血清γ-痕迹蛋白对新生儿ABO溶血症肾功能损害的诊断价值

Diagnostic value of serum Cys-C for renal dysfunction in newborns with hemolytic disease of ABO incompatibility

目的探讨ABO溶血症(ABO-HDN)新生儿血清γ-痕迹蛋白(cystatin-C,Cys-C)水平变化及其在判断新生儿肾功能损伤状况中的临床价值。方法将入选新生儿分为2组:对照组20例,观察组40例。后者根据血清胆红素水平分为轻度组(18例)和中重度组(22例)。测定血清BUN、SCr、β2-MG及Cys-C,并计算肌酐清除率(CCr),比较各组间各指标的差异及相关性,行ROC曲线分析。结果轻度组血清Cys-C、β2-MG、CCr值与对照组比较,差异无统计学意义(P均>0.05);中重度组血清Cys-C、β2-MG值较对照组及轻度组显著升高(P均<0.05),CCr值较对照组及轻度组显著降低(P均<0.05)。各组BUN、SCr比较差异无统计学意义(P均>0.05)。血清1/Cys-C、1/β2-MG水平与CCr呈显著相关(r=0.524、0.463,P均<0.05)。血清Cys-C最佳截断点为1.83 mg/L,敏感度为90.3%,特异度为89.5%;β2-MG最佳截断点为4.87 mg/L,敏感度为85.2%,特异度为87.1%。血清Cys-C、β2-MG ROC曲线下面积分别为0.892、0.805,差异有统计学意义(P<0.05)。结论血清Cys-C比β2-MG更能反映新生儿肾小球滤过功能的损害,可作为ABO-HDN新生儿肾功能损害的敏感诊断指标。

Objective To study the changes of serum cystatin-C levels in newborns with hemolytic disease of ABO incompatibility and its diagnostic value for renal dysfunction.Methods Eighteen cases were included as mild ABO hemolytic disease of the newborn（ABO-HDN）group and 22 cases as moderate-severe ABO-HDN group,20 normal newborns were selected as controls.The serum levels of blood urea nitrogen（BUN）,serum creatinine（SCr）,β2-MG β2-microglobulin（β2-MG）,and cystatin C（Cys-C）were measured.The creatinine clearance rate（CCr）was calculated by Schwartz formula.Their differences and the correlations for different parameters were assayed.Analysis of the receiver operating characteristic（ROC）was undertaken.Results The levels of serum Cys-C,β2-MG and CCr had no statistically difference between mild ABO-HDN group and control group（P 0.05）.The concentrations of serum Cys-C and β2-MG in moderate-severe ABO-HDN group were significantly higher than those in mild ABO-HDN group and control group,while the level of CCr was significantly lower than that in two groups（P 0.05）.The blood BUN and Cr had not significant difference among all groups（P 0.05）.Significant correlations were found between 1/CysC,1/β2-MG and CCr level（r = 0.524 and 0.463,respectively,P 0.05）.The cut-off point of the Cys-C test was 1.83 mg/L,the sensitivity and the specificity was 90.3% and 89.5% respectively.The cut-off point of β2-MG test was 4.87 mg/L,the sensitivity and the specificity was 85.2% and 87.1% respectively.The area under the ROC curve of serum Cys-C and β2-MG was 0.892 and 0.805 respectively（P 0.05）.Conclusions Cys-C can reflect the damage degree of renal filtration function in neonates better than β2-MG.Thus,Cys-C could be used as a sensitive index of renal dysfunction for neonates with hemolytic disease of ABO incompatibility.