Olivier Hermine MD,PhD - … · Mastocytosis Olivier Hermine MD, PhD HematologyDepartment, Necker...

Mastocytosis

Olivier Hermine MD,PhD

CNRS UMR 8147 (Director M DY)

Service d’hématologieCentre de référence des mastocytoses

Hôpital Necker-Enfants MaladesFaculté de Médecine Necker-Cochin

Paris

Mastocytosis

Olivier Hermine MD, PhD

Hematology Department, Necker Hospital

Centre National de référence des mastocytoses, Necker Hospital

CNRS UMR 81 47

Institut Imagine, Necker HospitalInstitut Imagine, Necker Hospital

Paris, France

Centre de Référence Des MastocytosesCEREMAST

Coordonnateur

Pr Olivier HERMINE

Co-coordonnateurs

Pr Christine BODEMER

Pr Olivier LORTHOLARY

Dr Stéphane BARETE pour EMSED

Laboratoires de référence

Pr Patrice DUBREUIL - INSERM

Pr Olivier HERMINE - CNRS UMR 8147Dr Sophie GEORGIN-LAVIALLE - CNRS UMR 81 47

Dr Sylvie FRAITAG -Anatomopathologie (peau)

Dr Danielle CANIONI - Anatomopathologie (moëlle)

Dr Vahid ASNAFI - Laboratoire d'hématologie

Responsible du projet CEREMAST

Dr Olivia CHANDESRIS

Attachée de recherche clinique

Isabelle HIRSCH

Psychologue

Daniéla MOURA

Secrétaire de coordination

Anne-Florence BELLAIS

Dr Vahid ASNAFI - Laboratoire d'hématologie

Pr Serge ROMANA - Cytologie

Anesthésiste Responsable

Dr Pascale DEWACHTER

avis.ceremast@nck.aphp.fr

Par téléphone : 01 40 61 54 11

Par fax : 01 40 61 56 02

CEREMAST - Faculté Necker,156, Rue de Vaugirard, 75015 Paris

Mast cells are tissue cells

They are prevalent in areaswhich interface directly with

the external environmentclose to blood vessels and

Mast cells are sentinentals with strategic location

close to blood vessels andnerve endings

They can respond veryrapidy to a stimulus

with the production of awhole array of mediators

from JS. Marshall, Nature Rev Immunol 420: 787- (200 4)

Mastocytosis : DefinitionMastocytosis : Definition

-- HETEROGENEOUS GROUP OF DISORDERS CHARACTERIZED BY HETEROGENEOUS GROUP OF DISORDERS CHARACTERIZED BY ABNORMAL GROWTH AND ACCUMULATION OF MAST CELLS IN ON E ABNORMAL GROWTH AND ACCUMULATION OF MAST CELLS IN ON E OR MORE ORGANS,OR MORE ORGANS,

-- CONSIDERED AS A MYELOPROLIFERATIVE DISORDER,CONSIDERED AS A MYELOPROLIFERATIVE DISORDER,-- CONSIDERED AS A MYELOPROLIFERATIVE DISORDER,CONSIDERED AS A MYELOPROLIFERATIVE DISORDER,

-- DIVIDED INTO CUTANEOUS FORMS AND SYSTEMIC FORMSDIVIDED INTO CUTANEOUS FORMS AND SYSTEMIC FORMS

-- CLASSICAL SPONTANEOUS RESOLUTION FOR PEDIATRIC CA SESCLASSICAL SPONTANEOUS RESOLUTION FOR PEDIATRIC CASE S

-- ASSOCIATION WITH HEMATOLOGICAL DISORDERSASSOCIATION WITH HEMATOLOGICAL DISORDERS

•I - Localized•Cutaneous mastocytosis

•Mast cell sarcoma

•Extracutaneous mastocytoma

••CONSENSUS CLASSIFICATION OF MASTOCYTOSIS CONSENSUS CLASSIFICATION OF MASTOCYTOSIS ••(simplified From Valent et al, 2001)(simplified From Valent et al, 2001)

•Extracutaneous mastocytoma

•II - Generalized•Systemic mastocytosis

•- Indolent (no organ dysfunction)

•- With an AHNMD

•- Agressive (organ dysfunction)

•Mast cell leukemia (> 20%MC in BM)

PhysiopathologyPhysiopathology

MCTC MCT

SCF

����CD 34+c-kit high

MCC

IL-4SCF

?

