Myelodysplastic, Myeloproliferative, and Histiocytic Disorders

Kenneth McClain M.D. Ph.D.

Texas Children’s Cancer Center

Houston, TX

Disclosure Information

• Own common stock of Johnson & Johnson Co.• No discussion of unlabeled uses

*=New material not in syllabus

What is Myelodysplastic Syndrome (MDS)or… When Do Blasts in the Marrow Not =

Leukemia?

Pediatric version of WHO Criteria for MDS• Absence of AML cytogenetic findings• Two or more of the following:

Sustained cytopeniaDysplasia in 2 cell linesClonal cytognenetic abnormality (5q-, monosomy 7)5-19% Blasts (>20% Blasts = AML)

MDS Can Become AML,But is not AML a priori

• May need several marrow exams to establish diagnosis of MDS vs. AML

• Incidence of MDS ~ 1.5 per million10-20% become AML

Pediatric MDS Classification

Three major categories:

1. Adult-Type Myelodysplastic Syndromes

2. Down Syndrome with abnormal megakaryocyte proliferation

3. Myelodysplastic/Myeloproliferative Syndrome: JMML

For Perspective-Adult MDS

• Predominant feature: Marrow Failure• Most frequent in adults 40-60 yrs. • Two major clinical groups

1. High incidence of progression to AML:Multilineage/Mutator Phenotype

2. Low Progression to AML:Unilineage

Types of Adult MDS

• High Incidence of progression to AML:Refractory Cytopenia with multilineage dysplasia: (RCMD)Refractory Anemia with excess Blasts (RAEB)

• Low Incidence of progression to AML:Refractory AnemiaRefractory anemia with ringed sideroblastsdel 5q: Macrocytic anemia

Pediatric MDS• Often with an underlying condition:

Aplastic anemia, Fanconi anemia, platelet storage pool defect, neurofibromatosis, secondary to malignancy treatment

Syndromes: Down, Kostmann’s, Shwachman-Diamond, Dyskeratosis congenita, Bloom’s, Noonan’s

Amegakaryocytic thrombocytopeniaFamilial monosomy 7, 5q-

Differential Diagnoses of MDS:Need >1 Marrow Finding and Cytogenetic

Data

• Other anemias:megaloblasticcongenital dyserythropoieticsideroblastic anemia

• Leukemia/pre-leukemia:Megakaryocytic leuk.MyelofibrosisPNH

• Toxins: Arsenic, chemotherapy• Virus: HIV

Myelodysplastic Syndrome (MDS)

• Refractory cytopenia (RC): <2% PB blasts,<5% marrow blasts

• Refractory anemia with excess blasts (RAEB):2-19% PB blasts, 5-19% marrow blasts

• *RAEB in transformation (RAEB-T) PB or marrow blasts 20-29%: Now = AML(Change from Handout)

• Marrow abnormalities: 2-3 lineages dysmorphic, erythroid most abnormal

Molecular Genetics of MDS

• AML1/RUNX1 gene: point mutationsRegulates hematopoiesis & most frequent translocation in MDSAML

• Chromosome 7 & 20 abnormalities in Shwachman synd: “mutator phenotype”

Treatment of MDS

• Refractory cytopenia: “expectant follow-up”• RAEB/RAEB-T:

Chemotherapy BMT

Event-free survival: 14-55% 65-80%

(If successful induction)

Down Syndrome Proliferative Diseases

• Transient abnormal myelopoiesis (TAM)

• Myelodysplastic syndrome (MDS)/acute myeloid leukemia (AML)

DOWN SYNDROMETransient Myeloproliferative Disorder or

Transient Abnormal Myelopoiesis

• TMD/TAM: leukemoid reaction: usually megakaryocytic

• Progression to megakaryocytic leukemia:20%Blasts same in both by morphology, immuno-phenotype GATA-1 *exon 2 mutations in leukemia onlyUltimately clonal cytogenetic data differentiates

Transient Abnormal Myelopoiesis in Down Syndrome

Median RangeAge at onset (days) 2 0-180Hepatosplenomegaly 69%Bruising/petech/bleeding 25%Resp. distress 21%WBC (per l) 47,000 5,000-384,000Absolute blast ct. 13,000 0-280,000Hgb (g/dl) 16.8 4-23.2Platelets (per l) 102,000 5,000-1,800,000

