Lee Chen Yu Jamie, Elliott Mark D, Lehman Anna, Farah Myriam, McRae Susanna A, Riazy Maziar
Department of Pathology, Cedars-Sinai Medical Center, Los Angeles, CA.
Department of Pathology, University of British Columbia, Vancouver, BC, Canada.
Kidney Med. 2025 Sep 16;7(11):101107. doi: 10.1016/j.xkme.2025.101107. eCollection 2025 Nov.
Adult Refsum disease is a rare hereditary peroxisomal disorder characterized by impaired phytanic acid metabolism. The accumulation of phytanic acid in tissues, especially adipose and neural, is believed to contribute to disease manifestations. Clinically apparent kidney dysfunction has been reported in only 2 cases. We describe a 55-year-old woman with adult Refsum disease, who was referred to nephrology for impaired kidney function without proteinuria. Kidney biopsy showed vacuolization of proximal tubular epithelium and unremarkable glomeruli. Focally, distal tubular cytoplasm showed variably sized crystals with ultrastructural laminated substructures (or "paracrystalline formation"). To the best of our knowledge, the light microscopy for these crystals in a peroxisomal disease has not been previously described, and adult Refsum disease has not been described as a significant metabolic kidney disorder. These unique morphologic features contribute to the spectrum of findings in this rare genetic condition. This case also demonstrates the value of kidney function monitoring and therapeutic plasma exchange for these patients.
成人Refsum病是一种罕见的遗传性过氧化物酶体疾病，其特征为植烷酸代谢受损。植烷酸在组织中尤其是脂肪组织和神经组织中的蓄积被认为是疾病表现的原因。临床上明显的肾功能障碍仅在2例中被报道过。我们描述了一名55岁患有成人Refsum病的女性，她因肾功能受损但无蛋白尿而被转诊至肾病科。肾脏活检显示近端肾小管上皮细胞空泡化，肾小球无明显异常。局部可见远端肾小管细胞质中有大小不一的晶体，具有超微结构的层状亚结构（或“类晶体形成”）。据我们所知，此前尚未描述过过氧化物酶体疾病中这些晶体的光学显微镜表现，成人Refsum病也未被描述为一种显著的代谢性肾脏疾病。这些独特的形态学特征丰富了这种罕见遗传病的表现谱。该病例还证明了对这些患者进行肾功能监测和治疗性血浆置换的价值。