TISSUES

IL-4Survival :SCFNGFIL-4IFN- γγγγ…...

Stem Cell CD34+Bone marrow

CIRCULATIONSCFIL-10IL-6

c-kit highFcεεεεRI negCD13+

SimplifiedSimplified pathwayspathways of of humanhuman MC MC differentiationdifferentiation

•• CC--kit activation pathwaykit activation pathway•• CC--kit activation pathwaykit activation pathway

•Lyn•Lyn

Mutations de c-kit dans les lignées cellulaires et chez les patients atteints de mastocytose

P815 souris D814Y PTFMA3 souris d573-579 JMRBL-2H3 rat D817Y PTHMC-1 humain V560G JM

D816V PT

Lignées cellulaires

ENFANT ADULTE CAS FAMILIAUX

Pas de mutationou E839K

formes extensives:D816VD816YD816F

Pas de MutationD816V/H-Systémique (80%)-Atteinte cutanée (30-50%)

V560G (rare)D820G (leukemia)

Patients avec Mastocytose

•Mastocytosis and c-Kit mutations

•Cutaneous biopsies -> RT-PCR

•Cutaneous mastocytosis UP and systemic mastocytosis

•P. Dubreuil, F Palmérini , L Nasca , (IPC Marseille - réseau AFIRMM – M Arock, O Hermine )

Augmentation de la sensibilité de détection de la mutation D816V

PCR: 2295S / 2661R

(exons 17 to 18 Fragment of 366 pb)

Ig1 Ig2 Ig3 Ig4 Ig5

TM JM TK1 TK2

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

WT D816V

Digestion BsmaI

Nested-PCR amplification

Sequence

•D479N

•V560G� ∆∆∆∆418

� ∆∆∆∆564-576

•E860G� ∆∆∆∆419 (12)

•InsFF419

•C443Y•S476I

•ITD501-502(2)

•D572A•D816Y(4)

•D816I•D816V(353)

•Ig1 •Ig2 •Ig3 •Ig4 •Ig5

•TM •JM •TK1 •TK2

•1 •2 •3 •4 •5 •6 •7 •8 •9 •10 •11 •12 •13 •14 •15 •16 •17 •18 •19 •20 •21

� ∆∆∆∆417-418 D419Y

•n=603•Human mastocytosis

•Collaboration : K Hahn Houston USA

•MCL leukemia

•And Sarcoma•Systemic•Pediatric

•Ig1 •Ig2 •Ig3 •Ig4 •Ig5

•TM •JM •TK1 •TK2

•1 •2 •3 •4 •5 •6 •7 •8 •9 •10 •11 •12 •13 •14 •15 •16 •17 •18 •19 •20 •21

•Dog mast cell tumor� ∆∆∆∆826826826826−−−−828- InsDT•Q430R

•ins421 aa45

•S479I4

•N508I

•Del/Ins555-559(5)

•ITD571-590(15)

•n=88

•Team 4 : Cell Signaling, Hematopoiesis and Mechanisms of Oncogenesis

•ITD

•ITD505-508

•K509I(6)

•ITD502-503(4)

•30% of the dogs are mutated

•And Sarcoma•Systemic

•Mastocytosis 85%

•Indolent and agressive

•Pediatric

•Mastocytosis 85%

•Adultes : STAT1_3_5 • Enfants : AKT – GSK3b

•Mutations ECD and D816X signalisation

•P. Dubreuil

•Differential colony-forming ability of ECD and D816X mutants expressing Rat2 cells

•Without

•SCF

•With

•SCF•SCF

•Outcome and mutations of c-kit

Patients mastocytosisStatut of c-Kit

WTMutation autre que

D816VD816V

Children (N= 59) 15% 46% 39%

Adults (N= 485) 28% 3% 69%

•Mutation %

•age

•Mutation %

•persistent

•Mutations

•ex8 & ex9

•puberty

•Mutations

•D816V

•regressive

•50

•75

•25

•Targeting telomerase and telomeres

•AZT

•P53•P53

•Senescence

•Conséquences du raccourcissement des télomères•Catalado RT, NEJM 2009

•Crise

•Instabilité

télomérique

•Sénescence

•Télomères : taille

critique

•Cellule somatique

•p53

•pRb •Cellule

immortalisée

•Stabilisation des télomères

•Divisions cellulaires

•Taille des

télomères

•Cellule souche

•Cellule souche

Re

lati

ve t

elo

me

rase

act

ivit

y

•In Culture Mast cells dye by senescence (6 weeks)

•Telomerase activity ?

