1. Pakistan Society Of Chemical Pathologists Distance Learning Programme In Chemical Pathology (DLP-2) Lesson No 12 Porphyrias- “Made Easy” By Brig Aamir Ijaz MCPS, FCPS, FRCP (Edin) Professor of Pathology / Consultant Chemical Pathologist AFIP Rawalpindi

2. Haem in the Body
Heme is mostly used for its incorporation into haemoglobin and role in red blood cells.
But is also needed for cytochrome P450 function.
Other uses of Haem include:
Catalase
Myoglobin
Nitric oxide synthase

3. Introduction
Porphyrias is a set of diseases that result from enzyme deficiencies in the heme synthesis pathway.
Each disease is associated with a deficiency in one of the seven enzymes in the pathway

4. Seven Enzymes – Seven Disorders

5. Free Radicals – The real Culprits
The respective enzymatic deficiencies lead to the accumulation of porphyrins and porphyrin precursors that ultimately produce free radicals.
For acute hepatic porphyrias, delta-aminolaevulinic acid (ALA) and porphobilinogen (PBG) accumulate and produce free radicals via autoxidation.
For erythropoietic porphyrias, uroporphyrins, coproporphyrins, and protoporphyrins accumulate and produce free radicals via the absorption of visible light.
The generated free radicals participate in oxidative stress reactions, such as lipid oxidation and protein crosslinking, that lead to membrane and mitochondrial damage, ultimately promoting cell death.
Loss of negative feedback of heme leads to further accumulation of porphyrins.

6. Genetics Autosomal Dominant Autosomal recessive Acquired AIP HCP VP
EPP
Autosomal recessive
ADP
CEP
Acquired
PCT

7. Environmental Factors
Due to incomplete penetrance, inheritance of an enzyme deficiency of an autosomal dominant porphyria does not necessarily lead to clinical symptoms.
Symptoms of acute porphyrias tend to come in the form of "attacks" which may be induced by other genetic factors or environmental factors, such as agents that promote porphyrin and porphyrin precursor synthesis and/or agents that induce cytochrome P450s.

8. Part I Short Answer Questions:

9. Q. 1: Porphyria's are usually classified as ‘Acute and Non-acute’, ‘With or Without cutaneous lesions’, pattern of inheritance, ‘congenital or acquired’. Please write name(s) of porphyrias falling in following five categories. Please write only the names of the disorders and NOT the names of effected enzymes (one mark each): a. Acute (neurovisceral) without any cutaneous lesions b. Acute (neurovisceral) with blistering cutaneous lesions c. Non-acute (non-neurovisceral) with blistering cutaneous lesions d. Acute photosensitivity and non-blistering lesions e. Acquired
11/13/2018

10. Classification of Porphyrias
a. Acute (neurovisceral) without any cutaneous lesions
Acute intermittent porphyria (AIP)
ALA dehydratase deficiency porphyria (ALADP)
Acute (neurovisceral) with blistering cutaneous lesions
Variegate porphyria (VP)
Hereditary coproporphyria (HCP)
Non-acute (non-neurovisceral) with blistering cutaneous lesions
• Porphyria cutanea tarda (PCT)
Hepatic erythropoietic porphyria (HEP)
• Congenital erythropoietic porphyria (CEP)
Acute photosensitivity and non-blistering lesions
Erythropoietic porphyria (EPP)
Acquired
Porphyria cutanea tarda (PCT)
11/13/2018

11. Slides courtesy of Dr Shahnaz Noor, QAMC BWP
Types of Porphyrias
Slides courtesy of Dr Shahnaz Noor, QAMC BWP

12. Types of Porphyrias Cutaneous Bullous lesions Non-bullous Lesions
PCT & HEP
CEP
Non-bullous Lesions
EPP
Acute Presentation (Hepatic Porphyrias):
AIP
ADP
Mixed Disorders (Acute and Cutaneous manifestations) VP
HCP

14. Q. 2: Porphyria's cannot be diagnosed without intelligent use of laboratory investigations. Please answer following questions regarding appropriate use of laboratory tests helpful in various clinical situations (one mark each): a. A 25 years female complains of abdominal pain for the last 24 hours. Her blood counts (CBC) and abdominal ultrasound are normal. She has been referred to you for the exclusion of a porphyria. Name TWO laboratory tests which will be most helpful in reaching the diagnosis of a porphyria and how will you interpret these tests? b. What patient safety issues can arise if a false negative or false positive test result is given in the female patient mentioned in 2 (a) above. C A 30 year old male has bullous skin lesions which have erupted gradually over a period of one week. His biochemical findings were: ALT: 64 U/L Ferritin: 330 ng/ml HFE gene mutation: Positive Which porphyria comes to your mind in this patient and how will you rule out /diagnose this porphyria by using appropriate laboratory test(s)?
11/13/2018

