Difference between revisions of "Neutrophilia"

From WikiVet English
Jump to navigation Jump to search
 
(17 intermediate revisions by 4 users not shown)
Line 1: Line 1:
{{unfinished}}
+
==Description==
==Introduction==
+
Neutrophilia refers to an increase in the number of [[Neutrophil|neutrophils]] in the blood. In many cases, neutrophilia is accompanied by the release of substantial numbers of immature neutrophils into the blood stream from the bone marrow. The nuclei of these '''Band cells''' are not segmented and they appear to be elongated bent tubes in the cytoplasm. The presence of band cells in the blood indicates that there is an intense need for neutrophils to maintain normal blood levels as they are lost in a purulent process somewhere in the body. When the percentage of the total neutrophil population that is contributed by these immature forms is high, the neutrophilia is described as having a '''regenerative left shift'''.
* Neutrophilia is an increase in the number of [[Neutrophil|neutrophils]] in the blood.
+
 
* Neutrophilia is often accompanied by the release of substantial numbers of immature neutrophils into the blood stream.  
+
==Neutrophilia: degenerative right shift==
** Do not have segmented nuclei.
+
Very severe diseases that deplete the neutrophils may also exhaust the reserve supply of these cells in the bone marrow.  In such situations, there is a neutropenia without band cells in the circulation and degenerate neutrophils are seen - this is known as a degenerative right shift. Degenerate neutrophils have a highly segmented nucleus, often in the shape of the 'Victoria Cross'. Some severe localised infections (including pyometras) may cause a neutrophilia of much greater magnitude than is usually observed.  This so-called '''leukaemoid response''' may precede a right shift.
*** Nuclei appear as elongated bent tubes in the cytoplasm .
 
** Are called "band cells".
 
** The presence of band cells in the blood represent an intense need for neutrophils due to them being lost in the purulence.  
 
** When the percentage of these immature forms is high, it is referred to as a "left shift".
 
  
 
==Causes of Neutrophilia==
 
==Causes of Neutrophilia==
Purulent Foci:
+
There are numerous causes of neutrophilia and it is the most common and least specific abnormal finding when blood samples undergo haematological analysisCommon causes include:
* Purulent foci and abscesses in the body produce substantial neutrophilia.
 
* For example, neutrophilia is produced in
 
** Pyometra
 
*** Pus in the uterus.
 
** Empyema
 
*** Pus in a body cavity
 
**** E.g. [[:Category:Nocardia species|''Nocardia'']] infection in the thoracic cavity.
 
*  In very severe infections, such at those above, the neutrophil  granules  become more apparent in the cytoplasm and stain bluish, and  some  cytoplasmic vacuolation may be seen.
 
** These 'toxic' neutrophils have decreased bactericidal capability and do not respond as quickly to chemotactic stimuli.
 
 
 
Bacteria
 
* Bacteria,particularly pyogenic forms, cause neutrophilia.
 
  
Necrosis
+
*'''Purulent foci''' and '''abscesses''' in the body can produce a substantial neutrophilia. Examples include pyometra, severe pyoderma and empyema (purulent inflammation of a body cavity).  In severe cases of purulent inflammation, neutrophils may appear '''toxic''' when observed on cytological slides.  These toxic cells have evident, blue-staining cytoplasmic granules and some cytoplasmic vacuolation.  These cells have decreased bactericidal capability and do not respond as quickly to chemotactic stimuli. In contrast, abscesses that have become walled off may fail to induce the expected neutrophilia.
* Necrosis of any kind will result in neutrophilia.
 
** Necrosis from burns, malignancies and infection are particularly involved.
 
  
Fungi
+
*'''Bacterial infection''' may result in neutrophilia as neutrophils are the major type of leucocyte that act to control this type of pathogen.  Some bacteria, particularly Gram positive species, are particularly pyogenic due to their ability to resist intracellular killing by neutrophils.
* For example, [[Aspergillus spp.|aspergillosis]].
 
  
Viruses
+
*'''Necrosis''' of any tissue will result in neutrophilia.  Common causes of tissue necrosis include burns, malignancies and infections.
* Neutrophils may be present, but are not the main component of inflammaory cells.
 
* Examples:
 
** [[Paramyxoviridae#Canine Distemper Virus (CDV)|Canine Distemper]]
 
** [[Herpesviridae|Equine Herpes Rhinotracheitis]]
 
** [[Herpesviridae#Bovine herpesvirus -1|Infectious Bovine Rhinotracheitis]]
 
  
Parasites
+
*'''Fungal infection''' with, for example ''[[Aspergillus spp.]]''.
* Neutrophils may be present, but are not the main componentof inflammatory cells.
 
