DEFINITION - CHRONIC PRODUCTIVE OR DIFFUSE NEPHRITIS WITH A chronic inflammation of the kidney attended with a growth of new connective tissue in the stroma, permanent changes in the glom eruli, degeneration of the renal epithelium, exudation from the blood vessels, and sometimes changes in the walls of the arteries.
Bright's disease; Chronic parenchymatous nephritis ; Chronic glomerulo-nephritis; Waxy kidney; Large white kidney ; Chronic diffuse nephritis ; Chronic desquamative nephritis.
It has been customary to hold that in all these kidneys the pri mary and most important changes are in the renal epithelium, while in another set of kidneys the primary and important changes are in the strorna. In other words, that the cases of chronic nephritis can be divided into two classes—parenchymatous nephritis and intersti tial nephritis.
I do not think that this classification is supported by facts.
In all the forms of chronic nephritis changes are to be found in the renal epithelium, the glomernli, and the stroma. Whether the changes in the strorna, the glomeruli, or the epithelium are the more marked makes no difference in the clinical symptoms. But the pres ence or absence of exudation from the renal blood-vessels does corre spond to a marked difference in the symptoms. The existence of the exudation from the renal vessels is easily shown by the presence of serum albumin in the urine. In this way we readily distinguish two forms of chronic nephritis, one with exudation and one without.
The way of looking at the matter, then, is this : We find after death from chronic nephritis a great many varieties in the gross appearance of the kidneys. Some are large, some are small, some are red, some are white, etc. There is no regular corre spondence between these different gross appearances of the kidneys and the clinical symptoms.
We find in these same kidneys change in the renal epithelium, in the stroma, in the glomeruli, and in the arteries. Sometimes one, sometimes the other of these elements of the kidneys is the most changed. There is no regular correspondence between the predom inance of the changes in one of the kidney elements over the other and the clinical symptoms.
The easiest working scheme is to admit that in chronic nephritis all the elements of the kidney are more or less changed, but that the cases vary as to whether there is or is not an exudation of serum from the blood-vessels. The presence or absence of such an exudation does correspond to a well-marked difference in the clinical symptoms.
In the present state of our knowledge and for clinical purposes we divide all the cases of nephritis into two classes, chronic nephritis with exudation and chronic nephritis without exudation.
It is admitted that it is easy to divide up these kidneys according to their anatomical changes into a number of fairly well-marked classes. But as this division does not correspond to clinical divisions it is valueless for clinical purposes.
Although it is convenient to describe two forms of chronic ne phritis—one with much albuminuria and dropsy, and one with little or no albuminuria, or dropsy—yet it must be remembered that these are not separate lesions of the kidneys, but varieties of the same lesion. For in all these kidneys two changes are constant—produc tive inflammation of the glomeruli and stroma, and degeneration of the renal epithelium. The only real difference between the kidneys is whether, besides the growth of new tissue and degeneration of renal epithelium, there is or is not an exudation of serum from the blood-vessels of the kidneys.
In speaking of the exudation of serum from the vessels and its presence in the urine, we speak of it as it occurs during the whole course of the disease, and not as it occurs for short periods. We mean that in an exudative chronic nephritis there is usually a large quantity of albumin in the urine, but that there may be periods dur ing which the albumin diminishes or entirely disappears. In the same way in a non-exudative nephritis there may be periods during which albumin is present in considerable quantities. Generally speaking, the character of the clinical symptoms will vary with the presence or absence of the albumin.
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