Pharmacological Approaches to Visceral Leishmaniasis in Patients with Immunocompromised Status

Abstract

Visceral leishmaniasis (VL) is a chronic parasitosis which is hypoendemic in the Mediterranean area but hyperendemic in areas such as Bihar, Sudan, and Northeastern Brazil. Leishmania donovani and Leishmania infantum are the main etiological agents. After infection by vectors (phlebotomine sandflies), VL symptoms range from a low-symptomatic disease to a rapidly evolving severe syndrome. When VL affects immunocompromised adults, the infection frequently appears paucisymptomatic or as an insidious clinical manifestation with atypical signs and low-grade fever. Patients with human immunodeficiency virus (HIV) infection and organ-transplant recipients have an increased risk of VL and HIV/VL coinfection, which is worrying risk factor in Southwestern Europe and many hyperendemic areas. The availability of effective therapies is limited, and the prognosis of the patients with immunocompromised status is unpredictable. Compared with other therapies, treatment based on the use of liposomal amphotericin B is associated with a lower incidence of side effects, but the cost precludes its use in low-income countries. Antimonials are the longest-used drugs. However, adverse reactions are common, and the mechanisms of resistance to this class of drugs have been enhanced. Miltefosine, the only oral drug available, has uncertain effectiveness against L. infantum infection. Data about the efficacy of paromomycin are also limited. Relapses and resistance to drugs are observed in patients with VL/HIV coinfection.

Keywords

• visceral leishmaniasis
• immunocompromised patients
• drugs