrin
  3. Protoporphyrin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The three forms of porphyrins (Uroporphyrin, Coproporphyrin, Protoporphyrin) are found within the biological ____ produced by the body

A

Fluids

Note: Increased levels in body fluids indicate abnormal heme synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
  • Most porphyrins in the body are present in this form
  • This is a functional form of the compound that must be used in heme synthesis
  • Are believed to be colorless, unstable, and do not fluoresce
A

Porphyrinogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q
  • Initially, porphyrins are in the form of ____
  • It will be converted to porphyrins for heme synthesis when they are ____ in the body
A
  1. Porphyrinogens
  2. Oxidized
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

In cases wherein a sample contains porphyrinogens upon excretion, when they are exposed to ____, the porphyrinogens will be converted to porphyrin

A

Air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Pathway of Heme Synthesis

  1. The ____ and ____ are the main sites of heme synthesis
  2. The conversion of one product to another through enzymatic action happens ____ the cell
  3. Reduced enzymatic activity results in excess production of one or more ____ substances
A
  1. Liver and Bone Marrow
  2. Inside
  3. Precursor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Pathway of Heme Synthesis

  1. ____ and ____ are present in the mitochondria and will serve as raw materials for heme synthesis
  2. The 2 raw materials will be acted upon by ____ to produce ____
A
  1. Glycine and Succinyl-CoA
  2. ALA synthase; δ-aminolevulinic acid (ALA)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Pathway of Heme Synthesis

  1. As δ-aminolevulinic acid (ALA) is produced, it will be acted upon by ____ therefore producing ____
  2. ____ molecules of ALA will produce ____ molecules of the new product
A
  1. ALA dehydratase; Porphobilinogen (PBG)
  2. (2) for ALA and (4) for PBG
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Pathway of Heme Synthesis

  1. The PBG will be acted upon by ____ to produce ____ which is a linear tetrapyrrole
  2. The new product will now be the substrate of ____ in producing ____
A
  1. Uroporphyrinogen-I Synthase; Hydroxymethylbilane
  2. Uroporphyrinogen-III Co-Synthase; Uroporphyrinogen-III

Note: Uroporphyrinogen-I Synthase is aka Hydroxymethylbilane Synthase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Pathway of Heme Synthesis

  1. Hydroxymethylbilane will be spontaneously acted upon by a specific enzyme to produce ____
  2. As Uropophyrinogen-III is being produced, it will be acted upon by ____ to produce ____
A
  1. Uroporphyrinogen-I
  2. Uroporphyrinogen carboxylase; Coproporphyrinogen-III
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Pathway of Heme Synthesis

  1. As Coproporphyrinogen-III is produced, it will be acted upon by ____ to produce ____
  2. The new product will then by acted upon by ____ to produce ____
A
  1. Coproporphyrinogen oxidase; Protoporphyrinogen-III
  2. Protoporphyrinogen oxidase; Protoporphyrin III

Note: Protoporphyrin III is aka Protoporphyrin IX

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Pathway of Heme Synthesis

The Protoporphyrin ring IX will be acted upon by ____ producing your heme

A

Ferrochelatase (heme synthase)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Pathway of Heme Synthesis

Heme, protoporphyrin IX, protoporphyrinogen IX, and the conversion of glycine + succinyl-CoA to delta aminolevulinic acid happens where?

A

In the mitochondria (because the process needs energy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Pathway of Heme Synthesis

The conversion that happens from delta-aminolevulinic acid to coproporphyrinogen happens where?

A

Cytoplasm (it needs less energy than those processes that occur in the mitochondria)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

In the heme synthesis pathway, it can also relate to ____ because this targets heme synthesis, specifically ALA dehydratase and ferrochelatase

A

Lead poisoning/ Presence of Lead

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

A deficiency of one enzyme involved in the heme synthesis pathway will lead to porphyria EXCEPT for what enzyme?

A

ALA Synthase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

If the deficiency of ALA Synthase does not lead to porphyria, what does it result to?

