Open AccessDetection of amastigotes and histopathological alterations in the thymus of Leishmania infantum ‐infected dogs
Author(s) -
Silva Aurea V. A.,
Souza Tainã L.,
Figueiredo Fabiano B.,
Mendes Artur A. V.,
Ferreira Luiz C.,
Filgueira Camila P. B.,
Cuervo Patricia,
Porrozzi Renato,
Menezes Rodrigo C.,
Morgado Fernanda N.
Publication year - 2020
Publication title -
immunity, inflammation and disease
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 18
ISSN - 2050-4527
DOI - 10.1002/iid3.285
Subject(s) - leishmania infantum , amastigote , spleen , biology , pathology , lymph , leishmania , immunohistochemistry , histopathology , lymph node , canine leishmaniasis , leishmaniasis , visceral leishmaniasis , polymerase chain reaction , immunology , parasite hosting , medicine , gene , biochemistry , world wide web , computer science
In canine visceral leishmaniasis (CVL), lymphopenia, and the disorganization of lymphoid organs such as spleen and lymph nodes have been demonstrated. However, the involvement of thymus in CVL has not been evaluated so far. Herein, we investigated whether the thymus can be colonized by Leishmania infantum in naturally infected dogs. Methods Thymus were obtained from 16 of 58 dogs and samples of this organ were submitted to immunohistochemistry for laminin and fibronectin detection, histopathology, in situ hybridization and polymerase chain reaction (PCR) targeting the gene ITS‐1 for Leishmania and sequenced. Samples of spleen, skin and popliteal lymph nodes were collected and submitted to immunohistochemistry and parasitological culture followed by multilocus enzyme electrophoresis. Results L. infantum was identified in all dogs. DNA and amastigote forms of Leishmania were detected in the thymus from 16 dogs by PCR and in eight by immunohistochemistry. Besides thymus, parasites were detected in spleen, lymph nodes, and skin. A granulomatous or pyogranulomatous thymitis was observed in eight dogs associated to intact amastigotes forms of this parasite. Fibronectin deposition in thymus was higher in dogs with more clinical signs. Conclusions These results demonstrate that the thymus of dogs can be parasitized by L. infantum , which may generate inflammatory reactions leading to alterations in thymic microarchitecture.