血浆极长链脂肪酸GC-MS测定方法的建立和应用

Establishment of GC-MS method for the determination of plasma very long fatty acid and clinical application

目的通过建立血浆极长链脂肪酸(VLCFAs)气相色谱-质谱(GC-MS)方法,确立实验室血浆VLCFAs正常参比值,为以脑白质营养不良为表现的过氧化酶体病研究提供检测手段。方法对血浆中VLCFAs进行提取、酯化,并应用GC-MS检测,用选择离子扫描进行定量。检测47例正常人血浆VLCFAs和60例经临床和影像学(脑CT或MRI)初步诊断为脑白质营养不良者,并对9例X_连锁肾上腺脑白质营养不良(X_ALD)中的6例进行头颅氢质子磁共振波谱检测。结果正常对照组血浆C22∶0、C24∶0、C26∶0分别为(32.20±9.39)μmol/L、(24.82±7.20)μmol/L和(0.51±0.13)μmol/L;C24∶0/C22∶0和C26∶0/C22∶0分别为0.883±0.277和0.017±0.006。60例脑白质营养不良患者中有9例血浆C22∶0下降,C24∶0、C26∶0、C24∶0/C22∶0和C26∶0/C22∶0均明显高于正常对照组,结合影像学检查可确诊为X_ALD。结论应用GC-MS法检测血浆VLCFAs的方法,灵敏度、准确性均得到提高,且用血量较少,稳定性好,能为临床诊断提供重要的生化依据。影像学检查和血浆VLCFAs测定相结合是诊断X_ALD的可靠方法。

Objective To establish the normal reference range of plasma very long chain fatty acids （VLCFAs） with gas chromatography-mass spectrometry（GC- MS） and provide chemical diagnostic evidence for inherited disorders of peroxisome. Methods VLCFAs were extracted from blood samples and esterifled. Quantitative analysis was performed using selected ion scan on GC-MS. Sixty patients diagnosed as leukoencephalopathy by brain CT or MRI and 47 normal controls involved in our study. 6 of 9 patients with X-link adrenoleukodystrophy（X-ALD） were examined with 1^H-magnetic resonance spectrum（1^HMRS） . Resuits Plasma C22 ： 0, C24 ： 0, C26 ： 0 values in normal group were （32.20±9.39）mol/L, （24.82±7.20）mol/ L and （0.51 ± 0.13） mol/L respectively, and the ratios of C24 ： 0/C22 ： 0 and C26 ： 0/C22 ： 0 were 0.883± 0.277,0. O17±0. 006, respectively. C22：0 decreased and C24： 0, C26 ： 0,C24 ： 0/C22 ： 0, C26 ： 0/C22：0 increased significantly in 9 confirmed X-ALD patients. Conclusions Determination of plasma very long fatty acid using GC-MS is stable,reliable and helpful for the chemical diagnosis of leukoencephalopathy.