immunology of infectious and parasitic diseases - XXXVII Congress ...

CANINE VISCERAL LEISHMANIASIS AND SPLEEN CELLS
REDISTRIBUTION: MARGINAL ZONE MACROPHAGES AND PLASMA
CELLS
THAÍS CARVALHO SANTOS 1,2 ; JOSELLI SANTOS SILVA 2 ; DEBORAH
2 2
BITTENCOURT MOTHÉ FRAGA ; MANUELA DA SILVA SOLCÀ ;
WASHINGTON LUIS CONRADO DOS SANTOS 1,2
¹ Escola Bahiana de Medicina e Saúde Pública; 2 Laboratório de Patologia e
Biointervenção, Centro de Pesquisas Gonçalo Moniz – Fundação Oswaldo
Cruz, Salvador, Bahia, Brasil.
Introduction: Visceral leishmaniasis is associated with disruption of splenic
lymphoid tissue and redistribution of cell populations involved with the immune
defense. In this work, we studied the alterations in distribution of marginal zone
macrophages and plasma cells in the spleen of dogs naturally infected with
Leishmania infantum.
Methods and Results: Spleen samples from 30 dogs grouped into three
categories (N=10): noninfected animals with organized white pulp, infected
animals with organized white pulp and infected animals with disorganized white
pulp, were used in the study. The sections were labeled with IH1 antibody (anticanine
marginal zone macrophages) and anti-dog IgG, IgM and IgA antibodies
for plasma cells identification. The number and distribution of marginal zone
macrophages and plasma cells were estimated. Additionally, the clinical and
laboratory data (biochemistry and hematology) of the animals were reviewed.
Plasmacytosis was greater in infected animals with disorganized white pulp
(7/10) than in noninfected animals (2/10, Chi-square, P < 0.04). The
albumin/globulin ratio and the clinical score related to canine visceral
leishmaniasis were higher in the animals with disorganized white pulp in
comparison with the animals with organized white pulp. No difference was
observed by morphometric analysis in the number and distribution of marginal
zone macrophages between the animal groups.
Conclusion: The plasmacytosis and disglobulinemia associated with visceral
leishmaniasis may result of a disruption of the white pulp of the spleen, affecting
B cell differentiation.
Financial support: Conselho Nacional de Desenvolvimento Científico e
Tecnológico - CNPq