Effects of platelet-rich plasma on corneal re-epithelization and metalloproteinase expression in the cornea of sheep with experimentally-induced infectious keratoconjunctivitis.

Background and Aim: Infectious bovine keratoconjunctivitis is the most crucial ophthalmic disease among ruminants worldwide. Moraxella is the bacteria generally associated with this disease and leads to keratitis, conjunctivitis, corneal ulcers, or blindness. Platelet-rich plasma (PRP) effects in corneal ulcers and different ocular superficial diseases in animals and humans are beneficial and enhance rapid healing and improvement, but the effects in infectious keratoconjunctivitis in ruminants are uncertain. This study aimed to examine the effect of PRP on re-epithelization, corneal tissue, clinical signs, and matrix metalloproteinase (MMP) expression in sheep with infectious keratoconjunctivitis. Materials and Methods: Eighteen sheep were divided into three groups and subjected to a disease-induction experiment. Group 1 (G1) was administered 1.0 mL PRP subconjunctivally, Group 2 (G2) was administered 1.0 mL PRP subconjunctivally and 50 µL gentamicin drops, and the control group (CG) was administered 50 µL saline solution topically every 12 h. Clinical ophthalmologic examination, fluorescein staining, and photography were carried out. Ulcerated areas were measured employing J-Image software. Five and eleven days following the procedure, half of the animals from each group were euthanized, and their corneas were evaluated by histopathology and zymography. Results: Control Group and G2 epithelialized more rapidly. The CG exhibited fewer clinical signs of ocular disease. In histopathological analysis, in G2, alterations were observed only in the epithelium. The CG and G1 exhibited alterations in the epithelium, stroma, and Descemet's membrane. In zymography, a decline in MMP-2 expression in the animals treated with PRP was detected. Matrix metalloproteinase-9 was significantly expressed in the animals treated with PRP monotherapy, whereas PRP + gentamicin and CG caused a decrease. Conclusion: Platelet-rich plasma alone did not demonstrate any beneficial effect on re-epithelialization, a decline in clinical signs, tissue alterations, and expression of metalloproteinases. Platelet-rich plasma combined with gentamicin was capable of suppressing MMPs, primarily MMP-9, but do not display positive effects in re-epithelization, reduction of clinical signs, or tissue effects. These outcomes are similar to those discovered in untreated animals, so the use of PRP in patients with infectious keratoconjunctivitis does not offer greater benefits in sheep. Additional research is required to validate the results of PRP use in natural disease presentation.

Canine transmissible venereal tumor with spontaneous remission: case study with emphasis on clinical and cytopathological exams to monitor tumor evolution / Tumor venéreo transmissível canino com remissão espontânea: estudo de caso com ênfase aos exames clínico e citopatológico para monitoramento da evolução tumoral

The canine transmissible venereal tumor (TVTC) is a neoplasm transmitted mainly through copulation and with a high incidence in stray dogs in Brazil. In the process of tumor evolution of TVTC, the progression, stationary and regression phases are recognized. The host immunity is related to the disease's biological behavior, however, spontaneous regression observation in cases of naturally occurring TVTC is uncommon. A canine patient was attended, after beeing rescued from the street, due to an ulcerated mass in the external genitália and tick infestation. Cytopathological examination, which diagnosed TVTC, and laboratory tests that showed mild anemia and severe thrombocytopenia were performed. In view of the impossibility of carrying out other exams, it was made the presumptive diagnosis of canine monocytic ehrlichiosis (CME), and treatment was instituted. During follow-up it was observed quick improvement in clinical signs and laboratory changes, as well as a reduction in tumor mass. A new cytopathological evaluation was carried out, and was verified increase in mature lymphocytes and plasmocytes in the midst of the tumor cells, finding compatible with the stationary phase of the disease. From that moment on, it was decided to perform only clinical and cytopathological follow-up. In the following evaluations, continuous clinical remission and cytopathological findings compatible with those described in the regression phase were observed, until its complete remission. It is considered that the improvement in the general health of the patient after the treatment of CME is related to the spontaneous regression of TVTC, and that simultaneous performance of serial clinical and cytopathological exams may be feasible and useful for monitoring the stages of evolution of TVTC.

