Urine excretion of protein HC in proteinuric glomerular diseases correlates to urine IgG but not to albuminuria
Urine excretion of protein HC in proteinuric glomerular diseases correlates to urine IgG but not to albuminuria
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DOI：
10.1046/j.1523-1755.2001.00018.x
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发表时间：
2001-11-01
影响因子：
19.6
通讯作者：
Tencer, J
中科院分区：
文献类型：
--
作者：
Bakoush, O;Grubb, A;Tencer, J
背景蛋白尿性肾小球疾病常与肾小管间质损伤有关，后者对肾功能衰竭的进展有促进作用。肾小管损伤部分归因于滤过血浆蛋白对肾小管上皮细胞的毒性作用。非选择性蛋白尿患者，即高分子量血浆蛋白（如IgG）的尿液排泄量高于白蛋白，通常肾脏结局较差。本观察性研究检测了肾小管损伤程度与尿IgG和白蛋白尿水平之间的相关性，肾小管损伤程度通过尿蛋白HC浓度测量。在诊断性肾活检时和平均49个月的随访中，对56例非糖尿病性肾小球疾病的蛋白尿患者（33例男性和23例女性）进行了尿IgG、白蛋白和蛋白HC浓度的测定。尿IgG排泄量与尿蛋白HC浓度在观察开始和结束时均呈高度显著相关（r分别为0.74和0.65，P <0.001）。单例患者尿中两种蛋白排泄量的变化呈显著相关（r = 0.84，P <0.001）。在肾活检时，蛋白尿程度与蛋白HC排泄之间的相关性是显著的，但在随访期间不再存在。逐步线性回归分析显示，与肌酐清除率和尿白蛋白相比，只有尿IgG排泄量的变化与相应的尿蛋白HC排泄量的变化相关（r = 0.84和r '= 0.7，P <0.001）。本研究结果提示，在蛋白尿性肾小球疾病的病程中，尿蛋白HC浓度与IgG尿的程度相关，而与蛋白尿的程度无关。这种相关性是否是由IgG或其他一些高分子量蛋白质对肾小管细胞的内在毒性作用来解释的，需要进一步研究。然而，这些结果有助于了解肾小球疾病和非选择性蛋白尿患者的肾脏存活率低。
Background. Proteinuric glomerular diseases often are associated with tubulointerstitial injury, which imposes on the progression of renal failure. Tubular damage is partly referable to toxic effects on the tubular epithelial cells induced by filtered plasma proteins. Patients with nonselective proteinuria, that is, increased urine excretion of high-molecular-weight plasma proteins such as IgG in comparison to albumin, often have poor renal outcome. The present observational study examined correlations between the degree of tubular damage, measured by urine concentration of protein HC, and the levels of urine IgG and albuminuria.Methods. Measurements of urine concentrations of IgG, albumin, and protein HC were performed in 56 proteinuric patients (33 males and 23 females) with nondiabetic glomerular diseases at the time of the diagnostic renal biopsy and at a mean of 49 follow-up months.Results. A highly significant correlation between the urine IgG excretion and the urine protein HC concentration was found both at the start and at the end of the observational time (r = 0.74 and 0.65, respectively, P < 0.001). Furthermore, alterations in the urinary excretion of the two proteins in single patients correlated significantly to each other (r = 0.84, P < 0.001). The correlation between the degree of albuminuria and the protein HC excretion was significant at the time of kidney biopsy, but ceased to exist during the follow-up time. Stepwise linear regression analysis showed that in comparison with the creatinine clearance and albuminuria, only the changes in urinary IgG excretion were related to the corresponding changes in urinary protein HC excretion (r = 0.84 and r' = 0.7, P < 0.001).Conclusion. The findings of the study suggest that the urinary protein HC concentration correlates to the degree of IgG-uria but not to the degree of albuminuria during the course of proteinuric glomerular disease. Whether this correlation is to be explained by an intrinsic toxic effect on tubular cells executed by IgG or perhaps by some other high molecular weight proteins, needs to be investigated further. However, the results contribute to the understanding of the poor renal survival in patients with glomerular diseases and nonselective proteinuria.