Kyung A. Lee

The multiplex bead array approach to identifying serum biomarkers associated with breast cancer

IntroductionBreast cancer is the most common type of cancer seen in women in western countries. Thus, diagnostic modalities sensitive to early-stage breast cancer are needed. Antibody-based array platforms of a data-driven type, which are expected to facilitate more rapid and sensitive detection of novel biomarkers, have emerged as a direct, rapid means for profiling cancer-specific signatures using small samples. In line with this concept, our group constructed an antibody bead array panel for 35 analytes that were selected during the discovery step. This study was aimed at testing the performance of this 35-plex array panel in profiling signatures specific for primary non-metastatic breast cancer and validating its diagnostic utility in this independent population.MethodsThirty-five analytes were selected from more than 50 markers through screening steps using a serum bank consisting of 4,500 samples from various types of cancer. An antibody-bead array of 35 markers was constructed using the Luminex™ bead array platform. A study population consisting of 98 breast cancer patients and 96 normal subjects was analysed using this panel. Multivariate classification algorithms were used to find discriminating biomarkers and validated with another independent population of 90 breast cancer and 79 healthy controls.ResultsSerum concentrations of epidermal growth factor, soluble CD40-ligand and proapolipoprotein A1 were increased in breast cancer patients. High-molecular-weight-kininogen, apolipoprotein A1, soluble vascular cell adhesion molecule-1, plasminogen activator inhibitor-1, vitamin-D binding protein and vitronectin were decreased in the cancer group. Multivariate classification algorithms distinguished breast cancer patients from the normal population with high accuracy (91.8% with random forest, 91.5% with support vector machine, 87.6% with linear discriminant analysis). Combinatorial markers also detected breast cancer at an early stage with greater sensitivity.ConclusionsThe current study demonstrated the usefulness of the antibody-bead array approach in finding signatures specific for primary non-metastatic breast cancer and illustrated the potential for early, high sensitivity detection of breast cancer. Further validation is required before array-based technology is used routinely for early detection of breast cancer.

Intraamniotic infection with genital mycoplasmas exhibits a more intense inflammatory response than intraamniotic infection with other microorganisms in patients with preterm premature rupture of membranes

OBJECTIVE The objective of the study was to compare the intensity of inflammatory responses between intraamniotic infection with genital mycoplasmas and intraamniotic infection with other microorganisms. STUDY DESIGN We examined the intensity of intraamniotic and maternal inflammatory responses in 99 patients with preterm premature rupture of membranes and a positive amniotic fluid (AF) culture. AF was obtained by transabdominal amniocentesis or at the time of cesarean delivery. Patients were divided according to the recovered microorganisms: (1) genital mycoplasmas (n = 62); (2) other microorganisms (n = 31); or (3) mixed infection (n = 6). RESULTS The median AF white blood cell (WBC) count, maternal blood WBC count, and plasma C-reactive protein concentrations were significantly higher in patients with intraamniotic infection with genital mycoplasmas than in those with intraamniotic infection with other microorganisms (P < .05 for each). CONCLUSION Intraamniotic and maternal inflammatory responses are more intense in intraamniotic infection with genital mycoplasmas than in intraamniotic infection with other microorganisms in patients with preterm premature rupture of membranes.

The frequency and risk factors of funisitis and histologic chorioamnionitis in pregnant women at term who delivered after the spontaneous onset of labor

Objective. To examine the frequency and risk factors of funisitis and histologic chorioamnionitis in the placentas of term pregnant women who delivered after the spontaneous onset of labor. Methods. The frequency of funisitis and histologic chorioamnionitis was examined in consecutive pregnant women at term with singleton pregnancies who delivered after the spontaneous onset of labor. Nonparametric statistics were used for data analysis. Results. (1) The frequency of funisitis and histologic chorioamnionitis was 6.7% (88/1316) and 23.6% (310/1316), respectively; (2) Patients with funisitis had significantly higher rates of nulliparity, regional analgesia, operative vaginal delivery, longer duration of labor and rupture of membranes (ROM), and higher gestational age and birthweight than those without funisitis (p < 0.05 for each); (3) Patients with histologic chorioamnionitis had significantly higher rates of nulliparity, oxytocin augmentation, regional analgesia, cesarean section or operative vaginal delivery, longer duration of labor and ROM, and higher gestational age and birthweight than those without histologic chorioamnionitis (p < 0.05 for each); (4) Multiple logistic regression analysis indicated that the longer the duration of labor, the higher the risk of funisitis, and that nulliparity and the duration of labor significantly increased the odds of histologic chorioamnionitis (p < 0.05 for each). Conclusion. The longer the duration of labor, the higher the risk of funisitis and histologic chorioamnionitis in pregnant women at term who delivered after the spontaneous onset of labor.

