Gaines J J, Pai G M
Arch Pathol Lab Med. 1987 Oct;111(10):991-4.
A 64-year-old man with alkaptonuric ochronosis required aortic valve replacement for severe aortic stenosis and single-vessel aortocoronary artery bypass grafting for a subtotally occluded obtuse marginal branch of the circumflex coronary artery. Operative findings included ochronosis of a partly calcified aortic valve and the aortic intima. The aortic valve and a punch biopsy specimen of the ascending aorta were removed at surgery and were studied with transmission electron microscopy and light microscopy. The ultrastructural studies of the aortic valve revealed intracellular and extracellular deposits of ochronotic pigment. A portion of the extracellular ochronotic pigment represented degenerated cells. Large deposits of extracellular ochronotic pigment were associated with areas of valvular calcification. Electron microscopic study of the aorta disclosed ochronotic pigment in macrophages and smooth-muscle cells. Aggregates of extracellular ochronotic pigment in the intima and media appeared to be in locations of necrotic cells. Light microscopy also showed intracellular and extracellular deposits of ochronotic pigment. Our study suggests that extensive extracellular deposits of ochronotic pigment in the aortic valve may serve as a stimulus for dystrophic calcification. This may play a role in the development of aortic valve calcification and aortic stenosis associated with alkaptonuric ochronosis. To our knowledge, this is the first ultrastructural study of the aortic valve and aorta in alkaptonuric ochronosis.
一名患有尿黑酸尿性褐黄病的64岁男性因严重主动脉瓣狭窄需要进行主动脉瓣置换术，并因回旋支冠状动脉钝缘支几乎完全闭塞而进行单支冠状动脉搭桥术。手术发现包括部分钙化的主动脉瓣和主动脉内膜的褐黄病改变。手术中切除了主动脉瓣和升主动脉的穿刺活检标本，并进行了透射电子显微镜和光学显微镜检查。主动脉瓣的超微结构研究显示了尿黑酸色素的细胞内和细胞外沉积。部分细胞外尿黑酸色素代表退化的细胞。大量细胞外尿黑酸色素沉积与瓣膜钙化区域相关。主动脉的电子显微镜研究发现巨噬细胞和平滑肌细胞中有尿黑酸色素。内膜和中膜中细胞外尿黑酸色素的聚集似乎位于坏死细胞的位置。光学显微镜也显示了尿黑酸色素的细胞内和细胞外沉积。我们的研究表明，主动脉瓣中广泛的细胞外尿黑酸色素沉积可能是营养不良性钙化的刺激因素。这可能在与尿黑酸尿性褐黄病相关的主动脉瓣钙化和主动脉狭窄的发展中起作用。据我们所知，这是首次对尿黑酸尿性褐黄病患者的主动脉瓣和主动脉进行超微结构研究。