TAM Marrow Characteristics

• Hypo- to hypercellular• Fibrosis common• Blasts 32% (range 6.8-80%)• *Immunophenotype: CD7,33,45,34+

Platelet markers CD41/42b/61: variably +Best is EM with immunogold labeling of CD61

TAMClinical Outcomes

• Onset: median 16 mo. (range 1-30 mo.) No clinical differences between those with or without ANLL

• Duration: *Clear blasts median 2 mo., max 6 mo.• *Leukemia 20% (9-38 mo.) 90% M7, rare ALL• 17% died in first few mo. (not leukemia): sepsis,

congestive heart failure, hyperviscosity, “crib death”, DIC

• But….33% additional hematologic problems: 84% of these developed ANLL Others: CML, MDS, chronic thrombocytopenia

Pediatric MDS Classification:Myelodysplastic/myeloproliferative

• Juvenile myelomonocytic leukemia1% of pediatric leukemia cases

• Chronic myelomonocytic leukemiaVery uncommon in children

• BCR/ABL-negative chronic myelogenous leukemia

Juvenile Myelomonocytic Leukemia JMML

• Clinical criteria: hepatosplenomegaly, lymphadenopathy, pallor, fever, skin rash

• Minimal lab criteria (need all 3) No t9;22 or bcr/abl rearrangement

Peripheral blood monocytosis: >1X109/L

Bone marrow blasts <20% (differs from handout)

JMMLAdditional Lab Criteria

Need at least 2 of these:-Hgb F increased for age-Myeloid precursors in periph. blood smear-WBC >109/L-Clonal abnormality not always present (monosomy 7, t(5;8), trisomy 8, monosomy 22)-GM-CSF hypersensitivity of monocyte progenitors in vitro-Autonomous growth of CD34+ cells

Molecular Pathogenesis of JMML

• Frequent deletions of NF1Negative regulator of Ras signaling

• Missense mutations in PTPN11: all Noonan synd. Pts with JMML and 35% of other JMML

• Mutations of KRAS2 & NRAS

Bottom line: Ras activation central to JMML and other leukemias

MDS vs AML vs JMML

DiagnosisMDS

Age

< 7 yr

Spleen/liver 20-25%

Nodes Rare

AML > 7 yr >50% ~25%

JMML 1.3 yr 75-80% 40%

MDS vs AML vs JMML

Diagnosis

MDS

Extra-medul. Dx. No

WBC

~7,000/l

NormalCytogenet.23%

AML Rare+ M4/M5

>20,000/l Rare

JMML 77% >25,000/l 78%

Transformation to Leukemia:JMML/MDS/TMS

TIME <2

TO

2-5

TRANSFORM (yr) 5-10

Total

JMML 5/60 3 8/6013%

MDS 33/101 6 2 41/10141%

TMS 4/6 1 5/6 83%

Total 42 10 2 54/167 32%

Treatment of JMML

• Chemotherapy: 16% survival rate @ 3 yrs.Median time diagnosis to death is 15 mo.

• Stem cell transplant: 50% survival• *Current COG trial: pre-transplant chemotherapy

cis-Retinoic acid: inhib “spontanteous outgrowth CFU-GMfludarabine: potentiate metabolism of Ara-C to Ara-CTPAra-C: potent anti-myeloid malignancy therapyfarnesyl protein transferase inhb: anti-Ras

*= New data not in syllabus

What is a myeloproliferative disorder?

