Department of Pathology, Stanford University School of Medicine, Stanford.
Department of Pathology, University of California San Francisco, San Francisco.
Am J Surg Pathol. 2024 Sep 1;48(9):1138-1145. doi: 10.1097/PAS.0000000000002253. Epub 2024 May 28.
Bietti crystalline dystrophy (BCD) is a rare heritable retinal disease characterized by crystal deposition primarily in the retina. It is associated with atrophy of the retinal pigment epithelium (RPE) and is caused by variants in CYP4V2 , which encodes a cytochrome P450 hemethiolate protein superfamily member. CYP4V2 is involved in the selective hydrolysis of saturated medium chain fatty acids, and patients with BCD demonstrate abnormalities in fatty acid metabolism, including abnormal lipid profiles and the accumulation of the pathogenic crystals within the RPE, which leads to the visual pathologies characteristic of BCD. However, the precise identity of the crystals is currently unknown, and BCD has no established extraocular manifestations. Here, we report granulomatous hepatitis associated with abundant diffuse crystalline clefts in the hepatic parenchyma in 3 patients with retinal dystrophy and dyslipidemia: 2 with pathogenic CYP4V2 variants and 1 patient with clinical ophthalmologic findings suggestive of BCD but without available genetic testing. The unique and striking histologic features unifying the liver biopsies in all 3 patients strongly support a process related to abnormal fatty acid metabolism underlying the genetic disease of BCD, expanding the spectrum of BCD and shedding light on the importance of CYP4V2 in systemic fatty acid metabolism.
Bietti 结晶性营养不良症 (BCD) 是一种罕见的遗传性视网膜疾病,其特征是主要在视网膜中出现晶体沉积。它与视网膜色素上皮 (RPE) 的萎缩有关,是由 CYP4V2 的变异引起的,CYP4V2 编码细胞色素 P450 硫醇盐蛋白超家族成员。CYP4V2 参与饱和中链脂肪酸的选择性水解,而 BCD 患者表现出脂肪酸代谢异常,包括脂质谱异常和 RPE 内致病性晶体的积累,这导致了 BCD 特有的视觉病理学。然而,目前尚不清楚这些晶体的确切性质,并且 BCD 没有明确的眼外表现。在这里,我们报告了 3 名视网膜营养不良和血脂异常患者的肝实质中存在大量弥漫性结晶裂隙的肉芽肿性肝炎:2 名患者携带致病性 CYP4V2 变异,1 名患者具有临床眼科表现提示 BCD,但无可用的基因检测。所有 3 名患者的肝脏活检均具有独特而引人注目的组织学特征,强烈支持了 BCD 这种遗传性疾病的异常脂肪酸代谢相关过程,扩大了 BCD 的范围,并强调了 CYP4V2 在系统性脂肪酸代谢中的重要性。
Cell Commun Signal. 2024-7-11
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