Posters

Abstract

The complement system, an important effector mechanism of innate immunity can be activated by three distinct mechanisms designated classical, alternative and lectin pathways. The functional activity of complement can be assessed by hemolytic assays that are valuable screening tools for complement component deficiencies. The aim of this study was to evaluate the alternative complement pathway in normal canine serum samples using the hemolytic assay (AH50). First the canine alternative pathway activation by erythrocytes from different animal species was evaluated. Erythrocytes suspensions (2,8% in borate Mg-EGTA buffer) from rabbit, chicken, sheep and guinea pig were incubated with 1:10 dilution of canine serum for 30 min at 37 o C and the percentage of lysis were evaluated by supernatant analysis at 492 nm. Guinea pig erythrocytes were more effective than rabbit, chicken and sheep for canine alternative pathway activation (hemolysis of 66.6%, 12.7%; 12.6% and 10.7%, respectively) and were used in the AH50 assay. A standard AH50 method was used to evaluate ten serum samples obtained from apparently healthy adult dogs and the values ranged from 7.8 to 222.2 AH50/ml. The next step should be the evaluation of AH50 levels in dogs with different diseases.