尿β2-微球蛋白测定影响因素的实验评价及纠正方法

Experimental Evaluation and Corrective Method on Influence Factors of β2-Microglobulin Determination in Urine

目的 分析不同pH、贮存温度及放置时间对测定尿β2-微球蛋白（β2-MG）结果的影响并提出纠正方法.方法 210例共420份尿液标本（每例2份）以尿常规pH值分成7组（pH4.5,pH5.0,pH5.5,pH6.0,pH6.5,pH7.0,pH7.5,每组30例,含肾小管损伤的病例组20例,健康对照组10例）,在不同pH、贮存温度（25℃,4℃）及放置时间（0,60,120,240 min）采用Axsym免疫分析仪分别测定每份标本的尿β2-MG结果,分析不同影响因素对测定结果的干扰程度并进行校正.结果 相同贮存温度及放置时间各pH组内病例组与对照组之间的尿β2-MG降解率差异无统计学意义（t=0.156~1.852,P〉0.05）;25℃时pH5.0以下,4℃时pH4.5的尿β2-MG降解率、测定值与贮存温度、放置时间存在差异且与放置时间呈负相关（t=2.486~21.685,P〈0.05或〈0.001;相关系数r=-0.863^-0.946,P〈0.05）,采用校正系数对尿β2-MG测定结果进行校正,平均相对误差在1.99%~8.58%之间.结论 对25℃时pH5.0以下、4℃时pH4.5的尿β2-MG测定结果进行校正是可行的和可靠的.

Objective To explore the influence of different urinary pH,preserving temperature and storage time on β2-microglobulin （β2-MG） determination in urine,and put forward the correcting method. Methods According to routine analysis results of urinary pH, 210 cases were divided into 7 groups with urinary pH range of 4. 5 to 7. 5,including 20 patients with renal tubular injury （ease group） and 10 health individuals（control group） in each group. The results of β2-MG in each of 420 urine specimens were measured by the Axsym analyzer at different urinary pH, preservating temperature （25℃, 4℃2） and storage time （0,60,120,240 min）, respectively. Effect of different factors on results of β2-MG determination were analyzed and corrected. Results The degradation rate of urinary β2-MG showed no significant difference between the case and the control group in each pH group at same preservating temperature and storage time （t= 0. 156 - 1. 852, P〉0. 05）. There were differences between degradation rate or the value of β2-MG determination and preservating temperature or storage time （t=2. 486-21. 685 ,P〈0. 05 or 〈0. 001） ,and it were negatively correlated with the storage time （r=-0. 863%-0. 946, P〈0. 05 ） ,and the average relative errors were 1.99% -8. 58% when the results of urinary β2-MG determination were further corrected with the correction coefficient,in urine specimens below pHS. 0 groups at 25℃ and pH4. 5 group at 4℃. Conlusion It is feasible and reliable for correction of urine β2-MG results. Keywords： β2-microglobulin; determination; influence factor; corrective method