Uso tópico de células-tronco mesenquimais heterólogas de tecido adiposo canino no tratamento da ceratoconjuntivite seca em cães

Abstract

Dry keratoconjunctivitis (CCS) is a chronic inflammatory ocular disease, mainly immunomediated in dogs and men. Studies describe the use of injectable mesenchymal stem cells (CTM) in the canine lacrimal gland in the treatment of CCS. This is the first study with topical use of CTM that would be a more practical technique. The objective of this research was to analyze the efficacy of topical use of heterologous CTMs of canine adipose tissue in the treatment of CCS in dogs. Twenty-two dogs with bilateral diagnosis for CCS evaluated by ocular signs, Schirmer's Lacrimal Test 1 (TLS-1), Lacrimal Film Rupture Test (TRFL), Fluorescein Test (TF) and Green Lissamina Test (TLV) were used. For cytological analysis, conjunctival exfoliative cytology was performed and histopathological analysis was performed conjunctival biopsy and fine needle aspiration of the gland of the third eyelid. The animals were topically treated with 50μl (1x106 CTM) in both eyes in 4 applications at 7 day intervals, and propylene glycol lubricant eye drops, 1 drop, 3 times a day, in both eyes, for only 30 days, and observed for 180 days with periodic ocular exams. There was a significant improvement (p <0.05) in ocular clinical signs and resolution of corneal ulcers, and a significant (p <0.05) increase in TRFL and TLS-1 by the end of the study. There was a return of ocular secretion and conjunctivitis in 7 animals (31.8%) until the end of the study. In the cytological and histopathological evaluation, there was a significant increase (p <0.05) in the number of goblet cells and a significant decrease (p <0.05) in polymorphonuclear and mononuclear, metaplastic, and corneal scales. All markers (CD4, IL-6, IL-1, TNFα) were reduced in both histopathological techniques evaluated (immunohistochemistry and immunocytochemistry). The topical use of CTM and the therapeutic protocol used demonstrated great potential in the adjuvant treatment of CCS. There was a significant decrease in inflammatory markers. In addition, these markers may be excellent tools for the diagnosis and progression of CCS, but some animals showed a return of clinical signs of CCS, possibly due to a reactivation of immune-mediated aggression to the lacrimal glands. In this way, more studies should be performed to minimize the immune-mediated aggression, possibly with the use of immunosuppressants after the topical application of CTM.