A

Sideroblastic Anemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q
  • Refers to conditions wherein there is an aberration or disturbance in heme synthesis leading to the accumulation of porphyrins
  • A group of rare, inherited, or acquired metabolic disorders caused by a loss or gain of function and a mutation in the enzymes responsible for heme biosynthesis
A

Porphyria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Types of Porphyria

Refers to the overproduction of heme precursors in the 1.) liver and 2.) bone marrow

A
  1. Hepatoerythropoietic Porphyria (HEP)
  2. Erythropoietic Porphyria (EP)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Types of Porphyria

These 2 types are the only acquired ones while the rest are all inherited

A
  1. Plumboporphyria (PP)
  2. Porphyria Cutanea Tarda (PCT)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The ending of all these types of porphyrias is that there is always an overproduction, accumulation, and excretion of toxic ____ compounds and porphyrins

A

Precursor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Symptoms of Porphyria

  • Manifestations include abdominal pain, vomiting, constipation, tachycardia, hypertension, etc.
  • Plumboporphyria (PP) and Acute Intermittent Porphyria (AIP) present with this type of symptom
A

Neurologic/Neuropsychiatric

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Symptoms of Porphyria

  • Manifestations include photosensitivity (most usual presenting symptom), blisters, facial hair, and hyperpigmentation
  • Congenital Erythropoietic Porphyria (CEP), Porphyria Cutanea Tarda (PCT), Hepatoerythropoietic Porphyria (HEP), and Erythropoietic Porphyria (EP) present with this type of symptom
A

Cutaneous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Symptoms of Porphyria

  • Includes both neurologic/neuropsychiatric and cutaneous manifestations
  • Hereditary Coproporphyria (HCP) and Variegate Protoporphyria (VP) present with this type of symptom
A

Neurocutaneous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Symptoms of Porphyria

Give the porphyrias associated with this symptom: Neurologic/ Neuropsychiatric

A
  1. Plumboporphyria (PP)
  2. Acute Intermittent Porphyria (AIP)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Symptoms of Porphyria

Give the porphyrias associated with this symptom: Cutaneous

A
  1. Congenital Erythropoietic Porphyria (CEP)
  2. Porphyria Cutanea Tarda (PCT)
  3. Hepatoerythropoietic Porphyria (HEP)
  4. Erythropoietic Porphyria (EP)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Symptoms of Porphyria

Give the porphyrias associated with this symptom: Neurocutaneous

A
  1. Hereditary Coproporphyria (HCP)
  2. Variegate Protoporphyria (VP)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Types of Porphyria

There is increased aminolevulinic acid (ALA) and porphobilinogen (PBG) in urine producing a black or red color but turns dark brown upon exposure to air or light

A
  1. Plumboporphyria (PP)
  2. Acute Intermittent Porphyria (AIP)

Note: The porphyrias that present with neurologic symptoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Types of Porphyria

In Plumboporphyria (PP) and Acute Intermittent Porphyria (AIP), what 2 substances give the characteristic red and black color of urine respectively?

A
  • Red: Porphyrin
  • Black: Porphobilin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Types of Porphyria

  • Is aka ALA-dehydratase (ALAD) deficiency porphyria
  • Lead and ferrochelatase are inhibitors to ALAD
  • There is increased urine aminolevulinic acid (ALA) but with normal excretion of porphobilinogen (PBG)
A

Plumboporphyria (PB)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Types of Porphyria

  • Dithiothreitol or sulfhydryl reagent is used to differentiate this type with lead poisoning
  • It is sometimes mistaken for lead poisoning due to a similar presentation of increased ALA
A

Plumboporphyria (PB)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Types of Porphyria

In Plumboporphyria (PB) testing, if you add the dithiothreitol or sulfhydryl reagent and the ALA increases, what does it mean?

A

(+) for Plumboporphyria (PB)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Types of Porphyria

In Plumboporphyria (PB) testing, if the ALA in urine is increased at first but then turns normal upon the addition of the dithiothreitol or sulfhydryl reagent, what does it mean?

