Interferon-gamma (INF-γ), IL4 expression levels and Leishmania DNA load as prognostic markers for monitoring response to treatment of leishmaniotic dogs with miltefosine and allopurinol

Abstract

In this study, we searched for a connection between Leishmania load and cytokine expression levels in the tissues of Leishmania infantum naturally infected dogs and the efficacy of treatment with miltefosine and allopurinol. To this purpose, we exploited a real-time PCR system to detect Leishmania load and the expression levels of IFN-γ and IL-4 mRNAs at the time of diagnosis and during the follow up post-treatment. In particular, we measured the amount of parasites in blood and lymph node samples, while the expression levels of IFN-γ and IL-4 cytokines were assessed in the blood of the animals. We employed different targeted real-time PCR assays on 20 naturally infected dogs with clinical signs. Three healthy dogs living in a non-endemic area were selected as negative controls. The overall results obtained demonstrate that the simultaneous evaluation of parasites and cytokine levels in different kinds of tissue might represent a reliable tool to evaluate the immune response, the efficacy of the therapy and to predict the relapses during the treatment.