肾小球PLA2R检测在膜性肾病诊断中的应用

Application of glomerular PLA2R in the diagnosis of membranous nephropathy

目的分析血清抗M型磷脂酶A2受体(PLA2R)抗体、肾小球PLA2R表达及IgG亚型沉积在膜性肾病中的作用,探讨其在膜性肾病中的诊断价值。方法选取经肾活检术诊断的膜性肾病79例,其中特发性膜性肾病(IMN)65例,继发性膜性肾病(SMN)14例(其中11例Ⅴ型狼疮肾炎,2例乙型肝炎病毒相关性膜性肾病,1例梅毒相关性膜性肾病)。血清抗PLA2R抗体应用欧蒙间接免疫荧光实验(IIFT)检测,肾小球PLA2R表达及IgG亚型沉积采用免疫荧光法,并比较特发性膜性肾病和继发性膜性肾病2组患者临床资料是否有差异。结果 65例IMN患者中,肾小球PLA2R表达阳性者57例(87.7%);血清抗PLA2R抗体阳性者47例(72.3%);IgG4亚型沉积阳性者59例(90.8%)。14例SMN患者肾小球PLA2R表达均阴性,血清抗PLA2R抗体阳性者2例(14.3%),IgG4亚型沉积阳性者4例(28.6%)。肾小球PLA2R表达阳性诊断IMN灵敏度为87.7%,特异度为100%;血清抗PLA2R抗体阳性诊断IMN灵敏度为72.3%,特异度为85.7%。IMN患者中肾小球PLA2R表达、血清抗PLA2R抗体、IgG4亚型沉积阳性比例高于SMN。2组患者临床资料在性别构成比存在统计学差异,年龄、白蛋白、血肌酐、总胆固醇、24小时尿蛋白定量、肾小球滤过率2组差异无统计学意义(P>0.05)。结论 IMN患者中肾小球PLA2R表达阳性率高,在膜性肾病鉴别诊断中具有优势作用。

Objective To analyze serum anti-M-type phospholipase A2 receptor（ PLA2R） antibodies and glomerular deposition of PLA2R and Ig G subclass in patients with membranous nephropathy（ MN）,explore its diagnostic value in membranous nephropathy. Methods 79 cases diagnosed by renal biopsy as membranous nephropathy were selected,65 patients with idiopathic membranous nephropathy and 14 patients with secondary membranous nephropathy（ 11 cases V-type lupus nephritis,2 cases of hepatitis B virus-associated membranous nephropathy（ HBV-MN）,1 case of syphilis-related membranous nephropathy）. Serum anti-PLA2R antibody was detected by indirect immunofluorescence assay（ IIFT）,glomerular PLA2R and Ig G subtclass by immunofluorescence,and clinical data difference of the two groups were compared. Results In 65 cases with IMN,57 patients were glomerular PLA2R positive,and the positive ratio was 87.7%; 47 cases of serum anti PLA2R antibody were positive with the proportion of 72.3%; 59 cases of IgG4 subclass were positive with the positive ratio of 90. 8%. 14 cases of glomerular PLA2R were negative. 2 case of serum antibody PLA2R were positive,and the positive ratio was 14.3%. 4 cases of IgG4 subclass were positive and the positive ratio was 28.6%. The sensitivity of glomerular PLA2R in diagnosing IMN was 87.7% and the specificity was 100%. The sensitivity of serum PLA2R in diagnosing IMN was 72.3% and the specificity was 85.7%. Positive ratio of glomerular PLA2R,serum PLA2R,IgG4 subclass in IMN patients was higher than in SMN. There was a statistically significant difference in sex composition between the two groups,Age,albumin,serum creatinine, total cholesterol, 24 hour proteinuria, and glomerular filtration rate were not significantly different.Conclusion Glomerular PLA2R has a high expression in IMN patients,which has a dominant role in the differential diagnosis of membranous nephropathy.