6. WBC and inflammation Flashcards
Causes of infection
Parasitic, bacterial (septic), rickettsial, fungal, viral (infectious agent!!)
Causes of Inflammation
- infection
- endotoxin mediated
- sterile necrosis (i.e. pancreatitis, tumour, trauma),
- chemical (injections, toxins, acids, alkalines),
- immune mediated (SLE)
Laboratory examinations of inflammatory processes
- Haematology (qualitative and quantitative=complete blood count, CBC)
- Erythrocyte sedimentation rate (ESR)
- Cytology
- Serum biochemistry: routine biochemical parameters (substrates, enzymes), acute phase proteins
- Microbiology
- Parasitology
- Immunology (ELISA, RIA etc. methods)
- Molecular biology
- Morphological pathology, histology
Samples used for WBC counting
- Anticoagulated blood. Na2EDTA, K2EDTA, or Nacitrate.
- In case of bird, reptile, fish samples: Li-, or Ca heparin
Ways to count WBC´s
- WBC counting by using Bürker-chamber
- WBC counting by hematology analyser
- Automatic cell counters can count WBC
- Laser cell counters
Qualitative blood count: staining methods
- May-Grünwald
- Romanowsky
- Giemsa
- Diff-Quick etc.
Qualitative blood count:
- Type of power used?
- Number of cells counted?
- Differentiate according to?
- First low power should be used, then high 1000x magnification can be provided by using immersion lens (and immersion oil).
- 50-200 cells
- Differentiate according to the morphological pattern of the cell types
Qualitative blood count: different cell types?
- Neutrophil granulocyte cell line: myeloblast, promyelocyte, myelocyte, metamyelocyte (jugend), band forms (stab), segmented forms
- Lymphoid cell line: lymphoblast, small lymphocyte, middle sized lymphocyte, reactive T lymphocyte
- Eosinophil cell line:, young form (band nucleated) eosinophil granulocyte, segmented form eosinophil granulocyte
- Basophil cell line: young form (band nucleated) basophil granulocyte, segmented form basophil granulocyte
- Monocyte cell line: monocytic (young) form, reactive macrophage form
Calculation of relative % of the cell type
relative % of the cell type = (relative % of the cell type / 100) x WBC count (x10^9/l)
Absolute WBC numbers in % and Absolute No x10^9/l
- Neutrophil granulocyte
b) metamyelocyte (jugend)
c) segmented form - Lymphocyte
- Eosinophil granulocyte
- Basophil granulocyte
- Monocyte
- Neutrophil granulocyte - - 3-11,8
b) metamyelocyte (jugend) 0-3 - 0-0,3
c) segmented form 60-77 - 3-11,5 - Lymphocyte 12-30 - 1-4,8
- Eosinophil granulocyte 2-10 - 0,1-1,35
- Basophil granulocyte < 1 - -
- Monocyte 1-5 - 0,1-0,5
White blood cell (WBC) pools in the body:
- In the bone marrow
- In the blood vessels
- In the circulating blood
- In the tissues of different organs
- In the bone marrow: mitotic- (very young cells, proliferating), maturation- (under differentiation) and storage- pools (mature, differentiated WBCs).
- In the blood vessels: marginal pool, cells attached to the inner surface of the blood vessels (mostly neutrophil granulocytes), cells can be mobilised very quickly from this pool!
- In the circulating blood: we take our sample from here, the circulating pool.
- In the tissues of different organs: tissue pool.
How does physiological leukocytosis develop?
Due to acute or chronic stress (epinephrine, norepinephrine, glucocorticoids).
The effects of catecholamines during physiological leukocytosis?
Visible within seconds (neutrophilia, lymphocytosis- as cells are mobilised from the marginal pool /cells attached to the vessels, lymphatic vessels, and organs/).
The effects of ACTH, or glucocorticoids during physiological leukocytosis?
Detectable after hours (or in some instances minutes) (neutrophilia, lymphopenia, eosinopenia).
What happens with cats during stress?
Can cause an extreme neutrophilia, as the marginal pool is bigger (two third of the total neutrophilic count) in cats.
Acute inflammation lab. signs
Increase of positive acute phase proteins (APP) in the blood and the decrease of negative acute phase proteins
Neutropenia
- When does neutropenia occur?
- What is the causes?
- What is the effect?
- What important lab. procedure in important due to this?
- During the first period of the inflammatory process, or widespread severe inflammation.
- Caused by the migrating factors (i.e. leukotriens, interleukins etc.) produced by tissue cells, macrophages. 3. Neutrophils are migrating out of the blood vessels to
the site of inflammation, and this can lead to a transient decrease in total WBC count. - Usually do not take blood samples in this early phase of inflam., that is why many people are convinced that inflammation always cause high WBC count
Neutrophilia:
- When does it occur?
- Causes?
- Effect?
- During later phases of inflammation
- Due to the granulocyte colony stimulating factor (G-CSF), or granulocyte macrophage colony stimulating factors GM-CSF produced by the macrophages.
- These factors stimulate WBC prod. in bone marrow, which leads to an increased total WBC count.
How can be observe a Left shift?
- More young WBCs appaear in the circulating blood.
- Young metamyelocytes (jugend), and band (stab) forms are visible in greater proportion and absolute number in the blood smear.
Types of left shift
- Regenerative left shift: Increased WBC count, neutrophilia, and left shift (younger neutrophils).
- Degenerative left shift: Low, or normal WBC, and neutrophil count and left shift (younger forms). It is a sign of poor prognosis, it means that the disease is very serious and needs immediate treatment.
Leukemoid reaction
- Occurance?
- Causes?
- What can it be confused with during blood smear analysis?
- In some cases, when there is a great stimulus for producing neutrophil granulocytes an enormous number (WBC count can be >70x109/l) of neutrophils can be present in the peripheral blood due to increased effects of G-CSF, GM-CSF.
- Big abscesses, endometritis (pyometra) and in case of some neoplastic (but not leukaemia) diseases.
- Chronic myelogenous leukemia.
Toxic neutrophils
- Occurance?
- How can it be observed?
- In very severe inflam. processes the granulocytopoesis can be disturbed.
- When the granule prod. is not physiological, some azurophilic (orange-red) granules can be seen in basophilic cytoplasm. These are “toxic” neutrophils, or we can say that this process is the toxic granulation of neutrophils.
Döhle-bodies:
- Occurance?
- When is it more common?
- Due to toxic effects some angular, basophilic inclusion bodies can be seen in some neutrophil granulocytes. These are the remnants of the endoplasmatic reticulum. 2. Appearance of Döhlebodies is more common in cats.
Chronic inflammation - Right shift: What is it?
Right shift means that many segmented and hypersegmented, old neutrophils (3-4 segments are on one nucleus) are seen in the smear.