Enteritis, Lymphocytic - Plasmacytic

Signalment

• Often affects older animals but kittens of 16 weeks old and puppies of 20 weeks old have been reported.
• Basenjis have been reported to suffer from a severe form known as immunoproliferative disease.

Description

Lymphocytic - plasmacytic enteritis (LPE) is the most common form of Inflammatory Bowel Disease (IBD). As its name suggests, the predominant cell type in the intestinal mucosa is lymphocytes and plasma cells. Enteric parasites, bacteria in dogs and Toxoplasma in cats have been reported to associated with LPE. This disorder in cats have also been shown to associate with concurrent disease of the pancreas and liver such as pancreatitis, cholangitis and hepatic lipidosis. LPE is believed to be caused by an abnormal mucosal associated lymphoid tissue (MALT) response to luminal bacterial, dietary or self-antigens.

The small intestines are affected to a variable degree of severity. It has also been known to affect other parts of the gastrointestinal tract such as the stomach and the colon. In severely affected animals, this will result in a protein-losing enteropathy (PLE).

Diagnosis

Clinical Signs

Most common:

• small intestinal diarrhoea
• weight loss
• protein - losing enteropathy in severe cases
• chronic vomiting (more common presentation in cats compared to the other signs)
• thickened small intestinal loops and mesenteric lymphadenopathy may be detected on physical examination in cats

Others:

• appetite changes
• excessive borborygmi
• abdominal discomfort
• ascites or subcutaneous oedema if severe PLE resulting in hypoproteinaemia
• concurrent systemic immune-mediated response and thromboembolism (rare)

Laboratory Tests

Haematology

• Panhypoproteinaemia (non-specific)

Biochemistry

• Leucocytosis (non-specific)

Other Tests

• Serum trypsin-like immunoassay (TLI) to rule out exocrine pancreatic insufficiency (EPI).
• Faecal analysis to rule out endoparasite and pathogenic bacteria.

Diagnostic Imaging

• Abdominal radiography is unremarkable, but it can be used to eliminate other differential diagnosis.
• Abdominal ultrasonography may reveal thickened intestinal walls, mesenteric lymphadenopathy or abdominal effusion.

Histopathology

Intestinal biopsy is needed for a definitive diagnosis once all the other differential diagnoses have been eliminated.

Refer to Lymphocytic - Plasmacytic Enteritis for pathology.

Treatment

Refer to IBD

Prognosis

Refer to IBD

References

• Ettinger, S.J. and Feldman, E. C. (2000) Textbook of Veterinary Internal Medicine Diseases of the Dog and Cat Volume 2 (Fifth Edition) W.B. Saunders Company.
• Hall, E.J, Simpson, J.W. and Williams, D.A. (2005) BSAVA Manual of Canine and Feline Gastroenterology (2nd Edition) BSAVA
• Nelson, R.W. and Couto, C.G. (2009) Small Animal Internal Medicine (Fourth Edition) Mosby Elsevier.

Lymphocytic - Plasmacytic Enteritis

Pathology

• Hypersensitivity reaction results in increased GIT permeablility and recruitment of inflammatory cells.
• Histologically:
  • Mucosal epithelial-glandular alterations.
  • Variably increased mucosal infiltrate of lymphocytes and plasma cells.
    • In these dogs there is an increase in the number of IgA and IgG containing cells and CD3+ T-cells.
      • Can develop into lymphoma.
    • Changes in the relative and absolute numbers of plasma cells and lymphocytes have been associated with IBD in humans.