physiopathologie - apset...quality of life 0,0 5,0 10,0 15,0 20,0 25,0 physical emotional social...
TRANSCRIPT
PHYSIOPATHOLOGIE
• Défaut du transporteur
lysosomal de cystine:
CYSTINOSINE
• Gène CTNS (23 kb)
• Transmission autosomique
récessive: 1/200 000
naissances vivantes
• Accumulation et cristallisation
intralysosomiale de cystine =
Maladie systémique
W Gahl, 2002 04/03/2019 2
TROIS FORMES CLINIQUES selon la sévérité et l’âge du diagnostic
1. Forme infantile (96%)
2. Forme juvénile (4%)
• Atteinte rénale et extra-rénale
moins sévère
3. Forme adulte (<1%)
• Atteinte cornéenne
• Absence d’atteinte rénale
04/03/2019 3
MODE DE PRESENTATION
• Cassure de la courbe de croissance après 6 mois • Rachitisme hypophosphatémique • Anorexie, Vomissements, Déshydratation extracellulaire
sévère • Syndrome de Fanconi
– Perte de sel, hypokaliémie, – Diabète phosphaté – Acidose métabolique, – Hypo-uricémie, – glucosurie orthoglycémique, amino-acidurie – Protéinurie tubulaire, a1 et b2 microglobinurie, RBPurie
• Alcalose hypokaliémique • Atteinte cornéenne isolée
04/03/2019 4
DIAGNOSTIC
• EXAMEN OPHTALMOLOGIQUE
• CYSTINE INTRALEUCYTAIRE
• GENETIQUE MOLECULAIRE
04/03/2019 5
TUBE CONTOURNÉ PROXIMAL syndrome de Fanconi
Sodium Pump
K+
ATP
ADP
Na+
GL
UC
OS
E
O2
GLUT2
FGF23
AQP3
AQP1
H2 O
Na-G
luco
se
Na-A
cides am
inés
Na-A
cides o
rgan
iqu
es
NPT2a
NPT2c
NHERF
+
Lysosome
PROTEINES
Cl-
OCRL1
Cystin
+
AA
ClC5
CT
NS
mégaline-
cubuline
exocytosis
endocytosis CO2
+ H2O
Car4,Car14
Car2
H++ HCO3--
CO2 + H2O
H++ HCO3--
Na-bicarbonates
HCO3-- Na+
NH
E 4
geo
rges
.des
chen
es@
rdb
.ap
hp
.fr
04/03/2019 6
TRAITEMENT DU SYNDROME DE FANCONI
• Supplémentations
– Bicarbonate de sodium
– Bicarbonate de potassium
– Chlorure de sodium
– Phosphate disodique
– 1 a calcidol
• AINS
– Indométacine 1-3 mg/Kg/jour
– ou Ibuprofen 10-30 mg/kg/jour
– Arrêt quand le DFG est < 30 ml/min/1.73m²
04/03/2019 7
PROGRESSION DE L’INSUFFISANCE RENALE
W Gahl, 2002 04/03/2019 8
CYSTINOSIS A SYSTEMIC DISEASE
• Growth failure
• Poor nutritional status
• Renal failure
• Endocrine disease
– Hypothyroidism
– Diabetes
– Delayed puberty
– Hypofertility or infertility
• Liver disease
– Portal hypertension
– Hepatomegaly
• Bone disease
– Fracture
– Deformations
– Teeth delay & enamel defects
• Dysmorphology
• Neuromuscular involvement – Myopathy, muscle weakness
– Respiratory failure
– Swallowing deficiency
– Intracranial hypertension
– Brain calcification
– Cognition disability
– Mental deterioration
• Ocular deposition – Cornea
– Retinopathy
04/03/2019 9
La myopathie
04/03/2019 10
A STANDARD FOLLOW-UP
M. CA… age 9 years, • BW 24 kg 700. Height 121,8 cm BP 97/70 mmHg. • Plasma Creatinine 56 µmol/l, blood urea 6 mmol/l, cystatin C 0,89 mg/l,
sodium 139 mmol/l, potassium 4,1 mmol/l, chloride 102 mmol/l, bicarbonates 31 mmol/l, total protides 75 g/l.