•MC

•WT

•MC

•D816V

•R

ela

tive

te

lom

era

se a

ctiv

ity

•Figure 1 : « differential expression of telomerase and telomerase activity in children and adults

mastocytosis »•B •C •D

•E •F

•A

•Children

•N=15

•Adults

•N=16

•%

hT

ER

T+

c-K

it+

ce

lls

•G

•h

TE

RT

/c-K

it m

RN

A e

xpre

ssio

n

•Children

•n=60

•Adults

•n=48

•E

•MC

•WT

•MC

•D816V

•R

ela

tive

te

lom

era

se a

ctiv

ity

•F •G

•Children n=46

•n=17•n=18 •n=11

•p = 0,043

•Fibroblastes primaires humains D816V

•DAPI •Cy3 •Merge

•Mesure de la longueur des télomères

•Par analyse FISH Cy3-(CCCTAA)3

•Fibroblastes primaires humains Del417-419 InsY

•DAPI •Cy3 •Merge

•In vitro studies in transfected fibroblasts and BMMC

•A •B

•***•*

•**

•WT •Empty •Del417/ •AY502 •D816V

•*•***

•WT •Empty •Del417/ •AY502 •D816V

•C

•WT •Empty

Vector

•Del417/

8+D419Y

•AY502

/503•D816V•WT •Empty

Vector

•Del417/

8+D419Y

•AY502

/503•D816V

•WT •EV •417 •816•502 •EV •417 •816•502

•D •E

•Mutation Val560Gly

•(JM)

•C-Kit-hTERT

•A: moelle osseuse du patient

•10 Kb

•7,4 Kb

•M L. rate

•CT sain, apparié

en âge

•TRF2

•PML

•DAPI

•Colocalisation

PML et TRF2

•Cytospin sarcome

•A: moelle osseuse du patient

•B: sarcome du patient

•D: témoins (ISM)

•C: témoin (ISM)

•Collaboration Cytogénétique Serge Romana, G Soler

•Collaboration Curie •Arturo Londono

•Role of Telomerase activity

•Mutation

•D816V

•(Exon 17)

•C-Kit

• Mastocyte Survival

•=> immortalisation

•Indolent Mastocytosis

•Télomerase activity

•Spontaneous

Regression

•Mutation

•Exons 8 à 11

•C-Kit et WT•Proliferation

•Senescence

•-No telomerase

activity

•Short telomeres

•SCF

Regression

•Tumor progression

- Instabilité génétique

- ALT

Heterogenity of diseases associated

with D816V mutations

Agressive and Hematological diseases Agressive and Hematological diseases

association vs Indolent

•5-me-Cytosine •5-hme-Cytosine

•Tet2

•Tet2 is involved in the conversion of 5 meC to 5hmeC

•at specific genomic loci

•Cytosine

•Dnmt•Inhibitors

•(e.g. RG108)

•5-me-Cytosine •5-hme-Cytosine

•Tet2

•Tet2 is involved in the conversion of 5 meC to 5hmeC

•at specific genomic loci

•Cytosine

•Dnmt•Inhibitors

•(e.g. RG108) •Mutations in SMP and AML

•CMML++

•CMML is associated with MS

•Tet2 mutations are frequent and are correlated to aggressive disease

•Mastocytosis Patient Cohort:

•KitD816V increases proliferation of Tet2-deficient BMMCs

0 3 6 10 12 14

•Li

ve C

ell C

ou

nts

(lo

g 10)

•(-/-)

•n=4

•(+/-)

•n=4

•(+/+)

•n=4

•8

•0

•2

•4

•6

•7

•1

•3

•5

•A •B

•The combination of Tet2 loss and c-Kit activation provides factor independent survival of

BMMCs

•Time after IL3 withdrawal (Days)

•0

•C

•Gating on

•GFP +

•Bone marrow derived Tet2-deficient mast cells infected with c-KitD816V have a competitive

growth advantage

CD117

•cKitD816V+ •cKitD816V+ •cKitD816V+

� Confirmed in two independent Tet2-KO models

(lacz and flox)

� Consistent whether infections are done using

« young » or « old » MC cultures (old > 80 days

culture with IL3)

•CD117

•Tet2(+/+)

•GFP

•Tet2(+/-) •Tet2(-/-)

