Matsuura Keiko, Uesugi Noriko, Hijiya Naoki, Uchida Tomohisa, Moriyama Masatsugu
Department of Molecular Pathology, Faculty of Medicine, Oita University, Hasama-machi, Yufu, Oita 879-5593, Japan.
Hum Pathol. 2007 Mar;38(3):410-9. doi: 10.1016/j.humpath.2006.09.006. Epub 2007 Jan 19.
Cardiac ankyrin-repeated protein (CARP) was originally identified as a protein specifically expressed in cardiomyocytes, but has recently been found to be upregulated in some muscle diseases including muscular dystrophy and myopathy, suggesting that CARP may be induced in some pathologic conditions. In this study, we immunohistochemically analyzed 69 renal biopsy samples from patients with glomerular diseases and 2 individuals with normal kidney. We found that CARP was expressed in renal podocytes at a high level in 10 of 13 cases of crescentic glomerulonephritis, 7 of 19 cases of diabetic nephropathy, and 12 of 20 cases of lupus nephritis, although it was not expressed in endocapillary glomerulonephritis, minimal change disease, thin basement membrane disease, membranous glomerulonephritis, and normal kidney. Interestingly, in lupus nephritis, CARP expression tended to be induced in cases exhibiting nephrotic syndrome, but less so in cases without nephrotic syndrome, suggesting that CARP expression is correlated with the severity of proteinuria. Furthermore, we found that CARP was not expressed in membranous glomerulonephritis but evidently expressed in most cases of membranous lupus nephritis. Although membranous glomerulonephritis and membranous lupus nephritis are sometimes morphologically indistinguishable, it is suggested that their pathologic mechanisms differ. Therefore, we propose that examination of CARP expression is useful for precise differential diagnosis of membranous glomerulonephritis and membranous lupus nephritis.
心肌锚蛋白重复蛋白（CARP）最初被鉴定为一种在心肌细胞中特异性表达的蛋白质，但最近发现它在包括肌肉萎缩症和肌病在内的一些肌肉疾病中上调，这表明CARP可能在某些病理条件下被诱导表达。在本研究中，我们对69例肾小球疾病患者的肾活检样本以及2例正常肾脏个体进行了免疫组织化学分析。我们发现，CARP在13例新月体性肾小球肾炎中的10例、19例糖尿病肾病中的7例以及20例狼疮性肾炎中的12例的肾足细胞中高水平表达，而在内生性肾小球肾炎、微小病变肾病、薄基底膜肾病、膜性肾小球肾炎以及正常肾脏中未表达。有趣的是，在狼疮性肾炎中，CARP表达倾向于在表现为肾病综合征的病例中被诱导，而在无肾病综合征的病例中诱导程度较低，这表明CARP表达与蛋白尿的严重程度相关。此外，我们发现CARP在膜性肾小球肾炎中未表达，但在大多数膜性狼疮性肾炎病例中明显表达。尽管膜性肾小球肾炎和膜性狼疮性肾炎有时在形态上难以区分，但提示它们的病理机制不同。因此，我们认为检测CARP表达有助于膜性肾小球肾炎和膜性狼疮性肾炎的精确鉴别诊断。