• Plasma renin 130 mU/L (11-110) • Plasma aldosterone 2153 pg/mL (N 70-700) • Glomerular filtration rate (integrated Schwartz formula 2009) : 72
ml/min/1.73 m². (N>90) • Total Calcium 2,50 mmol/l, ionized calcium 1,25 mmol/l, alcaline
phosphatases 154 UI/l, PTH 25 ng/L. • T3 : 6 pmol/l, T4 : 24,7 pmol/l, TSH 3,33 mUI/l. • Serum Glucose 5,1 mmol/l, HbA1c 5,2 %, glucosuria 1,8 mmol/l. • Total carnitin 49 µmol/L (N25-50); free carnitin 37 µmol/L (20-40) • Hemoglobin 14,2 g/dl, VGM 87 µ3, leucocytes 5 000/mm3, plaquettes 478
000/mm3, ferritine 57 µg/l, transferrin saturation 19 %. • Proteinuria 0,75 g/l, calciuria 3,74 mmol/l, ur creatinine 3,60 mmol/l. • WBC cystin 0.69 nmol/mg protein
04/03/2019 11/45
A STANDARD PRESCRIPTION
S. CO… age 6 years, BW 16 Kg Paris, April 4, 2012 • INDOCID : 15 mg x 2/day, • PHOSPHONEUROS : 1 ml x 2/jour, • BICARBONATE DE SODIUM : 10 g/day, • NaCl : 1 g x 2/day, • POTASSIUM BICARBONATE : 1 g x 2/day, • DIFFU-K 1 pill x2/day • UN ALFACALCIDOL : 0,4 µg/day, • UVESTEROL : 1 dose n°1/day, • LEVOCARNIL : 500 mg x 2/day • L-THYROXIN 75 µg/day • RP103 : 325 mg x 2/day • CYSTEAMINE eyedrops : 1 drop/eye x 4/day.
31 pills/day 04/03/2019 12
the seminal work
Thoene 1976
04/03/2019 14
the seminal work
04/03/2019 15
the seminal work
Thoene 1976 IV Cysteamine 10 mg/kgBW
Cysteamine every 6 h Dosage at 3 hours
04/03/2019 16
Mechanism of action the disulphide interchange
Wilmer 2011, adapted from Gahl, 1985
PQLC2
04/03/2019 17
Cysteamine bitartrate
• CYSTAGON® – Immediate release
(stomach) – 4 times a day
• Dose kids 1900 mg/m²/d • Dose adults 2 g/day
• PROCYSBI® – Delayed release (small
intestine) – Twice a day – Cost x 20
• Dose kids 1900 mg/m²/d • Dose adults 2 g/day
04/03/2019 18
Pharmacokinetics dosage of cysteamine
• Blood sample into ACD
• Denaturation of plasma by DTT (reduction of disulfide bonds)
• Deproteination of plasma by sulfosalicylic acid
• Addition of NEM
• Dosage using LC-MS/MS
04/03/2019 19
Pharmacodynamics dosage of intracellular cystin
The classical method • Blood sample intocitric
acidcitrate-dextrose (ACD) • Total WBC • liquid chromatography-
tandem mass spectrometry: dosage of cysteine
• Protein dosage by BCA • Released in
nmol/mg protein of hemicystine
• Target < 1
The accurate method • Blood sample intocitric
acidcitrate-dextrose (ACD) • Neutrophils (PNN) • liquid chromatography-
tandem mass spectrometry: dosage of cysteine
• Protein dosage by Lowry • Released in
nmol/mg protein of hemicystine
• Target < 2.5
04/03/2019 20
No clear correlation between PD & PK
Langman 2014
04/03/2019 21/45
Pharmacokinetics & pharmacodynamics individual variability
Plasma cysteamin PNM cystin concentration
Bouazza 2011
2 µmol/L
30 µmol/L Methods of dosage: PNN-MS-Lowry
04/03/2019 22
LA VRAIE VIE
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
20/
01/1
999
08/07/1
999
24/05/2
000
22/11/2
000
30/05/2
001
30/05/2
002
24/09/2
003
21/06/2
004
24/02/2
005
04/10/2
005
24/05/2
006
12/02/2
007
28/08/2
007
08/07/2
008
09/12/2
008
23/06/2
009
21/01/2
010
08/07/2
010
cy
sta
go
n m
g/d
-6
-4
-2
0
2
4
6
8
10
12
14
PN
N c
ys
tin
nm
ol/m
g
04/03/2019 23
CYS
TAG
ON
(m
g/j
)
Cys
tin
e in
tra-
leu
cocy
tair
e (n
mo
l/m
g p
roté
ine)
Adaptation to body weight or to body surface ?
