Transcript Hot Topics in Liver Disease Wilson Disease a-1

Hot Topics in Liver Disease
Wilson Disease
a-1-Antitrypsin Deficiency
Norman L. Sussman, MD
Baylor College of Medicine
St. Luke’s Center for Liver Disease
S
Copper Absorption
and Excretion
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CMT1: Copper membrane transporter 1
ATOX1
Metallothionein
 Copper is a cofactor for a number of enzymes
 Ceruloplasmin (CPN), cytochrome c oxidase, dopamine b-
hydroxylase, superoxide dismutase, tyrosinase
 ATP7B (P-type ATPase)
 Catalyzes self-phosphorylation of aspartate in the Cu2+ pump
 Excretes copper into the canaliculus
 Attaches copper to ceruloplasmin
Samuel Alexander Kinnier Wilson
1878 – 1937
 Born in Cedarville, NJ, moved to
Edinburgh at one year of age after the
death of his father
 Graduated with MB from University
of Edinburgh in 1902
 Trained in Paris with Pierre Marie and
Joseph Babinski
 Returned to King’s College in London
 MD in 1912: "Progressive lenticular
degeneration” and introduced the
word “extrapyramidal”
Question 1
Which of the following is true of Wilson
disease (one answer):
A. Autosomal dominant
disease.
47%
B. Is caused by a mutation in
the ceruloplasmin gene.
C. Is caused by a mutation in
the ATP7B gene.
23%
17%
13%
D. Is always associated with
discoloration of the cornea
(Kayser-Fleishcher rings).
A.
B.
C.
D.
The Genetic Basis of Wilson Disease
Hepatoleticular Degeneration
Autosomal Recessive
 Copper storage disease – caused by
defective copper export
 Accumulates in the liver, brain, cornea
 Not added to ceruloplasmin 
shortened half-life (low serum level)
 Not added to AP  low level
 Mutations in ATP7B - multiple mutations
 The gene was identified in 1993
 Prevalence ~30/million population
Kayser–Fleischer Rings
50% in patients with liver disease
98% in patients with neurologic disease
Schrag A, Schott JM. N Engl J Med 2012;366:e18.
Question 2
Which of the following is not true (one
answer):
40%
A. Wilson disease may cause acute
37%
hepatitis in children.
B. Wilson disease may cause acute
liver failure
C. Adults with Wilson disease may
14%
have no definite liver disease
D. Neurological disease is the most
9%
common presentation in
newborns
A.
B.
C.
D.
Wilson Disease
Clinical Manifestations
 Hepatic, neurologic, psychiatric, hemolysis (ALF) –
presentation may vary, even within a family
 Liver: 18-84%
 Neurologic: 18-73%
 Psychiatric: 10-100%
 Usually present at 5-35 years (up to 70s)
 Children typically present with liver disease (9-13 years)
 Older patients usually present with neurologic and/or
psychiatric symptoms (15-21 years)
Wilson Disease
Clinical Manfestations
 Mild: abnormal liver tests, hepatomegaly, NAFLD
 Advanced: cirrhosis (with all complications)
 Acute liver failure (ALF)
 Neurologic
 Movement disorders (arms, gait, swallowing)
 Psychiatric
Sunflower Cataract
Wilson Disease – Diagnosis
 Classic presentation (about 50% of patients)
 5-40 years old, cirrhosis, neurological findings,
K-F rings, low ceruloplasmin
 Genetic diagnosis – better for confirmation
 Expensive
 Not universally available
 Sometimes inconclusive
 The rest – scoring system
Wilson Disease – Diagnosis
 Very low ceruloplasmin (CPN) is strongly predictive
 Uric acid – usually low, but not validated
 Non-CPN bound copper is usually >25 mg/dL (250 mg/L)
in untreated patients (normal = 15 mg/dL)
 Binding is ~3.15 mg of Cu2+ per mg CPN
 Free Cu2+ = serum Cu2+ (mg/dL) – 3x CPN (mg/dL)
 Google: ceruloplasmin-free copper calculator
 Caveat: may be elevated in chronic cholestasis, copper
intoxication, and ALF of any cause
Wilson Disease – Diagnosis
24-Hour Urine Copper
 Diagnostic at 100 mg/24 hours (1.6 mmol/24
hours) in symptomatic patients
 Many labs use 40 mg as the cutoff
 May be <100 mg at presentation in 16%-23%
 Penicillamine challenge (500 mg at 0 and 12
Hr)  1,600 mg (25 mol) copper/24 hours
 Validated in children, but not adults
Wilson Disease – Diagnosis
Liver Biopsy
 Early: mild steatosis (micro and macrovesicular)
 May show classic histological features of AIH
 Cirrhosis – macronodular and micronodular
 May be absent, even with neurological disease
 Copper stain is unreliable (metallothionein-bound)
 Absence of stainable copper does not exclude WD
 ALF – massive necrosis on a background of cirrhosis
Copper Stains
Rhodanine
Electron Microscopy
Wilson disease with steatosis
 Mitochondria vary in size and
shape
