Oortwijn Beatrijs D, Rastaldi Maria Pia, Roos Anja, Mattinzoli Deborah, Daha Mohamed R, van Kooten Cees
Department of Nephrology, Leiden University Medical Center, Leiden, The Netherlands.
Nephrol Dial Transplant. 2007 Nov;22(11):3191-5. doi: 10.1093/ndt/gfm346. Epub 2007 Jun 2.
Recently we reported a possible role for secretory IgA (SIgA) in IgA nephropathy (IgAN), as suggested by increased serum levels in patients with active disease and accumulation of SIgA in a glomerular eluate. Therefore, we attempted to find support for these findings by analysis of the presence of SIgA in biopsies of IgAN patients.
Renal biopsies of 26 patients with biopsy-proven IgAN were analysed for the presence of SIgA and complement proteins.
In 15% mesangial deposition of SIgA was demonstrated, using a specific staining for secretory component (SC) and colocalization with IgA. The presence of SIgA in these biopsies showed a strong correlation with deposition of mannose-binding lectin (MBL) and C4d. Moreover, we observed a strong colocalization between SIgA and MBL or C4d. This local complement activation has previously been linked to more severe renal disease.
Therefore, these data provide additional evidence for a pathogenic role for SIgA in IgA nephropathy.
最近我们报道了分泌型IgA（SIgA）在IgA肾病（IgAN）中可能发挥的作用，这是由活动性疾病患者血清水平升高以及肾小球洗脱液中SIgA的积聚所提示的。因此，我们试图通过分析IgAN患者活检组织中SIgA的存在情况来支持这些发现。
对26例经活检证实为IgAN的患者的肾活检组织进行SIgA和补体蛋白检测。
使用分泌成分（SC）特异性染色并与IgA共定位，证实15%的患者存在系膜区SIgA沉积。这些活检组织中SIgA的存在与甘露糖结合凝集素（MBL）和C4d的沉积密切相关。此外，我们观察到SIgA与MBL或C4d之间存在强烈的共定位。这种局部补体激活此前已与更严重的肾脏疾病相关联。
因此，这些数据为SIgA在IgA肾病中的致病作用提供了额外证据。
