OBJECTIVE: We investigated the lack of mannose-binding lectin (MBL) deposition in patients with secondary MNs (sMNs) with the presence of IgG4 deposition in relation to the presence of MBL deposition in patients with primary MNs (pMNs). We also established a connection between the stage of MN and MBL deposition.
METHODS: Materials from 72 renal biopsies with proven MN were used for immunohistochemistry staining (IHC) for the phospholipase A2 receptor (PLA2R), immunoglobulin subtype IgG4, and MBL. Patients were separated into one of the following three groups: primary MN (pMN), idiopathic MN (iMN), and secondary MN (sMN). Serum antibodies for PLA2R and thrombospondin type-I-domain-containing 7A (THSD7A) were also used for the precise evaluation of the type of MN, as well as for detecting positivity for PLA2R using IHC. Which stage of MN was present in relation to the deposition of MBL was evaluated.
RESULTS: In total, 50 patients were positive for IgG4, 34 with pMN, 12 with iMN, and 4 with sMN. A total of 20 patients were positive for MBL, 14 with pMN and 6 with iMN; no MBL deposits were found in patients with sMN. MBL positivity was predominantly present in the first two stages of MN, with a gradual reduction in the later stages.
CONCLUSIONS: The activation of the lectin-complement pathway occurs in the early stages of the disease and is associated with the deposition of IgG4; IgG4 deposition is present in sMN, but there is no MBL deposition. IgG4 cannot be used for the differentiation of primary from secondary MNs, but the lack of MBL can be used as a marker for sMN in the early stages of the disease.
目的:我们研究了存在IgG4沉积的继发性MNs(sMNs)患者中甘露糖结合凝集素(MBL)沉积的缺乏与原发性MNs(pMNs)患者MBL沉积的关系。我们还在MN和MBL沉积阶段之间建立了联系。
方法:将72例肾活检证实为MN的材料用于磷脂酶A2受体(PLA2R)的免疫组织化学染色(IHC),免疫球蛋白亚型IgG4和MBL。患者分为以下三组之一:原发性MN(pMN),特发性MN(iMN),和二级MN(sMN)。PLA2R和含血小板反应蛋白I型结构域7A(THSD7A)的血清抗体也用于精确评估MN的类型。以及使用IHC检测PLA2R的阳性。评估了与MBL沉积有关的MN的哪个阶段。
结果:总计,50例IgG4阳性,34例pMN阳性,12与iMN,和4与sMN。共有20例患者MBL阳性,pMN为14,iMN为6;在sMN患者中未发现MBL沉积物。MBL阳性主要存在于MN的前两个阶段,在后期逐渐减少。
结论:凝集素-补体途径的激活发生在疾病的早期阶段,并且与IgG4的沉积有关;IgG4沉积存在于sMN中,但没有MBL沉积.IgG4不能用于区分初级和次级MN,但是MBL的缺乏可以在疾病的早期阶段用作sMN的标志物。