The leishmaniasis parasite

CDC

[CARACAS] Cuban and Venezuelan researchers are to begin a project analysing the human genes involved in defence against the Leishmania parasite.

They hope the research will help in designing 'personalised medicine' — drugs tailor-made to individuals — to fight leishmaniasis.

Scientists from the Venezuelan Institute for Scientific Research (IVIC) and Cuba's Center for Genetic Engineering and Biotechnology will begin their research next year in Araira in northern Venezuela.

Northern Venezuela is a hot spot for cutaneous leishmaniasis, the most common form of the disease, characterised by sores on the skin.

The Leishmania parasite is transmitted to humans through biting sandflies and in addition to skin sores causes fever, anaemia and damage to the liver and spleen.

Cutaneous leishmaniasis can progress to more serious forms of the disease, the most serious of which is visceral leishmaniasis, which can be fatal if left untreated.

The researchers will recruit 200 people for DNA samples — 100 infected with the Leishmania parasite and 100 without the infection — to detect the human genes responsible for protection from leishmaniasis.

IVIC scientist Mercerdes Fernández-Mestre, one of the lead researchers on the project, told SciDev.Net that several genes are involved in the immune response to infection, and it is important to study variations in those genes between people.

These variations could explain why some individuals living in endemic areas have been healthy for more than 20 years, she says.

The variations could also explain why some people seem predisposed to getting a more severe form of the illness, like diffuse cutaneous leishmaniasis, in which patients have extensive skin lesions that are hard to treat.

Fernández-Mestre said they intend to analyse genes that activate macrophages, immune cells that engulf and destroy the Leishmania parasite.

In some people, these genes fail to switch on and they have a poor macrophage response against the parasite.

The hope is that eventually drugs could be designed to turn these specific genes on, improving that person's immune response to the infection.

Venezuela's first laboratory specialising in pharmacogenomics — the science of understanding the link between an individual's unique genetic make-up and their response to drug treatment — will also be built.

The researchers hope to have their first results by the end of 2008.