Orfila C, Lepert J C, Modesto A, Bernadet P, Suc J M
INSERM U 133, CHU, Toulouse-Rangueil, France.
Am J Nephrol. 1991;11(4):345-9. doi: 10.1159/000168336.
A 59-year-old woman with kappa light-chain myeloma had Fanconi's syndrome characterized by renal glycosuria, generalized aminoaciduria, bicarbonaturia and decrease of phosphorus and uric acid reabsorption. A bone marrow biopsy showed the presence of 27% of dystrophic plasma cells; the cytoplasm of these cells was intensely stained with anti-kappa light-chain monoclonal antibodies. By light microscopy, the renal biopsy revealed a tubulointerstitial nephritis without glomerular lesions and with intratubular casts. By immunofluorescence, no deposits were observed along the glomerular and tubular basement membranes, but a positivity with anti-kappa light chain was noticed in some tubular epithelia and casts. By electron microscopy, fibrils (35-nm diameter) were observed in the cytoplasm of proximal tubular cells. These fibrils were situated in vesicles (100- to 600-nm diameter) in the luminal side of tubular cells. In the basal pole of the cell, fibrils seemed to group in crystals (120- to 200-nm diameter). Only kappa light-chain protein was demonstrated in these fibrils and crystals by an immunoelectron microscopic technique. These data suggested the pathogenic role of the fibrils and crystals present in tubular epithelium in the tubular proximal syndrome.
一名59岁的κ轻链骨髓瘤女性患有范科尼综合征，其特征为肾性糖尿、全身性氨基酸尿、重碳酸盐尿以及磷和尿酸重吸收减少。骨髓活检显示存在27%的营养不良性浆细胞；这些细胞的细胞质被抗κ轻链单克隆抗体强烈染色。光镜下，肾活检显示为肾小管间质性肾炎，无肾小球病变，有肾小管内管型。免疫荧光检查显示，沿肾小球和肾小管基底膜未观察到沉积物，但在一些肾小管上皮细胞和管型中发现抗κ轻链呈阳性。电镜下，在近端肾小管细胞的细胞质中观察到直径为35nm的原纤维。这些原纤维位于肾小管细胞腔侧直径为100至600nm的小泡内。在细胞的基底部，原纤维似乎聚集成直径为120至200nm的晶体。通过免疫电镜技术，在这些原纤维和晶体中仅证实了κ轻链蛋白。这些数据提示肾小管上皮细胞中存在的原纤维和晶体在近端肾小管综合征中具有致病作用。
