Equine Severe Combined Immune Deficiency - Revision history

HarrietL: /* Diagnosis */

2017-04-27T18:03:50Z

Diagnosis

Kitnmre at 22:45, 15 June 2016

2016-06-15T22:45:43Z

Bara at 17:45, 31 July 2012

2012-07-31T17:45:06Z

Bara at 22:14, 22 August 2011

2011-08-22T22:14:35Z

Bara: /* References */

2011-01-07T13:34:36Z

References

Suzannah.stacey: /* Diagnosis */

2010-10-29T15:52:32Z

Diagnosis

Bara: Text replace - "Category:To Do - SophieIgnarski" to ""

2010-10-09T23:28:43Z

Text replace - "Category:To Do - SophieIgnarski" to ""

Bara at 21:51, 7 October 2010

2010-10-07T21:51:19Z

Signarski at 17:33, 5 September 2010

2010-09-05T17:33:18Z

Signarski at 12:28, 25 August 2010

2010-08-25T12:28:40Z

@@ Line 17: / Line 17: @@
 ==Diagnosis==
-Diagnosis may not be straightforward as the clinical signs may resemble those of many other infections occurring in foals. The antemortem diagnosis of SCID is usually based on three criteria; a) a persistent lymphopaenia (occurring over 1-2 weeks) with less than 1000 lymphocytes per ml, b) a lack of serum IgM in foals over four weeks of age and c) lymphoid hypoplasia. Affected foals may also develop [[Regenerative and Non-Regenerative Anaemias|anaemia]] late in the course of the disease.
+Diagnosis may not be straightforward as the clinical signs may resemble those of many other infections occurring in foals. The antemortem diagnosis of SCID is usually based on three criteria; a) a persistent lymphopaenia (occurring over 1-2 weeks) with less than 1000 lymphocytes per microlitre, b) a lack of serum IgM in foals over four weeks of age and c) lymphoid hypoplasia. Affected foals may also develop [[Regenerative and Non-Regenerative Anaemias|anaemia]] late in the course of the disease.
 The '''intradermal phytohemagglutinin (PHA) test''' may be used as a test for immunocompetence and assesses T lymphocyte function. It can be performed in foals of all ages as the test is not affected by maternal antibodies. Intradermal PHA causes a [[Type IV Hypersensitivity|delayed hypersensitivity]] reaction, resulting in a skin swelling. A foal suffering from SCID fails to respond to intradermal PHA.

@@ Line 46: / Line 46: @@
 {{OpenPages}}
 [[Category:Primary Adaptive Immunity Deficiencies]]
 [[Category:Expert Review - Horse]]
 [[Category:Immunological Diseases - Horse]]

@@ Line 1: / Line 1: @@
 Also known as: '''''Equine SCID — ESCID
@@ Line 43: / Line 44: @@
 {{review}}
 [[Category:Primary Adaptive Immunity Deficiencies]]
 [[Category:Expert Review - Horse]]
 [[Category:Immunological Diseases - Horse]]

@@ Line 1: / Line 1: @@
 Also known as: '''''Equine SCID — ESCID
@@ Line 14: / Line 12: @@
 SCID occurs due to a mutation in the allele encoding for DNA-dependent protein kinase (DNA-PK) that is involved in V(D)J lymphocyte recombination. V(D)J recombination is required for antigenic receptor expression on B and T lymphocytes. Without these receptors, differentiation of B and T lymphocytes does not occur and lymphoid tissue fails to develop. The result of this mutation is a severe immunodeficiency.
-==Clinical signs==
+==Clinical Signs==
 Affected foals are clinically normal at birth and usually develop infections at around two to three months of age due to declining maternal antibodies in the colostrum. The most common clinical signs relate to infections of the respiratory tract such as nasal discharge, cough, dyspnoea or increased respiratory sounds. Other clinical signs may reflect further sites of infection including intermittent fever, pneumonia, colic, weight loss and diarrhoea. Infection of the pancreas may result in loss of functional endocrine tissue leading to stunted growth and weight loss.
@@ Line 33: / Line 31: @@
 SCID may be prevented in foals by DNA testing of the mare and stallion and only breeding non-carrier animals.
-==Literature Search==
+{{Learning
-[[File:CABI logo.jpg|left|90px]]
+|flashcards = [[Equine Internal Medicine Q&A 16]]
+|literature search =[http://www.cabdirect.org/search.html?start=0&q=title:(%22Equine+Severe+Combined+Immune+Deficiency%22)+OR+((title:(%22Severe+Combined+Immune+Deficiency%22)++OR+title:(SCID))+AND+od:(horses))+OR+title:(ESCID) Equine Severe Combined Immune Deficiency publications]
+}}
 ==References==
@@ Line 46: / Line 41: @@
 *Swinburne, J., Lockhart, L., Scott, M., Binns, M. M. (1999) '''Estimation of the prevalence of Severe Combined Immunodeficiency Disease in UK Arab horses as determined by a DNA-based test''' ''The Veterinary Record 145 22-23''
 [[Category:Primary Adaptive Immunity Deficiencies]]
+[[Category:Expert Review - Horse]]
 [[Category:Immunological Diseases - Horse]]

← Older revision		Revision as of 13:34, 7 January 2011
Line 49:		Line 49:

