Abstract:

Objective　To investigate the changes and diagnostic value of urinary hydrogen sulfide（H2S） in the patients with methylmalonic acidemia（MMA）. Methods　The urine samples from 20 cases（13 males and 7 females，patient group） of MMA were collected when the patients visited Peking University First Hospital from September 2016 to November 2017. The normal urine samples were collected from 20 healthy children（11 males and 9 females，control group） who had normal development and metabolic condition. H2S in the urine of normal children and MMA children was determined by free radical detector. The differences of urinary H2S concentration between the two groups were analyzed. The ROC curve of urine samples was evaluated. Results　The urinary H2S concentration of the 20 MMA cases was higher than that in the control group（64.9±52.0） μmol/L vs.（43.9±40.0） μmol/L. The difference was significant statistically（Z＝-3.435，P＝0.001）. The area under the curve（AUC） was 0.818 in the ROC curve analysis of MMA with urinary H2S concentration and 47.72 μmmol/L in urine H2S as a cut-off value. The sensitivity and specificity were 95% and 60% respectively. Conclusion　The concentration of urinary H2S is increased in the patients with MMA. Urinary H2S concentration might be a biochemical marker for the early diagnosis MMA in neonatal screening. It is helpful to evaluate the treatment patients and follow-up of MMA.

Key words: methylmalonic acidemia, methylmalonic acid, hydrogen sulfide, diagnosis

摘要：

目的　探讨尿硫化氢（H2S）在甲基丙二酸血症（methylmalonic acidemia，MMA）患儿尿液中的变化及临床价值。方法　将2016年9月至2017年11月在北京大学第一医院就诊的20例MMA 患儿作为病例组（男13例，女7例），同时将20例健康儿童作为对照组（男11例，女9例），留取所有儿童新鲜尿液。采用自由基检测仪检测正常儿童与MMA 患儿尿液中的H2S浓度，对照病例组与对照组尿H2S浓度的差异，并对结果进行分析。结果　20例MMA患儿尿H2S浓度（64.9±52.0） μmmol/L高于对照组尿H2S 浓度（43.9±40.0） μmmol/L，差异具有统计学意义（Z＝-3.435，P＝0.001）；尿H2S浓度辅助判断MMA的ROC 曲线分析中曲线下面积（AUC）为0.818，以尿H2S浓度47.72 μmmol/L为界值，辅助判断MMA 的敏感度为95%，特异度为60%。结论　MMA 患儿尿液H2S含量高，尿H2S浓度检测有助于MMA的尽早诊断，或可作为新生儿筛查、MMA 患儿动态观察和疗效评估的参考指标。

关键词: 甲基丙二酸血症, 甲基丙二酸, 硫化氢, 诊断