肾移植术后抗体介导排斥反应合并膜性肾病

Antibody-mediated rejection and membranous nephropathy in renal allograft recipients

目的观察肾移植术后抗体介导的排斥反应(antibody-mediated rejection,AMR)合并膜性肾病的临床病理特点,以及膜性肾病可能的发病机制。方法回顾性分析了临床确认的2例肾移植术后AMR合并膜性肾病(membranous nephropathy,MN)患者。总结2例患者的临床表现、实验室检查病理特点和预后,并对比2例患者之间的异同。结果 2例患者的临床表现均为尿蛋白及血肌酐升高,血清中存在供者特异性抗体(donor-specific antibody,DSA),肾脏病理光镜下可见肾小球炎、肾小管周围毛细血管炎,免疫荧光示IgG沉积,呈颗粒状沉积于血管袢;免疫组织化学示人类白细胞抗原-DR(human leukocyte antigen-DR,HLA-DR)抗原染色阳性,电镜下示肾小球足细胞足突广泛融合,基膜上皮侧中-高电子密度的致密物沉积,肾小球袢腔内偶见单核细胞浸润。病例1原发病为膜性肾病,血清抗磷脂酶A2抗体阳性,肾组织中血清抗磷脂酶A2受体(serum anti-phospholipase A2 receptor,PLA2R)阳性;而病例2原发病为原发性醛固酮增多症,PLA2R抗体阴性,肾组织中PLA2R阴性。结论肾移植术后AMR与MN可同时存在;二者临床及光镜下病理表现相似,但是血清中PLA2R抗体和肾组织中PLA2R抗体染色存在差别,有助于鉴别可能不同的发病机制。

Objective To observe the clinical anti pathological ffatures of antibody-mediated rejection （AMR） and membranous nepbropathy （MN） in renal allograft recipients, as well as tbe possible pathogenesis of MN. Methods A retrospective analysis was carried out in two cases of AMR with MN. The clinical manifestations, laboratory tests, pathologic features and prognosis of the two patients were summarized and the similarities and differences between the two patients were compared. Results Two patients showed the similar clinical manifestations as follow ： elevated urinary protein and serum ereati,fine as the clinical manifestations ： The presence of donnr-specific antibody （DSA）, glomerulosclerosis, peritubular capillaries can be seen under light microscopic. lmmunnflunrescence staining for lgG sbowed granular subepithelial deposits globally involving glomerular basement membranes. H LA-DR antigen was positive by immunohistochemistry ; Electron microscopy sbowed that the glomerular podoeytes were extensively fused, electron-dense deposits could be seen subepithelial to the glomerular basement membrane and mononuelear cell infihration could be occasionally seen by glomerular loop cavity. There were also differences： The primary disease of case 1 was idiopathic MN and case 2 was primary aldosteronism. Serum antiphospholipase A2 receptor （PLA2R） antibody of case 1 was positive while case 2 was negative. Conclusion AMR and MN may be present at the same time after renal transplantation. Both of them have similar clinical and light microscopic findings; However, there was a difference in PLA2R antibody staining in renal tissue and in serum, which may help to identify different pathogenesis..