Presence of Kimmelstiel-Wilson like lesions in canine renal faillure

Background: Nodular increases in mesangial matrix is the definition of Kimmelstiel-Wilson (K-W) lesions. In man, focal mesangiolyses and K-W nodules were positively associated with diabetes, proteinuria and hyalinization of afferent and efferent arterioles. Although, nodular sclerotic lesions may also occur in the absence of diabetic nephropathy and are clinically related to hypertension, smoking, hypercholesterolemia, among others. This study aimed to assess the presence of nodular glomerulosclerosis in dogs in non-diabetic chronic kidney disease. Materials and Methods A retrospective study including dogs with non-diabetic chronic kidney disease (n=27) was performed. Samples were stained with haematoxylin-eosin and periodic acid of Schiff and classified according to Maxie (2007). Lesions were classified as absent or present and the later, as non-convincing and convincing K-W like lesions. Univariate logistic regression models were performed to measure the association between a positive histological diagnosis of K-W lesions and the accessed histological features (variables membranes, inflammation, atrophy and fibrosis) by using statistical software R with Epicalc package. Results Nodular glomerulosclerosis was present in 66.66% of evaluated cases (n=18) of which, 38.88% (n=7) were classified as convincing and 61.11% (n=11) as non-convincing. The convincing K-W like lesions observed, revealed similar microscopic aspects to the descriptions in literature related to man. The presence of fibrosis was positively associated to the diagnosis of K-W lesions (OR=6; p<0.05). The remaining variables were not statistically associated (p>0.05). Conclusion Presence of K-W like lesions, in dogs with renal failure exposed a possible association with end-stage renal disease. Therefore, the diagnosis of K-W like lesions could be helpful to specify and define renal biopsies.

This work was supported by Portuguese Foundation for Science and Technology, Center for Studies in Education, Technologies and by Health and by strategic project PEst-OE/CED/UI4016/2011