Pathomorphological changes of the spleen of pigs at different stages of development of clinically expressed PCV2-infection

Keywords: PCV2-infection; spleen; lymph nodules; periarterial lymphoid sheaths; relative area; immunohistochemistry

Abstract

The spleen is an organ that controls the antigenic homeostasis of the blood and provides its filtration. With purpose of determination of pathomorphological changes in the spleen of pigs at different stages of the development of clinically expressed PCV2-infection the comprehensive research was carried out in pig farms of Ukraine, with intensive technology of pig rearing, at the department of normal and pathological anatomy of agricultural animals and the Scientific and Research Center for Biosafety and Environmental Control of the Agroindustrial Complex Resources of Dnipro State Agrarian and Economic University. On the ground of pathological and immunohistochemical studies, the pathomorphological changes of the spleen of pigs at different stages of the development of clinically expressed PCV2-infection have been determined. For pathomorphological studies, animals with clinical signs of active PCV2-infection (in 1 ml of whole blood contained more than 107 copies of the gene, equivalent to the PCV2-virus), as well as piglets with positive optical density of specific antibodies (Ig G and Ig M) in serum blood were selected. It was established, that in the case of clinically expressed PCV2-infection, the spleen had severe symptoms of the disease, the intensity of which depended on the stage of the disease. The stage of early active PCV2-infection is characterized by moderate increase in the macromorphometric parameters of the organ, significant increase in the relative area of the white pulp (at the expense of periarterial lymphoid sheaths and lymph nodules). At the stage of active chronic PCV2-infection, the sharp increase in organometric parameters of the spleen, decrease in the relative indices of white pulp on the background of  increase in the area of connective tissue stroma and red pulp are observed. The stage of resolution of PCV2-infection is characterized by symptoms of sclerosis of lymphoid parenchyma of the organ. With that its macroscopic and morphometric parameters somewhat increase, but the morphometric indices of the white pulp are minimal, and the indices of the connective tissue stroma are maximal. The development of the infectious process for clinically expressed PCV2-infection is manifested by reactive and acute inflammatory processes in the parenchyma of the spleen. Due to the lymphotropic properties of the pathogen, its ability to be stored in macrophages, the acute inflammatory process is gradually transformed into chronic, and reactive inflammation – into a productive granulomatous type, which is related to immunopathological hypersensitivity reactions of the delayed type.

Downloads

Download data is not yet available.

References

Alarcon, P., Rushton, J., & Wieland, B. (2013). Cost of post-weaning multi-systemic wasting syndrome and porcine circovirus type-2 subclinical infection in England – an economic disease model. Preventive Veterinary Medicine, 110(2), 88–102.

Brunborg, I. M., Moldal, T., & Jonassen, C. M. (2004). Quantitation of porcine circovirus type 2 isolated from serum/plasma and tissue samples of healthy pigs and pigs with postweaning multisystemic wasting syndrome using a TaqMan-based real-time PCR. Journal of Virological Methods, 122(2), 171–178.

Chianini, F., Majó, N., Segalés, J., Domı́nguez, J., & Domingo, M. (2003). Immunohistochemical characterisation of PCV2 associate lesions in lymphoid and non-lymphoid tissues of pigs with natural postweaning multisystemic wasting syndrome (PMWS). Veterinary Immunology and Immunopathology, 94(1-2), 63–75.

Doster, A. R., Subramaniam, S., Yhee, J.-Y., Kwon, B.-J., Yu, C.-H., Kwon, S.-Y., Osorio, F. A., & Sur, J.-H. (2010). Distribution and characterization of IL-10-secreting cells in lymphoid tissues of PCV2-infected pigs. Journal of Veterinary Science, 11(3), 177.

Dvorak, C. M. T., Puvanendiran, S., & Murtaugh, M. P. (2013). Cellular pathogenesis of porcine circovirus type 2 infection. Virus Research, 174(1-2), 60–68.

Evert, V., Gavrilin, P., & Lieshchova, M. (2018). Morphometric characterization of universal hematopoietic organs in piglets during postnatal adaptation. Scientific Messenger of LNU of Veterinary Medicine and Biotechnologies. Series: Veterinary Sciences, 20(83), 13-18.

Gavrilin, P. N., & Evert, V. V. (2015). The concept of mechanisms of damage to organs of the immune system in pigs with circovirus infection (syndrome of multisystem exhaustion). Science and Technology Bulletin of SRC for Biosafety and Environmental Control of Agro-industrial Complex, 3 (2), 12-20 (in Ukrainian).

Gavrilin, P. N., Lieshchova, M. A., Gavrilina, O. G., & Boldyreva, T. F. (2018а). Prenatal morphogenesis of compartments of the parenchyma of the lymph nodes of domestic cattle (Bos taurus). Regulatory Mechanisms in Biosystems, 9(1), 95–104.

Gavrilina, O. G., & Evert, V. V. (2016). Methodical features of application of immunohistochemical diagnostics of circovirus infection of pigs. Veterinary, Animal Husbandry and Nature Management Technologies, 32(2), 294–301 (in Ukrainian).

Gavrilin, P., Oliyar, A., & Evert, V. (2018b). Pollutionality of morphogenesis of cereals dusts in the early postnotal period of ontogenesis. Veterinary Science, Technologies of Animal Husbandry and Nature Management, (1), 112-116.

Goralsky, L. P., Khomich, V. T., & Kononsky, O. I. (2011). Basis of histological technology and morphofunctional methods of dosage in normology with pathology. Zhitomir, Polissya (in Ukrainian).

Krakowka, S., Ellis, J. A., McNeilly, F., Ringler, S., Rings, D. M., & Krakowka, S., Ellis, J. A., McNeilly, F., Ringler, S., Rings, D. M., & Allan, G. (2001). Activation of the immune system is the pivotal event in the production of wasting disease in pigs infected with Porcine Circovirus-2 (PCV-2). Veterinary Pathology, 38(1), 31–42.

Oliiar, A. V., & Lieshchova, M. A. (2019). Structural and functional organization of central organs of hematopoiesis and immune protection of piglets during the early postnatal period of ontogenesis. Theoretical and Applied Veterinary Medicine, 7(1), 8–13.

Opriessnig, T., Meng, X.-J., & Halbur, P. G. (2007). Porcine circovirus type 2-associated disease: Update on current terminology, clinical manifestations, pathogenesis, diagnosis, and intervention strategies. Journal of Veterinary Diagnostic Investigation, 19(6), 591–615.


Abstract views: 308
PDF Downloads: 131
Published
2019-06-10
How to Cite
Evert, V. V. (2019). Pathomorphological changes of the spleen of pigs at different stages of development of clinically expressed PCV2-infection. Theoretical and Applied Veterinary Medicine, 7(2), 126-132. https://doi.org/10.32819/2019.71023