Trombotic risk in dogs with primary immune-mediated hemolytic anemia and secondary to E. canis under treatment with micofenolate mofetil

Author(s)

Tatiana Geraissate Gorenstein

• Document type: Master's Dissertation
• Press: Botucatu. 2018-09-06.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Medicina Veterinária e Zootecnia. Botucatu
• Defense date: 2018-07-30
• Advisor: Regina Kiomi Takahira

Abstract

Immune-mediated hemolytic anemia (IMHA) is the most prevalent immune disorder in dogs. This condition is characterized as a type II hypersensitivity and leads to the premature destruction of red blood cells. Among the main complications, hypercoagulability, which predisposes dogs to disseminated intravascular coagulation and pulmonary thromboembolism, is the most important and leading cause of death in more than 80% of cases. Primary IMHA cannot be associated with an obvious predisposition, besides breed predilection, because of this it is a diagnostic exclusion. Secondary IMHA is related to several agents, and among the infectious ones, ehrlichiosis stands out. Animal selection for this study was based on hematological, biochemical, and urine tests. Dogs with moderate to severe anemia (hematocrit ≤ 25%), with symptoms of immune-mediated hemolysis, such as spherocytosis, positive saline agglutination, bilirubinuria and/or hemoglobinuria, were included. The treatment is directed towards immune response suppression, for which glucocorticoids and mycophenolate mofetil are frequently used. This study aimed to clarify whether the thrombotic risk changes after the initiation of immunosuppressive therapy with mycophenolate mofetil, through thromboelastometry, in animals with primary IMHA and secondary to E. canis infection. The animals under study were submitted to hemogram, reticulocyte count, spherocytosis screening, serum biochemistry, urinalysis, urinary protein/creatinine ratio, coagulation tests, thromboelastometry; PCR for E. sp, E. canis and B. canis; serology for Leptospira spp and abdominal ultrasonography. Twelve dogs with a diagnosis of IMHA were selected and a thromboelastic examination was performed at two moments: before the start of treatment with mycophenolate mofetila, when the patient used doxycycline, omeprazole and prednisolone (M1) and after the addition of mycophenolate mofetila to the protocol mentioned above, when there was clinical and hematological improvement (M2). Five animals died before moment 2. The Willcox nonparametric test was used to compare the two moments of the surviving group, and the nonparametric Mann-Whitney test was used to compare the moment 1 of the surviving group with the death group, both with 5% significance value. No change in the coagulation state of animals treated with mycophenolate mofetil was observed. The animals that showed lower coagulation at the time of diagnosis exhibited a worse prognosis, and the reticulocyte count showed a better prognostic value than the red blood cell count at the time of diagnosis (AU)

• FAPESP's process: 16/23403-1 - Thrombotic risk in dogs with primary immune-mediated haemolytic anemia under treatment with mycophenolate mofetila
• Grantee: Tatiana Geraissate Gorenstein
• Support Opportunities: Scholarships in Brazil - Master