全身性エリテマトーデスの病理学

Abstract

Histological and histochemcal studies of systemic lupus erythematosus (SLE) were performed on 31 autopsy cases. Results obtained and brief comments on them were as follows. Hematoxylin bodies (HX bodies) and fibrinoid necrosis of the vascular system were the main pathologic condions in SLE. HX bodies were found in 16 cases, with regularity in areas of fibrinoid necrosis. They were considered to represent the in vivo counterpart of the in vitro LE phenomenon, even though some tinctorial characteristics were different. HX bodies were PAS positive, not metachromatic, and might show reduced Feulgen reaction. When some of HX bodies were ingested by polymorphonuclear luekocytes, LE cells could be detected in the tissue. Fibrinoid necrosis had occasionally been described in other conditions and considered not pathognomonic of SLE. However, in SLE vascular lesions were widespread, and so often took the form of fibrinoid necrosis. Not only Libman-Sacks endocarditis but also glomerular lesions called “wire loop” lesion and “hyaline thrombi” could be regarded as variants of fibrinoid necrosis. In this meaning, fibrinoid necrosis could be regarded as almost pathognomonic of SLE. Fibrinoid necrosis of small vessels was frequent and encountered in 16 cases. Severe necrotizing angiitis as seen in periarteritis nodosa was noted in 6 cases. Endocarditis occurred in 10 cases and fully developed lesions conforming to the description of Libman and Sacks were present in 5 cases. Fibrinoid necrosis of the cardiovascular system was a common site of HX bodies, and not infrequently had a diffuse hematoxyphilic tincture suggesting the deposition of the nuclear substance. Lupus nephritis characterized by pleomorphic and irregular glomerular damage was noted in 25 cases. The most distinctive features included necrosis (often fibrinoid necrosis), karyorrhexis, hyaline thrombi, wire loop lesion and HX bodies. The frequency of the latter three findings was 48%, 61% and 39%, respctively. Thickening of the basement membrane refered to as wire loop lesion was brightly eosinophilic and a hard refractile appearance. Hyaline thrombi were eosinophilic globules filling the lumen of capillaries and closely resembled wire loop lesions. Both lesions had similar staining properties as noted in the vascular fibrinoid and were frequent sites of HX bodies. They showed not rarely a rather diffuse hematoxyphilic tincture, where Feulgen reaction was weakly positive. Another important and the most frequent change in SLE was the concentric lamination of dense collagen fibers arround the central arterioles of the spleen. This change called onion skin lesion was noted in 29 cases. The most remarkable pulmonary change in SLE was a variety of the interstitial pneumonia. This lesion occurred in 11 cases and the most distinctive features included were alveolar exsudate containing fibrin, hyaline membrane, HX bodies, formation of Masson bodies, and fibrosis of alveolar septa. The majority of lesions in SLE might be induced by the immune complexes deposited in the affected vessels. The lesion is histologically characterized by changes in the vessel wall leading to fibrinoid necrosis and the basement membrane thickening, in which deposition of immunoglobulin, complement and fibrinogen are detected. The presence of hematoxyphilic substance with positive Feulgen reaction suggests the deposition of the nuclear substance. Actually DNA antigen has been demonstrated in the glomeruli and the acid eluate from affected glomeruli is said to be rich in antinuclear antibodies. When regard to the pathogeneis of SLE, simultaneous presence of DNA and anti-DNA antibodies in the lesion should raise attention to the role of immune complexes on the vascular system including renal glomeruli.