Yamagata Akira, Uchida Takahiro, Yamada Yuji, Nakanishi Takashi, Nagai Kazue, Imakiire Toshihiko, Oshima Naoki, Kumagai Hiroo
Department of Nephrology and Endocrinology, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8513, Japan.
Department of Rheumatology, National Defense Medical College, Tokorozawa, Saitama, Japan.
BMC Nephrol. 2017 Dec 29;18(1):377. doi: 10.1186/s12882-017-0799-8.
Amyloid A amyloidosis is one of the most common forms of amyloidosis. It is secondary to rheumatoid arthritis, which is difficult to manage and has a poor prognosis. We present a patient with rheumatoid arthritis and amyloid A amyloidosis who was treated with tocilizumab, a humanized monoclonal antibody against interleukin 6 receptor, resulting in improvement in both proteinuria and gastrointestinal symptoms; however, amyloid deposition remained.
A 67-year-old woman who had previously been treated for rheumatoid arthritis presented with abdominal pain and diarrhea. Right renal cell carcinoma was found, and amyloid A amyloidosis was diagnosed concomitantly based on colon biopsy. The renal cell carcinoma was resected, and the non-cancerous part of the renal tissue also showed amyloid A deposition. Following surgery, protein levels in the urine increased to the nephrotic range, and administration of tocilizumab was initiated, which resulted in resolution of the proteinuria. The patient's gastrointestinal symptoms were also alleviated. However, repeat colon biopsy showed amyloid deposition.
This case of amyloid A amyloidosis suggests that amyloid deposition indicates only structural change of the affected tissue, and that it is not amyloid deposition per se that causes the clinical symptoms of amyloidosis.
淀粉样蛋白A淀粉样变性是淀粉样变性最常见的形式之一。它继发于类风湿关节炎，后者难以治疗且预后较差。我们报告一例类风湿关节炎合并淀粉样蛋白A淀粉样变性的患者，该患者接受了托珠单抗治疗，托珠单抗是一种抗白细胞介素6受体的人源化单克隆抗体，治疗后蛋白尿和胃肠道症状均有所改善；然而，淀粉样蛋白沉积仍然存在。
一名67岁女性，既往曾接受类风湿关节炎治疗，现出现腹痛和腹泻。发现右肾细胞癌，同时根据结肠活检诊断为淀粉样蛋白A淀粉样变性。切除肾细胞癌，肾组织的非癌部分也显示有淀粉样蛋白A沉积。手术后，尿蛋白水平升至肾病范围，遂开始使用托珠单抗治疗，蛋白尿得以缓解。患者的胃肠道症状也得到缓解。然而，再次结肠活检显示有淀粉样蛋白沉积。
该例淀粉样蛋白A淀粉样变性提示，淀粉样蛋白沉积仅表明受累组织的结构改变，并非淀粉样蛋白沉积本身导致淀粉样变性的临床症状。
