Histopathologic Patterns of Nephropathy in Naturally Acquired Canine Visceral Leishmaniasis

Abstract

Abstract. Although the nephropathy of visceral leishmaniasis (VL) is known both in humans and dogs, histopathologic alterations have not been thoroughly studied. We examined renal alterations in 55 dogs with naturally acquired VL compared with five noninfected dogs from an endemic area in northeastern Brazil. Glomerulonephritis was found in 55 dogs, interstitial alterations in 53 dogs, and tubular changes in 43 dogs with VL. The glomerular alterations found were minor glomerular abnormalities (n ϭ 8, 14.5%), focal segmental glomerulosclerosis (n ϭ 10, 18.2%), mesangial proliferative glomerulonephritis (n ϭ 17, 32.7%), membranoproliferative glomerulonephritis ,(n ϭ 18, 30.9%), crescentic glomerulonephritis (n ϭ 1, 1.8%), and chronic glomerulonephritis (n ϭ 1, 1.8%). Morphometric and ultrastructural studies complemented the analysis. The five control animals exhibited no glomerular alterations. The glomerular lesions were related to functional alterations. Considering that the alterations of canine and human nephropathy in VL are very similar, the data obtained in this study constitute an important contribution to the understanding of canine and human VL nephropathy.Key words: Dogs; glomerulonephritis; morphometry; renal pathology; ultrastructure; visceral leishmaniasis.Canine visceral leishmaniasis (VL) is a highly prevalent infection encountered throughout the world. In Brazil, VL results from infection by the protozoan Leishmania (Leishmania) chagasi, which occurs in 18 of 27 Brazilian states. 20,22,26 VL is endemic to northeastern Brazil, and in Teresina, in the State of Piaui, some 1,600 dogs presenting naturally acquired VL were known when this study was initiated. At present, VL is also spreading to other urban areas in the southern and southeast regions, where the disease was not previously endemic. 31 In the infectious cycle of VL, the dog is the most important domestic reservoir and exhibits chronic evolution of the disease. 1,8,21 Leishmania is an obligatory intracellular parasite of mononuclear phagocytes. During infection, various host organs are affected including the kidney. Although VL-related nephropathy is known both in humans and dogs, the histopathologic patterns of the lesions present in VL have not been clearly established because most studies are based on very few cases and mainly because well-defined, lesion classification criteria were not used. 3,4,9,10,24,37,38 In human VL, glomerulosclerosis, mesangial cell proliferation, and interstitial nephritis have been reported. 3,9,10,16,18,38 Renal involvement in canine VL is also frequent, and the renal changes are similar to those seen in humans. 2,5,8,23,32 This similarity renders the study of canine VL nephropathy of interest with regard to human pathology. The renal lesion itself does not lead to renal insufficiency. However, when moderate or severe renal lesions are present, VL patients with systemic complications such as secondary infections, sepsis, and hypotension do develop renal insufficiency. 16 Furthermore, glomerular lesions appare...

Renal involvement in canine leishmaniasis: a morphological and immunohistochemical study

“…Differently from the IgG reactions that were weaker in the renal glomeruli, the presence of mesangial cells with fluorescent staining in the cytoplasm was more frequent, and the inflammatory infiltrate was frequently stained in these kidney sections. As to the localization of granules, reaction intensity, and pattern of distribution, the results corroborate those found in renal immunohistochemical assay of 26 dogs with naturally acquired Leishmania chagasi infection (Costa et al, 2003).…”

“…The immunoglobulin deposits were granular and were located on the glomerular capillary walls more than in the mesangium, for IgG as well as for IgM. The distribution of these in the glomerulus was irregular, sometimes focal or diffuse, sometimes global or focal segmental (Costa et al, 2003).…”

Immunoactivation and immunopathogeny during active visceral leishmaniasis

“…We detected CD4 + T cells in the glomeruli of five dogs with naturally acquired visceral leishmaniasis from an area where the disease is endemic 17 . Furthermore, in a parallel study we identified glomerulonephritis in 55 dogs naturally infected with visceral leishmaniasis, characterized their glomerular alterations histopathologically, and classified them into six different patterns (proliferative patterns were most common) 16 . Both studies strongly suggested that the migration and proliferation of cells, including T cells, plays a role in the pathogenesis of glomerulonephritis in visceral leishmaniasis.…”

“…Dogs and hamsters with visceral leishmaniasis presenting lesions similar to those in humans are used as models to understand human pathology 16,57 . Until recently, studies of glomerular alterations in visceral leishmaniasis pathogenesis have only found immune complex deposition 19,53,58 .…”

Lesões do sistema urinário em 1.063 cães

“…A deposição de imunocomplexos nos glomérulos é o principal mecanismo desencadeador, que pode ocorrer em cães com doenças auto-imunes (como lúpus eritematoso sistêmico), em infecções persistentes (como nos casos de piometra, leishmaniose e diroϐilariose) ou em cães com neoplasmas (Costa et al 2003, Maxie & Newman 2007, Serakides 2010. Cães adultos e idosos podem apresentar deposição de imunocomplexos nos glomérulos, sem, no entanto apresentar sinais de doença renal (Rouse & Lewis 1975).…”