Birmingham Daniel J, Rovin Brad H, Shidham Ganesh, Bissell Michael, Nagaraja Haikady N, Hebert Lee A
Department of Internal Medicine, Ohio State University Medical Center, Columbus, OH 43210-1250, USA.
Clin J Am Soc Nephrol. 2008 Jul;3(4):1028-33. doi: 10.2215/CJN.04761107. Epub 2008 May 1.
Albuminuria is regarded a sensitive measure of progression of glomerular disease. This study was undertaken in patients who had systemic lupus erythematosus glomerulonephritis (n = 57) and were followed in the Ohio SLE Study to determine whether measuring albuminuria offered clinical advantages over that of total proteinuria.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Twenty-four-hour urine collections (n = 127) were obtained at baseline and annually for measurement of microalbumin, total protein, and creatinine.
There was a strong linear relationship between microalbumin-creatinine and protein-creatinine ratios over the entire range of protein-creatinine ratios; however, in the protein-creatinine ratio range 0.0 to 0.3, as the protein-creatinine ratio increased, the microalbumin-protein ratio increased much more than the protein-creatinine ratio. Also, the greater the protein-creatinine ratio, the greater was the evidence for nonselective proteinuria (protein-creatinine ratio--microalbumin-creatinine ratio).
For the diagnosis of proteinuria renal flare, measuring albuminuria offers no advantage over measuring total proteinuria because changes in protein-creatinine and microalbumin-creatinine ratios are highly correlated over the designated ranges for systemic lupus erythematosus glomerulonephritis proteinuric flares. In those with normal-range proteinuria, subsequent changes in microalbumin-protein ratio might be a better forecaster of renal flare than changes in protein-creatinine or microalbumin-creatinine ratio. High protein-creatinine ratios are associated with evidence of nonselective proteinuria, which may increase the nephrotoxicity of proteinuria. Thus, using high-threshold criteria for systemic lupus erythematosus flare (allowing greater proteinuria increase before flare is declared) may expose the kidney to greater nephrotoxicity than using the low-threshold criteria for systemic lupus erythematosus flare.
蛋白尿被视为肾小球疾病进展的一项敏感指标。本研究针对患有系统性红斑狼疮性肾小球肾炎的患者（n = 57）开展，这些患者参与了俄亥俄州系统性红斑狼疮研究，旨在确定测量蛋白尿相较于测量总蛋白尿是否具有临床优势。
设计、地点、参与者及测量方法：在基线时以及每年收集24小时尿液样本（n = 127），用于测量微量白蛋白、总蛋白和肌酐。
在整个肌酐比值范围内，微量白蛋白 - 肌酐比值与蛋白 - 肌酐比值之间存在很强的线性关系；然而，在蛋白 - 肌酐比值范围为0.0至0.3时，随着蛋白 - 肌酐比值增加，微量白蛋白 - 蛋白比值的增加幅度远大于蛋白 - 肌酐比值。此外，蛋白 - 肌酐比值越高，非选择性蛋白尿的证据越明显（蛋白 - 肌酐比值 - 微量白蛋白 - 肌酐比值）。
对于蛋白尿性肾病情复发的诊断，测量蛋白尿相较于测量总蛋白尿并无优势，因为在系统性红斑狼疮性肾小球肾炎蛋白尿性病情复发的指定范围内，蛋白 - 肌酐比值和微量白蛋白 - 肌酐比值的变化高度相关。在蛋白尿处于正常范围的患者中，相较于蛋白 - 肌酐比值或微量白蛋白 - 肌酐比值的变化，微量白蛋白 - 蛋白比值随后的变化可能是肾病情复发的更好预测指标。高蛋白 - 肌酐比值与非选择性蛋白尿的证据相关，这可能会增加蛋白尿的肾毒性。因此，对于系统性红斑狼疮病情复发采用高阈值标准（在宣布病情复发前允许更大的蛋白尿增加）可能会使肾脏比采用低阈值标准面临更大的肾毒性。
