Terapia celular regenerativa injetável no tratamento da ceratoconjuntivite seca em cães

Abstract

Keratoconjunctivitis sicca (KCS) is an inflammatory disease, mainly immune-mediated, that affects the lacrimal glands and the ocular surface, which can be unilateral or bilateral, causing a decrease in the aqueous portion of the tear film and/or excessive evaporation. The objective of the study was to compare the effectiveness of injectable regenerative medicine treatments in dogs diagnosed with KCS, using mesenchymal stem cells (MSC) and homologous platelet-rich plasma (HPRP) with conventional topical treatment with the immunosuppressant tacrolimus 0.03%, in addition to the use of MSC associated or not with oral omega 3. Fifty dogs with bilateral KCS were evaluated over a period of 6 months, which were divided into 2 studies: study 1 with 30 dogs, distributed into 3 groups: Topical 0.03% tacrolimus (GT) Group, injectable MSC (GMSC) Group and HPRP Group (GHPRP) injectable; and study 2 with 20 dogs divided into 2 groups: injectable MSC Group (GMSC) and injectable MSC Group associated with the use of oral omega 3 (GMSCO). The groups that used the GMSC, GMSCO and GHPRP treatments were injected once a month into the gland of the third eyelid (0.1 ml), upper palpebral conjunctiva (0.1 ml) and lower (0.1 ml), totaling up to 3 applications, as needed based on improvement in ophthalmic exams and GMSCO had daily omega 3 supplementation and GT used eye drops twice a day, in all groups they used artificial lubricant twice a day. Ophthalmic exams were performed once a month Schirmer Tear Test 1 (STT-1), Tear Breakup Film Rupture Test (TBUT) and collection of aspiration cytology in M0, M3 and M6 and biopsy of the conjunctiva of M0 and M6. The studies were approved by CEUA n. 6412 (study 1) and n. 6484 (study 2). All groups showed improvements in tear production, tear film quality and ocular surface health, in addition to a reduction in the inflammatory process and an increase in goblet cells. The MSC group demonstrated better efficacy compared to the T and GHPRP groups, with omega 3 supplementation leading to an increase in the effectiveness of injectable MSC. The studies highlight the effectiveness in the treatment of KCS in dogs with monthly injectable regenerative medicine with MSC and HPRP, being an alternative to conventional treatment with the immunosuppressant tacrolimus 0.03% topical with daily and continuous instillation, and which may be unfeasible in some situations such as aggressive or uncooperative dogs, elderly owners or those with work schedules that do not allow daily instillation of eye drops, or even in dogs allergic or refractory to immunosuppressive eye drops.