O tumor venéreo transmissível canino (TVTC) é uma neoplasia transmitida principalmente através da cópula, com elevada incidência em cães errantes no Brasil. No processo de evolução tumoral do TVTC, são reconhecidas as fases de progressão, estacionária e de regressão. O estado imunológico do hospedeiro está relacionado ao comportamento biológico da doença, contudo, a observação de regressão espontânea em casos de TVTC de ocorrência natural é incomum. Foi atendida uma paciente canina, resgatada da rua, por apresentar massa ulcerada na genitália externa e infestação por carrapatos. Foram realizados exame citopatológico, que diagnosticou TVTC, e exames laboratoriais que evidenciaram anemia discreta e grave trombocitopenia. Com isso e diante da impossibilidade de realizar outros exames, foi também estabelecido o diagnóstico presuntivo de erlichiose monocítica canina (EMC) e instituído tratamento para a hemoparasitose. Durante o acompanhamento, foi observada rápida melhora dos sinais clínicos e das alterações laboratoriais, bem como a redução espontânea da massa tumoral. Em sequência, foi realizada nova avaliação citopatológica do TVTC e verificado o aumento quantitativo de linfócitos maduros e plasmócitos, em meio as células tumorais, achado compatível com a fase estacionária da doença. A partir desse momento, optou-se por realizar apenas acompanhamento clínico e avaliação citopatológica da neoplasia. Foram observados contínua remissão clínica e achados microscópicos compatíveis com a fase de regressão do tumor, até sua remissão completa. Pondera-se que a melhora na saúde geral da paciente após o tratamento da EMC esteja relacionada à regressão espontânea do TVTC, e que realização simultânea de exames clínico e citopatológico seriados pode ser viável e útil ao acompanhamento das fases de evolução do TVTC.

Relationship between ocular abnormalities and hematologic alterations in patients infected naturally by Ehrlichia canis / Alterações hematológicas e sua relação com anormalidades oculares em pacientes infectados naturalmente com Ehrlichia canis

ABSTRACT: To determine the association between ocular abnormalities and hematologic findings in Ehrlichia canis-infected dogs, 120 dogs suspected of canine ehrlichiosis were studied. All patients were subjected to rapid serologic diagnostic test for Ehrlichia canis, and the diagnosis was confirmed by quantitative PCR. PCR-positive patients underwent ophthalmologic examination and a hemogram and were grouped into patients with thrombocytopenia and anemia (G1), patients with thrombocytopenia (G2), and patients without hematologic disorders (G3). For ophthalmic evaluation, the patients were grouped into those having mild, severe, both mild and severe, and no ocular alterations. All patients presented with uveitis (100%). Severe ocular disorders predominated in G1 and G2 patients. Dogs with anemia and leukopenia showed severe ocular disorders. In dogs with a greater number of leukocytes and copies/µl of the TRAG gene, the intraocular pressure (IOP) tends to decrease and vice versa (r = −0.23, r = −0.26). In conclusion, uveitis is the earliest ocular alteration of canine ehrlichiosis. The severity of ocular abnormalities in patients with ehrlichiosis is associated with thrombocytopenia and may be aggravated by anemia and leukopenia. The hemogram and IOP are useful tools for predicting eye involvement in Ehrlichia canis-infected patients. In regions where Ehrlichia canis is endemic, the use of the tonometer should be routinely in dog general consultation.

RESUMO: Para determinar a associação entre anormalidades oculares e achados hematológicos em cães infectados com Ehrlichia canis, foram estudados 120 cães com suspeita de erliquiose canina. Todos os pacientes foram submetidos a um teste diagnóstico sorológico rápido para Ehrlichia canis, e o diagnóstico foi confirmado por PCR quantitativa. Os pacientes com PCR positivo foram submetidos a exame oftalmológico e hemograma completo e foram agrupados em pacientes com trombocitopenia e anemia (G1), pacientes com trombocitopenia (G2) e pacientes sem distúrbios hematológicos (G3). Para avaliação oftalmológica, os pacientes foram agrupados em pacientes com alterações leves ou graves, leves e graves e sem anormalidades oculares. Todos os pacientes apresentaram uveíte (100%). Os distúrbios oculares graves predominaram nos pacientes do G1 e G2. Cães com anemia e leucopenia apresentaram distúrbios oculares graves. Em cães com maior número de leucócitos e cópias/µl do gene TRAG, a pressão intra-ocular tendeu a diminuir e vice-versa (r = -0.23, r = -0.26). Em conclusão, a uveíte é o primeiro distúrbio ocular da erliquiose canina. A gravidade das anormalidades oculares em pacientes com erliquiose está associada à trombocitopenia e pode ser agravada por anemia e leucopenia. Hemograma e PIO são ferramentas úteis para prever o envolvimento ocular em pacientes infectados com Ehrlichia canis. Nas regiões em que o Ehrlichia canis é endêmico, o uso do tonômetro deve ser rotineiro nas consultas gerais de cães.