More on Bacterial Antigen in the Kidney

Chronic pyelonephritis remains a confused and confusing entity. One of the chief reasons is the loose way in which the term is applied to kidneys that show parenchymal scars in which there is predominantly tubular loss, interstitial fibrosis accompanied by chronic inflammatory cells, and variable changes in glomeruli, which in their extreme form are completely solidified. It is now appreciated that such scarred areas may be caused by several different processes, chief among which are ischemia, infection and obstruction. In many cases, however, the etiologic factors and pathogenetic mechanisms are unknown, and for this group, it seems advisable at present.