• Elevated numbers of a particular cell line in peripheral blood

• Hyperplasia of that lineage in the marrow• No secondary causes: infection, drugs, toxins,

autoimmune, non-hematologic malignancy, trauma

Types of Myeloproliferative Syndromes

• Erythroid: polycythemia vera• Granulocytic: CML• Monocytic: JMML• Megakaryocytic: Essential or familial

thrombocytosis, myeloproliferative disease of Down syndrome

• Gain of function mutation in Janus kinase 2 (9pLOH):polycythemia vera & familial thrombocytosis

Myeloproliferative DisordersPolycythemia Vera

• <1% before age 25 • Symptoms:headache, weakness, pruritus,

dizziness, night sweats, weight loss• P.E.: hypertension, hepatosplenomegaly• Marrow: hypercellular• Erythropoietin normal or min. decreased• 10-25% have clonal abnormality

Polycythemia Vera:Criteria for diagnosis

Need A1-3 or A1 &2 plus 2 of Category B

Category A:1. RBC vol. Males >36ml/kg, females>32ml/kg

2. Arterial oxygen saturation >92% (normal P-50)

3. Splenomegaly

Category B:

1. Thrombocytosis (>400,000/l)

2. Leucocytosis (12,000/ l)

3. Increased leukocyte alkaline phosphatase

4. Increased vit B12 (900 pg/ml) or unsat. B12 binding capacity (>2200 pg/ml)

Polycythemia Vera

• Treatment: phlebotomy, keep hct <45%• Problems: vascular occlusion, bleeding,

thrombosis, myelofibrosis, leukemia

Essential Thrombocytosis

After ruling out: nutritional, metabolic, infectious, traumatic, inflammatory, neoplastic, drug, and misc.

• Platelet count > 600,000/l• Hgb not > 13 gm/dl• Normal iron stores• No Ph. Chromosome• No fibrosis of marrow

Essential Thrombocythemia

• Presents with: headache, thrombosis (0-32%), bleeding (12-37%) (G.I.,hemoptysis)

• Over ½ peds cases familial• Splenomegaly (30-60%)• Hepatomegaly (7-43%)• Abnl plt morphol: 75-85% (hyperlobulated,

dysplastic, early megs.,

Essential Thrombocytosis:Therapy and late effects

• Safest therapy: anagrelide: anti-aggregating and decreased platelet synthesisOthers: hydroxyurea,

• Malignant transformation:0% Familial, 11% non-familial

• Thrombosis can occur @ plt cts of 600-800K

Histiocytosis Syndromes

• Langerhans cell • Macrophage proliferations

Hemophagocytic lymphohistiocytosis Familial and “Secondary” to many etiologiesMacrophage activation syndromeRosai-Dorfman SyndromeJuvenile Xanthogranuloma

• Malignancies of macrophages or dendritic cells

Where do all those histiocytes come from?

Stem Cell

Langerhans Cell LCH

FollicularDC

Myeloid DCHLH/RD

InterstitialDCJXG/ECD

Common Myeloid Progenitor

Common lymphoidProgenitor

Mono/preDC1

Monocyte

preDC2

Plasmcytoid DC

GM-CSF. IL-4TGF-, Flt-3L

TNF-, GM-CSF

TGF-

Langerhans cell histiocysosis

• Incidence: 5-8/million children• Male/female: 1.3/1• Average age at presentation: 2.4 yrs• Multisystem and single system disease

Severity depends on organs involved• Epidemiologic associations: increased incidence

of thyroid/autoimmune disease in family

Langerhans Cell Characteristics

• Dendritic cells derived from bone marrow stem cells

• Critical antigen-presenting cell• For correct diagnosis:

Intracellular Birbeck granules that stain with CD207 (Langerin) or Extracellular staining with CD1a

• Also found, but not specific: S100+

Langerhans Cell Histiocytosis: Langerhans Cell Histiocytosis: Clinical manifestations IClinical manifestations I

• painful swelling of bonespainful swelling of bones– unifocal bone lesion (31% at presentation)unifocal bone lesion (31% at presentation)– isolated multifocal bone involvement (19%)isolated multifocal bone involvement (19%)

• persistent otitis / mastoiditispersistent otitis / mastoiditis• mandible involvement (“floating teeth”) mandible involvement (“floating teeth”) • Papular/scaly rash (37% at presentation)Papular/scaly rash (37% at presentation)• hepatosplenomegaly hepatosplenomegaly • lymphadenopathylymphadenopathy

Langerhans Cell Histiocytosis: Langerhans Cell Histiocytosis: Clinical manifestations IIClinical manifestations II

