Division of Immunology & Rheumatology, Department of Medicine, Fu Jen Catholic University Hospital & College of Medicine, Fu Jen Catholic University, New Taipei City 24352, Taiwan.
Division of Rheumatology, Immunology & Allergy, Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei 106319, Taiwan.
Int J Mol Sci. 2023 Jun 13;24(12):10066. doi: 10.3390/ijms241210066.
Lupus nephritis (LN) is one of the most severe complications in patients with systemic lupus erythematosus (SLE). Traditionally, LN is regarded as an immune complex (IC) deposition disease led by dsDNA-anti-dsDNA-complement interactions in the subendothelial and/or subepithelial basement membrane of glomeruli to cause inflammation. The activated complements in the IC act as chemoattractants to chemically attract both innate and adaptive immune cells to the kidney tissues, causing inflammatory reactions. However, recent investigations have unveiled that not only the infiltrating immune-related cells, but resident kidney cells, including glomerular mesangial cells, podocytes, macrophage-like cells, tubular epithelial cells and endothelial cells, may also actively participate in the inflammatory and immunological reactions in the kidney. Furthermore, the adaptive immune cells that are infiltrated are genetically restricted to autoimmune predilection. The autoantibodies commonly found in SLE, including anti-dsDNA, are cross-reacting with not only a broad spectrum of chromatin substances, but also extracellular matrix components, including α-actinin, annexin II, laminin, collagen III and IV, and heparan sulfate proteoglycan. Besides, the glycosylation on the Fab portion of IgG anti-dsDNA antibodies can also affect the pathogenic properties of the autoantibodies in that α-2,6-sialylation alleviates, whereas fucosylation aggravates their nephritogenic activity. Some of the coexisting autoantibodies, including anti-cardiolipin, anti-C1q, anti-ribosomal P autoantibodies, may also enhance the pathogenic role of anti-dsDNA antibodies. In clinical practice, the identification of useful biomarkers for diagnosing, monitoring, and following up on LN is quite important for its treatments. The development of a more specific therapeutic strategy to target the pathogenic factors of LN is also critical. We will discuss these issues in detail in the present article.
狼疮肾炎 (LN) 是系统性红斑狼疮 (SLE) 患者最严重的并发症之一。传统上,LN 被认为是一种免疫复合物 (IC) 沉积疾病,由 dsDNA-抗 dsDNA-补体相互作用在肾小球的 subendothelial 和/或 subepithelial 基底膜中引起炎症。IC 中的激活补体作为趋化因子,化学吸引先天和适应性免疫细胞到肾脏组织,引起炎症反应。然而,最近的研究表明,不仅浸润的免疫相关细胞,而且包括肾小球系膜细胞、足细胞、巨噬细胞样细胞、肾小管上皮细胞和内皮细胞在内的固有肾脏细胞,也可能积极参与肾脏的炎症和免疫反应。此外,浸润的适应性免疫细胞在遗传上受到自身免疫倾向的限制。SLE 中常见的自身抗体,包括抗 dsDNA,不仅与广泛的染色质物质发生交叉反应,还与细胞外基质成分发生交叉反应,包括α-肌动蛋白、连接蛋白 II、层粘连蛋白、胶原 III 和 IV 以及硫酸乙酰肝素蛋白聚糖。此外,IgG 抗 dsDNA 抗体 Fab 部分的糖基化也可以影响自身抗体的致病特性,即α-2,6-唾液酸化减轻,而岩藻糖基化则加重其肾炎活性。一些共存的自身抗体,包括抗心磷脂抗体、抗 C1q 抗体、抗核糖体 P 自身抗体,也可能增强抗 dsDNA 抗体的致病作用。在临床实践中,识别用于诊断、监测和随访 LN 的有用生物标志物对于其治疗非常重要。开发更针对 LN 致病因素的特异性治疗策略也至关重要。我们将在本文中详细讨论这些问题。