Wu Alan H B
Clinical Chemistry Laboratory, Department of Laboratory Medicine, San Francisco General Hospital, University of California, San Francisco, CA 94110, USA.
Am Heart J. 2006 Nov;152(5):828-34. doi: 10.1016/j.ahj.2006.08.021.
B-Type natriuretic peptide (BNP) and NTpro-BNP are widely used for diagnosis and risk stratification of patients with heart failure (HF). Although not currently cleared by the Food and Drug Administration as a test indication, there is interest in using these biomarkers for monitoring the success of HF medications. An assessment of the analytical and biologic variations is necessary to interpret the results of serial testing.
The intra-individual biologic variances and analytical assay variances of BNP and NT-proBNP from healthy subjects and those with stable HF were reviewed. The analytical variability of BNP and NT-proBNP assays was reported, as some have suggested that only the analytical variance is important in interpreting the results of tightly regulated hormones. The reference change values (RCV) for serial measurements were derived and used to interpret results of therapeutic studies whereby serial changes in BNP and NT-proBNP concentrations were obtained to evaluate the therapeutic success of short-term (inpatient) and long-term (outpatient) management. The use of RCV may also be important in studies comparing BNP-guided versus physician-guided HF drug therapy.
Relative to the RCV, short-term therapeutic studies of inpatients have largely resulted in a statistically significant decline in BNP and NT-proBNP with clinical evidence of patient improvements. In contrast, many therapeutic studies involving long-term outpatient monitoring have produced changes in BNP/NT-proBNP that do not exceed the biologic variances. The value of BNP for monitoring therapeutic success can be questioned for trials that demonstrate clinical benefit without statistically significant decreases in biomarker levels.
B型利钠肽（BNP）和N末端B型利钠肽原（NTpro-BNP）广泛用于心力衰竭（HF）患者的诊断和风险分层。尽管目前未被美国食品药品监督管理局批准作为一项检测指标，但人们有兴趣使用这些生物标志物来监测HF药物治疗的效果。评估分析变异和生物学变异对于解释系列检测结果是必要的。
回顾了健康受试者和稳定HF患者的BNP和NT-proBNP的个体内生物学变异和分析检测变异。报告了BNP和NT-proBNP检测的分析变异性，因为一些人认为在解释严格调控激素的检测结果时只有分析变异是重要的。推导了系列测量的参考变化值（RCV），并用于解释治疗研究的结果，从而获得BNP和NT-proBNP浓度的系列变化，以评估短期（住院患者）和长期（门诊患者）管理的治疗效果。RCV的使用在比较BNP指导与医生指导的HF药物治疗的研究中可能也很重要。
相对于RCV，住院患者的短期治疗研究在很大程度上导致BNP和NT-proBNP有统计学意义的下降，并有患者改善的临床证据。相比之下，许多涉及长期门诊监测的治疗研究中，BNP/NT-proBNP的变化未超过生物学变异。对于那些在生物标志物水平无统计学显著下降但显示出临床益处的试验，BNP用于监测治疗效果的价值可能受到质疑。