 Increased density of the matrix
 Inclusions including lipid and
fine granular material (copper)
 Pathognomonic increased
intracristal space & dilatation of
the tips of the cristae
Elongated mitochondria and
dense deposits. X15,000
Iancu & Manov, Technion, Haifa
Wilson Disease – Diagnosis
Hepatic Parenchymal Copper Concentration
 Copper copper content >250 mg/g dry weight
 8% were <250, and all were >95 mg/g*
 Heterozygotes rarely exceed 250 mg/g
 Chronic cholestasis and copper intoxication
 Heterogeneous distribution – biopsy size
 Copper stain – unreliable (metallothionein-bound)
 Radiocopper labeling – rarely performed
*Merle U, Schaefer M, Ferenci P, Stremmel W. Gut 2007;56:115-120
MRI Brain – T2-weighted Images
Hyperintense signal in
the bilateral thalami and
putamen
“Face of the giant panda”
in the midbrain with high
signal in tegmentum and
normal red nuclei (arrow)
“Face of miniature panda”
in pons with hypointensity
of central tegmental tracts
(arrow) with hyperintensity
of aqueductal (4th ventricle)
Genetic Analysis
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Screening after the proband is diagnosed
Over 300 mutations around ATP7B
Not all gene changes cause Wilson Disease
Single predominant mutation in some populations
 Sardinia, Iceland, Korea, Japan, Taiwan, Spain,
Brazil and Canary Islands
 Eastern Europe –H1069Q mutation
Wilson Disease – Therapy
Uniformly Fatal Without Therapy
 British anti-Lewisite (BAL, dimercaprol) –
introduced in1951
 Developed to treat arsenic-based chemical
warfare agent
 Still used for metal poisoning (arsenic,
antimony, gold, etc.)
 Free sulfhydryl groups binds copper
Wilson Disease – Therapy
D-penicillamine – John Walsh, 1956
Chelates, induces metalothionein, prevents collagen crosslinking, immunosuppressant
 Initial worsening of neurologic symptoms in 10-50%
 Intolerance – 30% of patients
 Early – fever, eruptions, lymphadenopathy, neutropenia,
thrombocytopenia
 Late – lupus-like (ANA+) – renal injury (hematuria,
proteinuria), skin lesions
 Monitor with 24-hr urine and serum free copper
 1,000 mg (16 mmol) (early) to 200-500 mg (3-8 mmol)/24h
 Non-ceruloplasmin copper
 Non-compliance vs inadequate chelation
Wilson Disease – Therapy
Trientine (triethylene tetramine dihydrochloride
or 2,2,2-tetramine, trien
 Polyamine-like structure - copper forms a stable
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complex with 4 nitrogens in a planar ring
Neurological worsening less common then with
penicillamine
Do not co-administer with iron:
 Chelates iron  toxic complex
Check effectiveness as for penicillamine
Non-adherence: non-ceruloplasmin bound copper
is over 150 mg/L
Wilson Disease – Therapy
Zinc
 Zinc induces enterocyte metallothionein which
has a greater affinity for copper than for zinc 
binds copper in the enterocyte  feces
 Used for maintenance or early cases – less toxic
and more specific than chelating agents
 Dosed in mg elemental zinc – 50 mg TID for
adults
Wilson Disease – Therapy
Ammonium Tetrathiomolybdate
 Strong de-coppering agent – two mechanisms:
 Interferes with intestinal uptake if taken with meals
 Binds copper from plasma if taken between meals
 TM remains an experimental therapy in the USA
 Does not cause neurological deterioration
And Now for Something Completely
Different
Question 3
Which of the following is true of AAT
A. The null mutation causes severe liver
disease
B. A mutation in one AAT gene may
predispose a patient to alcoholic liver
disease
C. Liver disease and lung disease are both
caused by low circulating levels of the
enzyme
D. Patients with the SS phenotype are
particularly predisposed to liver disease
35%
26%
23%
16%
A.
B.
C.
D.
a-1 Antitrypsin (AAT) Deficiency
A Tale of Two Diseases
 Common in Caucasians – 1-3% of pts with COPD
 ~ 25 million people carry at least 1 deficient gene.
 The mutant protein is not secreted
 Liver: gets stuck in the hepatocyte  injury
 Lung: Inadequate protection from leukocyte
proteases e.g. trypsin, elastase, proteinase 3
 May affect neonates (hepatitis) or adults (CLD,
COPD)
a-1 Antitrypsin
Serpins – enzyme inhibitors
 Acute phase protein
 52-kDa protein - 394 amino acids
 Produced in the liver – secreted
into blood
 Complex folding – globular
tertiary structure
 Neutrophil elastase binding site
a-1 Antitrypsin (AAT) Deficiency
a-1 Antitrypsin (AAT) Deficiency
 Pair of genes at the protease inhibitor (Pi) locus.