A

(+) for Lead Poisoning

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Types of Porphyria

The enzyme deficient in this condition is the porphobilinogen deaminase or hydroxymethylbilane synthase/uroporphyrinogen-I-synthase

A

Acute Intermittent Porphyria (AIP)

38
Q

Types of Porphyria

  • The rarest among all porphyrias and is also the most severe
  • The enzyme deficient is Uroporphyrinogen III cosynthase (Gunther’s disease)
A

Congenital Erythropoietic Porphyria (CEP)

39
Q

Types of Porphyria

  • There is an increase of uroporphyrin and coproporphyrin in urine and stool
  • The teeth fluoresce red (erythrodontia) under UV light due to the deposition of porphyrin in the dentin
  • Manifestations are seen as early in infants
  • Infants produce red to brown urine and exhibit cutaneous photosensitivity (usual symptom)
A

Congenital Erythropoietic Porphyria (CEP)

40
Q

Types of Porphyria

  • The enzyme deficient is Uroporphyrinogen decarboxylase
  • The most common porphyria
  • Manifested by having blisters and fragility in light-exposed skin due to free radicals present in the skin leading to oxidative damage
A

Porphyria Cutanea Tarda (PCT)

41
Q

Types of Porphyria

  • Liver damage is also possible because of iron depletion
  • There is abnormal growth of hair present
  • There’s increased isocoproporphyrin and uroporphyrin in the patient’s biologic fluids
A

Porphyria Cutanea Tarda (PCT)

42
Q

Types of Porphyria

Types of Porphyria Cutanea Tarda (PCT):
1. Deficiency of the enzyme is restricted to liver
2. Deficiency of the enzyme is present in all tissues

A
  1. Type 1 PCT
  2. Type 2 PCT
43
Q

Types of Porphyria

  • The enzyme that is deficient is Uroporphyrinogen decarboxylase (reduced activity of 90% and more)
  • Affects both the liver and bone marrow
  • Photosensitivity begins in childhood
A

Hepatoerythropoietic Porphyria (HEP)

44
Q

Types of Porphyria

  • Hepatic diseases are common and present later on
  • There is presence of abnormal/excess facial hair and scarring (blisters) of the hands and face
  • There is increased isocoproporphyrin, uroporphyrin, and zinc protoporphyrin (ZPP)
A

Hepatoerythropoietic Porphyria (HEP)

45
Q

Types of Porphyria

  • The enzyme deficient is ferrochelatase
  • It is the second most common porphyria
  • Manifested as burning of light-exposed skin
A

Erythropoietic Porphyria (EP)

46
Q

Types of Porphyria

  • There is increased free erythrocyte protoporphyrin (FEP) and Zn protoporphyrin in RBC, plasma, and stool because iron is not incorporated in the RBC
  • Symptoms include photosensitivity, burning, itching, pain in the skin, excessive hair growth, and liver disease
A

Erythropoietic Porphyria (EP)

47
Q

Types of Porphyria

  • The enzyme deficient is coproporphyrinogen oxidase
  • The hallmark is increased coproporphyrin in stool (sometimes in urine)
  • There is increased ALA and PBG
  • Harderoporphyria is a rare erythropoietic form of it
A

Hereditary Coproporphyria (HCP)

48
Q

Types of Porphyria

  • Aka South African porphyria
  • The enzyme deficient is protoporphyrinogen oxidase
  • Its manifestations are the same with Acute Intermittent Porphyria (AIP)
  • The hallmark is increased protoporphyrin and coproporphyrin in stool
A

Variegate Protoporphyria (VP)

49
Q

Types of Porphyria

  • These are aka porphyrinurias wherein there is an increased excretion of urinary porphyrins
  • It is not a defect in the biochemical synthesis of heme but a result of conditions such as toxins and drugs
A

Secondary Porphyrias

50
Q

Types of Porphyria

Regular or Secondary porphyrias?
1. Increased ALA and porphobilinogen in urine and other body fluids
2. Increased ALA but with normal porphobilinogen in urine

A
  1. Regular porphyria
  2. Secondary porphyria
51
Q

Treatment

If a patient suffers from porphyria of the cutaneous type, they should avoid what?

