AUTOMATED PLATELET VARIABLES (ADVIA 2120) RESULTS IN DOGS WITH SYSTEMIC INFLAMMATORY DISEASES: A RETROSPECTIVE EVALUATION

Introduction: Platelet activation plays an important role in the pathogenesis of systemic inflammatory response syndrome (SIRS) and contributes to morbidity and mortality in hospitalized pa- tients. ADVIA 2120, a flow-cytometry-based haematology system, yields different platelet parameters (PPs) using two-dimensional laser technology. The purpose of this study was to evaluate PPs in different clinical setting of canine SIRS, and to compare them with a control series of healthy dogs. Methods: The medical records of dogs admitted to a veterinary teaching hospital (2013-2015) were retrospectively evaluated, and SIRS dogs affected by primary immune-mediated haemolytic anaemia (IMHA), bacterial sepsis and pyometra were selected. A group of healthy blood donor dogs was used as control and to establish reference intervals. Blood samples were collected and processed with standardized procedure and timing. Among haematological variables platelet count (PLT, 103cells/μl), plateletcrit (PCT %), mean platelet volume (MPV, fL), platelet volume distribution width (PDW, %), mean platelet component (MPC, g/dL), platelet component distribution width (PCDW, g/dL), mean platelet mass (MPM, pg), platelet mass distribution width (PMDW, pg), large platelets (L-PLT, 103cells/μl) and platelet clumps (PLT-clumps) were measured and MPC/MPV ratio calcu- lated. Differences between groups were determined using non-parametric statistics. The significance level was set at p< .05. Results: PPs were available in 17 IMHA, 59 bacterial sepsis, 27 pyometra, and 105 healthy dogs. A significantly increased PLT was reported in dogs with pyometra, only. MPV, PDW, MPM, and PMDW were significantly increased in sick dogs compared to controls. IMHA dogs presented significantly higher MPV, MPM and PMDW and lower MPC/MPV compared to other groups. MPC and PCDW were not significantly different among groups. Dogs with IMHA and pyometra had increased L-PLT if compared to septic and healthy dogs, while PLT-clumps were significantly elevated in IMHA than in other groups. Conclusions: Dogs with SIRS show relevant alterations of PPs mainly attributed to volume and mass indexes. These changes are more significant in IMHA dogs suggesting a severe platelet release from the bone marrow and a potential platelet activation. The investigation on the potential of the MPC/MPV ratio as an indirect marker of platelet activation is warranted.