Cytokine expression in the duodenal mucosa of patients with visceral leishmaniasis.
BACKGROUND
Visceral leishmaniasis (VL) is a neglected tropical disease with a complex immune response in different organs. This pattern of organ-specific immune response has never been evaluated in the gastrointestinal tract. The aim of this study was to determine the in situ immune response in duodenal biopsies on patients with VL.


METHODS
A case-control study was conducted on 13 patients with VL in comparison with nine controls. The immune response was evaluated using immunohistochemistry, for CD4, CD8, CD68, IL-4, IFN-gamma, TNF-alpha and IL-10. Histological findings from the villi, crypts and inflammatory process were analyzed.


RESULTS
All the cases of VL presented Leishmania antigens. No antigen was detected in the control group. The villus size was greater in the VL patients (p < 0.05). CD68 (macrophages) and CD4 levels were higher in the VL patients (p < 0.05). No differences in the expression of CD8, TNF-alpha, IL-10 or IL-4 were demonstrated. The number of cells expressing IFN-gamma was lower in the VL patients (p < 0.05).


CONCLUSIONS
Low levels of cytokines were found in the gastrointestinal tract of patients with VL. This pattern was not found in other organs affected by the disease. Immunotolerance of this tissue against Leishmania could explain these findings, as occurs with intestinal bacteria.
Luz
Kleber Giovanni
KG
Department of Infectious Diseases, Federal University of Rio Grande do Norte, Natal, RN, Brazil. luz@ufrnet.br
Tuon
Felipe Francisco
FF
Duarte
Maria Irma Seixas
MI
Maia
Guilherme Mariz
GM
Matos
Paulo
P
Ramos
Ana Maria de Oliveira
AM
Nicodemo
Antônio Carlos
AC
D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D016207:Cytokines / Q000032:analysis* / Q000276:immunology; D004386:Duodenum / Q000276:immunology* / Q000469:parasitology; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D007413:Intestinal Mucosa / Q000276:immunology* / Q000469:parasitology; D007898:Leishmaniasis, Visceral / Q000276:immunology* / Q000473:pathology; D008264:Macrophages / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
D016207:Cytokines