Safety, immunogenicity & possible efficacy of immunochemotherapy of persistent post-kalasar dermal leishmaniasis

Abstract

Background: Post kala-azar dermal leishmaniasis (PKDL) is a common skin condition that follows successful treatment of visceral leishmaniasis (VL) in Sudanese patients. Lesions persist for years in 15% of patients and are viewed as reservoirs for the disease. Drug treatment is protracted, toxic and costly. Cure is strongly correlated with conversion in the leishmanin skin test.

Objective of the study: To determine safety, immunogenecity and possible efficacy of Alum-precipitated autoclaved L. major + BCG VL candidate vaccine combined with sodium stibogluconate (SSG) in patients with persistent PKDL.

Methodology and results: Following informed consent, the vaccine mixture was administered in a stepwise manner as follows: 5 patients received a single intradermal injection of 10µg, 5 patients received a single dose of 100µg and 2 patients received 4 doses of 100µg at weekly intervals. Subsequently, the three groups of patients received means of 63.0 ± 8.0, 53.0 ± 5.0 and 40 days courses of SSG treatment respectively and were cured. Side effects were minimal and were confined to the vaccine injection site. Following completion of the safety study, eight patients were injected with 4-6 vaccine doses of 100µg/dose at weekly intervals in combination with SSG. Patients were closely followed up in hospital, with minimal side effects and complete clearance of the skin rash in forty days.

Conclusion: Alum/ALM + BCG vaccine mixture plus SSG was safe and was apparently effective in healing persistent PKDL lesions. SSG treatment duration could be shortened with the SSG/vaccine combination.

Keywords: PKDL, Immunochemotherapy, alum/ALM+BCG candidate vaccine

Sudanese Journal of Dermatology Vol. 3(2) 2005: 63-72