1. White Blood Cell Disorders
Paul Basciano, MD
March 2013

2. Jack of all trades, master of none
Certainly better than master of one

3. Overview
• Neutrophils: Neutropenia
– Aquired: Immune and drug-induced
– Congenital
• Eosinophils: Hypereosinophilic Syndromes
• Basophils/Mast Cells: Mastocytosis
• Histiocytes
– Hemophagocytic Syndrome
– Langerhans Histiocytosis
– Rosai-Dorfman

4. NEUTROPHILS

5. Neutropenia
• Peripheral blood ANC does not necessarily represent neutrophil
pool:
– Bone marrow, marginated in vessels, circulating blood (3%)
• Therefore level ANC does not always correlate with risk of infection
• Number of PMNS in reserves are what really matter
– Also normal neutrophil function
– Disease causing reduction in PMNs may cause increase in infectious
risk per se
• ANC can be a general guide; more sensitive than specific for risk of
infection
– Mild (ANC 1-1.5k/ul): Low risk
– Moderate (ANC 0.5-1.0): Intermediate risk
– Severe (ANC <0.5): Highest risk
• Physical findings such as oral ulcers and gingivitis suggest a more
severe neutropenia

6. Causes of Neutropenia and Risk
• Low risk neutropenias (adequate reserves):
– Benign/ethnic
– Hypersplenism
– Post-infectious
• Moderate risk neutropenias (questionable reserves):
– Drug-induced
– Infectious
– Cyclic
– Immune-mediated
• High risk neutropenia (inadequate reserves):
– Drug-induced
– Infectious
– Post-chemotherapy
– MDS, myelofibrosis, aplastic anemia
– LGL
– Some congenital: Kostmann, Schwachman-Diamond

7. Benign Ethnic Neutropenia
• African americans, certain Jewish populations, certain Arab populations
• Defective release from marrow
• No increase in infectious risk, including after chemotherapy

8. Infectious Neutropenia
• Viral: all
• Rickettsial diseases
• Leshmaniasis, malaria
• Bacterial:
Typhoid, Shigella, Brucella, Tularemia, Tubercu
losis

9. Drug-Induced Neutropenia
• Classics: antipsychotics (clozapine), antithyroid meds,
sulfasalazine/sulfamethoxazole, and ticlopidine
• Keep in mind: H-2 blockers, pretty much all antibiotics, TCAs,
ACE-Is, antiarrhythmics, NSAIDs, dapsone, deferipone
• Rituximab (30-175dd after dose)
• Withdraw the offending agent (good luck finding it)—recovery
can take 1-3 weeks
• The role of GCSF is unclear; probably shortens duration, but of
unclear overall benefit

10. Immune Neutropenia
• Circulating abs, normal marrow reserves: no risk of infection from
neutropenia
• Circulating abs, normal marrow reserves, underlying
immunodeficiency: risk of infection from immunodeficiency
• Circulating abs, normal marrow reserves, vasculitis: risk of infection
from vasculitis/mucosal injury
• Circulating abs/cytotoxic T cells, absent marrow reserves: high risk
of neutropenic infections
– LGL
• BUT you don’t know risk if you don’t do a marrow…
• Serologies or direct detection of abs on neutrophils is of very
limited use
– Questionable sensitivity and specificity; do not change managment

11. AutoImmune Neutropenia and Chronic
Idiopathic Neutropenia
• Usually moderate degree of neutropenia (ANC 0.5-1)
• AIN is primary (Chronic Benign Neutropenia) in most infants and
secondary in most adults
– Serologies of questionable utility
– Normal bone marrow reserves
– Usually resolves over time
• CIN is more common in adults
– Same clinical and diagnostic considerations
– Does not resolve over time
• Treatment is supportive; the role of GCSF remains unclear
– Marrow reserves only adequate if maturation proceeds past meta-myelocyte
stage
– Steroids, IVIG—side effects likely outweigh benefits
– Rituximab? Alemtuzumab?
– What is driving the infection? The neutropenia or the underlying disease?

