LOPH and D-MHC in the treatment of FeLV associated acute leukemia in a cat

ABSTRACT

Background: Bone marrow primary malignancies are denominated leukemias, classified as myeloid or lymphoid, according to the cell lineage, and acute or chronic, according to the cell´s state of maturation. In cats, acute lymphoid leukemiais the most common form, especially in regions endemic for feline leukemia virus and / or feline immunodeficiency virus.A new treatment protocol for lymphomas, called LOPH, was described for animals with FeLV persistent viremia. Thisstudy aimed to report a case of a cat presenting with FeLV associated acute leukemia and treated with the LOPH protocol,and, in the rescue phase, a modification of the D-MAC protocol, denominated D-MHC.Case A 4-year-old mixed breed intact queen was attended due to lethargy and inappetence. The patient did not present anyrelevant abnormalities in the clinical exam and complementary exams were performed including complete blood count,biochemical profile, SNAP Feline Triple Test, chest radiographs and abdominal ultrasound. Imaging tests and biochemicalvalues were unremarkable, but the patient presented a reagent result for FeLV and severe leukocytosis due to lymphocytosis. The morphological evaluation of the blood smear revealed the presence of blasts, in a concentration greater than 20%of the nucleated cells, which allowed the characterization of a leukemic state, probably lymphoid. First-line treatmentwas based on the LOPH protocol, including Lomustine, Vincristine, Prednisolone and Doxorubicin, in four-week cycles.Nevertheless, during the third cycle, 66 days after the institution of this protocol, the patient presented a febrile conditionalong with marked leukocytosis due to lymphocytosis, confirming leukemia recurrence. A rescue attempt was performedwith a modification of the D-MAC protocol, originally consisting of the combination of dexamethasone, melphalan, actinomycin-D and cytarabine, but with replacement of actinomycin-D by doxorubicin, and therefore denominated D-MHC....(AU)