Influence of naturally acquired feline leukemia virus (FeLV) infection on the phagocytic and respiratory burst activity of neutrophils and monocytes of peripheral blood.

The purpose of this study was cytometric evaluation of phagocytic and oxidative burst activity of neutrophils and monocytes in cats naturally infected with FeLV. To conduct the study, the peripheral blood was obtained from 33 cats naturally infected with FeLV. The control group consisted of 30 FeLV-, FIV-, clinically healthy cats. The percentage of phagocytizing neutrophils of peripheral blood was lower in FeLV+ than in FeLV- cats. The percentage of neutrophils and monocytes in which an oxidative burst occurred was lower in FeLV+ than in FeLV-animals. Also an oxidative product formation in neutrophils after E. coli and PMA stimulation was lower in FeLV+ than in FeLV-animals. Obtained results allow to conclude that diminished phagocytic and oxidative burst activity of peripheral blood leukocytes may cause impairment of innate immunity in cats infected with FeLV.

Influence of dexamethasone on some cellular aspects of the immune system in cats.

In view of the frequent use of glucocorticoids in the treatment of cats, we studied the effect of dexamethasone on their immunological system. The phagocytic activity and oxidative burst of neutrophils and monocytes were evaluated by cytometric analysis using commercial kits and the subpopulations of lymphocytes were assessed. Neutrophilia and monocytosis reduced phagocytic activity, as shown from the number of phagocytized bacteria, and variations in the intensity of the oxidative burst in activated neutrophils and monocytes were observed. Dexamethasone also caused an increase in the number of B lymphocytes.

A retrospective study of the incidence and prognostic factors of multicentric lymphoma in dogs (1998-2000).

Sixty-three dogs with multicentric lymphoma were evaluated for risk of diseases. The greatest risk of disease concerned rottweilers as compared to other breeds (odds ratio 6.01 to 0.32-2.75, respectively). A group of 43 dogs under chemotherapy was evaluated for defining factors influencing first remission time duration and survival time. The most important factors for results of chemotherapy were response to therapy, stage and sub-stage of disease according the World Health Organization staging system at the time of diagnosis.

Cytometric evaluation of peripheral blood lymphocytes in dogs with lymphoma during chemotherapy.

Twenty dogs with clinically diagnosed multicentric lymphoma were evaluated for percentages of peripheral blood lymphocyte subpopulations. Cytometric analysis was performed before and during chemotherapy. The results were compared to those obtained from a control group of healthy dogs. The percentages of CD5+, CD4+ and CD8+ cells were markedly decreased and CD21-like+ cells markedly increased in dogs with lymphoma in comparison with the control group. During the course of chemotherapy these values returned to ranges observed in healthy animals.

Alpha-fetoprotein in canine multicentric lymphoma.

The concentrations of AFP were evaluated in the sera from groups of healthy dogs and of dogs with multicentric lymphoma, before and while receiving chemotherapy. The concentration of AFP was highest in the affected dogs, especially during the fifth stage of lymphoma. Chemotherapy caused a decrease in AFP serum concentration, during both the induction and the maintenance phases of treatment, when compared to the same animals before therapy. Determination of the concentration of AFP in the serum may be an additional indicator in the evaluation of the stage of lymphoma, and of value in assessing the extent of neoplastic infiltration of the liver.