Lecture 3 Neutrophil Toxic Changes & Reactive Lymphocytes Flashcards
What cells are most commonly seen in a neutrophil left shift?
Bands general predominate and may be the only cell line involved.
A smaller number of myelocytes and metamyelocytes may also be present.
What causes toxic granules to appear in bands and neutrophils?
Toxic granules appear in bands and neutrophils in response to foreign organisms or antigens when a person has a bacterial infection, drug poisoning or burns.
What can make it look like the neutrophil has toxic granules but is actually an artifact? What helps you distinguish real from artifact?
Over-staining is an artifact that can make it look like neutrophils have toxic granules. In this case ALL neutrophils appear to have toxic granules so you then can know that is not real.
Also real toxic granules can be clustered in some areas of the cytoplasm but over-staining of cells does not result in that and also the granules seen in Alder-Reilly anomaly.
What causes neutrophil cytoplasmic vacuolation?
Neutrophil cytoplasmic vacuolation is caused by phagocytosis.
What type of bodies are seen in neutrophils undergoing toxic changes? Describe them & what they are made of?
Dohle bodies.
- Round or elongated bodies, pale blue or gray-blue, 1-5 um in size. Often near periphery.
- Made of cytoplasmic inclusions consisting of ribosomal RNA.
What circumstances are dohle bodies seen in neutrophils?
Dohle bodies seen in neutrophils:
1. May reflect sudden storage pool release.
2. Usually present in first 1-3 days of infection then disappear.
3. Bacterial infection, poisoning, burns, chemotherapy, May-Hegglin anomaly, pregnancy.
How do toxic changes develop in neutrophils?
While the post-mitotic myeloid precursor in the bone marrow is maturing its expression and density receptor is altered and hence:
a) Cell more readily exits marrow –> Left Shift
b) More spontaneous membrane internalization –> Toxic Vacuolization
c) Maturation cut short; persistence of synthetic machinery in cell –> Dohle bodies.
d) Enhanced lysosomal enzyme production and packaging results in large granules –> toxic granulation.
What is a reactive-plasmacytoid?
Reactive-plasmacytoid:
a) Benign lymphocyte response to some stimulus.
b) Vary in appearance, different stages in lymphocyte transformation
When are reactive-plasmacytoids considered diagnostic and need to be reported?
Reactive-plasmacytoids are normal in small numbers.
Large numbers considered diagnostic and should be reported.
Describe the reactive lymphocyte morphology?
Reactive lymphocyte morphology
- wide variety of lympochyte morphology with increased cytoplasm, basophilia, lobulated or oval nuclei with clumps of chromatin.
What causes infectious monocucleosis?
Infectious mononucleosis is caused by the Epstein Barr virus (EBV).
Virus found in body fluids especially saliva (“kissing disease”)
Incubation period 3-7 weeks. Highest incidence in young adults 15-24 years.
What are the symptoms of infectious mononucleosis?
Symptoms of infectious mononucleosis:
- Sore throat
- Fever, chills
- Lymphadenopathy
- Possible splenomegaly (often only detected by ultrasound)
- Fatigue
- Malaise
- Loss of appetite & nausea
Recovery normally within 4 weeks but fatigue may last for months.
What are the laboratory findings for infectious monocucleosis?
Infectious Mononucleosis lab findings:
- May be mild normocytic, normochromic anemia
- WBC Count usually elevated
- Differential show relative neutrophenia w/ relative and absolute lymphocytosis.
- wide variety of lympochyte morphology with increased cytoplasm, basophilia, lobulated or oval nuclei with clumps of chromatin.
Morphology reflects T cell response to infection of B cells by EBV.
What conditions are reactive lymphocytes seen in?
Reactive lymphocytes are seen in viral infections such as:
1. Infectious Mononucleosis
2. Cytomegalovirus
3. Viral influenza
4. Hepatitis A and B
Note: Infectious Mononucleosis most notable cause of reactive lymphocytes.
What type of testing can be done to help diagnose Infectious Mononucleosis?
Testing for Infectious Mononucleosis (IM) includes:
1. Rapid latex screening test for detection of heterophile antibody with sheep or horse red cells
2. Definitive testing for IM is detection of IgM or IgG antibodies.
Note: Heterophile antibodies are Abs which cross react with Ags from other species.
