Canine atopic dermatitis is a genetically predisposed inflammatory and pruritic skin disease. In humans, increasing evidence suggests atopic dermatitis may be systemic. Experimental studies have shown an increase in CD34+ progenitor cells in humans with atopic dermatitis. The main source of these cells is the bone marrow. CD34+ cells have not yet been confirmed in canine peripheral blood.
In this study, flow cytometry was used to identify and measure the number of CD34+ cells from 13 healthy dogs, 16 dogs with nonallergic inflammatory diseases, and 27 dogs with nonfoodinduced atopic dermatitis. Clinical data included the Canine Atopic Dermatitis and Severity Index for clinical signs and client-scored visual analog scale for pruritus. The mean number of CD34+ cells was significantly higher in dogs with atopic dermatitis as compared with the other 2 groups; there was no difference between the inflammatory and control groups. There was no correlation between the number of CD34+ cells and the severity index or analog scale scores. Future studies could investigate the potential utility of monitoring CD34+ cell counts to assess of treatment response.
This study highlighted the emerging complexity of canine atopic dermatitis. The study of bone marrow progenitor cells in animal diseases, particularly dermatologic ones, is relatively new.
It has been documented that in humans, increased numbers of CD34+ progenitor cells are released from bone marrow and migrate to areas of allergic inflammation, then differentiate into allergy effector cells (eg, mast cells, eosinophils). These cells might also behave as proinflammatory effectors that contribute to the allergic reaction.1 CD34+ cells were found in the sputum of allergic humans, with numbers increasing in response to specific allergy challenge.
It is unknown how findings will impact the study of veterinary allergy and its treatment. It was not long ago that lymphocyte testing was a research tool, and it is now common in the diagnosis and management of many veterinary diseases (eg, neoplasia).—Karen A. Moriello, DVM, DACVD
This capsule is part of the One Health Initiative.
- Allakhverdi Z, Comeau MR, Smith DE, et al. CD34+ hemopoietic progenitor cells are potent effectors of allergic inflammation. J Allergy Clin Immunol. 2009;123(2):472-478.
Bruet V, Lieubeau B, Herve J, et al. Increased numbers of peripheral blood CD34+ cells in dogs with canine atopic dermatitis. Vet Dermatol. 2015;26(3):160-164, e33.
Material from Clinician’s Brief may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.