12. Neutropenia and Primary
Immunodeficiencies
• Most primary immunodeficiencies will present in childhood
• CVID is an exception
– Severe reduction in IgG, some loss of IgA, IgM
– Onset between puberty and age 30

13. Congenital Neutropenias
• Severe Congenital Neutropenia (incl Kostmann syndrome)
– Severe, stable neutropenia
– Generally respond to GSCF
– Propensity for dysplasia and progression to AML
– Multiple genes, including ELANE
• Cyclic Neutropenia
– 21d cycle of neutropenia lasting about 6 days
– Severe neutropenia at nadir
– Infectious and mucosal symptoms
– ELANE mutation
– Not a pre-leukemic state
• WHIM: Warts, hypogammaglobulinemia, immunedificiency, myelokathesix
(neurtrophils stuck in the marrow); CXCR4 mutation
• Schwachman Diamond syndrome: SBDS (ribosome and microtubule protein):
marrow hypoplasia, neutropenia, pre-leuekemic, pancreatic exocrine dysfucntion
– N.b. this is NOT Diamond Blackfan anemia, which also involves a ribosomal protein
• Chediak-Higashi: albimism, platelet granule disorder (dense bodies), neutrophil
inclusions, progression to multisystem disease with histiocytosis

16. Disorders of Neutrophil Function
Disease Gene Characteristics
MPO deficiency MPO -Most asymptomatic; maybe increase in
Candida
LAD deficiency Intergrins -Delayed wound healing
ITGB2 -Neutrophilia
FUCT2 -Recurrent bacterial infections
FERMT3 -Some have platelet disorders
Chronic Granulomatous NADPH -Skin and lung infections (Aspergillus,
Disease oxidase Burkholderia, S aureus, Nocardia,
genes Mycobacteria)
-Dihydrorhoadmine 123 flow assay or
burst nitroblue tetrazolium test
Job syndrome (HyperIgE) STAT3 Skin, lung, sinus infections, Candida infections
High IgE levels

17. EOSINOPHILS

18. Hypereosinophilic Syndrome
• A broad syndrome with varying clinical
manifestations and etiologies
• New revised criteria:
– Acknowledges importance of peripheral blood eosinophilia as early disease, as
well as some syndromes to have tissue damage without peripheral blood
eosinophilia

19. **EAEs: Churg-Strass, Angioedema with eosinophilia, Eosinophilia-associated GI
disorers, eosinophilic pneumonia, eosinophilic fasciitis

20. Primary work-up of eosinophilia
• For both exclusion of secondary causes as well as
identification of organ involvement
• Complete history: travel history, drug history
• Exam (rashes, joints, muscles/fascia)
• IgE, B12 levels, tryptase
• HIV serology, stool parasite
screen, strongyloigdes serologies
• EKG, Echo, PFTs
• CT C/A/P
• Bone marrow aspirate and biopsy

21. -Days to years after initiation
-May have tissue restricted
manifestations
(nephritis, myositis, DRESS
-Often difficult to find offending
agent
-May take months to resolve
-Strongyloidiasis: may have
hyperinfection with steroid
treatment; consider empiric
treatement prior to steroids

22. **EAEs: Churg-Strass, Angioedema with eosinophilia, Eosinophilia-associated GI
disorers, eosinophilic pneumonia, eosinophilic fasciitis

23. Myeloproliferative Variant
• Based on rearrangements involving the PDGFRA
gene
– Classically and most common FIP1L1-PDGFRA MPN M-HES Mastocytosis
(Chronic Eosinophilic Leukemia) JAK2V617F PDGFRA- D816KIT
• RT-PCR or CHIC2 deletion by FISH FIP1L1
– Multiple others identified (PDGFRB, FGFR1)—need
specialized testing
• Clinical presentation:
– Dysplastic
eos, splenomegaly, anemia, thrombcotyoepnia, bon
e marrow fibrosis/hypercellulartiy, atypical mast
cells, increased tryptase, eosinophil-related tissue
damage and fibrosis
• Overlap between MPN, M-HES, and mastocytosis
• True diagnosis may be difficult to make

