Immunochemotherapy for Leishmania donovani infection in golden hamsters: combinatorial action of poly ICLC plus L-arginine and sodium stibogluconate (Stibanate).

We demonstrate that golden hamsters infected with Leishmania donovani amastigotes develop the capacity to eliminate intracellular pathogens on treatment with low-dose standard antileishmanial sodium stibogluconate (Stibanate) in combination with polyinosinic-polycytidilic acid stabilized with polylysine and carboxymethycellulose (poly ICLC), a potent inducer of interferon (IFN) and immune enhancer, plus L-arginine. Data suggest that low doses of both Stibanate and poly ICLC plus L-arginine provide marginal inhibition against L. donovani infection in golden hamsters. When given in combination, however, a significant inhibition was achieved without toxicity, as all the animals survived up to 45 or 60 days. These results suggest that combination therapy using Stibanate and poly ICLC plus L-arginine may be very effective in reducing the dose of Stibanate and, hence, its dose-dependent toxicity in clinical situations.