•TET2 MUTATION

•Model of Oncogenic Co-operation

••KITD816V KITD816V

••OTHER MUTATIONSOTHER MUTATIONS••HETEROGENEOUS DISEASE PHENOTYPEHETEROGENEOUS DISEASE PHENOTYPE••AGRESSIVE DISEASEAGRESSIVE DISEASE

•Proliferation

•Differentiation

••HETEROGENEOUS DISEASE PHENOTYPEHETEROGENEOUS DISEASE PHENOTYPE••AGRESSIVE DISEASEAGRESSIVE DISEASE

•Indolent

•Mast cell tumor

•Htert activiy

•C-kit D816V

•Survival

•Immortalization

•Mast cell tumor

• regression•C-kit (WT exon 8,9,11)

•Proliferation

•SCF

•Survival

•No immortalization

•No htert activity

•Telomeres shortening•Mast cell

•progressiopn

•Genetic instability

•Htert expression

AHNMD• Fréquence 30%• Physiopathologie?• Pronostic habituellement mauvais

• Hémopathie myéloïde : SMP, SMD, SMP/SMD– LMMC: précurseur commun?, monocytes D816V, Mutation TET2 30%, évolution

possible vers LAM– LAM : t(8;21) ++, présence SM souvent occulte et péjore le pronostic de la LAM. De

même, présence LAM péjore pronostic de la MS– LMC: pas de BCR-Abl– LMC: pas de BCR-Abl– Hyper-éosinophilie (<20%):

– SHE, leucémie chronique à éosinophiles– FIP1-PDGFRa = imatinib– SM-eo: pas de retentissement habituel cardiaque ou pulmonaire

• Hémopathie lymphoïde: rare. NHL, gammapathie mc

• Si indiqué, traitement dissocié de l’une et l’autre pathologie et traiter l’hémopathie comme si elle était de novo.

• Pas d’effet des HD-CT sur la mastocytose

Mastocytosis Heterogeneity and c-kit

•Tet2

•ASXL1

•CMML

•C-kit 816 V

•negative

•C-kit 816 V

•Other ckit mutations •Other ckit mutations

•other ?

•NHL

•Cytokines (CD40L)

•Tet2

•ASXL1

•C-kit 816 V

•Tet2

•MDS

•CMML

•AML

•Sarcoma

•MCL

•Indolent Masotcytosis

•Agressive mastocytosis

•C-kit 816 V •JAK2,

• FIP1L1-PDGFR,

•Regression

•C-kit 816 V

•Other ?•Pediatric forms

•Other ckit mutations

•WT c-kit

•Adult Forms

•Sarcoma

•MCL

•Other ckit mutations

•WT c-kit

•Others SMP

•Agressive

•Masotcytosis (rare)

•Tet2

•ASXL1

•others

Effect of kinase Inhibitors on Mast cellsand Mastocytosis

C-kit inhibitionC-kit inhibition

STI 571 ?

Effect of STI 571on proliferation of cell lines with juxtamembrane or V814 c-kit mutations

80

100

120

% C

PM

0

20

40

60

0 0.1 1 10

µM

% C

PM

Ba/F3 Kit+IL3

Ba/F3 Kit+SCF

∂27

FMA 3

KIT G559

IC2 V814

P815 (V814)

FMA3 K∆27 KG559 KV814 P815

STI571 (µM) 0 1 10 0 1 10 0 1 10 0 1 10 0 1 10

KWT

.1 1 10

KL - + + - - - - - - - - - - - - - - -

IP anti KIT / Blot anti PY

000

- ++

--

175 kDa

83 kDa

MW

Ct

KIT

Effect of STI 571on wild type, juxtamembrane or V81 4c-kit phosphorylation

IP anti KIT / Blot anti PY

Total cell lysate & Blot anti Grb2

IP anti KIT / Blot anti KIT

--

175 kDa

83 kDa

MW

KIT

Grb226 kDa -

Effects of STI571 on Mastocytosis

• No effect on Mast cells with C-kit mutations within the catalytic domain (D816V)

• In vitro effect on Mast cells without catalytic domain C-kit mutations

c-kit Mutations in Mastocytosis

NH2

cc

cc

cc

Akin et al. Blood. 103:3222, 2004

•Location: Exon 10 (Transmembrane)•Type: Germline•Clinical features:

Childhood onset CMSSM in early 20sWell-differentiated phenotype

COOH

cc

F522C

Well-differentiated phenotype•Functional studies: Gain-of-function•Inhibition by imatinib: Yes (in vitro and clinically)