• Pulmonary involvement : interstitial pattern -> Pulmonary involvement : interstitial pattern -> “honeycombing” (cysts) and nodules“honeycombing” (cysts) and nodules

• Marrow infiltration: cytopenias , sometimes Marrow infiltration: cytopenias , sometimes hemophagocytosis-macrophage activationhemophagocytosis-macrophage activation

• GI involvement (diarrhea, malabsorption)GI involvement (diarrhea, malabsorption)• Endocrine involvement:Endocrine involvement:

– diabetes insipidusdiabetes insipidus– growth failuregrowth failure– hypothyroidismhypothyroidism

Originally thought to be a viral rash

Pulmonary LCH in Children

• Presentation: wheezing, cough, pain,or nothing• Chest xray: interstitial infiltrates, sometimes

see nodules, cysts, or pneumothorax• Chest CT needed to define presence of nodules

and cysts. Probably reasonable to do on all infants

CNS PROBLEMS IN LCH PTS. WITH BASE OF SKULL LESIONS

• Mastoid, orbital, temporal bone lesions:• If single agent or no treatment: 40%

incidence of diabetes insipidus• Velban/prednisone: still 20% D.I.• Chance of parenchymal brain disease:

May present 10 yrs after initial diagnosis

Neurologic Syndromes in LCH

• Present with ataxia, dysarthria, dysmetria, behavior changes

• MRI: Masses or T2 hyper-intense signal in cerebellar white matter, pons, or basal ganglia may be long before symptoms appear

• Secondary to neurodegeneration/gliosis• Cause: Cytokines? Direct infiltration with

Langerhans cells or lymphocytes?

Enhanced T2-weighted images in LCH patient with neurodegenerative syndrome

LCH Therapy

• “Low Risk” (bone +/-skin,lymph nodes): velban/prednisone 6-12 mo.

• “High Risk” (liver, spleen, lung, bone marrow)velban/prednisone/6MP vs velban/prednisone/6MP/methotrexateBoth 12 mo.

• Etoposide (VP-16) no better than velban, now not considered “standard therapy”

• Radiotherapy or intra-lesion steroids only for spine, femur, or non-CNS Risk skull lesions

LCH Therapy Results

• “Low Risk” pts: 100% cured18-25% reactivations

• “High Risk” pts: Depends on response @ 6wks

Good response: 6% fatalitiesIntermediate: 21% fatalities

Non-responder: 60% fatalities

Hemophagocytic LymphohistiocytosisHLH

• Autosomal recessive and secondary formsBoth may be triggered by infections, malignancy, or immunizations

• Presentation: fever, irritability, rash, lymphadenopathy, hepatosplenomegaly

• Labs: pancytopenia, coagulopathy, elevated: LFTs, ferritin, triglyceride

• Histology of marrow, nodes, or liver: macrophages actively engulfing any blood cell

HLH: Associated Conditions• Familial, especially in cultures with

consanguinity• Secondary to any infectious agent

Especially EBV, CMV, parvo• Malignancies: T and B cell leukemias, T-cell

lymphoma, germ cell tumor• Kawasaki synd., JRA, lupus• Other syndromes: X-linked lymphoprolif.,

Griscelli, Chediak-Higashi

HLH Epidemiology

• Frequency: 1.2/million children or 1/50,000 live births. Compare PKU 1/31,000 or galactosemia 1/84,000

• Likely under-diagnosed. “Looks like” hepatitis, sepsis, multi-organ failure syndromes

HLH: Clinical Signs

• Fever 91%• Hepatopmegaly 90%• Splenomegaly 84%• Neurologic symptoms 47%• Rash 43%• Lymphadenopathy 42%

CNS Problems in HLH

• Cranial nerve signs• Confusion, seizures, increased intracranial

pressure• Brain stem symptoms, ataxia• Subdural effusions & bleeds, retinal hemorh.• CSF: mononuclear pleocytosis (lymphs &

monos), RBC• MRI: parameningeal infiltrations, masses or

necrosis- hypodense areas

Diagnostic Criteria for HLH

• Familial disease/known genetic defect

• 5 of the following :

