Department of Pathology, Corewell Health (East), Royal Oak, MI, USA.
William Beaumont School of Medicine, Oakland University, Rochester, MI, USA.
Ann Clin Lab Sci. 2023 Sep;53(5):712-718. Epub 2023 Nov 9.
It remains unclear if C4d staining is related to any peritubular and glomerular injury during antibody mediated rejection (ABMR). The goal of this study was to determine if myeloperoxidase (MPO) staining can highlight endothelial injury in peritubular capillaries (PTC) and glomeruli.
The study included 12 native negative controls, 19 transplant biopsies with borderline changes (BC) as transplant controls, and one group of renal transplant biopsies with ABMR as the study group (acute/chronic, n=22). All three groups were stained for MPO immunohistochemically, and the MPO expressions in the endothelium of PTC and glomeruli were evaluated and correlated with serum creatinine (SCr). In addition, the ultrastructural layers of the PTC (an index for chronic allograft rejection) were correlated with MPO indices in PTC.
The negative control group and the transplant controls showed no MPO expression in the endothelium of glomeruli and PTC. However, in the biopsies with ABMR, there were MPO-positive stains in the endothelial cells of glomeruli (15/21 cases, 71.4 %) and PTC (16/22 cases, 72.7 %). There were significant correlations between the peritubular MPO staining versus SCr (r=0.355 and =0.0106) and glomerular MPO staining versus SCr (r=0.365 and =0.0092). Furthermore, the layers of PTC by electron microscopy were significantly correlated with MPO scores in PTC (r=0.696, =0.0001).
Our data suggest that the MPO-positive endothelial injuries are most likely the cause leading to renal graft dysfunction following ABMR.
目前尚不清楚 C4d 染色是否与抗体介导的排斥反应（ABMR）期间的肾小管周围和肾小球损伤有关。本研究的目的是确定髓过氧化物酶（MPO）染色是否可以突出肾小管周围毛细血管（PTC）和肾小球内皮细胞的损伤。
该研究包括 12 例正常阴性对照、19 例有边界改变的移植活检（作为移植对照）和一组 22 例 ABMR 肾移植活检（急性/慢性）。所有三组均进行 MPO 免疫组织化学染色，评估 MPO 在 PTC 和肾小球内皮细胞中的表达，并与血清肌酐（SCr）相关。此外，还将 PTC 的超微结构层（慢性同种异体移植排斥的指标）与 PTC 中的 MPO 指标相关联。
阴性对照组和移植对照组肾小球和 PTC 内皮细胞无 MPO 表达。然而，在 ABMR 活检中，肾小球（15/21 例，71.4%）和 PTC（16/22 例，72.7%）的内皮细胞有 MPO 阳性染色。PTC 与 SCr 之间的 PTC 间质性 MPO 染色与 SCr 之间存在显著相关性（r=0.355 和 =0.0106），肾小球 MPO 染色与 SCr 之间存在显著相关性（r=0.365 和 =0.0092）。此外，电镜下的 PTC 层与 PTC 中的 MPO 评分显著相关（r=0.696，=0.0001）。
我们的数据表明，MPO 阳性内皮损伤很可能是导致 ABMR 后肾移植功能障碍的原因。