04/03/2019 24
CYSTAGON: Night pause 6 hours vs 9 hours
Levtchenko 2006
n = 17 n = 5
Methods: HPLC on PNM/BCA 04/03/2019 25
Residual plasma cysteamine concentration µmol/L
Bouaza 2011
Weight (kg) Observed with PNN cystin < 2
Estimated by the PK-PD model
10-17 4.8 4.3
17-25 6.1 5.4
25-40 6.4 6.5
40-70 7.0 7.9
Median in µmol/L
In my clinical experience: 2-3 µmol/L
04/03/2019 26
Effect of diet on PK
Dohil, 2012
04/03/2019 27
intestinal absorption
Dohill 2006 04/03/2019 28
Delayed release cysteamine Cystagon vs Procysbi – PK & PD
Langman 2012
Methods of dosage: WBC-MS-BCA 04/03/2019 29
Quality of life
0,0
5,0
10,0
15,0
20,0
25,0
Physical Emotional Social School Total
PEDSQL score (%) improvement after switch from cysteamine IR Q6H to cysteamine DR Q12H and
estimated trend at 24 months
% Change in PedsQL score (6 weeks)
% Change in PedsQL score at 24 months (trend)
p=0,05
NS NS
NS
NS
P<0,05
P<0,01
NS
P<0,05
NS
Langman 2014
04/03/2019 30
Prevention of Fanconi syndrome in sibling: a success in 1 case
Da silva 1985
04/03/2019 31/45
Prevention of Fanconi syndrome in sibling: a failure in 3 cases
Reznik 1991
1 2 3 N
Cysteamin dose
g/m²
1.30 1.95 1.95 -
Age at start 12 h 9 d 3 w -
FE phosphate % 45 35 38 <20
Proteinuria
g/mmol 1.3 0.5 1.6 <0.20
Aminoaciduria
µmol/kg/d
900 433 1000 <200
GFR
mL/min/1.73 m² 95 113 82 >90
Age at Fanconi syndrome in 1st Siblings F1: 2 years,
F2: 9 months F3: 6 months
04/03/2019 32
death
Brodin Sartorius 2012
treatment
started < 5 years of age
no treatment
treatment
started
< 5 years
of age
04/03/2019 33
delayed ESRD
Brodin Sartorius 2012
treatment
started
< 5 years of age
or no treatment
treatment
started
< 5 years of age
04/03/2019 34
extrarenal disease
Brodin Sartorius 2012
Treatment started < 5 years of age
Treatment started > 5 years of age
No treatment
04/03/2019 35
Adverse events halitosis
Besouw 2007
04/03/2019 36
Adverse events gastrointestinal intolerance
Dohil, J Pediatr 2003;143:224-30 04/03/2019 37
Adverse events skin & angioendotheliomatosis
Besouw 2011 & 2013
HDMVEC viability Newly formed vessels
04/03/2019 38
Adverse events cancer?
type Age (years) reference
Renal carcinoma 18 Cameron 2008
Cerebral medulloblastoma 4 Greco 2010
hemangioblastoma 13 Greco 2010
Thyroid follicular adenoma 23 Greco 2010
04/03/2019 39
Adverse events pseudo-osteolathyrism?
• Neurotoxin – β-N-oxalyle-L-alpha β-
diaminopropionic acid (βODAP)
• Bone toxin – beta-aminopropionitrile
(BAPN)
– Antagonist of lysyl oxydase
Lativus sathyris Or
Spanish lentils
Besouw 2013 04/03/2019 40
Compliance to Cystagon a major issue at adolescence
patient motivation self-reported adherence
self-reported daily doses
Ariceta 2014
04/03/2019 41/45
Compliance a major issue to delay ESRD
Nesterova 2015
Compliance score
score Level of WBC cystin nmol/mg proteins
0 ≥3
1 ≥2 to <3
2 ≥1 to <2
3 <1
Sum of score/year prior to ESRD
04/03/2019 42
No effect on mTOR down-regulation
Andrzejewska 2015
Level of phosphorylation of the ribosomal protein S6 kinase beta-1 [SISK1] in %
aminoacids Fetal Bovine Serum
04/03/2019 43
an alternative to cysteamine or a dream ?
