肾小管间质性肾炎中抗肾小管基底膜抗体的检测

Detection of anti-tubular basement membrane antibodies in sera from patients with tubulointerstitial nephritis

目的 :探讨肾小管间质性肾炎 (tubulointerstitialnephritis,TIN)患者血清中抗肾小管基底膜抗体及其意义。方法 :选取北京大学第一医院肾内科 2 0 0 0年至 2 0 0 2年经肾穿刺活检确诊为TIN患者 4 6例。抗肾小管基底膜抗体检测用Western blot方法。人肾小管来源于肾肿瘤切除肾脏的正常肾皮质 ,并经不同目数的筛网获得。肾小管基底膜 (tubularbasementmembrane ,TBM )经超声粉碎细胞后得到 ,在经 6mol/L盐酸胍处理后即为TBM可溶性抗原。分别对阳性和阴性患者的临床指标进行统计分析。结果 :其中 1 1人检出抗TBM抗体 ,可识别 34× 1 0 3 、5 5× 1 0 3 、6 1× 1 0 3 、72× 1 0 3 、85× 1 0 3 、94× 1 0 3 、1 1 9× 1 0 3 蛋白条带 ,其中识别 5 5× 1 0 3 的患者最多 ,占 6 3.6 %。抗TBM抗体阳性率在急性TIN患者中为 2 9.6 % ,慢性TIN患者中为 2 1 .1 % ,两者相比差异无显著性。急性TIN患者抗TBM抗体阳性者与阴性者相比 ,其血沉和血清IgG、IgM均较高 ,差异有显著性。其它指标包括性别、年龄、血红蛋白、补体C3 、IgA、血肌酐及内生肌酐清除率等差异均无显著性。慢性TIN患者上述指标差异均无显著性。结论 :部分TIN患者血清中可检测到抗TBM抗体 。

Objective: To detect anti tubular basement membrane antibodies in sera from patients with tubulointerstitial nephritis (TIN) and investigate its clinical significance. Methods: The sera were studied from 46 patients with renal biopsy proven TIN. The normal human renal cortex was obtained from patients with nephroectomy, far from carcinoma. Tubules were isolated by a differential sieving technique. The fragments of renal epithelia were removed from tubular basement membrane enriched materials by sonication and centrifugation. Tubular basement membrane antigens were solubilized with 6 mol/L guanidine HCl. The soluble proteins were used as antigens in Western blot analysis to detect autoantibodies in sera from patients with TIN. The clinical characteristics of positive and negative patients were statistically analyzed. Results: Eleven patients with tubulointerstitial nephritis had anti tubular basement membrane antibodies by Western blot analysis, and seven protein bands could be blotted by the TIN sera. The positive prevalence of anti 55×10 3 antibody (63.8%) was higher than that of other antibodies. Eight of 27 (29.6%) patients with acute tubulointerstitial nephritis and four of 19 (21.1%) patients with chronic tubulointerstitial nephritis had anti tubular basement membrane antibodies. ESR,serum IgG and IgM in patients with acute TIN with positive anti tubular basement membrane antibodies were higher than those of the negative group There was no significant difference in the other clinical variables such as gender,age,hemoglobin,complement C 3,serum IgA,serum creatinine,blood urea nitrogen and creatinine clearance in patients with acute TIN between the positive and negative groups .There was no significant difference in clinical variables mentioned above in patients with chronic TIN between the positive and negative groups. Conclusion: Circulating anti tubular basement membrane antibodies could be detected in sera from some patients with TIN, and autoimmunity may play a role in the pathogenesis of TIN.