Matsuura Motokazu, Abe Hideharu, Tominaga Tatsuya, Sakurai Akiko, Murakami Taichi, Kishi Seiji, Bando Yoshimi, Minakuchi Jun, Nagai Kojiro, Doi Toshio
Division of Clinical Laboratory, Tokushima University Hospital.
Department of Nephrology, Institute of Biomedical Sciences, Tokushima University Graduate School.
J Med Invest. 2017;64(3.4):217-221. doi: 10.2152/jmi.64.217.
Amyloidosis is often overlooked because its clinical manifestations can mimic those of more-common diseases. It is important to get a precise diagnosis as early as possible for the prevention of further organ damages. Amyloidosis is a disorder caused by deposition of insoluble abnormal amyloid. The kidney is a frequent site of amyloid deposition. The amyloid fibrils have a characteristic appearance and generate birefringence under polarized light when stained with the Congo red dye. Classification of amyloidosis is based on the precursor protein that forms the amyloid fibrils and the distribution of amyloid deposits as either systemic or localized. Involvement of amyloid fibrils in kidneys mainly occurs as amyloid light-chain (AL) or amyloid A (AA) amyloidosis. The potassium permanganate method with Congo red staining was once used widely to discriminate AL and AA amyloidoses, but this method has a problem of false positive results. We found that extracellular and cytoplasmic glomerular 4', 6-diamidino-2-phenylindole (DAPI)-positive areas were clearly consistent with amyloid deposition in AL amyloidosis. In contrast, the overlapping staining was not seen in AA amyloidosis. Therefore, we propose that DAPI staining readily distinguishes AL renal amyloidosis from AA renal amyloidosis as a simple and reproducible histochemical method. J. Med. Invest. 64: 217-221, August, 2017.
淀粉样变性常常被忽视，因为其临床表现可能与更常见疾病的临床表现相似。尽早进行精确诊断对于预防进一步的器官损害很重要。淀粉样变性是一种由不溶性异常淀粉样蛋白沉积引起的疾病。肾脏是淀粉样蛋白沉积的常见部位。淀粉样纤维具有特征性外观，用刚果红染料染色后在偏振光下产生双折射。淀粉样变性的分类基于形成淀粉样纤维的前体蛋白以及淀粉样沉积物是全身性还是局限性的分布情况。淀粉样纤维在肾脏中的累及主要表现为淀粉样轻链（AL）或淀粉样A（AA）淀粉样变性。用刚果红染色的高锰酸钾法曾被广泛用于区分AL和AA淀粉样变性，但该方法存在假阳性结果的问题。我们发现细胞外和细胞质肾小球4',6-二脒基-2-苯基吲哚（DAPI）阳性区域与AL淀粉样变性中的淀粉样蛋白沉积明显一致。相比之下，在AA淀粉样变性中未见重叠染色。因此，我们提出DAPI染色作为一种简单且可重复的组织化学方法，能够很容易地将AL肾淀粉样变性与AA肾淀粉样变性区分开来。《医学研究杂志》64: 217 - 221，2017年8月。
