The Consequences of Tubulo-Interstitial Changes for Renal Function in Glomerulopathies: A Morphometric and Cytological Analysis

Abstract

In recent years it has become recognized to an increasing extent that a wide range of inflammatory and non-inflammatory glomerular diseases may be complicated with varying frequency by disease in the region of the post-glomerular intertubular capillaries. Thus we found additional disease of the tubulo-interstitial system in 4.0 – 69.5% of patients with the diseases listed in Table 1. Amongst these diseases, accompanying inflammation of the renal cortical interstitium occurs least often in endocapillary glomerulonephritis and most often in diabetic glomerulosclerosis. Amongst the glomerulonephritides, interstitial inflammation leading to fibrosis is observed most frequently in rapidly progressive glomerulonephritis and membranoproliferative glomerulonephritis. Interstitial inflammation is found relatively often in glomerular amyloidosis. As a result of investigations we have undertaken in the last three years, it has been possible to demonstrate that the character of the inflammatory interstitial changes that accompany glomerular diseases is always the same, no matter what the glomerulopathy may be. The cells most predominantly involved in the inflammatory process are T lymphocytes, macrophages, fibroblasts and fibrocytes. Thus dense foci of T lymphocytes and macrophages are seen not only in

Table 1 Survey of the incidence of intertubular inflammation associated with interstitial fibrosis in various glomerulopathies.

mesangioproliferative glomerulonephritis, but also in the interstitial inflammation that complicates renal amyloidosis. The tubulo-interstitial inflammation of diabetic glomerulosclerosis is also characterized by T lymphocytes, macrophages, fibroblasts and fibrocytes.

Supported by the Deutsche Forschungsgemeinschaft