Therapy with imatinib in a patient with transmembrane c-kit mutation: Proof of concept

150

200

Try

ptas

e (n

g/m

l)

100 mg/d

200 mg/d

300 mg/d

0 25 50 75 100 1250

50

100

Days

Try

ptas

e (n

g/m

l)

300 mg/d

400 mg/d

Akin, Fumo, Yavuz, Lipsky, Neckers, Metcalfe. Blood, 103:3222, 2004

PKC412 (N-benzyl staurosporine)

• Inhibits PKC, VEGFR, Kit, PDGFR, flt3

• Phase I/II trials in hematologic and solid hematologic and solid tumors– Nausea, vomiting,

diarrhea, fatigue

• Inhibits D816V c-kit•Gotlib et al. Blood, in press, 2005

•BAF3 D816V cells

PKC 412

• Agressive mastocytosis

• Mastocytosis associated with C-kit D816V mutation

Signaling of PI-3k/Akt/mTOR•C-KIT

•-•PI •3 kinase

•AKT

•-•m•TOR •RAPAMYCINE

•1•Cyclin D•CDK’s

•G•1 •S

•Cell division

•G•0

•(resting cell)

•+

•P-p70S6k

•Translation/apoptosis

•4EBP/eIF4E

•BMMC

•Lignée BMMC•cellules mastocytaires dérivées de moelle osseuse de souris

•transgéniques pour le c-kit humain

•BMMC

•c-kit wt•BMMC

•c-kit 816

•La mutation D816V du c-kit confère à la cellule BMMC la sensibilité à la Rapamycine

Rapamycin and MS

•Stop

IFN

•CDA

1

•CDA

2

•Start

IFN

•Start Rapamycin

•Masitinib formula: C28H30N6OS

•Molecular weight:

•AB1010 (mesylate salt): 594.76

•Masivet® belongs to the ATP binding pocket molecules kinaseinhibitor 2-amino-4-aryl-thiazole family

•c-Kit •c-Kit

•Proliferation

•AB1010

•Proliferation

Me

N

S

NH

NH

O

N

N

N

Me

0,0

0,2

0,4

0,6

0,8

1,0

1,2

1,4

1010,10,050,01

DO

490

nm

AB 1010 (µM)

Inhibition of c-Kit phosphorylation

•AB1010 (mesylate salt): 594.76

•AB1003 (free base): 498.66

•Proliferation •Proliferation

•AB1010

•Anti-c-Kit

•Anti-Phospho Kit Tyr 729

•Anti-Phospho Tyr 4G10

•Masitinib formula: C28H30N6OS

•Molecular weight:

•AB1010 (mesylate salt): 594.76

•Masivet® belongs to the ATP binding pocket molecules kinaseinhibitor 2-amino-4-aryl-thiazole family

•c-Kit •c-Kit

•Proliferation

•AB1010

•Proliferation

Me

N

S

NH

NH

O

N

N

N

Me

0,0

0,2

0,4

0,6

0,8

1,0

1,2

1,4

1010,10,050,01

DO

490

nm

AB 1010 (µM)

Inhibition of c-Kit phosphorylation

•AB1010 (mesylate salt): 594.76

•AB1003 (free base): 498.66

•Proliferation •Proliferation

•AB1010

•Anti-c-Kit

•Anti-Phospho Kit Tyr 729

•Anti-Phospho Tyr 4G10

•Masivet® potently and selectively inhibits c-kit, PDGF receptors, and LynB

••Major target of Major target of MasivetMasivet® (IC® (IC5050 below 1µM)below 1µM)Major targets

(IC50 in nM)

Inhibition of cell proliferation Inhibition of kinase activity

ligandTransfected cells Tumor cell lines

Human c-Kit

WT 150 150 (TF-1) 200 SCF

EC (exon 9) 100 NA NA -

JM (exon 11) 3 50 (HMCI-a155) NA -

TK1 (exon 13) ND 40 (GIST 882) ND -

TK2 (exon 17) 5000 5000 (HMCI) > 10,000 -

Dog c -Kit

Masivet® is a novel, orally administered, protein-t yrosine kinase inhibitor, which potently and selectively inhibits c-kit, PDGF recep tors, and Lyn.

