Quantitative enzymatic and immunologic computer-assisted histophotometry of human kidney tissue following neoplastic and other clinically significant alterations.

Renal tissue sections from 178 patients, whose kidneys were either normal or altered by various conditions such as hydronephrosis, interstitial nephropathies, chronic graft rejection, renal cancer etc., were investigated by computer-assisted histophotometry. We used enzyme histochemical and immunologic methods to measure kidneys suffering from various urological diseases quantitatively. Through this procedure, we were able to obtain information that allowed us to determine the degree of alteration in the metabolic state of tubular epithelial cells. The tissue activities of the following enzymes of the proximal tubule were investigated: alanine aminopeptidase (AAP), alkaline phosphatase (AP) and maltase (Ma) as membrane-bound markers, and beta-glucuronidase (beta-Gl) as a lysosomal marker. In addition, AAP and gamma-glutamyltranspeptidase (GGTP) were measured by immunofluorescent microscopy after having added specific anti-enzyme antibodies to the tissue sections. Compared to normal kidneys, quantitative enzyme histograms of diseased kidneys revealed a significant decrease in marker protein concentration of the tubule. The decline in tissue enzyme activities of AP, AAP, Ma and beta-Gl was accompanied by a significant decrease of enzyme concentrations as measured by the immuno histological method. This was especially true in cases with kidney cancer and in kidney tissues adjacent to infiltration adenocarcinoma. Morphological analyses of alterations were generally improved by enzymatic and/or immunologic histophotometry.