Leishmania infantum-specific IFN-? production in stimulated blood from cats living in areas where canine leishmaniosis is endemic

Priolo, Vito; Martínez-Orellana, Pamela; Pennisi, Maria Grazia; Masucci, Marisa; Prandi, David; Ippolito, Dorotea; Bruno, Federica; Castelli, Germano; Solano-Gallego, Laia

A minimum sample size of 173 cats was calculated for cat enrollment, based on the prevalence of feline L. infantum infection in areas under study (Catalonia and Sicily) [14, 19, 20, 23] , and on the assumptions of 99% confidence level and 5% precision [24] . Fisher's exact test was used to compare groups defined by categorical variables. Results of tests for L. infantum exposure of cats did not pass the D' Agostino-Pearson normality test. Accordingly, the Mann-Whitney U-test was used to compare unmatched continuous data and the Wilcoxon signed-rank test to compare paired continuous variables. Spearman's correlation coefficient was calculated to evaluate relationships between ELISA, IFAT and PCR results and between levels of IFN-γ, anti-Leishmania antibodies, and L. infantum DNA in blood of cats studied. P-values<0.05 were considered significant. The D' Agostino-Pearson normality test and Fisher's exact test were performed using Prism 7 for Mac IOS and all other tests were performed using SPSS software v.17.0 for Windows. Finally, Cohen's kappa coefficient was measured analyzing results of ELISA and IFAT with blood PCR (https ://idost atist ics.com/cohen -kappa -free-calcu lator ).