52
Q

Treatment

This can be given for a hematin limit synthesis of porphyrins in the cells of the bone marrow

53
Q

Treatment

Decrease the heme load by having therapeutic ____ or giving ____ to chelate the iron present

A
  1. Phlebotomy
  2. Deferoxamine
54
Q

Laboratory Determination

What 2 qualitative screening tests can be used to measure porphobilinogen (PBG) and ALA?

A
  1. Watson-Schwartz
  2. Hoesch Test
55
Q

Laboratory Determination

In order to measure PBG and ALA quantitatively, what test can be performed?

A

Ion Exchange Column

56
Q

Laboratory Determination

Between the Watson-Schwartz and Hoesch Test, what is the confirmatory test for the other one?

A

Hoesch Test (it confirms the result of Watson-Schwartz)

57
Q

Laboratory Determination

  • Porphobilinogen (PBG) forms a ____ color when mixed with ____
  • It is a qualitative ____ test for the detection and differentiation of ____ and porphobilinogen
  • A positive result for PBG and ALA in urine is indicated by a ____ color
A
  1. Red-orange; Ehrlich’s reagent (pdab)
  2. Screening; urobilinogen
  3. Red-orange

Note: pdab means para-dimethylaminobenzaldehyde

58
Q

Laboratory Determination

  • An extraction method is done
  • Urine is added with Ehrlich’s reagent alongside sodium acetate
  • If the tube turns red or pink, it is (+) for either urobilinogen or porphobilinogen
  • Add chloroform to determine whether urobilinogen or porphobilinogen is present
  • There will be a production of 2 layers afterwards
A

Watson-Schwartz

59
Q

Laboratory Determination

In Watson-Schwartz, what do you add to differentiate urobilinogen from porphobilinogen that forms 2 layers?

A

Chloroform OR Butanol

60
Q

Laboratory Determination

In Watson-Schwartz, the Ehrlich’s reagent is added alongside what other substance to produce a red/pink color?

A

Sodium Acetate

61
Q

Laboratory Determination

Watson-Schwartz:
- The top layer is aqueous and the red/pink chloroform settled at the bottom
- After adding butanol, the red/pink color is present at the top

A

Urobilinogen

Note: Butanol can be used if chloroform is not present

62
Q

Laboratory Determination

Watson-Schwartz:
- The bottom layer is aqueous and the red/pink chloroform settled at the top
- After adding butanol, the red/pink color is present at the bottom

Note: Butanol can be used if chloroform is not present

A

Porphobilinogen

63
Q

Laboratory Determination

What interfering agents sometimes act up when performing Watson-Schwartz?

A

Urobilinogen and Indole

64
Q

Laboratory Determination

The reagent used for this test does not react with urobilinogen as this is only used to confirm the result of the other test

A

Hoesch Test

65
Q

Laboratory Determination

What specimens (3) can be used?

A
  1. 24H urine
  2. Whole blood
  3. 1g of fecal sample

Note: The 3 sources of porphyrins are urine, blood, and stool

66
Q

Laboratory Determination

What is the anticoagulant of choice?

