Kaga Hajime, Komatsuda Atsushi, Yamamoto Soh, Kikuchi Tadashi, Kamata Mika, Sato Akiko, Odaka Masafumi, Yokota Shin-Ichi, Takahashi Naoto, Wakui Hideki
Department of Hematology, Nephrology, and Rheumatology, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita City, Akita, 010-8543, Japan.
Department of Microbiology, Sapporo Medical University School of Medicine, Sapporo City, Japan.
Clin Exp Nephrol. 2019 Apr;23(4):465-473. doi: 10.1007/s10157-019-01712-x. Epub 2019 Feb 13.
The prevalence of antibodies against M-type anti-phospholipase A2 receptor (PLA2R) was reported to be ~ 70-80% in early studies on idiopathic membranous nephropathy (iMN) cohorts from Western countries, China, and Korea, and ~ 50% in recent studies on two Japanese iMN cohorts.
We developed an in-house enzyme-linked immunosorbent assay (ELISA) for the detection of anti-PLA2R antibodies, and examined sera from 217 patients with iMN, 22 patients with secondary MN (sMN), and 50 healthy individuals. All patients and healthy individuals were Japanese. The relationships between levels of anti-PLA2R antibodies and clinical parameters were analyzed. Serum samples were also tested using a standardized commercial ELISA (Euroimmun, Germany).
In our ELISA, OD values greater than the mean + 3 standard deviation of healthy subjects were considered to be positive for anti-PLA2R antibodies. Of the patients with iMN, 33.6% (73/217) were positive, but all sMN patients were negative. Our ELISA and the Euroimmun ELISA had a high concordance (93.5%). The proportion of patients with nephrotic syndrome was significantly higher in anti-PLA2R antibody-positive patients than in antibody-negative patients (65.8 vs. 37.5%, P < 0.001). Levels of anti-PLA2R antibodies were significantly correlated with levels of urinary protein and serum albumin (P = 0.004 and P < 0.001, respectively).
The prevalence of anti-PLA2R antibodies in our Japanese iMN cohort was lower than that in the previous studies from other countries and other Japanese institutes. The low prevalence of antibodies may be related with the characteristics of enrolled patients with mild proteinuria and undetectable antibody levels.
在早期针对来自西方国家、中国和韩国的特发性膜性肾病（iMN）队列研究中，抗M型抗磷脂酶A2受体（PLA2R）抗体的患病率据报道约为70 - 80%，而在近期针对两个日本iMN队列的研究中约为50%。
我们开发了一种用于检测抗PLA2R抗体的内部酶联免疫吸附测定（ELISA），并检测了217例iMN患者、22例继发性膜性肾病（sMN）患者和50名健康个体的血清。所有患者和健康个体均为日本人。分析了抗PLA2R抗体水平与临床参数之间的关系。血清样本还使用标准化的商业ELISA（德国欧蒙公司）进行检测。
在我们的ELISA中，抗PLA2R抗体阳性定义为OD值大于健康受试者平均值 + 3个标准差。iMN患者中，33.6%（73/217）为阳性，但所有sMN患者均为阴性。我们的ELISA与欧蒙ELISA具有高度一致性（93.5%）。抗PLA2R抗体阳性患者中肾病综合征患者的比例显著高于抗体阴性患者（65.8%对37.5%，P < 0.001）。抗PLA2R抗体水平与尿蛋白水平和血清白蛋白水平显著相关（分别为P = 0.004和P < 0.001）。
我们的日本iMN队列中抗PLA2R抗体的患病率低于其他国家和其他日本机构之前的研究。抗体患病率低可能与入组患者蛋白尿较轻且抗体水平检测不到的特征有关。
