Histopathological assessment of the liver during experimental infection with Leishmania (Leishmania) chagasi in immunosuppressed balb/c mice

Abstract

BALB/c mice were experimentally infected with L. (L.) chagasi and immunosuppressed for the
study of the histopathological changes present in their liver. The 96 studied mice were
subdivided into four groups: control (I) – no treatment; immunosuppressed (II) – treatment with
dexamethasone (DXM) and pentoxifylline (PTX); infected (III) – infection with L. (L.) chagasi;
and infected and immunosuppressed (IV) - infection with L. (L.) chagasi and treatment with
DXM and PTX. The day of infection was considered the day zero and immunosuppression
occurred at 60 days P.I. Samples were obtained at distinct moments, 15, 30, 60, 75 and 90 days
P.I., by collecting liver fragments for histopathological assessment. There was progressive and
constant inflammatory reaction of inflammatory infiltrate and complete granulomas, which was
renewed in all observation phases. For inoculated groups, the presence of amastigotes was
confirmed by means of immunohistochemistry. The immunosuppressed group showed weak
inflammatory reaction and rare incomplete granulomas. Immunosuppression influenced the
immune response of the liver, which is capable of controlling murine visceral leishmaniasis.