The risk of intra-amniotic infection, inflammation and histologic chorioamnionitis in term pregnant women with intact membranes and labor.

OBJECTIVE A previous study has demonstrated that term labor is associated with an increased risk of microbial invasion of the amniotic cavity, intra-amniotic inflammation and histologic chorioamnionitis. This study was performed to determine when the risk of intra-amniotic infection, inflammation and histologic chorioamnionitis begins to increase during the course of labor. STUDY DESIGN Amniotic fluid (AF) was obtained from 926 term singleton pregnant women with intact membranes during cesarean section. AF was cultured for aerobic, anaerobic bacteria and genital mycoplasmas. An AF white blood cell (WBC) count was determined. Patients were divided into five groups according to the absence or presence of regular uterine contractions and the degree of cervical dilatation. Intra-amniotic inflammation was defined as an AF WBC ≥ 19/mm(3). Histologic chorioamnionitis was defined as the presence of acute inflammatory changes in the extra-placental membranes or the chorionic plate of the placenta, and funisitis was diagnosed in the presence of neutrophil infiltration into the umbilical vessel walls or Whartons jelly. RESULTS (1) The more advanced the cervical dilatation, the greater the risk of intra-amniotic infection and/or inflammation and histologic chorioamnionitis; (2) The risk of intra-amniotic infection and/or inflammation increased after the cervix began to dilate (7.8% in group 1 [without regular uterine contractions] vs. 18.3% in group 2 [regular uterine contractions and cervical dilation ≤1 cm], p < 0.01); (3) however, histologic chorioamnionitis was significantly more common in women in group 3 than in group 2 (4.2% in group 2 [regular uterine contractions and cervical dilatation ≤1 cm] vs. 23.1% in group 3 [regular uterine contractions and a cervical dilatation of 2-3 cm], p < 0.05). CONCLUSIONS The risk of intra-amniotic infection and/or inflammation increases after the cervix begins to dilate and that of histologic chorioamnionitis increases after the cervix dilates 2 cm in term pregnant women with regular uterine contractions with intact membranes.

The frequency of meconium-stained amniotic fluid increases as a function of the duration of labor

Objective. The purpose of this study was to determine whether there is a relationship between the frequency of meconium-stained amniotic fluid (MSAF) and the duration of labor in term singleton gestation. Methods. The clinical characteristics of women who delivered term singleton live newborns between 2001 and 2006 were examined. The cases involving neonates with major congenital anomalies were excluded. Results. (1) The frequency of MSAF in term pregnancies was 18.4% (806/4376); (2) MSAF was found in only 2.8% (28/1008) of women who delivered by elective cesarean, but in 23.1% (778/3368) of women who delivered after the onset of labor (p < 0.001); (3) The longer the duration of labor (first stage, second stage, or total), the higher the frequency of MSAF (p < 0.001 for each); this remained significant after adjusting for other confounding variables such as parity, duration of rupture of membranes, gestational age at delivery, and mode of delivery (p < 0.001 for each). Conclusion. MSAF was found in only 2.8% (28/1008) of women who delivered before the onset of labor, but in 23.1% (778/3368) of women who delivered after the onset of labor. The longer the duration of labor, the higher the risk of MSAF in term singleton gestation.