24. Lymphocytic-Variant MES
• Clonal populations of
activated, phenotypically-aberant T
lymphocytes (CD3-CD4+)
• More protracted course
• More dermatologic, GI, and lung
– Less fibrotic manifestations
• Progression to lymphoma is possible (T-cell
lymphoma)

26. HES: Treatment
• Corticosteroids
– Rapid reduction of eosinophil counts (within hours)
– More likely useful in I-HES and L-HES; M-HES unlikely to respond
– Doses variable
• 1-2mg/kg prednisone for high risk of morbidity
• 0.5-1mg/kg for more indolent disease
• Hydrea
– Most often combined with other agents
– Acts centrally, and leads to slow reduction in eos
– 500mg-2g daily; GI and hematologic side effects >1g/d
• IFN-a
– Slow effects
– Slow up-titrating in dosing
– PEG-IFN-a likely as efficacious and less side effects
– Likely useful in all subtypes of F/Pneg HES (including L-HES)

27. HES: Imatinib
• Multi-TKI
• Likely useful for all CEL rearrangements
• F/P fusion protein 100-fold more sensitive than BCR-ABL
• Relatively rapid effect (1 week) with reversal of most effects
except cardiac fibrosis
• Should be used with steroids in patients with cardiac
involvement
• Mirrors CML with effects, clone clearance, need for
continuous treatment, evolution of resistant clones
• Definite utility in CEL; worth a try in M-HES and I-HES
(higher doses); unlikely to work in L-HES

28. HES: Anti-IL-5
• Mepolizumab
– Induces rapid clearence of peripheral blood eos
– Long lastin effect (3mos) but not curative
– Allows tapering of steroid therapy
– Only available in compassionate-use trial for
patients with lifethreatening disease and failure of
three other agens

29. HES: Kitchen Sink
• Cytoxan, MTX, Vincristine, chlorambucil
• Alemtuzumab—possibly useful, highly toxic
• Transplant

30. High dose IV +/- empiric parasite
Life/Limb Threatening steroids treatment
Complications +
Imatinib (if
c/w M-HES)
F/P+ Imatinib 100mg
Refractory or
Other TKIs, other
CEL resistance
Imatinib 400mg development therapies, SCT
No F/P, Cardiac Sxs
with taper+ Pred
Symptomatic Response Taper; +/- HU, IFNa
Steroids
I-HES
Failure Imatinib 400mg Failure Kitchen
(short course)
Sink
Symptomatic Steroids, +/-
L-HES IFNa

31. MAST CELLS

32. Mastocytosis
• Clonal disorder of mast cells usually driven by
mutations in c-KIT
– Release multiple mediators from granules associated with
allergic-type symptoms, fibrosis, vasodilation, expansion of
other blood cells)
• Disease is driven by mediator-release symptoms and
infiltration/fibrosis
• Two main forms:
– Cutaneous
– Systemic:
• Indolent
• Aggressive (with tissue dysfunction)
• Mast cell leukemia
• Associated with hematologic non-mast cell lineage disorder
(MPD, MDS, lymphoid)

33. Mastocytosis
• Manifestations(in both cutaneous and systemic)
– Cutaneous
• Urticaria pigmentosa
• Telangiectasia, bullous lesions, Darier’s sign
– Mediator release symptoms:
• Anaphylaxis (IgE or non-specific; seen in Cutaneous and Systemic)
• GI: Abd pain, nausea, vomiting, diarrhea, bleeding, ulcers (histamine)
• Neuropsychiatric
• Musculoskeletal: pain, osteopenia
• Infiltrative symptoms/signs:
– Hepatosplenogmealy
– Anemia, thrombocytopenia
– Malabsorption
– Lytic bone lesions
• Associated blood findings: eosinophilia, monocytosis

