title: Prediction of fetal lung maturity using the lecithin/sphingomyelin (L/S) ratio analysis with a simplified sample preparation, using a commercial microtip-column combined with mass spectrometric analysis.
abstract: Fetal lung maturity is estimated using the lecithin/sphingomyelin ratio (L/S ratio) in amniotic fluid and it is commonly measured with thin-layer chromatography (TLC). The TLC method is time consuming and technically difficult; however, it is widely used because there is no alternative. We evaluated a novel method for measuring the L/S ratio, which involves a tip-column with a cation-exchange resin and mass spectrometry. Phospholipids in the amniotic fluid were extracted using methanol and chloroform. Choline-containing phospholipids such as lecithin and sphingomyelin were purified by passing them through the tip-column. LC-MS/MS and MALDI-TOF were used to directly analyze the purified samples. The L/S ratio by mass spectrometry was calculated from the sum peak intensity of the six lecithin, and that of sphingomyelin 34:1. In 20 samples, the L/S ratio determined with TLC was significantly correlated with that obtained by LC-MS/MS and MALDI-TOF. There was a 100% concordance between the L/S ratio by TLC and that by LC-MS/MS (kappa value=1.0). The concordance between the L/S ratio by TLC and that by MALDI-TOF was also 100% (kappa value=1.0). Our method provides a faster, simpler, and more reliable assessment of fetal lung maturity. The L/S ratio measured by LC-MS/MS and MALDI-TOF offers a compelling alternative method to traditional TLC.
authors.affiliation: Department of Laboratory Medicine, Cheil General Hospital & Women's Healthcare Center, Dankook University College of Medicine, Seoul, Republic of Korea.
authors.forename: Ho-Seok
authors.initials: HS
authors.lastname: Kwak
authors.affiliation: Department of Laboratory Medicine, Cheil General Hospital & Women's Healthcare Center, Dankook University College of Medicine, Seoul, Republic of Korea. Electronic address: vivid.hee@gmail.com.
authors.forename: Hee-Jung
authors.initials: HJ
authors.lastname: Chung
authors.affiliation: Department of Chemistry, Inha University, Incheon, Republic of Korea.
authors.forename: Young Sik
authors.initials: YS
authors.lastname: Choi
authors.affiliation: Department of Laboratory Medicine, University of Ulsan College of Medicine & Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Won-Ki
authors.initials: WK
authors.lastname: Min
authors.affiliation: Department of Surgery, Hallym University Kangnam Sacred Heart Hospital, Seoul, Republic of Korea.
authors.forename: So Young
authors.initials: SY
authors.lastname: Jung
mesh_terms: D000653:Amniotic Fluid / Q000737:chemistry; D005260:Female; D005865:Gestational Age; D006801:Humans; D054709:Lecithins / Q000032:analysis*; D008168:Lung / Q000196:embryology*; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D011247:Pregnancy; D013109:Sphingomyelins / Q000032:analysis*
chemical_list: D054709:Lecithins; D013109:Sphingomyelins
keywords: Cation-exchange resin; ESI-MS/MS; Fetal lung maturity; Lecithin/sphingomyelin ratio; MALDI-TOF