Adesão leucocitária e MDA sérico em cães naturalmente infectados por Leishmania infantum* Leukocyte adhesion and MDA serum levels in naturally infected dogs by Leishmania infantum

The present study evaluated the oxidative stress and leukocyte adhesion (LA) in dogs naturally infected by Leishmania infantum. Healthy dogs (HD = 10) and dogs affected by canine visceral leishmaniasis (CVL) in symptomatic form (SD= 10) were previously submitted to indirect immunofluorescence reaction (IIF), enzyme-linked immunosorbent assay (ELISA) and detection of parasites in bone marrow aspirates. Serum was used to assess malondialdeid (MDA) by thiobarbituric acid reactive species (TBARS) assay and AL was determined by nylon column method using whole blood stored in EDTA, citrate and heparin. AL data was expressed as percentage and MDA data as mean ± standard deviation, both submitted to the unpaired student’s T test (p < 0.05). Heparin samples showed higher levels of AL in CS group (55.62 %, p < 0.05) when compared with EDTA and citrate (10.46% and 5.28%). Citrate and EDTA inhibit AL in healthy and sick dogs, while heparin preserved AL in both groups. Neutrophil proportion in heparin samples were lower (85% to 67%, p <0.05) compared with citrate and EDTA, which in turn remained practically unchanged (83% to 80%). MDA levels were higher in SD (0.0117μM ± 0.002) when compared to HD (0.0057μM ± 0.001) (p <0.05). These data support the conclusion that CVL induces oxidative stress enhance and leukocyte adhesion increase, indicating systemic inflammatory response. The choice of anticoagulant is an important decision for implementing LA assays.