Montuschi Paolo, Martello Simona, Felli Marialinda, Mondino Chiara, Chiarotti Marcello
Department of Pharmacology, Faculty of Medicine, Catholic University of the Sacred Heart, Rome, Italy.
Rapid Commun Mass Spectrom. 2004;18(22):2723-9. doi: 10.1002/rcm.1682.
The objective of this study is the measurement of leukotriene B7 (LTB4), a potent inflammatory mediator, in exhaled breath condensate by using liquid chromatography/mass spectrometry (LC/MS and LC/MS/MS). Condensation of exhaled breath is a non-invasive method to collect airway secretions. Deuterated (d4)-LTB4 was used as internal standard. The MS and MS/MS behavior of LTB4 and LTB4-d4 was studied by electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) in both positive and negative ion polarity mode. Preliminary results show that monitoring negative ions in ESI mode has the best sensitivity for both LTB4 and LTB4-d4. Therefore, negative ESI was chosen, and the [M-H]- ions at m/z 335 and 339 were selected for quantification. The lower limit of quantification for LTB4, expressed as the lowest point of the calibration curve, was 100 pg/mL. Using this technique, we measured LTB4 in exhaled breath condensate in two healthy subjects, four asthmatic patients on anti-inflammatory treatment, and four asthmatic patients who were not on anti-inflammatory drugs. Exhaled LTB4 concentrations were detected only in asthmatic patients who were not on anti-inflammatory therapy. This method is potentially useful for non-invasive assessment of airway inflammation, but the sensitivity of the technique needs to be improved.
本研究的目的是通过液相色谱/质谱联用（LC/MS和LC/MS/MS）测定呼出气体冷凝物中的白三烯B7（LTB4），一种强效炎症介质。呼出气体冷凝是一种收集气道分泌物的非侵入性方法。氘代（d4）-LTB4用作内标。通过电喷雾电离（ESI）和大气压化学电离（APCI）在正离子和负离子极性模式下研究了LTB4和LTB4-d4的质谱和串联质谱行为。初步结果表明，在ESI模式下监测负离子对LTB4和LTB4-d4均具有最佳灵敏度。因此，选择了负ESI模式，并选择m/z 335和339处的[M-H]-离子进行定量。以校准曲线的最低点表示，LTB4的定量下限为100 pg/mL。使用该技术，我们测定了两名健康受试者、四名接受抗炎治疗的哮喘患者和四名未使用抗炎药物的哮喘患者呼出气体冷凝物中的LTB4。仅在未接受抗炎治疗的哮喘患者中检测到呼出LTB4浓度。该方法可能有助于气道炎症的非侵入性评估，但该技术的灵敏度有待提高。