34. Trigger of Mediator Release
• Exercise, massage, spicy food, heat and cold
• Surgery, instrumentation
• Alcohol
• Medications:
narcotics, NSAIDs, contrast, Vancomycin, Ceph
alosporins
• Emotional stress
• Bites, stings, venoms

35. Diangosis
• Skin and organ biopsies; bone marrow biopsy
– Mast cell morphology (spindle); tryptase staining
– Immunophenotype: CD25, CD2, CD117
• Imaging of bones and viscera
• Serum markers
– Typtase: also elevated after anaphylactic
reaction, AML, CML, MDS, CEL
• D816V KIT mutation analysis (marrow)
• Patients with symptoms of mast cell mediator release, OR
unexplained organomegaly, OR cutaneous findings c/w
mastocytosis should undergo bone marrow biopsy

37. Treatment
• Mast cell mediator symtpoms:
– Preparation to treat anaphylaxis (EpiPen)
– Avoidance of triggers
– Pre-treatment for unavoidable triggers:
• H2 + H1 blocker +/- moneluekast
• Indolent systemic: no mast cell treatment
needed
– Monitor for progression
– Treat for mast cell mediator symptoms

38. Treatment
• Aggressive systemic mastocytosis
– IFNs: 30-50% ORR; toxicities limit treatment;
treatment response may takes weeks to months
– Cladribine: 60% ORR; myelosuppression and infection;
most will relapse; use after INFs
– Imatinib: D816V KIT mutations will not respond; other
mutations or WT KIT may respond; other TKIs are
investigational
– Hydrea
– Transplant: role unlcear; especially for mast cell
leukemia
• Mast cell leukemia: full leukemia treatment

39. Langerhans cells
Monocytes/Macrophages
Dendritic Cells
HISTIOCYTES

40. Hemophagocytic Lymphohistiocytosis
• Condition of high inflammatory cytokines, T cell
activation, and histiocyte/macrophage activation
• Fever, cytopenias, splenomegaly
• Most will have liver inflammation/hepatitis
• Bleeding is common (DIC, platelet dysfunction)
• CNS dysfunction is common
• Primary (familial) associated with perforin gene
mutations in 50%; also congenital immunodficiencies
• Secondary associated with malignancy, immune
compromise, rheumatologic disorders (Still disease-
>Macrophage activation syndrome)Often not seen early in disease, sometimes
seen after response

41. HLH

43. Langerhans cell Histiocytosis
• Infiltrative disease of Langerhans-like cells
• Can be unifocal or multifocal, and single-organ or
multi-organ
– Bone is most common
• Lytic lesions
• Bone pain/swelling
• Loose teeth, cranial involvement (DI, pituitary disturbance)
– Skin
– LN, BM
– Hepatosplenomegaly
– Pulmonary

44. LCH
• Diagnosis is made by biopsy
– Typical morphology (eosinophilic, coffee bean
nuclei)
– S100, CD207 (langerhin, Birbeck granules), CD1a
• Treatment is by aggressivity:
– Single organ: observe, remove, or limited immune
suppression
– Multi-organ, progressive, or high risk
(BM, lung, liver involvement): systemic
therapy, transplant

45. Other histiocyte disorders
• Erdheim-Chester: non-Langerhans histiocytes;
abnormal morphology; sclerotic bone lesions
• Rosai-Dorfman (sinus histiocytosis with massive
lymphadenopathy)
– Non-malignant disorder
– Massive lymph nodes or solitary masses in tissues
(sinuses, mucosa)
– Treatment is observation versus other (MTX, IFN)
based on symtpoms
– Characteristic emperipolesis (lymphocytes and other
cells passing through/resting in histiocyte cytoplasm)