ABSTRACT
Asymptomatic infection (the absence or inapparent
signs and symptoms) has been observed in many endemic areas of
leishmaniasis, however, little is known about the parasitological and
immunological factors associated with this type of
infection. This study aimed to identify the
in vitro expression of IFN-γ in asymptomatic carriers of viable
Leishmania parasites.
Asymptomatic infection was identified using the
Montenegro skin test in an at-
risk population from Yucatan,
Mexico.
Parasite viability was evinced in the
blood by 7SL
RNA transcripts amplification. The expression of
mRNA IFN-γ was analyzed in
peripheral blood mononuclear cells stimulated with soluble
Leishmania antigen, using RT-qPCR.
Parasite viability was observed in 33.3 % (5/15) of asymptomatic subjects. No differences were found in the expression of IFN-γ between asymptomatic and
healthy subjects, and no correlation was found between the presence of viable
parasites and the expression of IFN-γ. This study demonstrates the persistence of
Leishmania parasites in the absence of an
in vitro IFN-γ response in asymptomatic carriers from
Mexico.