4-month post transplant 8-month post transplant
KO Knock-Out for cystinosin gene HSC Hematopoietic Stem Cells pCCL Construct of CTNS gene in lentivirus WT Wild Type
Harrisson et al 2013
Cys
tin
co
nte
nt
leve
l (n
mo
l/m
g p
rote
in)
KO transplanted with [pCCL ctns-/- HSC] or with [WT congenic HSC]
04/03/2019 44
Omar Fakhouri
Hôpital Universitaire Saint-Georges Beyrouth
Ocular Cystinosis:
< 1 year old: Periphery of the cornea DIAGNOSTIC TOOL
3 to 12 years old: All the cornea PHOTOPHOBIA
13 to 40 years old: All the eye RETINAL BLINDNESS
Ocular Cystinosis:
Systemic Cysteamine Systemic Cysteamine
PHOTOPHOBIA
Corneal Cystine Crystal Score (CCCS or Gahl’s score)
From photophobia…to blindness without treatment!
Corneal scaring
Cysteamine (gel-formulation)
CystadropsTM
V1 / Day 1 Score = 3,8
V2/Day 30 Score = 2,6
Crystals reduction evidence in the stroma between D1 & D30
Cysteamine (gel-formulation): Decrease of IVCM score after 30 days treatment
A, Labbé, 2014
-0.10
-1.16
-1.02
-0.74
-0.52
-0.43
-0.88
The efficacy of Cystadrops® was shown in each corneal layer
Cysteamine (gel-formulation): Crystal deposits decreased over time in all layers
A, Labbé, 2014
make them grow in length HOW?
• Prevent extracellular dehydration
• Prevent metabolic acidosis
• Prevent bone deformation
• Maintain nutritional intake
• If necessary, rGH, L-thyroxin
• Early treatment by cysteamine
SODIUM DEPLETION
1- FANCONI syndrome = sodium wasting
LOOP
30%
COLLECTING
DUCT
0-3%
Proximal
Convoluted
Tubule
60%
Distal
Convoluted
Tubule
7%
geo
rges
.des
chen
es@
rdb
.ap
hp
.fr
G
Initial volume
175 liters
Final urine
<1 liter
Final urine
>3 liters
Na + H2O
urinary
output
ECF - interstitium
Na + H2O
intake
ECF -
plasma
en
do
th
eliu
m
INTRACELLULAR FLUID
K+ Na+
Lymphatics &
Thoracic duct
H2O
ECF = EXTRACELLULAR FLUID
Homeostatic for the osmotic pressure
cell mass
SODIUM DEPLETION
2- sodium wasting = sodium depletion
= ECF contraction = chronic dehydration
– Hyponatremia
– Increased plasma Protides
– High plasma renin and aldosterone
– And urine sodium>0
– Growth impairment
– Severe acute dehydration and cardiovascular shock in case of gastroenteritis, vomiting, diarrhea
SODIUM DEPLETION
3- ECF contraction = failure to thrive
• ADD SODIUM INTAKE AND PREVENT
WASTING
– sodium chloride, sodium bicarbonates
– Non Steroidal Anti Inflamatory drugs • Indometacin 2-3 mg/kgBW/day
• Ibuprofen 10-30 mg/KgBW/day – pediatric suspension 20 mg/mL
– One dose for 1 KgBW = 0.5 mL
• STOP when GFR is < 30 ml/min/1,73m²
• BIOMARKERS TO FOLLOW
– Plasma protides, serum potassium
– Plasma renin
– Height
SODIUM DEPLETION
4- TREATMENT OF SODIUM DEPLETION
INDOMETACIN IMPROVES •Sodium reabsorption •Chronic extracellular
dehydration •Growth in length
ALDOSTERONE
PROSTAGLANDINS
+
-
-
PCT 60%
LOOP 30%
DCT 7%
CO
LLECTIN
G D
UC
T 0-3%
+
INDOMETHACIN X
SODIUM DEPLETION
5- prevent wasting: indomethacin
Sodium Pump
K+
ATP
ADP
Na+
GL
UC
OS
E
O2
GLUT2
FGF23
AQP3
AQP1
H2 O
Na-G
luco
se
Na-A
cides am
inés
Na-A