15. Q. 2: a. A 25 years female complains of abdominal pain for the last 24 hours. Her blood counts (CBC) and abdominal ultrasound are normal. She has been referred to you for the exclusion of a porphyria. Name TWO laboratory tests which will be most helpful in reaching the diagnosis of a porphyria and how will you interpret these tests? Urinary porphobilinogen (PBG) measurement o High levels are suggestive of acute porphyria (AIP, VP, HCP) Urinary δ aminolaevulinic acid (ALA) measurement (and repeat PBG) on same urine sample o In symptomatic patient with normal PBG, raised ALA levels are seen in ALADP, a very rare form of acute porphyrias and lead toxicity
11/13/2018

16. Q. 2: b. What patient safety issues can arise if a false negative or false positive test result is given in the female patient mentioned in 2 (a) above. Consequences of false positive result • Delay in the life saving treatment appropriate for patient’s actual diagnosis • Analgesic misuse and dependency Consequences of false negative result • Administration of porphyrinogenic drugs that will aggravate the attack and may increase fatality • Unnecessary surgery e.g. laparotomy for acute abdomen not only have its own risks but also deteriorate the acute porphyria attack
11/13/2018

17. Q. 2: c. A 30 year old male has bullous skin lesions which have erupted gradually over a period of one week. His biochemical findings were: • ALT: 64 U/L • Ferritin: 330 ng/ml • HFE gene mutation: Positive Which porphyria comes to your mind in this patient and how will you rule out /diagnose this porphyria by using appropriate laboratory test(s)? See answers on next slides
11/13/2018

18. Porphyria Cutanea Tarda because of following points o
Porphyria Cutanea Tarda because of following points o Nonacute porphyria o Bullous skin lesions o Male predominance o Raised ALT provides evidence of hepatocellular damage o HFE gene mutation has strong positive association with PCT
11/13/2018

19. Laboratory investigations o. Urine porphyrins – markedly increased -
Laboratory investigations o Urine porphyrins – markedly increased - Chromatographic separation based on carboxyl number reveals predominance of 8- and 7-carboxyl porphyrin fractions, with lesser amounts of 6-, 5-, and 4-carboxyl porphyrins, reflecting uroporphyrinogen decarboxylase (UROD) defect. o Serum or plasma porphyrins- also show increased polycarboxylated porphyrins o Fecal porphyrins – raised. Fractionation reveals complex pattern with increased isocoproporphyrin o Urine ALA and PBG – normal which exclude all acute porphyrias o Erythrocyte porphyrins – within reference range o Plasma fluorescence peaks at 620 nm o UROD enzyme activity in red blood cells- markedly reduced and is diagnostic of PCT
11/13/2018

20. Q. 3: Some tests of porphyrias are essential in any lab for the diagnosis of these disorders. Please answer following questions regarding porphyria related tests (one mark each): a. How do you test Porphobilinogen in urine and what precautions you will adopt in collection of urine sample? b. Write TWO lines about any ONE method used for analysis of porphyrins in plasma.
11/13/2018

21. Q 3a. Porphobilinogen tests in urine
Qualitative or semi quantitative method
screening method
formation of red colored PBG-Ehrlich compound on addition of Ehrlich reagent to urine that can be separated by solvent extraction
rapid, cheap and still widely used but has poor sensitivity and specificity
Most important interference: Urobilinogen

22. Q 3a. Porphobilinogen tests in urine (Cont)
Quantitative method
Preferred method for measurement of PBG in urine
Spectrophotometric quantification of the red product formed by PBG reaction with 4-dimethylaminobenzaldehyde in acid (Ehrlich’s reagent) at 550 nm after removal of urobilinogen and other interfering substances by anion exchange chromatography. Results should be expressed as µmol/mmol creatinine.
HPLC
Tandem mass spectrometry
Sensitive and accurate but time consuming

23. Q 3a. Porphobilinogen tests in urine (Cont)
Specimen collection for urinary porphobilinogen
Best specimen is freshly voided spot urine preferably early morning, 10-20ml without any preservative
Must be collected in colored bottle and kept well protected from light
If any delay in transport or analysis and after analysis, specimen must be kept at 4oC for 48 h and at -20oC for 1 month.

