Raw_data_Therapeutic efficacy of a mixed formulation of conventional and PEGylated liposomes containing meglumine antimoniate, combined with allopurinol, in dogs naturally infected with Leishmania infantum.xlsx

We reported previously that treatment of dogs naturally infected with Leishmania infantum with meglumine antimoniate (MA) encapsulated in conventional liposomes (LC), in association with allopurinol, promoted marked parasite load reductions in the main infection sites. Here, a new assay in naturally infected dogs was performed using a novel liposome formulation of MA consisting of a mixture of conventional and long-circulating (PEGylated) liposomes (LCP), with expected broader distribution among affected tissues of the mononucler phagocyte system. Experimental groups of infected dogs were as follows: LCP+Allop - received LCP (2 cycles of 6 doses of 6.5 mg Sb/kg/4-day interval between applications i.v.) plus allopurinol (30 mg/kg/12 h p.o.) during 4.3 months; LC+Allop - received LC (2 cycles of 6 doses of 6.5 mg Sb/kg/4-day interval between applications i.v.) plus allopurinol during 4.3 months; Allop- treated with allopurinol only; non-treated control. Parasite loads were evaluated by quantitative PCR in liver, spleen and bone marrow and by immunohistochemistry in the skin, before, just after treatment and 4 months later. Animals were also classified clinically by the results of the physical examinations, levels of anti-Leishmania antibodies determined by IFAT and ELISA, and laboratory findings in hemogram and sérum biochemistry (levels of sérum urea, creatinine, alanine aminotransferase, aspartate aminotransferase, total and direct bilirubin, total and direct bilirubin, total proteins, globulins, albumins, and albumin/globulin (A/G) ratio. Comparison of the parasite loads 4 months after treatment to those in the pre-treatment period showed significant reductions in both LCP+Allop and LC+Allop in the liver, spleen, bone marrow. Only LCP+Allop group showed significant lower parasite burden in the skin, in comparison to control group. On the basis of clinical staging and parasitological evaluations, LCP formulation exhibited a more favorable therapeutic profile, when compared to LC one, being therefore promising for treatment of canine visceral leishmaniasis.