Qualitative and quantitative analysis of fibrosis in the kidney.

Renal fibrosis results from an excess accumulation of connective tissue, primarily collagen, in response to tissue injury-associated aberrant wound healing, which is over-expressed in the renal vascular, glomerular and tubulointerstitial compartments. Despite being the final common pathway of end stage kidney disease, there is a lack of consensus on standardized approaches to measure fibrosis. In this article we therefore describe how a combination of immunohistochemical staining and biochemical measurement of hydroxyproline can be used to qualitatively and quantitatively examine the different forms of fibrosis. These techniques provide measures of both the composition of fibrosis, and a means of evaluating interventions in this significant process.