24. b. Write TWO lines about any ONE method used for analysis of porphyrins in plasma. Fluorescence emission spectroscopy • It utilizes the property of porphyrins to fluoresce at neutral pH between nm depending upon their structure and protein complex • Simple method that can differentiate among various cutaneous porphyrias
11/13/2018

25. Part II MCQs (One Best Type)

26. Q. 4 Heme is an important prosthetic group in many important substances of the body. Which of the following tissues / organs are the most active site of heme synthesis: a. Bone marrow b. Kidneys c. Liver d. Lungs e. Muscles
a. Bone marrow
11/13/2018

27. Slides courtesy of Dr Anwar Magsi, PNS SHIFA Karachi
Biosynthesis of Heme
Slides courtesy of Dr Anwar Magsi, PNS SHIFA Karachi

28. Synthesized in every human cell Liver (15%): Bone Marrow (80%)
Biosynthesis of Heme
Synthesized in every human cell
Liver (15%):
Bone Marrow (80%)

29. b. First step in the synthesis of heme
Q 5. Two different delta aminolaevulinic acid synthase (ALAS) enzyme systems have been found. Only ONE of the following features is common in ALAS1 and ALAS2 enzymes : a. Down-regulation by heme b. First step in the synthesis of heme c. Liver is the major location d. Mutations have been described in the genes coding these enzymes e. Up-regulation by iron
b. First step in the synthesis of heme
11/13/2018

30. Two Types of ALAS ALAS-1 ALAS-2
Present in liver and all other tissues for production of haem used for non-haemoglobin substances e.g. Cytochrome P450
ALAS-2
Present in erythrocytes for production of Haemoglobin

31. d. Porphyria cutanea tarda
Q 6. The most common human porphyria is: a. Acute intermittent porphyria b. ALA dehydratase porphyria c. Congenital erythropoietic porphyria d. Porphyria cutanea tarda e. Hereditary coproporphyria .
11/13/2018

32. Two Most Important Disorders
Acute intermittent porphyria (AIP) --- Most common acute
Porphyria Cutanea Tarda (PCT) The commonest

33. Acute Intermittent Porphyria (AIP)

34. Acute intermittent porphyria (AIP)
2nd most common form of porphyria
Caused by deficiency of PGB deaminase
Metabolite porphobilinogen accumulates in cytoplasm
Symptoms:
Localized abdominal pain
Urinary symptoms
Peripheral neuropathy
raised concentration of urinary porphyrins
Treatment
Haematin, Heme arginate
Do not cure but reduces symptoms
Inhibit ALA synthase which occurs at the beginning of heme biosynthesis
Explain what happens with accumulation of porphobilinogen

35. Best answer: a. Abdominal pain
A Supplementary Question The commonest presenting clinical feature of Acute Intermittent Porphyria is: a. Abdominal pain b. Dark urine c. Muscular weakness d. Severe constipation e. Tachycardia
Best answer:
a. Abdominal pain

36. Symptoms of Acute Forms
Originate mainly in nervous system
Symptoms last around 1-2 weeks
Possible mechanisms include damage by free radicals, direct neurotoxicity of ALA, and the deficiency in nervous tissue
Symptoms:
Severe abdominal pain
Muscle weakness and pain, tingling, or numbness and possibly paralysis
Pain in arms, legs, back
Constipation
Vomiting
Diarrhea
Insomnia
Seizures and Confusion
Anxiety and paranoia
Fever
LIST examples?

37. Symptoms of Cutaneous Forms
Occur most commonly with exposure to sunlight
Mainly skin symptoms that occur
Due to excess porphyrins that accumulate in surface of skin
Symptoms:
Fluid filled blisters
Changes in pigmentation
Breakdown (necrosis) of the skin
when exposed to sunlight
Overall skin can become scarred,
brown, blotchy and fragile

38. Q 7: Poisoning of which of the following metals resembles acute porphyria due to accumulation of ALA: a. Arsenic b. Copper c. Iron d. Lead e. Zinc
d. Lead
11/13/2018

39. Lead Toxicity and Porphyrias
Lead exposure causes increased ALA due to replacement of Zn by Lead in the enzyme.
The condition resembles ALADP
Also called ‘plumbporphyria’

40. b. High carbohydrate diet
Q 8: A 31 year female doctor has recently been diagnosed as a patient of Acute Intermittent Porphyria. She shows you a list of factors she has downloaded from internet to prevent precipitation of an acute attack. The list is given below, which of these factors she has wrongly noted: a. Ethanol b. High carbohydrate diet c. Non-steroidal anti-inflammatory drugs d. Oral contraceptive pills e. Smoking
b. High carbohydrate diet
11/13/2018

41. Treatment for Acute Forms
Carbohydrate such as glucose
To help limit the synthesis of porphyrins
Phlebotomy
To reduce excessive iron stores which improves heme synthesis
Sedatives to help with anxiety
Pain medications such as opiates
Haem arginine
Haem inhibit ALA synthase and the accumulation of toxic precursors

42. d. Treatment of wheat with a fungicide
Q 9 : In the 1950s, in eastern Turkey an outbreak of Porphyria Cutanea Tarda (PCT) occurred in thousands of adults and children after consumption of stored wheat to fight famine. This outbreak of PCT was a result of: a. Long exposure to sun during queues for wheat b. Periods of prolonged starvation due to famine c. Poor hygiene of the dwellers d. Treatment of wheat with a fungicide e. Tuberculosis due to malnutrition
d. Treatment of wheat with a fungicide
11/13/2018

