A Canine Model of Chronic Graft-versus-Host Disease

Abstract

In long-term survivors of allogeneic hematopoietic cell transplantation (HCT), chronic graft-versus-host disease (GVHD) is the major cause of morbidity and mortality and a major determinant of quality of life. Chronic GVHD responds poorly to current immunosuppressive drugs, and while T-cell depletion may be preventative, this gain is offset by increased relapse rates. A significant impediment to progress in treating chronic GVHD has been the limitations of existing animal models. The goal of this study was to develop a reproducible, comprehensive model of chronic GVHD in the dog. Ten recipient dogs received 920 cGy total body irradiation, infusion of marrow, and an infusion of buffy coat cells from a dog leukocyte antigen (DLA) mismatched unrelated donor. Postgrafting immunosuppression consisted of methotrexate (days 1, 3, 6, 11) and cyclosporine. The duration of cyclosporine administration was limited to 80 days instead of the clinically used 180 days. This was done in order to contain costs since chronic GVHD was expected to develop at earlier time points. All recipients were given ursodiol for liver protection. One dog had graft failure while 9 dogs showed stable engraftment. Eight of the 9 developed de novo chronic GVHD. Dogs progressed with clinical signs of chronic GVHD over a period of 43 to 164 (median 88) days after discontinuation of cyclosporine. Target organs showed the spectrum of chronic GVHD manifestations that are typically seen clinically. These included lichenoid changes of the skin, fasciitis, ocular involvement (xerophthalmia), conjunctivitis, bronchiolitis obliterans, salivary gland involvement, gingivitis, esophageal involvement, and hepatic involvement. Peripheral blood lymphocyte surface antigen expression of CD28 and ICOS was elevated in dogs with GHVD compared to normal dogs but not significantly so. Serum levels of IL-8 and MCP-1 in GVHD affected dogs at time of euthanasia were elevated, while levels of IL-15 were depressed compared to normal dogs. Results indicate that the canine model is well suited for future studies aimed at preventing or treating chronic GVHD.

Anti-Inducible Costimulator Monoclonal Antibody Treatment of Canine Chronic Graft-versus-Host Disease

“…All five dogs showed sustained hematopoietic cell engraftment after HCT. Mononuclear and granulocyte recovery for the five study dogs occurred within the same period and tempo as was seen in a group of ten transplanted dogs that were not given ICOS mAb therapy following development of chronic GVHD [1]. Donor cell chimerism values, 94 to 100 (median 100) percent, were comparable to that of the control dogs as previously reported (data not shown) [1].…”

“…HCT was performed identically to that previously reported [1]. Five days before and up to five days after transplantation, dogs were prophylactically treated with the antibiotic, enrofloxacin (2.2 mg/kg subcutaneously, twice daily).…”

“…We recently described a canine model of chronic graft-versus-host disease (GVHD) after hematopoietic cell transplantation (HCT) from unrelated donors that were mismatched for the major histocompatibility complex (MHC), dog leukocyte antigen (DLA) [1]. Recipients were conditioned for transplantation with 9.2 Gy total body irradiation (TBI) and were given post-grafting immunosuppression with a short course of methotrexate (MTX) and 80 days of cyclosporine (CSP).…”

Presumptive Development of Fibrotic Lung Disease From Bordetella bronchiseptica and Post-infectious Bronchiolitis Obliterans in a Dog

“…Injuries linked to BO in people include respiratory infections, chronic gastroesophageal reflux, allergic reactions, collagen vascular diseases, organ transplantation and chronic exposure to air pollutants or toxic fumes (5, 21). Experimental canine BO can be induced by respiratory infections [adenovirus (22, 23), mycoplasma (24) and co-infection of parainfluenza and Bordetella bronchiseptica (25, 26)], toxins (27), and allogeneic hematopoietic cell transplantation (28). Chronic small airway obstruction from inflammation and fibrosis leads to cough, wheeze and dyspnea in people (21, 29).…”

Developments and translational relevance for the canine haematopoietic cell transplantation preclinical model

“…124 To this end, we used DLA-mismatched unrelated marrow grafts infused into recipients following 920 cGy TBI which were given before post-grafting immunosuppression consisting of MTX (days 1, 3, 6, and 11) and CSP for 80 days. 124 Chronic GVHD, similar in scope and tempo to that seen in the clinic, was observed in eight of 10 dogs over a period of 43 to 164 days. Surface expression of CD28 and inducible costimulator (ICOS) molecules were elevated on PBMC identified in dogs with clinical signs of chronic GVHD.…”