	[[Category:Expert Review]]		[[Category:Expert Review]]
−	[[Category:Horse]]	+	[[Category:Immunological Diseases - Horse]]

@@ Line 47: / Line 47: @@
 [[Category:Primary Adaptive Immunity Deficiencies]]
-[[Category:To Do - SophieIgnarski]]
 [[Category:Expert Review]]
 [[Category:Horse]]

@@ Line 1: / Line 1: @@
-((Equine SCID)
+{{review}}
-{{unfinished}}
+Also known as: '''''Equine SCID — ESCID
-==Description==
+==Introduction==
 Severe combined immunodeficiency disease (SCID) of horses is an autosomal, recessive hereditary disease occurring in 2-3% of Arab or part-bred Arab foals. About 16-25% of Arabian horses are carriers of the disease and are phenotypically normal but pass on the defective gene to 50% of their offspring. Affected foals result from 25% of matings of two carrier horses.
-SCID is characterised by a complete absence of functional B and T lymphocytes and affected (homozygous) foals fail to produce antigen-specific immune responses. The disease results in the absence of a functional immune system and affected foals are unable to resist or recover from infections. The most common opportunistic infections in affected foals are pneumonia caused by viral (Adenovirus), bacterial (Rhodococcus equi), fungal (Pneumocystis carinii) or protozoal (Cryptosporidium) organisms.
 ==Signalment==
@@ Line 14: / Line 15: @@
 ==Clinical signs==
-Affected foals are clinically normal at birth and usually develop infections at around two to three months of age due to declining maternal antibodies in the colostrum. The most common clinical signs relate to infections of the respiratory tract such as nasal discharge, cough, dyspnoea or increased respiratory sounds. Other clinical signs may relect further sites of infection including intermittent fever, pneumonia, colic, weight loss and diarrhoea. Infection of the pancreas may result in loss of functional endocrine tissue leading to stunted growth and weight loss.
+Affected foals are clinically normal at birth and usually develop infections at around two to three months of age due to declining maternal antibodies in the colostrum. The most common clinical signs relate to infections of the respiratory tract such as nasal discharge, cough, dyspnoea or increased respiratory sounds. Other clinical signs may reflect further sites of infection including intermittent fever, pneumonia, colic, weight loss and diarrhoea. Infection of the pancreas may result in loss of functional endocrine tissue leading to stunted growth and weight loss.
 ==Diagnosis==
-Diagnosis may not be straightforward as the clinical signs may resemble those of many other infections occurring in foals. The antemortem diagnosis of SCID is usually based on three criteria; a) a persistent lymphopaenia (occurring over 1-2 weeks) with less than 1000 lymphocytes per ml, b) a lack of serum IgM in foals over four weeks of age and c) lymphoid hypoplasia. Affected foals may also develop anaemia late in the course of the disease.
+Diagnosis may not be straightforward as the clinical signs may resemble those of many other infections occurring in foals. The antemortem diagnosis of SCID is usually based on three criteria; a) a persistent lymphopaenia (occurring over 1-2 weeks) with less than 1000 lymphocytes per ml, b) a lack of serum IgM in foals over four weeks of age and c) lymphoid hypoplasia. Affected foals may also develop [[Anaemia - Introduction|anaemia]] late in the course of the disease.
-The intradermal phytohemagglutinin (PHA) test may be used as a test for immunocompetence and assesses T lymphocyte function. It can be performed in foals of all ages as the test is not affected by maternal antibodies. Intradermal PHA causes a delayed hypersensitivity reaction, resulting in a skin swelling. A foal suffering from SCID fails to respond to intradermal PHA.
+The '''intradermal phytohemagglutinin (PHA) test''' may be used as a test for immunocompetence and assesses T lymphocyte function. It can be performed in foals of all ages as the test is not affected by maternal antibodies. Intradermal PHA causes a [[Type IV Hypersensitivity|delayed hypersensitivity]] reaction, resulting in a skin swelling. A foal suffering from SCID fails to respond to intradermal PHA.
-In order to obtain a definitive diagnosis, blood or cheek swabs may be submitted for PCR to identify the mutant allele of the DNA-PK gene The test also identifies carriers of the disease which is important for screening prior to breeding. Additionally, post mortem findings of a small thymus and/or absent lymph nodes combined with the presence of opportunistic infections support a diagnosis of SCID. Histologically, lymph node follicles and germinal centres are absent with severe cellular hypoplasia of the thymus and lymph nodes.
+In order to obtain a definitive diagnosis, blood or cheek swabs may be submitted for '''PCR to identify the mutant allele of the DNA-PK gene'''. The test also identifies carriers of the disease which is important for screening prior to breeding. Additionally, post mortem findings of a small thymus and/or absent lymph nodes combined with the presence of opportunistic infections support a diagnosis of SCID. Histologically, lymph node follicles and germinal centres are absent with severe cellular hypoplasia of the thymus and lymph nodes.
 ==Treatment==
@@ Line 31: / Line 32: @@
 ==Prevention==
 SCID may be prevented in foals by DNA testing of the mare and stallion and only breeding non-carrier animals.
 ==References==
@@ Line 39: / Line 48: @@
 [[Category:Primary Adaptive Immunity Deficiencies]]
 [[Category:To Do - SophieIgnarski]]
-[[Category:To Do - Review]]
+[[Category:Expert Review]]
 [[Category:Horse]]