Ardoin Stacy, Birmingham Daniel J, Hebert Paul L, Yu Chack-Yung, Rovin Brad H, Hebert Lee A
The Ohio State University Medical Center, Columbus, OH, USA.
Arthritis Rheum. 2011 Jul;63(7):2031-7. doi: 10.1002/art.30345.
Published criteria on the degree of proteinuria increase that defines a proteinuric flare in systemic lupus erythematosus (SLE) with glomerulonephritis (GN) vary widely, likely because they are not evidence based, but are largely based on expert opinion. Ideally, the threshold for proteinuric flare should be set sufficiently high that spontaneous variation in proteinuria does not likely explain the increase, but not so high that the patient needlessly experiences prolonged severe proteinuria before a flare is declared and therapy is increased. The present study was undertaken to develop an evidence-based approach to setting the threshold for proteinuric flare, based on quantifying the spontaneous variation in the urine protein:creatinine ratio in SLE GN patients who are not experiencing SLE flare.
SLE GN patients (n = 71) in the Ohio SLE Study were tested at prespecified bimonthly intervals within windows of ±1 week. The median duration of followup was >44 months, and the rate of visit compliance was >90%. To assess spontaneous variation in the protein:creatinine ratio under no-flare conditions, we excluded protein:creatinine ratios measured within 4 months before or after renal flare.
Our findings showed that in the group of SLE GN patients with a mean no-flare protein:creatinine ratio of ≤0.5, the published flare thresholds are set well above the 99% confidence interval of the no-flare protein:creatinine ratio. The opposite was seen in the group with a mean no-flare protein:creatinine ratio of ≥1.0.
Current thresholds for defining proteinuric flare appear to be set either too high or too low. A randomized trial would be needed to test whether resetting the thresholds would result in faster remission, reduction in therapy, and decrease in the frequency of chronic kidney disease.
已发表的关于蛋白尿增加程度的标准差异很大，这些标准用于定义合并肾小球肾炎（GN）的系统性红斑狼疮（SLE）患者的蛋白尿复发，可能是因为它们并非基于证据，而是很大程度上基于专家意见。理想情况下，蛋白尿复发的阈值应设定得足够高，以使蛋白尿的自发变化不太可能解释其增加，但又不能设定得过高，以免患者在宣布复发并增加治疗之前不必要地经历长时间的严重蛋白尿。本研究旨在基于对未经历SLE复发的SLE GN患者尿蛋白：肌酐比值的自发变化进行量化，开发一种基于证据的方法来设定蛋白尿复发的阈值。
俄亥俄州SLE研究中的SLE GN患者（n = 71）在±1周的时间窗内按照预先指定的每两个月一次的间隔进行检测。随访的中位持续时间>44个月，就诊依从率>90%。为了评估无复发情况下蛋白：肌酐比值的自发变化，我们排除了在肾脏复发前后4个月内测得的蛋白：肌酐比值。
我们的研究结果表明，在平均无复发蛋白：肌酐比值≤0.5的SLE GN患者组中，已发表的复发阈值设定在无复发蛋白：肌酐比值的99%置信区间之上。在平均无复发蛋白：肌酐比值≥1.0的组中则观察到相反的情况。
目前定义蛋白尿复发的阈值似乎设定得过高或过低。需要进行一项随机试验来检验重新设定阈值是否会导致更快的缓解、治疗减少以及慢性肾脏病频率降低。
