快速免疫荧光法检测血浆NT-proBNP的分析性能评价

Evaluation of performance of a rapid immunofluorescence method for assaying plasma NT-proBNP

目的 评价快速免疫荧光（RAMP）法检测血浆NT-proBNP的分析性能.方法 RAMP法测定264名健康体检者及78例心衰患者血浆NT-proBNP,参照CLSI方法 学评价方案,评价RAMP法的精密度、线性、稳定性及干扰因素等,并与瑞士罗氏公司Elecsys法检测方法 进行比对.结果 CV=20%时RAMP法功能灵敏度为48 ng/L,CV=10%时灵敏度为57 ng/L,线性范围18～8 000 ng/L.RAMP法NT-proBNP室温下稳定24 h,4℃稳定3 d,-20 ℃稳定20 d,反复冻融3次对检测结果 无影响.EDTA-K2和肝素抗凝血浆RAMP法测定结果 比对,YEDTA-K2=0.953 9X肝素＋0.365 2,R2=0.982,P〈0.01,n=40.两种类型的抗凝标本在两种方法 间的测量结果 差异无统计学意义（P＞0.05）.轻度溶血（Hb=2 g/L）对RAMP法和Elecsys法测定结果 影响较小,偏差〈5%,中、重度溶血（Hb=3～4 g/L）对结果 影响大,偏差＞15%.加入3种浓度三酰甘油时RMAP法测定值从390 ng/L降为82 ng/L,Elecsys法测定值从390 ng/L降为178 ng/L;当标本中胆红素含量为16～330 μmol/L,两种方法 测定值从7 777 ng/L降为7 741 ng/L,RAMP法抗乳糜和黄疸的干扰能力与Elecsys法相近.45份EDTA-K2抗凝血浆标本用2种方法 检测比对,Passing和Bablok回归方程显示：YRAMP=0.972 8XElecsys-0.035 2,R2=0.994,P＞0.05,n=45.78份肝素抗凝血浆标本用2种方法 检测比对,Passing和Bablok回归方程显示：YRAMP=0.983 2XElecsys-0.037 6,R2=0.991,P＞0.05,n=78.健康人血浆NT-proBNP水平随年龄递增,与性别相关,女性为105（60～120）ng/L,男性为59（44～91）ng/L,女性高于男性（Z=3.264,P〈0.01）.结论 RAMP快速免疫荧光法重复性,稳定性较好、线性范围宽,检测结果 与罗氏电化学发光法一致性较好.

Objective To analyze the performance of a rapid immunofluorescence assay for plasma NT-proBNP. Methods Human plasma NT-proBNP was measured by RAMP in 264 healthy cases and 78 patients with heart failure. The precision, stability, linearity and interference factors of RAMP were evaluated according to the protocold from America CLSI. Meanwhile, the results were compared with those obtained by Elecsys. Results Functional sensitivity of RAMP in 20% CV and 10% CV were 48 ng/L and 57 ng/L respectively. The linear range was 18-8 000 ng/L. NT-proBNP in plasma samples detected by RAMP were stable at room temperature for 24 hours, 4 ℃ for 3 days and - 20 ℃ for 20 days. No influences on results were observed throughout three freeze-thaw cycles. The results measured by RAMP were compared between EDTA-K2 anticoagulant plasma and heparin anticoagulant plasma, which showed that YEDTA-K2 =0. 953 9 Xheparin ＋ 0. 365 2 （ R2 = 0. 982, P 〈 0. 01, n = 40 ）. The results of EDTA-K2 and heparin anticoagulant plasma using RAMP and Elecsys showed no significant difference（ P ＞0. 05）. Slight hemolysis（ Hb 2 g/L）had small effect on the results of PAMP and Elecsys assays and deviations of them were below 5%. However median and heavy hemolysis（ Hb 3-4 g/L ）obviously influenced the results with deviation were more than 15%. The values measured by RMAP fell from 390 ng/L to 82 ng/L, and those measured by Elecsys method fell from 390 ng/L to 178 ng/L when 3 different concentrations of triacylglycerol were added, the values measured by two methods fell from 7 777 ng/L to 7 741 ng/L when bilirubin （ 16-330 μmol/L） was added. The anti-interference ability of RAMP method was similar to Elecsys. Results detected with two methods in 45 EDTA-K2 anticoagulant plasma samples were analyzed with Passing and Bablok regression.The regression equation was YRAMP = 0. 972 8XElecsys - 0. 035 2 （R2 = 0. 994, P ＞ 0. 05, n = 45 ）. When heparin anticoagulant plasma samples increased to 78 samples, Passing and Bablok regression equation showed：YRAMP= 0. 983 2XElecsys - 0. 037 6 （ R2 = 0. 991, P ＞ 0. 05, n = 78 ）. NT-proBNP levels in healthy adults were elevated along with age and related to the gender. The median value of female[105（60-120） ng/L] was higher than that of male [59 （ 44-91 ） ng/L, Z = 3. 264, P 〈 0. 01] significantly. Conclusions RAMP method has good repeatability, outstanding stability, and broad linear range. The results detected by RAMP is consistent with results detected by Elecsys.