– Fever ≥ 7 days

– Splenomegaly

– Cytopenia ≥ 2 cell lines

– Hypertriglyceridemia and/or hypofibrinogenemia

– Ferritin ≥ 4000 μg/L

– sCD25 ≥ 2,400 U/mL

– Decreased or absent NK activity

– Hemophagocytosis (Absent 20% of time-treatment

may be indicated if other criteria fulfilled)

FEVER OF UNKNOWN ORIGIN: EVALUATION MAY LEAD TO A SURPRISE

O R D E RIn fec tiou s ag e n ts te s ts

L A B F IN D IN G SC B C A b n l

L F T s /B ili upL D H In c rea sed

S T A R T H L H R xIF :

B M A +B M A - & clin ica l c rite ria s tro ng

H E M E C O N S U L TB o n e m arro w a sp .

O T H E R L A B SP T /P T T up

F ib rin o ge n do w nF E R R IT IN : W A Y U P !!

C L IN IC A L F IN D IN G SF e ver

H yp o te n s ionR e sp ira to ry d is tre ss

Immune Dysfunction in LCH

• Defective NK cell function (number variable) Decreased killing of target cellsDecreased perforin (usually)

• Defective Cytotoxic T cellsDecreased perforin (usually), may differ fromNK cell findings

• Effects of above: unregulated cytokine production, no apoptosis of lymphs and monos

Peforin Defects in HLH

• Peforin: cytolytic effector protein, essential for regulation of NK and T cells

• Levels in NK and T cells depend on type of mutations in the gene. May be normal in patients with MUNC-13 or other mutations

• >50 mutations in the PRF1 gene known: cause absence of functional protein or truncated proteins. No gross deletions or insertions.

Molecular Genetics of Familial HLH

LocusName

GeneSymbol

Chrmsm. Locus

Protein Name

FHL1 Unknown 9q21.3-q22 Unknown

FHL2 PRF1 10q22 Peforin 1

FHL3 UNC13D 17q25.1 Unc-13 homolog D

FHL4 STX11 6q24.1 Syntaxin-11

Hypercytokinemia in HLH• Dysregulation of Th1 immunresponse

Markedly elevated levels of: Interferon ,TNF, IL-1, IL-6, IL-2 receptor (sCD-25)

• Cause fever, hyperlipidemia, endothelial activation, tissue infiltration by lymphs & histiocytes, hepatic triaditis, CNS vasculitis, demyelination, marrow hyperplasia or aplasia

HLH-94 RESULTS

• 113 Patients, 1994-1998, < 15 yrs of age

• 25 familial, 88 sporadic

• Overall survival 55% +/-9%, 51% for familial casesBMT need for familial or genetically proven patients

• 23/113 alive with only immunochemotherapy

VP-16/dexamethasone/cyclosporine

• 78% of children respond well to immunochemother.

• 93 bone marrow transplants62% survival (52% for <3mo to 71% for 12-24 mo)

One More---

Rosai Dorfman Syndrome ORSinus Histiocytosis with Massive

Lymphadenopathy

Anatomic Sites of SHMLSite Frequency (%)Lymph nodes 87Skin and soft tissue 16Nasal cavity 16Eye 11Bone 11Central Nervous System 7Salivary gland 7Kidney 3*Respiratory tract 3*Liver 1*Breast, GI, Heart <1

Immunohistochemistry

CD163

S100

• “Activated histiocyte”

– Pan macrophage

– Lysosomal

– Activation

• S100

• CD163

• Lacks CD1a

Differential Diagnosis

• Reactive hyperplasia

• Hemato-lymphoid malignancy

• Metastasis

• Storage disorders

• Histiocytoses, particularly, LCH

TreatmentThoughts from the Registry

• Randomized clinical trials unavailable

• Most patients do not require treatment?

• Treatment necessary in minority with organ

or life-threatening complications

Chemotherapy

• Vinca alkaloids/alkylating agents/steroids

• Methotrexate + 6-mercaptopurine (2/2CR)

• Purine analog 2-chlorodeoxyadenosine used in

refractory LCH

– Short-term symptomatic relief in 2 children

with CNS disease without clinical response

Rodriguez-Galindo J Pediatr Hematol Oncol 2004