THE KIDNEY IN PERIARTERITIS NODOSA1

THE association of renal lesions with periarteritis nodosa has been known since the publication of the first comprehensive description of the disease by Kussmaul and Maier (1866). The frequency of renal involvement has been stated to be 73 per cent, of cases (Gruber, 1925), 80 per cent, of cases (Arkin, 1930), and 87 per cent, of cases (Harris, Lynch, and O'Hare, 1939). Gruber's review of 108 cases from the literature shows that while multiple renal infarcts were a common finding, there were also cases in which diffuse changes in the renal parenchyma were present, and these were usually described as one or other form of nephritis. In the literature before and since Gruber's paper, opinions have varied as to the relation of these parenchymal changes to the periarteritis nodosa. Thus, Ophuls (1923) believed that the diffuse nephritis seen in periarteritis nodosa was an unrelated coincidental lesion, yet Kroetz (1921) thought that the same factor that involved the renal arteries was also the cause of the nephritic lesions. Meyer (1921) could not decide whether the nephritic lesions were secondary to the vascular involvement or directly due to a hypothetical toxic factor. Gray (1929) argued that the nephritic lesions were secondary to involvement of arterioles by periarteritis nodosa. Grant (1940) held that the renal changes were primary manifestations of periarteritis nodosa and not those of an independent glomerulonephritis. Furthermore, Lohlei