 The SERPINA1 (formerly Pi) gene on chr. 14
 More than 100 allelic variants – classified based on
serum levels of AAT protein.
 M alleles (Pi MM) are the most common
 Normal serum level
 Most patients with clinical disease are homozygous
ZZ or SS or heterozygous MS, MZ, or SZ
a-1 Antitrypsin (AAT) Deficiency
PAS-positive, diastase-resistant granules
a-1 Antitrypsin (AAT) Deficiency
 Normal is Pi MM – mutant alleles are S, Z, null
 Patients with liver disease typically have Pi ZZ
 Liver disease has no relationship to serum AAT
activity
 May progress to cirrhosis and/or HCC
 No specific therapy
 Cirrhosis and HCC are indications for liver
transplantation
a-1 Antitrypsin (AAT) Deficiency
Frequency
Country
Sweden
Pi ZZ
0.06%
Pi MZ
--
Pi SZ
0.05%
Year
1976
Netherlands
France
Spain
0.03%
0.01%
0.02%
-2%
--
0.04%
0.15%
0.2%
1980
2003
2003
Italy
Portugal
Australia
New Zealand
0.02%
0.02%
0.02%
0.02%
2.4%
2.5%
2.7%
4.5%
0.06%
0.3%
0.13%
0.17%
2003
2003
2003
2003
Canada
0.02%
2.7%
0.11%
2003
Kok et al. Netherlands Journal of Med, 2007
a-1 Antitrypsin (AAT) Deficiency
Frequency
Region
Pop/No. Tested
Pi MZ
Pi MS
Healthy donors/212
5 (2%)
7 (3.3%)
Minneapolis, MN
Blood donors/904
25 (2.8%)
37 (4.1%)
Tucson, AZ
General pop/2,944
88 (3.0%)
208 (7.1%)
Long Beach, CA
7th-graders/1,380
34 (2.5%)
110 (8.0%)
Los Angeles, CA
Blood donors/2,010
59 (2.9%)
95 (4.7%)
Rochester, NY
Consecutive/500
18 (3.6%)
30 (6.0%)
Rochester, NY
Random pts/930
21 (2.3%)
60 (6.4%)
St. Louis, MO
Blood donors/1,933
42 (2.2%)
130 (6.7%)
10,813
292 (2.7%)
670 (6.2%)
Rochester,MN
Total
Graziadei IW et al. Hepatology 1998 (4):1058-63.
a-1 Antitrypsin (AAT) Deficiency
Mayo: 641 OLT patients (Mar 1985 - Dec 1996)
 Phenotyping in 599 patients listed for liver transplant
– examined for the Z allele
 51 patients identified, 49 with MZ allele (8.2%)
 2x frequency reported in the US population (2-4%)
 Pi MZ found in 27% with cryptogenic cirrhosis
Graziadei IW et al. Hepatology 1998 (4):1058-63.
a-1 Antitrypsin (AAT) Deficiency
Heterozygotes Liver Disease
Swedish Study (1972-1974) – 200,000 Neonates Screened
 120 Pi ZZ (0.06%), 2 Pi Z-, 54 Pi SZ and 1 Pi S Only 14 Pi ZZ had prolonged jaundice – nine
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with severe disease
All appeared healthy at six months of age
Infants with a Pi SZ phenotype had no signs of
liver disease.
At 16 years, elevated liver enzymes were found in
17% of Pi ZZ adolescents and in 8% of Pi SZ
Adults with liver disease in infancy were
clinically healthy
Kok et al. Netherlands Journal of Med, 2007
a-1 Antitrypsin (AAT) Deficiency
Heterozygotes Liver Disease
Northern Itlay – Phenotyping in umbilical cord blood
 Early childhood:
 Pi SZ: 5% had elevated enzymes
 Pi MZ: 7% had elevated liver enzymes
 At the age of 5 and 10 years, none had liver
disease.
Kok et al. Netherlands Journal of Med, 2007
a-1 Antitrypsin (AAT) Deficiency
Liver Transplantation – Mayo Clinic 19872012: 5,246 patients
 73 patients – 50 with ZZ and 23 with SZ phenotype
 Mean age 52.8 years, 76% men
 Pre-OLT AAT levels were lower in ZZ than SZ patients
 28.3 vs 58.0 mg/dl, p=0.0001
 Coexistent liver disease
 8% in ZZ
 43% in SZ
 90% in MZ
Carey et al. Liver Transplantation, 2013 - epub
Summary
 Wilson disease – copper storage
 Caused by defect in ATP7B – low CPN
 Workup includes CPL, copper levels, biopsy
 Treatment with chelating agents and/or zinc
 AAT deficiency
 Pi ZZ may cause liver disease and HCC
 Pi MZ and Pi SZ may predispose to liver injury
 No treatment is available for liver disease besides
liver transplantation