Inflammatory response, parasite load and AgNOR expression in ear skin of symptomatic and asymptomatic Leishmania (Leishmania) chagasi infected dogs

Verçosa BLA (1), Borges ACJ (1), Mendes FJM (2), Costa MLS (2), Pereira NB (1), Melo MN (3), Mendonça IL (4), Costa FAL (4), Vasconcelos AC (1)

(1) Department of General Pathology, Center of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais State, Brazil; (2) Zoonosis Control Center, Timon, Maranhão State, Brazil; (3) Department of Parasitology, Center of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais State, Brazil; (4) Department of Clinical Veterinary Medicine and Surgery, Center of Agrarian Sciences, Federal University of Piauí, Teresina, Piauí State, Brazil.

Abstract: The skin has an important role in the transmission of visceral leishmaniasis (VL) as the infection pathway in dogs. To better characterize the inflammatory response of intact skin in VL, sixty infected dogs (30 symptomatic and 30 asymptomatic) and six non-infected controls were studied. Diagnosis of visceral leishmaniasis was confirmed by RIFI and ELISA; direct visualization of the parasite in bone marrow aspirate; imprints of popliteal lymph nodes, spleen, liver and skin; culture in NNN-phase liquid Schneider’s medium; and PCR (performed only in the ear skin). Amastigote forms of the parasite in intact skin were found only in symptomatic dogs. Inflammatory infiltrates were observed in all groups, varying from intense and/or moderate in symptomatic to discrete and/or negligible in asymptomatic and control animals. Parasite load was associated with the intensity of the inflammatory response and with clinical manifestations in canine visceral leishmaniasis. AgNOr as active transcription markers were expressed in inflammatory cells and within apoptotic bodies in all groups, including controls, with no statistical difference. Therefore, cell activation and transcription do occur in both symptomatic and asymptomatic canine visceral leishmaniasis and may result in more necrosis and inflammation or in apoptosis and less symptoms, depending on the parasite load.

Key words: visceral leishmaniasis, inflammation, parasites, Leishmania chagasi.

ACKNOWLEDGEMENTS

Thanks are due The National Council for Scientific and Technological Development (CNPq) and The State of Minas Gerais Research Foundation (FAPEMIG) which financially supported the present study.

COPYRIGHT

© CEVAP 2011

SUBMISSION STATUS

Received: February 15, 2001.

Accepted: June 13, 2011.

Abstract published online: June 17, 2011.

Full paper published online: August 31, 2011.

CONFLICTS OF INTEREST

There is no conflict.

FINANCIAL SOURCE

The National Council for Scientific and Technological Development (CNPq) and The State of Minas Gerais Research Foundation (FAPEMIG) provided the financial grants.

ETHICS COMMITTEE APPROVAL

The present study was approved by the Ethics Committee in Animal Experimentation of the Federal University of Minas Gerais (UFMG-CETEA, process number 198/2007, approved in March 27, 2008).

CORRESPONDENCE TO

BÁRBARA LAURICE ARAÚJO VERÇOSA, Laboratório de Apoptose, Departamento de Patologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais. Phone: +55 31 3409 2889. Fax: +55 31 3409 2878. Email: brbaravet@yahoo.com.br.