cides o
rgan
iqu
es
NPT2a
NPT2c
NHERF
+
Lysosome
PROTEINES
Cl-
OCRL1
Cystin
+
AA
ClC5
CT
NS
mégaline-
cubuline
exocytosis
endocytosis CO2
+ H2O
Car4,Car14
Car2
H++ HCO3--
CO2 + H2O
H++ HCO3--
Na-bicarbonates
HCO3-- Na+
NH
E 4
geo
rges
.des
chen
es@
rdb
.ap
hp
.fr
METABOLIC ACIDOSIS
1- BICARBONATES WASTING
H+
• BLOOD ACIDOSIS
– Growth retardation
– Inceased respiratory frequency
– Worsened tubular function
• ADD BICARBONATES or CITRATE
or BOTH
– Sodium bicarbonates or Na-citrate
– Potassium bicarbonates or K-citrate
• BIOMARKERS TO FOLLOW
– Serum bicarbonates and chlorides
– Height
METABOLIC ACIDOSIS 2- EFFECT AND TREATMENT
Sodium Pump
K+
ATP
ADP
Na+
GL
UC
OS
E
O2
GLUT2
FGF23
AQP3
AQP1
H2 O
Na-G
luco
se
Na-A
cides am
inés
Na-A
cides o
rgan
iqu
es
NPT2a
NPT2c
NHERF
+
Lysosome
PROTEINES
Cl-
OCRL1
Cystin
+
AA
ClC5
CT
NS
mégaline-
cubuline
exocytosis
endocytosis CO2
+ H2O
Car4,Car14
Car2
H++ HCO3--
CO2 + H2O
H++ HCO3--
Na-bicarbonates
HCO3-- Na+
NH
E 4
geo
rges
.des
chen
es@
rdb
.ap
hp
.fr
CONTROL PHOSPHATE DEPLETION
1- PHOSPHATE WASTING & VITAMIN D DEFICIENCY
H+
• SIGNS
– Hypophosphatemia
– Fatigue and muscle weakness
– Bone deformation
– Rickets
BONE DEFORMATION
2- PHOSPHATE DEPLETION & VITAMIN D DEFICIENCY
– DiSodium Phosphate (phocytan ®) • Vials of 10 mL at 0.66%: 10 ml = 6.6 mmol eq. to 200 mg
of phosphorus or 620 mg of phosphates (Na intake = 13.2 mmol)
• Flask of 100 ml at 0.33%: 100 mL = 33 mmol eq. to 1000 mg
of phosphorus or 3100 mg of phosphates (Na intake = 66 mmol)
– Phosphoric acid (phosphoneuros®) • 10 drops = 0.43 mL = 79 mg phosphorus
– alfacalcidol® • 1 drop = 0,1 µg • or capsules at 0.25, 0.50 & 1µg • Initial dose 0.25 µg/day then adapt to biomarkers
– BIOMARKERS
• Serum calcium and phosphate • Plasma PTH and FGF23
Age
Serum Phosphorus
[mg/dL]
Plasma
Phosphates mmol/L
Alcalines
Phosphatase
[UI/L]
0-12 months 4.8 - 7.4 1.55-2.39 >350
1-5 yrs 4.5 - 6.5 1.45-2.10 100 - 350
6-12 yrs 3.6 - 5.8 1.16-1.87 60 - 450
13-20 yrs 2.3 - 4.5 0.74-1.45 40 - 180
BONE DEFORMATION
2- TREATMENT BY SUPPLEMENTS
NUTRITIONAL STATUS
1- FEEDING TROUBLES
Elenberg 1998
Consider gastrostomy
in very young patients
NUTRITIONAL STATUS
2- GASTROSTOMY
Coleman 2000
Lean mass in KgBW
Fre
e c
arn
itin
in µ
mo
l/L
NO CARNITIN DEFECT IN GRAFTED PATIENTS
LEVOCARNIL 500 to 2000 mg per day
relationship between carnitin and lean mass
NUTRITIONAL STATUS
3- L-CARNITINE
Guillen Lopez 2015
RECOMBINANT GROWTH HORMONE
Recombinant Growth Hormone : 0.20 mg/kgBW/WEEK subcutaneous
Genotonorm ® Humatropen ® Nordipen ®
For instance final height 160 cm
indocid
GH
NaCl
deux soeurs
x x
x
x x
x x x
x x
x x
x
x
x
x x
x
x
traiter le plus tôt possible
CONCLUSIONS
• The cysteamine dramatically improves the prognosis of cystinosis but does not prevent the Fanconi syndrome
• Gastro-intestinal adverse events are frequent and often discouraging
• Compliance is a major issue
• Cysteamine is not all – other treatments remain to be discovered to complete lysosomal depletion
04/03/2019 73