血清IgG4检测在肾脏疾病中的意义

The significance of serum IgG4 detection in kidney disease

目的:分析常见肾脏疾病血清IgG4含量,探究血清IgG4与肾小管间质病变及其他实验室指标之间的关系。方法:收集485例不同肾脏疾病患者临床、实验室及病理(光学显微镜、免疫荧光、电子显微镜)资料,血清IgG4检测采用免疫散射比浊法。结果:485例不同肾脏疾病患者中30例患者血清IgG4>2 g/L,间质性肾炎和抗中性粒细胞胞质抗体(ANCA)相关性小血管炎患者血清IgG4升高比例较高,分别为24.0%和22.4%,明显高于其他肾脏疾病。间质性肾炎患者血清IgG4与血清Ig A及24 h尿α1微球蛋白(α1-MG)、24 h尿白蛋白(Alb)和24 h尿Ig G呈正相关关系(r=0.64,r=0.43,r=0.46,r=0.46;均P<0.05),ANCA相关性小血管炎和Ig A肾病血清IgG4与血清Ig E呈正相关关系(r=0.39,r=0.34;均P<0.05),膜性肾病血清IgG4与血清Ig G呈正相关关系(r=0.47,P<0.05),狼疮性肾炎血清IgG4与血清Ig G和Ig A呈正相关关系(r=0.65,r=0.37;均P<0.05)。在254例肾脏穿刺患者中肾间质重度炎性细胞浸润组血清IgG4明显高于无或轻度肾间质炎性细胞浸润组(P<0.05)。52例原发性膜性肾病患者肾小球IgG4阳性率为100%,与血清IgG4水平无明显相关性。结论:间质性肾炎和ANCA相关性小血管炎高IgG4血症发生率高,血清IgG4升高肾病患者应首先考虑这2种疾病可能,而确诊需结合血清学、病理和影像学检测结果 ,IgG4在肾脏疾病中的致病机制仍需进一步研究。

Objective To study the level of serum IgG4 in renal disease and the relationship between serum IgG4 level, renal tubulointerstitial lesion and other laboratory data, Methods A total of 485 cases with different renal diseases were enrolled in this study. The clinical, laboratory and pathological （light microscopy, immunofluorescence and electron microscopy） data were evaluated and analyzed. The serum IgG4 was measured by using immunonephelometry method. Results Of the 485 cases of different renal diseases, 30 had serum IgG4 greater than 2 g/L. The incidences of elevated serum IgG4 in patients with interstitial nephritis and anti-neutrophilc cytoplasmic antibodies （ANCA）-associated vasculitis was 24.0% and 22.4%, respectively, significantly higher than that in other renal diseases. There was a positive correlation between serum IgCA and serum lgA, 24 h urinary cq-mieroglobulin, 24 h urinary albumin, 24 h urinary IgG in patients with interstitial nephritis （r=0.64, r=0.43, r=0,46, r=0.46, respectively; all P〈0.05）. Positive correlation was also found between serum lgG4 and serum IgE in ANCA-assoeiated vaseulitis （r=0.39） and IgA nephropathy （r=0.34）. While the serum IgG4 and serum IgG was positively correlated in membranous glomerulonephritis （r=0.47）. Positive correlation was also observed between serum IgC,4 and serum IgG, IgA （r=0.65, r=0.37; all P〈0.05） in lupus nephritis. Of the 254 cases had renal biop- sy performed, the group with severe renal interstitial inflammatory cell infihration had significantly higher serum IgG4 than group with no or less renal interstitial infiltration （P〈0.05）. The glomerular IgC,-4 positive rate was 100% in 52 cases with primary membranous glomerulonephritis, however, it was not significantly correlated with serum IgG4 level. Conclusions Increased serum IgC,4 level was commonly observed in interstitial nephritis and ANCA-associated vasculitis. These two diseases should be considered when a patient with renal disease had elevated serum IgG4, and the diagnosis should be es- tablished in conjunction with serological, histological and radiological examinations. The role of IgG4 in pathogenesis of renal diseases needs to be further investigated.