67
Q

Specimen Considerations

  • Porphyrin is ____ sensitive, together with bilirubin
  • Store the specimen at ____ degrees Celsius for ____ hours
  • If not performing ASAP, store the specimen at ____ degrees Celsius
A
  1. Light
  2. 4 degrees for 48H
  3. 23 degrees
68
Q

Methods

  • The ____ and ____ lamps are used for qualitative screening methods
  • Porphyrins ____ under UV light
  • ____ colored fluorescence indicates a (+) result
A
  1. UV and Wood’s
  2. Fluoresce
  3. Orange-red
69
Q

Methods

  • Other qualitative tests include: ____ , ____ , and ____
  • An excitation wavelength is set at ____ to ____ nm
  • An emission wavelength is set at ____ to ____ nm
A
  1. Fluorometry, HPLC, and HP-TLC
  2. 400 to 405nm
  3. 594 to 598nm
70
Q

Identify the type of porphyria

ALA-D deficiency

A

Plumboporphyria (PB)

71
Q

Identify the type of porphyria

Increased urine ALA but with the normal porphobilinogen (PBG) excretion

A

Plumboporphyria (PB)

72
Q

Identify the type of porphyria

Dithiothreitol or sulfhydryl reagent

A

Plumboporphyria (PB)

73
Q

Identify the type of porphyria

Porphobilinogen deaminase or Hydroxymethylbilane synthase (uroporphyrinogen-I-synthase) is deficient

A

Acute Intermittent Porphyria (AIP)

74
Q

Identify the type of porphyria

Uroporphyrinogen III cosynthase is deficient

A

Congenital Erythropoietic Porphyria (CEP)

75
Q

Identify the type of porphyria

Gunther’s Disease

A

Congenital Erythropoietic Porphyria (CEP)

76
Q

Identify the type of porphyria

There is increased uroporphyrin and coproporphyrin in urine and stool

A

Congenital Erythropoietic Porphyria (CEP)

77
Q

Identify the type of porphyria

There is increased coproporphyrin in urine and stool

A
  1. Congenital Erythropoietic Porphyria (CEP)
  2. Hereditary Coproporphyria (HCP)
  3. Variegate Protoporphyria (VP)
78
Q

Identify the type of porphyria

There is photosensitivity

A
  1. Congenital Erythropoietic Porphyria (CEP)
  2. Porphyria Cutanea Tarda (PCT)
  3. Hepatoerythropoietic Porphyria (HEP)
  4. Erythropoietic Porphyria (EP)
79
Q

Identify the type of porphyria

Uroporphyrinogen decarboxylase is deficient

A
  1. Porphyria Cutanea Tarda (PCT)
  2. Hepatoerythropoietic Pophyria (HEP)
80
Q

Identify the type of porphyria

Liver damage/disease

A
  1. Porphyria Cutanea Tarda (PCT)
  2. Hepatoerythropoietic Porphyria (HEP)
  3. Erythropoietic Porphyria (EP)
81
Q

Identify the type of porphyria

Increased isocoproporphyrin, uroporphyrin, and zinc protoporphyrin (ZPP)

A

Hepatoerythropoietic Porphyria (HEP)

82
Q

Identify the type of porphyria

Ferrochelatase is deficient

A

Erythropoietic Porphyria (EP)

83
Q

Identify the type of porphyria

There is increased free erythrocyte protoporphyrin (FEP) and Zn protoporphyrin in RBC, plasma, and stool

A

Erythropoietic Porphyria (EP)

84
Q

Identify the type of porphyria

Coproporphyrinogen oxidase is deficient

A

Hereditary Coproporphyria (HCP)

85
Q

Identify the type of porphyria

Increased isocoproporphyrin
and uroporphyrin

A
  1. Porphyria Cutanea Tarda (PCT)
  2. Hepatoerythropoietic Porphyria (HEP)
86
Q

Identify the type of porphyria

Increased ALA and PBG

A

Hereditary Coproporphyria (HCP)

87
Q

Identify the type of porphyria

Harderopoporphyria

A

Hereditary Coproporphyria (HCP)

88
Q

Identify the type of porphyria

South African Porphyria

A

Variegate Protoporphyria (VP)

89
Q

Identify the type of porphyria

Protoporphyrinogen oxidase is deficient

A

Variegate Protoporphyria (VP)

90
Q

Identify the type of porphyria

There is increased protoporphyrin and coproporphyrin in stool

A

Variegate Protoporphyria (VP)

Clinical Chemistry 2 (CC2) (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions