Immunoglobulin A (IgA) Deficiency

Patty Khuly

Summary

Immunoglobulin A is one class of a group of immunoglobulin proteins known as antibodies. Different antibody types carry out specific functions. IgA (shorthand for Immunoglobulin A) is a class of antibodies that works to protect the surfaces of the body from the most immediate, superficial kind of invaders. The skin, along with the respiratory passages, digestive tract and exposed parts of the reproductive or urinary system are where most of the body’s IgA are concentrated.

Should the IgA class of antibodies falter, either in function or in numbers, the upshot is a compromised immune system prone to infections (chronic or episodic), allergies and/or other immune-mediated diseases.

When IgA is determined to be deficient in dogs, the condition may be diagnosed as “selective immunoglobulin A deficiency.”

A genetic basis is understood for this rare canine disease. Unfortunately, its mode of inheritance of is unknown.

Symptoms and Identification

Chronic or recurring infections of the skin, airways, stomach and/or intestines, urinary tract, reproductive tract are the most common manifestation of this deficiency. Pustules, itchiness, nasal discharge, coughing and sneezing, diarrhea, abnormal urination or vaginal discharge would be the most common signs.

Affected dogs would also be prone to developing allergies and/or immune-mediated dysfunctions.

Blood samples to measure the level of IgA will be repeatedly low in the case of affected dogs. No other, more specific tests are available to diagnose this condition.

Affected Breeds

The Chinese Shar-pei, Beagle and German Shepherd are all reported as potentially affected breeds.

Treatment

The treatment for this disease is typically undertaken only by way of handling infections secondary to it. Sometimes, Staphylococcal phage lysate and Propionibacterium acne vaccines are used to enhance IgA antibody production. At the very least, this therapy might assist in the treatment of recurrent or chronic skin infections.

Veterinary Cost

Diagnosis can be a frustrating thing to accomplish. Presumably, the insidious nature of this condition means that most cases are never diagnosed at all. However, if diagnosis is achieved, a $300-$400 expense is typically incurred in measuring IgA levels over time.

Otherwise, the cost of this condition is high due to the expense involved in treating chronic or recurrent bacterial infections with often-expensive antibiotics. If Staphylococcal phage lysate and Propionibacterium acnes vaccines are implemented, the expenses may top the low hundreds every month.

Prevention

Affected pets and their first degree relatives are removed from the breeding pool by way of preventing hereditary transmission of this disease.



References

Journal of the American Animal Hospital Association 39:247-250 (2003) © 2003 American Animal Hospital Association Evaluation of Systemic and Secretory IgA Concentrations and Immunohistochemical Stains for IgA-Containing B Cells in Mucosal Tissues of an Irish Setter With Selective IgA Deficiency Carol R. Norris, DVM, Diplomate ACVIM and Laurel J. Gershwin, DVM, PhD

Title: Selective IgA deficiency in German Shepherd dogs. Personal Authors: Magne, M. L. Author Affiliation: Veterinary Teaching Hospital, University of California, Davis, CA 95616, USA. Editors: No editors Document Title: Journal of Veterinary Allergy and Clinical Immunology