* Examples
 
** [[Trematodes|''Fasciola hepatica'']]
 
** [[Toxoplasma|''Toxoplasma gondii'']]
 
  
Immune-Mediated Conditions
+
*'''Viral infection''' may cause a neutrophilia but neutrophils are often not the major type of inflammatory cell responding to the infection and they may be reacting to the threat of secondary bacterial infections rather than the primary viral pathogen. Examples include [[Paramyxoviridae#Canine Distemper Virus (CDV)|canine distemper]], [[Equine Herpesvirus 1|equine rhinotracheitis virus]] (EHV-1) and [[Infectious Bovine Rhinotracheitis|infectious bovine rhinotracheitis]] (IBR or BHV-1).
* Neutrophils may be present, but are not the main component of inflammatory cells.
 
* Examples:
 
** Rheumatoid arthritis
 
** Systemic Lupus Erythematosus
 
** Autoimmune Haemolytic Anaemia
 
  
Other Factors
+
*'''Parasitic infection''' may cause a neutrophilia but neutrophils are often not the major type of inflammatory cell responding to the infection and [[Eosinophilia|eosinophilia]] is more likely. Examples include [[Fasciolosis|fasciolosis]] and [[Toxoplasmosis - Cat and Dog|toxoplasmosis]].
* Other factors which will produce a neutrophilia are:
 
** Excitement, fear, and strenuous exercise in young animals.
 
** Corticosteroids; either :
 
*** Released endogenously in pain or thermal stress, or
 
*** Exogenous therapeutic administration.
 
**** Neutrophilia oocures 4-8 hours post administration of the corticosteroid drug.
 
  
 +
*'''Immune-mediated disease''' frequently causes a neutrophilia, often with a concurrent [[Monocytosis|monocytosis]].  Examples include [[Rheumatoid Arthritis|rheumatoid arthritis]], [[Systemic Lupus Erythematosus|systemic lupus erythematosus]] and [[Immune Mediated Haemolytic Anaemia|immune-mediated haemolytic anaemia]] (IMHA).
  
 +
==Miscellaneous causes of neutrophilia==
 +
'''Miscellaneous factors''' that can cause neutrophilia include:
 +
*Excitement, fear and strenuous exercise in young animals.
 +
*Corticosteroids as part of a [[Stress Leucogram|stress leucogram]] with concurrent [[Monocytosis|monocytosis]], [[Eosinopenia|eosinopenia]] and [[Lymphopenia|lymphopenia]].  The corticosteroids may be endogenous (with pain, stress or [[Hyperadrenocorticism|hyperadrenocorticism]]) or exogenous with medical therapy for a variety of other diseases.
 +
*Neutrophilia can occur in response to any of the causes of [[Regenerative and Non-Regenerative Anaemias|anaemia]].
  
[[Category:Haematology Changes]][[Category:To Do - James]]
+
[[Category:Haematology Changes]]

Latest revision as of 16:15, 17 February 2014

Description

Neutrophilia refers to an increase in the number of neutrophils in the blood. In many cases, neutrophilia is accompanied by the release of substantial numbers of immature neutrophils into the blood stream from the bone marrow. The nuclei of these Band cells are not segmented and they appear to be elongated bent tubes in the cytoplasm. The presence of band cells in the blood indicates that there is an intense need for neutrophils to maintain normal blood levels as they are lost in a purulent process somewhere in the body. When the percentage of the total neutrophil population that is contributed by these immature forms is high, the neutrophilia is described as having a regenerative left shift.

Neutrophilia: degenerative right shift

Very severe diseases that deplete the neutrophils may also exhaust the reserve supply of these cells in the bone marrow. In such situations, there is a neutropenia without band cells in the circulation and degenerate neutrophils are seen - this is known as a degenerative right shift. Degenerate neutrophils have a highly segmented nucleus, often in the shape of the 'Victoria Cross'. Some severe localised infections (including pyometras) may cause a neutrophilia of much greater magnitude than is usually observed. This so-called leukaemoid response may precede a right shift.

Causes of Neutrophilia

There are numerous causes of neutrophilia and it is the most common and least specific abnormal finding when blood samples undergo haematological analysis. Common causes include:

  • Purulent foci and abscesses in the body can produce a substantial neutrophilia. Examples include pyometra, severe pyoderma and empyema (purulent inflammation of a body cavity). In severe cases of purulent inflammation, neutrophils may appear toxic when observed on cytological slides. These toxic cells have evident, blue-staining cytoplasmic granules and some cytoplasmic vacuolation. These cells have decreased bactericidal capability and do not respond as quickly to chemotactic stimuli. In contrast, abscesses that have become walled off may fail to induce the expected neutrophilia.
  • Bacterial infection may result in neutrophilia as neutrophils are the major type of leucocyte that act to control this type of pathogen. Some bacteria, particularly Gram positive species, are particularly pyogenic due to their ability to resist intracellular killing by neutrophils.
  • Necrosis of any tissue will result in neutrophilia. Common causes of tissue necrosis include burns, malignancies and infections.
  • Parasitic infection may cause a neutrophilia but neutrophils are often not the major type of inflammatory cell responding to the infection and eosinophilia is more likely. Examples include fasciolosis and toxoplasmosis.

Miscellaneous causes of neutrophilia

Miscellaneous factors that can cause neutrophilia include: