Clinical healing of antimony-resistant cutaneous or mucocutaneous Leishmaniasis following the combined administration of interferon-γ and pentavalent antimonials compounds

Abstract

Abstract. In an open trial, longer courses of pentavalent antimonials (Sbˇ) at sub-optimal doses (10 mg/kg body weight), in association with recombinant human interferon-γ (IFN-γ) (100 µg/m2 of body surface area) were administered, by daily intramuscular injections, to 13 patients with diagnoses of cutaneous or mucocutaneous leishmaniasis unresponsive to Sbˇ. Four patients presented with large skin ulcers, and 9 had mucosal involvement as the main manifestation, the latter affecting the nose (3 cases), nose and septum (2 cases), nose and oral cavity (1 case), and nose, pharynx and larynx (3 cases). Except for one case with severe involvement of the upper respiratory tract, the lesions were fully resolved by the end of therapy (mean duration 40 ± 12 [SD] d, range 30-60 d) in the 11 patients who completed therapy. The main side effects were headache and fever (7 cases), together with leucopenia and eosinophilia (4 cases). It is concluded that combined administration of low doses of Sbˇ plus IFN-γ may provide a novel therapeutic approach for the treatment of antimony-resistant cutaneous or mucocutaneous leishmaniasis. The possible mechanisms by which IFN-γ contributes to resolution of the disease are discussed.