43. Q 10: PCT has been found to be associated with which of the following viral infections: a. Cytomegalovirus b. Ebola virus c. Epstein Barr virus d. Hepatitis C virus e. Human papilloma virus
d. Hepatitis C virus
11/13/2018

44. a. Erythropoietic protoporphyria
Q 11: An 18 months infant has been referred to you for the investigation of porphyria. His mother describes that whenever she takes his son in the sun, his face and back of hands immediately get red and the child starts crying with pain. On examination you find no lesions on the face or hands, but his Serum AST levels are 2 folds increased. His laboratory investigations related to porphyrias carried out in your lab shows following results: • Urine Porphyrin nmol/mmol creat ( ) • Urine PBG µmol/mmol creat ( ) • Urine ALA µmol /mmol creat ( ) • Urine Creatinine mmol/L • Urinary porphyrin fractions: Not increased • Plasma fluorescence peak at 630 nm • Erythrocyte total protoporphyrins: markedly increased • Erythrocyte metal-free protoporphyria: Markedly increased (92% of total Erythrocytic protoporphyrins) • Erythrocyte Zinc Protoporphyrins: Marginally increased (8% of total Erythrocytic protoporphyrins) • Gene Mutation Studies: Ferrochelatase gene mutation detected What is the most probable diagnosis in this patient? a. Erythropoietic protoporphyria b. Hepatoerythropoietic porphyria c. Lead poisoning d. Porphyria cutanea tarda e. X-linked protoporphyria
a. Erythropoietic protoporphyria
11/13/2018

45. Erythropoietic Protoporphyria (EPP)

46. Erythropoietic Protoporphyria
Caused by deficiency of Ferrochelatase
Autosomal dominant
Photosensitivity- can be managed by limiting exposure

47. b. Aminolaevulinic acid dehydratase porphyria
Q 12: A 2 years Asian boy presented with abdominal pain, vomiting; neuropathic pain and neuropathy. His urine tests showed following results: • Total Porphyrin nmol/mmol creat ( ) • Porphobilinogen µmol/mmol creat ( ) • Delta-Aminolaevulinic Acid µmol /mmol creat ( ) • Creatinine mmol/L • Plasma fluorescence peak at 620 nm What is the most probable diagnosis in this patient? a. Acute intermittent porphyria b. Aminolaevulinic acid dehydratase porphyria c. Congenital erythropoietic porphyria d. Erythropoietic protoporphyria e. Hepatoerythropoietic porphyria
b. Aminolaevulinic acid dehydratase porphyria
11/13/2018

48. ALA Dehydratase Deficiency Porphyria (ALADP)

49. a. Congenital erythropoietic porphyria
Q 13: A 3 month infant presents with blisters on the skin and photosensitivity. Mother also tells about reddish-brown coloration of the diapers of the infant. He also has hemolytic anaemia and splenomegaly His laboratory investigations showed following results: • Urine Total Porphyrin nmol/mmol creat ( ) • Urine PBG µmol/mmol creat ( ) • Urine ALA µmol /mmol creat ( ) • Urine Creatinine mmol/L • Plasma fluorescence peak at 618 nm • Urinary porphyrin fractions: o Uroporphyrin I : Increased o Coproporphyrins I: Increased • Erythrocyte total protoporphyrins: markedly increased • Erythrocyte metal-free protoporphyria: Markedly increased (22% of total Erythrocytic protoporphyrins) • Erythrocyte Zinc Protoporphyrins: Marginally increased (68% of total Erythrocytic protoporphyrins) • Gene Mutation Studies: UROS gene mutation detected What is the most probable diagnosis in this patient? a. Congenital erythropoietic porphyria b. Hepatoerythropoietic porphyria c. Hereditary coproporphyria d. Porphyria cutanea tarda e. Variegate porphyria
a. Congenital erythropoietic porphyria
11/13/2018

50. Congenital Erythropoietic Porphyria (CEP)

51. Congenital erythropoietic porphyria (CEP)
Deficiency of Uroporphyrinogen III synthase
Rare autosomal recessive (1 in 1,000,000)
Severe photosensitivity

52. Other Porphyrias

53. Hereditary Coproporphyria (HCP)

54. HCP Deficiency of Coproporphyrinogen III Oxidase Autosomal dominant
No cure exists

55. Variegate Porphyria (VP)

56. VP
Deficiency in protoporphyrinogen IX-oxidase
Autosomal dominant

57. (Important for Haematologists, too !!!)
Inside Erythrocytes
(Important for Haematologists, too !!!)

58. Sideroblastic Anaemias and Erythropoietic Porphyrias
11/13/2018

59. Algorithms of Porphyrias

63. Thank You and Best Of Luck