Esdaile J M, Joseph L, MacKenzie T, Kashgarian M, Hayslett J P
Department of Medicine, Montreal General Hospital, McGill University, PQ, Canada.
J Rheumatol. 1994 Nov;21(11):2046-51.
In a cohort of 87 patients with lupus nephritis, delay between the detection of the onset of renal disease and renal biopsy was a significant predictor at the time of a first renal biopsy for subsequent renal insufficiency (relative risk - 4.9; 95% confidence interval = 1.7 to 14.5; p < 0.001) and death due to lupus renal involvement (relative risk = 6.7; 95% confidence interval = 2.1 to 21.2; p < 0.001). We evaluated the role of lead time bias, 2 variants of prognostic selection bias (length biased sampling), and the benefit of early treatment as explanations for this effect.
Evaluation using the time of renal onset rather than the time of renal biopsy for the analysis suggested that lead time bias was unlikely to be an explanation for the effect of duration on renal insufficiency or death due to renal involvement. Identical values of age, serum creatinine and 24 hour urinary protein excretion at renal onset for those with a long duration versus short duration prior to biopsy, suggested that differences in prognostic selection were unlikely to explain the observed results. A 2nd type of prognostic selection bias arising from the failure to include patients who did not undergo a renal biopsy was further assessed by statistical simulation. The results of this approach indicated that prognostic selection bias was not solely responsible for the significant associations. Because treatment with high dose prednisone and immunosuppressive drugs was not instituted until a renal biopsy had been performed, delay in instituting these therapies remained a possible explanation for the increased frequency of renal insufficiency and death due to renal involvement observed in those with longer delays before renal biopsy. In addition, there was significant deterioration in serum creatinine (median change 0.6 mg/dl) and 24 hour urinary protein excretion (median change 2.5 gm) over the period from renal onset to renal biopsy, and significantly higher scores for the activity, chronicity and tubulointerstitial indices on renal biopsy in those in whom therapy was delayed.
Prompt therapy with prednisone and immunosuppressive agents in lupus nephritis has a beneficial effect on longterm prognosis.
在一组87例狼疮性肾炎患者中，从肾病发病检测到肾活检的延迟是首次肾活检时后续肾功能不全（相对风险-4.9；95%置信区间=1.7至14.5；p<0.001）以及狼疮性肾脏受累导致死亡（相对风险=6.7；95%置信区间=2.1至21.2；p<0.001）的显著预测因素。我们评估了提前期偏倚、两种预后选择偏倚变体（长度偏倚抽样）以及早期治疗的益处，以此来解释这种效应。
使用肾病发病时间而非肾活检时间进行分析表明，提前期偏倚不太可能解释病程对肾功能不全或肾脏受累导致死亡的影响。活检前病程长与短的患者在肾病发病时年龄、血清肌酐和24小时尿蛋白排泄量相同，这表明预后选择差异不太可能解释观察到的结果。通过统计模拟进一步评估了因未纳入未进行肾活检的患者而产生的第二种预后选择偏倚。该方法的结果表明，预后选择偏倚并非这种显著关联的唯一原因。由于直到进行肾活检才开始使用高剂量泼尼松和免疫抑制药物治疗，在肾活检前延迟时间较长的患者中观察到的肾功能不全和肾脏受累导致死亡频率增加，延迟开始这些治疗仍然可能是一个解释。此外，从肾病发病到肾活检期间，血清肌酐（中位数变化0.6mg/dl）和24小时尿蛋白排泄量（中位数变化2.5g）有显著恶化，治疗延迟的患者肾活检时活动度、慢性度和肾小管间质指数得分显著更高。
狼疮性肾炎患者早期使用泼尼松和免疫抑制剂治疗对长期预后有有益影响。
