Eosinophilia
Churg-Strauss Syndrome
Necrotizing granulomatous inflammation with eosinophils involving multiple organs, especially lungs and heart usually in px with hx of asthma, airway hypersensitivity
nervous manifestions of eosinophilia
cerebellar dysfunction / ataxia seizures, stroke meningitis, encephalopathy mononeuritis multiplex paraparesis all mediated by neurotoxin
What causes hypereosinophilia? (3)
eosinophilic leukemia idiopathic HES (hypereosinophilic syndrome) Loeffler syndrome
pulmonary manifestions of eosinophilia
infiltrates, fibrosis, effusion, nodule
4 M/C solid tumors associated with eosinophilia?
lung, cervical, GI, carcinomatosis
Worldwide, M/C cause of eosinophilia is
parasitic infection
Mechanisms (2) by which eosinophils kill?
phagocytosis degranulation onto surface of large organisms
tx of eosinophilia?
prednisone hydroxyurea if prednisone cannot be titrated down
FIP1L1-PDGFRa fusion gene
recurrent molecular abnormality in patients with eosinophilia-associated myeloproliferative neoplasms aka CHIC2 deletion
eye manifestions of eosinophilia
retinal vasculitis, microthrombi
hypereosinophilia most affects what organ?
the heart
heart with eosinophilia often appears
thick with densely fibrotic ventricles
Eosinophil cationic protein
toxic to parasites, neurotoxin
high tryptase suggests
very active mast cells
What is in eosinophil granules?
- Major basic protein - cationic proteins - peroxidases - lipid mediators (PAF, Leukotriene C4) - neurotoxin - cytokines
common parasites leading to eosinophilia
- Strongyloides - Protozoa - Metazoa (nematodes, cestodes, trematodes, scabies)
cardiac manifestions of eosinophilia
- constrictive pericarditis - myocarditis - valve regurg (MR, TR)
Absolute eosinophil count should be less than
0.5 x 10^9
DRESS syndrome
Drugs, Rash, Eosinophilia, Swelling, Serum ALT
Which cytokines stimulate eosinophils?
IL-5 most specific IL-1, IL-3, GM-CSF
tx of eosinophilia with FIP1L1-PDGFRa fusion gene
Imatinib steroids
What do eosinophils use to kill parasites?
Major Basic Protein
Loeffler syndrome
A restrictive cardiomyopathy caused by an endomyocardial fibrosis with an eosinophilic infiltrate and eosinophilia
main role of IL-4 in allergic response is
driving IgE production
GI manifestions of eosinophilia
ascites, diarrhea, gastritis, colitis, pancreatitis, hepatitis, hepatic nodules
M/C cause of eosinophilia in industrialized countries?
atopy
Normal eosinophil count
0.5-4%
widespread organ dysfunction is seen in hypereosinophilia when eosinophil count is >
20k-100k / uL
clinically significant eosinophilia is defined as
> 1000-1500 / uL and sustained
eosinophilic esophagitis is defined by
> 20 eosinophils per HPF
hypereosinophilia is defined as
> 2000-5000 / uL this is usually associated with tissue damage d/t MBP release
skin manifestions of eosinophilia
angioedema, urticaria, paulonodular lesions, mucosal ulcerations
Eosinophilia mnemonic
PACCC MAN P - parasites A - asthma C - Churg Strauss C - chronic adrenal insufficiency C - collagen vascular disease M - myeloproliferative disorders A - allergies N - neoplasia (HL, other lymphomas) + dermatitis, drug reactions
Major basic protein (MBP)
Protein that is toxic to helminths - protein secreted by eosinophils.
Main cell that activates eosinophils?
Th2 (via IL-5) minor contribution from mast cells, basophils (in allergies)
After IDing FIP1L1-PDGFRa fusion gene, the next step is
bone marrow biopsy
AML with eosinophilia
broad and bright eosinophils in bone marrow inversion 16
primary function of eosinophils
destruction of parasitic infection
MSK manifestions of eosinophilia
destructive arthritis, effusions, arthralgias, myalgias
