Leukon #3: Congenital/Hereditary and Infectious Diseases Flashcards
1
Q
Pelger-Huet Anomaly
A
Description:
- Prominent hyposegmentation
- Mature chromatin (v. band usually has IMMATURE chromatin)
- Lack of mature segs
- May be involved any stage of maturation
- Involves any granulocyte
Significance:
- Hereditary condition, NOT inflammatory alone
- -Concern of describing erroneous left shifts (NOT actually a left shift)
- In inflammation, left shift is overestimated
Considerations:
- Species: dogs, cats, rabbits, horses, skunks
- -Esp. Australian shepherd, coonhound, and foxhound
- Humans: defect in the Lamin B receptor gene
- -Heterozygous animals: no clinical signs
- -Homozygous animals: skeleton deformities, but die in utero
- Look at relatives and past CBCs
- Look for other evidence of inflammation (fever, anorexia, etc.)
- If concurrent inflammation, look at sequential CBCs (Is inflammation resolving?)
2
Q
Neutrophil Pseudo Pelger-Huet Anomaly
A
Description:
- Morph similar to Pelger-Huet
- +/- helpful to find toxic, inflammatory changes
Significance:
- An acquired, inflammatory/dysplastic anomaly
- Should resolve with inflammation
Considerations:
- Clinical/lab support for inflammation
- Species/breed involved
- Sequential samples
- Other granulocytes are not affected
3
Q
Lysosomal Storage Diseases
A
Description:
- Enzyme deficiency in lysosomes
- -Accumulation of undigested substances
- -Clear vacuoles or granular material in lysosomes
- -Variable leukocytes affected
- -Ex: Mucopolysaccharidosis, gangliosidosis, etc.
Significance:
- Cell function affected
- Developmental, musculoskeletal, and nervous system diseases are common
Considerations:
- Rule out other causes of vacuoles/granules
- -Storage, aging*, toxicity, EDTA artifact (vacuoles)
- Associated clinical picture
- -Ex: Ingestion of locoweed
- Breed predispositions
- Diagnosis:
- -Genetic testing
- -Measure metabolites (esp. urine)
4
Q
Chediak-Higashi Syndrome
A
Description:
- Lysosomal fusion disease (large lysosomal inclusions)
- -Lysosome-lysosome
- -Lysosome-secondary granules
- Esp. neutrophils, platelets, melanocytes
- Mutation on gene LYST (lysosomal trafficking)
- Inclusions can be challenging to differentiate from other differentials
Significance:
- Associated abnormal functions
- -Infections (chemotaxis) and failure to form phagolysosomes
- -Bleeding (platelets)
- -Developmental anomalies (facial, other)
- -Diluted coat color (melanocytes)
Considerations:
- Abnormal cytoplasmic granules
- Autosomal recessive (carriers)
- Signalment:
- -Smoke-blue Persian cats
- -Fawn colored Hereford cattle
- -Beige colored mice
- -Aleutian mink
- -Silver blue Artic foxes
- -Albino killer whales
5
Q
Birman Cat Neutrophil Abnormality
A
Description:
-Prominent fine pink granules
Significance:
-Granules are functionally normal
Considerations:
- Breed-specific morphologic anomaly
- Do not confuse with toxic or pathologic hereditary granulation
- Appear rarely in other healthy cats (maybe Siamese)
6
Q
Bacteria
A
Description:
-Bacteria present on blood smear
Significance:
- Bacteremia
- Sample contamination and handling (in vitro)
Considerations:
- Is it a freshly made blood smear?
- Intracellular v. extracellular bacteria
- Are there CBC changes? (Severe inflammation)
- Are the clinical findings consistent?
7
Q
Bacteria - Mycobacteria spp.
A
Description:
- Clear, non-staining, rod-shaped bacteria
- Within monocytes, possibly neutrophils
- Higher order bacteria
Significance:
-Rare in blood
Considerations:
- Negative staining
- -Next step is to do acid-fast staining
8
Q
Bacteria - Anaplasmataceae
A
General Information:
- Family = Anaplasmataceae
- -Genera = Ehrlichia and Anaplasma
- Tick transmission
- May observe on blood smears (not sensitive)
- -Usually early in disease
- -0.5 um coccobacillus
- -Infects cell –> replication –> morula (cluster)
- Organisms often have host and cell preferences
- Obligate intracellular bacteria
- -Infects and kills leukocytes and platelets
- Key organisms of veterinary concern:
- -Ehrlichia canis
- -Ehrlichia ewingii
- -Anaplasma phagocytophilum (prev. E. equi)
- -Anaplasma platys
9
Q
Bacteria - Ehrlichia canis
A
- Infects mononuclear cells (monocytes, lymphocytes)
- Canine monocytic ehrlichiosis
- 4Dx SNAP test
10
Q
Bacteria - Ehrlichia ewingii
A
- Infects neutrophils and eosinophils (rarely)
- Mostly in dogs, deer, and humans (rarely)
- Canine granulocytic ehrlichiosis
- 4Dx SNAP test
11
Q
Bacteria - Anaplasma phagocytophilum
A
- Infects neutrophils and eosinophils (rarely)
- Dogs, horses, cattle, sheep, goats, humans
- -Most common in horses
- Human granulocytic anaplasmosis
- 4Dx SNAP test
12
Q
Bacteria - Anaplasma platys
A
- Infects platelets (looks like granules in platelets, difficult to see)
- Dogs
- 4Dx SNAP test
13
Q
Protozoa - Hepatozoon spp.
A
Description:
- Protozoa
- Large (4x9 um) oval gametes
- Found in monocytes and neutrophils
Significance:
- H. canis: no or mild symptoms, high #s in blood
- H. americanum: severe disease, low #s in blood, increased neutrophils
Considerations:
- H. canis not in US (South America, Europe, Asia, Africa)
- H. americanum (Southern US)
- Duel infections (ex: with Anaplasma)
14
Q
Protozoa - Leishmania spp.
A
Description:
- 2-4 um amastigote in monocytes (macrophages in tissues)
- Red nucleus, bar-shaped kinetoplast (irregular, jagged)
- Looks like little sailboats
Significance:
- Chronic MPS and lymphoid involvement
- Skin –> marrow, lymphoid tissues
Considerations:
- Transmission: sand flies
- Mediterranean travel
- USA endemic areas: OK and OH
15
Q
Fungal - Histoplasma capsulatum
A
Description
-2-4 um oval yeasts, clear wall, nuclear content
Significance
- GI, liver, hematopoietic tissues common
- Chronic diarrhea and wasting
- Often pyogranulomatous inflammation (in tissues)
- -Walled off, organized lesion
- -Immuno cells aid in recruitment of more macrophages and form multinucleated giant cells
- -“Pyo” means it involves neutrophils
Considerations
- Bird and bat droppings common source
- Deserted hen houses