Meconium aspiration syndrome: a role for fetal systemic inflammation

BACKGROUND Meconium aspiration syndrome (MAS) is a leading cause of morbidity and mortality in term infants. Meconium-stained amniotic fluid (MSAF) occurs in approximately 1 of every 7 pregnancies, but only 5% of neonates exposed to MSAF develop MAS. Why some infants exposed to meconium develop MAS while others do not is a fundamental question. Patients with MSAF have a higher frequency of intraamniotic inflammation/infection than those with clear fluid. We propose that fetal systemic inflammation is a risk factor for the development of MAS in patients with MSAF. OBJECTIVE We sought to investigate whether intraamniotic inflammation and funisitis, the histopathologic landmark of a fetal inflammatory response, predispose to MAS. STUDY DESIGN A prospective cohort study was conducted from 1995 through 2009. Amniotic fluid (AF) samples (n = 1281) were collected at the time of cesarean delivery from women who delivered singleton newborns at term (gestational age ≥38 weeks). Intraamniotic inflammation was diagnosed if the AF concentration of matrix metalloproteinase-8 was >23 ng/mL. Funisitis was diagnosed by histologic examination if inflammation was present in the umbilical cord. RESULTS The prevalence of MSAF was 9.2% (118/1281), and 10.2% (12/118) of neonates exposed to MSAF developed MAS. There were no significant differences in the median gestational age or umbilical cord arterial pH at birth between neonates who developed MAS and those who did not (each P > .1). Mothers whose newborns developed MAS had a higher median of AF matrix metalloproteinase-8 (456.8 vs 157.2 ng/mL, P < .05). Newborns exposed to intraamniotic inflammation had a higher rate of MAS than those who were not exposed to intraamniotic inflammation [13.0% (10/77) vs 0% (0/32), P = .03], as did those exposed to funisitis [31.3% (5/16) vs 7.3% (6/82); relative risk, 4.3; 95% confidence interval, 1.5-12.3]. Among the 89 newborns for whom both AF and placental histology were available, MAS was more common in patients with both intraamniotic inflammation and funisitis than in those without intraamniotic inflammation and funisitis [28.6% (4/14) vs 0% (0/28), P = .009], while the rate of MAS did not show a significant difference between patients with intraamniotic inflammation alone (without funisitis) and those without intraamniotic inflammation and funisitis [10.9% (5/46) vs 0% (0/28)]. CONCLUSION The combination of intraamniotic inflammation with fetal systemic inflammation is an important antecedent of MAS. This concept has implications for the understanding of the mechanisms of disease responsible for MAS and for the development of prognostic models and therapeutic interventions for this disorder.

The frequency and clinical significance of twin gestations according to zygosity and chorionicity.

BACKGROUND Although the clinical importance of chorionicity in twin pregnancies has been studied widely, the significance of perinatal determination of zygosity using molecular genetic analyses remains controversial. The purpose of this study was to determine the frequency and clinical significance of twin gestations according to zygosity and chorionicity in a Korean population. METHODS We enrolled 569 women who delivered twin newborns (> 24 weeks) at Seoul National University Hospital between 1999 and 2008. Chorionicity was established by histologic examination of placentae. Zygosity was determined with sex of neonates, chorionicity, and DNA analysis of umbilical cord blood. RESULTS The frequency of dizygotic (DZ) twins was 71.0% (404/569 pairs) based on the opposite sex (238/404 [58.9%]) and DNA analyses (166/404 [41.1%]); that of monozygotic (MZ) twins was 29.0% (165/569), including monochorionic (MC) (72.1% [119/165]) and dichorionic (DC) twins (27.9% [46/165]), which was confirmed by DNA analyses. Among spontaneously conceived twins, the frequency of MZ twins was more than twice that of DZ twins. The risk of low birth weight was 1.8-fold higher among MZDC twins and 1.9-fold higher among MZMC twins than among DZDC twins (p < .05). Bronchopulmonary dysplasia occurred more frequently among MZMC twins than among DZDC twins (adjusted OR 8.42, 95% CI 1.82-39.08, p < .01). However, the frequencies of other neonatal morbidities were not significantly higher in the MZMC group than in the MZDC and DZDC groups. The perinatal mortality rate was 15 per 1000 total births in the DZDC twins, 20 per 1000 total births in the MZDC and 56 per 1000 total births in the MZMC (p < .01). CONCLUSIONS Although monozygosity was shown to be a risk factor for perinatal death and accurate determination of zygosity plays a great role in the future consideration of organ transplantation and twin studies, the value of zygosity determination along with chorionicity in relation to overall neonatal morbidity was not definite.

Prenatal Diagnosis of Bilateral Pulmonary Agenesis: a Case Report

We report a case of bilateral pulmonary agenesis (BPA), which was suspected during a prenatal US examination and diagnosed by fetal magnetic resonance imaging (MRI). BPA is an extremely rare congenital anomaly and, although many fetal structural defects can be detected with a high degree of confidence after introducing high-resolution US, the prenatal diagnosis of BPA remains problematic. Other thoracic abnormalities, such as a congenital diaphragmatic hernia, congenital cystic adenomatoid malformation, and pulmonary sequestration, should be excluded from the list of possible diagnoses before coming to the conclusion of BPA, because BPA is absolutely incompatible with extrauterine life, and an accurate internal diagnosis can prevent a futile intervention from being performed.