Dog c -Kitd Kit WT 100 NA ND SCF

d Kit EC exon 8 20 NA NA -

d Kit EC exon 9 100 NA NA -

d Kit JM exon 11 5 20 (C2) NA -

Murine c-Kitm Kit WT 150 200 (BMMC) ND SCF

m Kit JM exon11 5 NA NA -

Platelet-derived growth factor (PDGF) receptors

PDGFRα WT 300 - 540 PDGF BB

FIP1L1-PDGFRα - 0.25 (EOL-1) ND -

PDGFRβ 30 ND 800 EGFR-chimera + EGF

Intracellular kinases

LynB NA NA 510 -

Masitinib inhibits Mast cell degranulation and migration

••Human : A model for DogHuman : A model for Dog

••and “vice versa”and “vice versa”

•53

Mast Cell Tumors in Dogs

• Most common cutaneous tumor– 16-21% of all canine

cutaneous tumorscutaneous tumors

• Tissue mast cells in the dermis

• Poor survival <6 months in grade III tumors

D479N

V560G∆∆∆∆418

∆∆∆∆564-576

E860G∆∆∆∆419 (12)

InsFF419

C443YS476I

ITD501-502(2)

D572AD816Y(4)

D816ID816V(353)

Ig1 Ig2 Ig3 Ig4 Ig5

TM JM TK1 TK2

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

∆∆∆∆417-418 D419Y

n=603Human mastocytosis

Collaboration : K Hahn Houston USA

Can we compare mastocytosis with dog mast cell tumors ?

Ig1 Ig2 Ig3 Ig4 Ig5

TM JM TK1 TK2

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

Dog mast cell tumor∆∆∆∆826826826826−−−−828- InsDTQ430R

ins 421 aa45

S479I4

N508I

Del/Ins 555-559(5)

ITD571-590(15)

n=88

Team 4 : Cell Signaling, Hematopoiesis and Mechanisms of Oncogenesis

ITD

ITD505-508

K509I(6)

ITD502-503(4)

30% of the dogs are mutated

•Case Report in Mast Cell Tumor.•Case Report in Mast Cell Tumor.

•DAY 0 •DAY 3 •DAY 18

•Case Report in Mast Cell Tumor.•Case Report in Mast Cell Tumor.

•Day •-•40• •Day 0 • •Day 15 • •Day 40••(treatment start) •

0. 25

0. 50

0. 75

1. 00

•EFFICACY of KINAVET on MAST CELL TUMOUR•Pivotal phase III study (n=202)

•Time To Progression – FIRST LINE

ITT population Median TTP (days)

Category n Mb Plc P

All First Line (FL) 85 253 75 0.001

Mutated c-Kit 25 NR 83 0.009

Wild-type c-Kit 53 253 66 0.008

•All First Line

0. 00

0. 25

0. 50

0. 75

1. 00

Ti me t o progressi on (days)

0 100 200 300 400 500 600

STRATA: group=AB1010 Censored group=AB1010 group=Pl acebo

0. 00

0. 25

0. 50

0. 75

1. 00

Ti me t o progressi on (days)

0 100 200 300 400 500

STRATA: group=AB1010 Censored group=AB1010group=Pl acebo Censored group=Pl acebo

0. 00

Ti me t o progressi on (days)

0 100 200 300 400 500 600

STRATA: group=AB1010 Censored group=AB1010group=Pl acebo Censored group=Pl acebo

Wild-type c-Kit 53 253 66 0.008

•Mutated c-kit •Wild-type c-kit

•Mb, masitinib; Plc, placebo; NR, not reached

Case Report of Agressive MC

• Female 67y past history of Flushes, Diarrhea, abdominal pain, syncopes.

– Hb 10,6, Plt 124000, wbc 8100; 4600 PNN, 7 % circulating mastocytosis

– Bone marrow aspiration 77% pathologic mast cells – Bone marrow aspiration 77% pathologic mast cells

– Bone marrow biopsy : 90 % infiltration

– Tryptase sérique 351 µg/L (N<15)

– Histamine sérique 14314 nmol/L (N<15)

– Caryotype: normal (46XX)

– Flow cytometry: 40% Ckit+, 12% CD25+, 2%

Biological findings

•Deletion 501-502

•Blood •Bone Marrow

In vitro effect of MasitinibPostive C

ontorol

Cos t

ransfected

Cos t

ransfected +masitinib

Cos t

ransfected+masitinib

1

•Cos

•Postive C

ontorol

•Cos t

ransfected

•Cos t

ransfected +masitinib

0.1

•Cos t

ransfected+masitinib

1

•Deletion 501-502