Acute suppurative nephritis is not a common disease, but it is a very serious and a very fatal one. In one case it supervened upon were much enlarged, evidently from a recent attack of acute inflammation, numerous small points of suppuration were scattered through them, and the left contained two large recent abscesses. This case occurred in King's Col lege Hospital, under the care of Dr. Todd.
Acute desquantative nephritis.—This form of disease occurs very frequently as a conse quence of scarlatina, and is occasionally pro duced by other animal poisons, as for instance that of typhus fever, small-pox, or measles. The same condition of kidney- very commonly occurs amongst the poor in large towns and elsewhere, as a consequence of that deterior ated condition of the blood, which results from an insufficient supply of animal food ; and it sometimes occurs as a consequence probably of a similarly deteriorated condition of the blood in persons who are much reduced by long-continued disease, as for instance secon dary syphilis or chronic abscess.
The kidney in these cases is enlarged, ap parently by the deposit of a white material in the cortical substance ; the vessels in the cortical portion where they are not compressed by this new material, are injected, and of a bright red hue ; the medullary cones are of a dark red colour, in consequence of the large veins which occupy these portions of the gland being distended with blood. The ap pearance of the entire organ is quite that of a part in a state of acute inflammation.
When the kidney has been in a softened condition before the occurrence of the inflam matory disease, as often happtns in elderly persons, the lobules on the surface appear larger and coarser than natural ; the veins being less compressed than v,hen the natural texture of the kidney is firmer and more un yielding, are much distended with blood, so that the entire organ is of a dark slate colour.
On a microscopical examination the con voluted tubes are seen filled, in different de grees, with nucleated cells, differing in no essential character from those which line the tubes of the healthy gland (fig. 168). The minish in quantity, and finally disappear; but traces of the casts may be seen some days after the urine has ceased to coagulate, on the application of heat or nitric acid.
Malpighittn bodies are for the most part trans parent and healthy, but the vessels of the tuft are sometimes rendered opaque by an accu mulation of small cells on their surface. Some
of the tubes contain blood, which has doubt less escaped from the gorged Malpighian vessels. There is no deposit exterior to the tubes.
The condition of the urine in these cases is clearly indicative of the process going on in the kidney. After it has been allowed to stand for a short time, a sediment forms ; and on placing a portion of this under the microscope, there may be seen blood-cor puscles, with epithelial cells in great numbers, partly free and partly entangled in cylindrical fibrinous casts of the urinary tubes*, and very commonly numerous crystals of lithic acid are present (fig. 169).
As the disease subsides, which under proper treatment it usually' does in a few days, the blood, fibrinous casts, and epithelial cells di The changes above described as occurring in the kidney are the result of a modification of the natural process of secretion produced by the presence of abnormal products in the blood. These products are eliminated by an excessive development of epithelial cells which are thrown into the tubes and washed out with the urine. The desquamation from the inner surface of the tubes is analogous to that which occurs on the skin subsequent to the eruption of scarlatina. I have, therefore, pro posed to apply the term " acute desquamative nephritis" to this form of disease.* Chronic desquamative nephritis is essentially of the same nature as the acute form of the disease. Its most frequent cause is the gouty diathesis, and it very rarely occurs except in those who are addicted to the use of alcoholic drinks.t In the earlier stage of the disease the kidney is of the natural size, or very slightly enlarged, and the structure of the organ appears confused, as if from the ad mixture of some abnormal product ; there is also some increase of vascularity. As the disease advances, the cortical portion gradually wastes, and the entire organ becomes con tracted, firrn, and granular, the medullary cones remaining comparatively unaffected even in the most advanced stages ; simultaneously with the diminution in the size of the kidney there is a decrease of vascularity. These changes occur very gradually ; the disease having a duration in most cases of many months, and in some even of several years.