狼疮肾炎肾小球和肾小管间质/血管免疫复合物 IgG 亚类的差异。

Discrepancies in glomerular and tubulointerstitial/vascular immune complex IgG subclasses in lupus nephritis.

机构信息

Department of Pathology, The Ohio State University Medical Center, M018 Starling Loving Hall, 320 W 10th Ave, Columbus, OH 43210, USA.

出版信息

Lupus. 2011 Nov;20(13):1396-403. doi: 10.1177/0961203311416533.

DOI:10.1177/0961203311416533

PMID:22095887

Abstract

BACKGROUND AND OBJECTIVES

Lupus nephritis is characterized by glomerular and extraglomerular immune complex deposition in the kidney. It is unclear whether the same circulating immune complexes deposit in the glomeruli and in extraglomerular structures, or whether they are pathogenetically different. Differences in the IgG subclass composition may point towards different pathways in the formation of glomerular and extraglomerular immune complexes. Therefore we investigated IgG subclass distribution in the immune complex deposits at these anatomic sites.

DESIGN

A total of 84 biopsies diagnosed as lupus nephritis and classified according to the International Society of Nephrology/Renal Pathology Society (ISN/RPS) 2003 classification, were examined by direct immunofluorescence staining for IgG subclasses. The IgG subclass composition in the glomerular, tubular basement membrane (TBM) and vascular wall deposits was compared. We also correlated the presence/absence of interstitial inflammation and IgG subclasses in the TBM and vascular deposits. Lastly, we looked for correlation between staining for IgG subclasses and complement C1q and C3 staining.

RESULTS

IgG staining was present in the TBM in 52/84 biopsies, and in the vascular walls in 40/84 biopsies. IgG subclass distribution was discrepant between glomerular and TBM deposits in 36/52 biopsies, and between glomerular and vascular deposits in 27/40 biopsies. Interstitial inflammation did not correlate with the presence of IgG staining or distribution of IgG subclasses in the TBM. Interstitial inflammation was more common in biopsies of African-American patients than Caucasian patients. The IgG subclass staining correlated with C1q staining in all the three compartments.

CONCLUSIONS

The antibody composition of the glomerular and extraglomerular immune complex deposits appear to differ from each other. They may not represent the same preformed immune complexes from the circulation. It is likely that their pathogenesis and site of formation are different.

摘要

背景与目的

狼疮肾炎的特征是肾小球和肾小球外免疫复合物在肾脏中的沉积。目前尚不清楚相同的循环免疫复合物是否沉积在肾小球和肾小球外结构中，或者它们是否具有不同的病理机制。IgG 亚类组成的差异可能指向肾小球和肾小球外免疫复合物形成的不同途径。因此，我们研究了这些解剖部位免疫复合物沉积中 IgG 亚类的分布。

设计

总共检查了 84 例经直接免疫荧光染色诊断为狼疮肾炎并根据国际肾脏病学会/肾脏病理学会（ISN/RPS）2003 分类法分类的活检标本，以检测 IgG 亚类。比较了肾小球、肾小管基底膜（TBM）和血管壁沉积物中 IgG 亚类的组成。我们还比较了 TBM 和血管沉积物中存在/不存在间质炎症和 IgG 亚类的情况。最后，我们观察了 IgG 亚类染色与补体 C1q 和 C3 染色之间的相关性。

结果

在 84 例活检标本中，有 52 例 TBM 中有 IgG 染色，40 例血管壁中有 IgG 染色。在 36 例活检标本中，肾小球和 TBM 沉积物中的 IgG 亚类分布不同，在 27 例活检标本中，肾小球和血管沉积物中的 IgG 亚类分布不同。间质炎症与 TBM 中 IgG 染色的存在或 IgG 亚类的分布无关。与白种人患者相比，非裔美国患者的间质炎症更为常见。在所有三个部位，IgG 亚类染色与 C1q 染色相关。