Application of Machine Learning Approaches to Predict Postnatal Growth Failure in Very Low Birth Weight Infants

Purpose@#The aims of the study were to develop and evaluate a machine learning model with which to predict postnatal growth failure (PGF) among very low birth weight (VLBW) infants. @*Materials and Methods@#Of 10425 VLBW infants registered in the Korean Neonatal Network between 2013 and 2017, 7954 infants were included. PGF was defined as a decrease in Z score >1.28 at discharge, compared to that at birth. Six metrics [area under the receiver operating characteristic curve (AUROC), accuracy, precision, sensitivity, specificity, and F1 score] were obtained at five time points (at birth, 7 days, 14 days, 28 days after birth, and at discharge). Machine learning models were built using four different techniques [extreme gradient boosting (XGB), random forest, support vector machine, and convolutional neural network] to compare against the conventional multiple logistic regression (MLR) model. @*Results@#The XGB algorithm showed the best performance with all six metrics across the board. When compared with MLR, XGB showed a significantly higher AUROC (p=0.03) for Day 7, which was the primary performance metric. Using optimal cut-off points, for Day 7, XGB still showed better performances in terms of AUROC (0.74), accuracy (0.68), and F1 score (0.67). AUROC values seemed to increase slightly from birth to 7 days after birth with significance, almost reaching a plateau after 7 days after birth. @*Conclusion@#We have shown the possibility of predicting PGF through machine learning algorithms, especially XGB. Such models may help neonatologists in the early diagnosis of high-risk infants for PGF for early intervention.

Growth Pattern With Morbidities From Birth to 5 Years of Age in Very Low Birth Weight Infants: Comparison of the Korean National Network and National Health Insurance Service

Background@#Long-term growth data of very low birth weight (VLBW) infants are currently collected in the Korean Neonatal Network (KNN) and National Health Insurance Service (NHIS) database. However, variance in the number of infants, check-up time, and check-up parameters led to decreased credibility of cumulated data. We aimed to compare the data on serial growth outcomes by major morbidities from birth to 5 years in VLBW infants between the KNN and NHIS databases. @*Methods@#We combined the NHIS and KNN data of VLBW infants born between 2013 and 2015. The check-up times in the NHIS database were at 4–6, 9–12, 18–24, 30–36, 42–48, and 54–60 months of age, whereas in the KNN were at 18–24 months of corrected age and at 36 months of age.Result: Among 8,864 VLBW infants enrolled based on the birth certificates from the Statistics Korea, 6,086 infants (69%) were enrolled in the KNN, and 5,086 infants (57%) participated in the NHIS health check-up. Among 6,068 infants, 3,428 infants (56%) were enrolled at a corrected age of 18–24 months and 2,572 infants (42%) were enrolled at a chronological age of 33–36 months according to the KNN follow-up registry. However, based on the national birth statistics data, the overall follow-up rate of the KNN at 36 months of age was as low as 29%. The NHIS screening rate was lower at first (23%); however, it increased over time to exceed the KNN follow-up rate. Growth failure (weight under 10th percentile) at corrected ages of 18–24 months and 36 months were more common in the NHIS than KNN (42% vs. 20%, 37% vs. 34.5%). Infants with bronchopulmonary dysplasia and periventricular leukomalacia showed similar rates of growth failure at 2 years but varying rates at 3 years between the KNN and NHIS. @*Conclusion@#By integrating the KNN and NHIS data indirectly at continuous time points according to morbidities, we found that there are discontinuities and discrepancies between the two databases among VLBW infants. Establishing an integrated system by patient level linking the KNN and NHIS databases can lead to better understanding and improved neonatal outcomes in VLBW infants in Korea.

Hearing Impairments in Preterm Infants: Factors Asso ciated with Discrepancies between Screening and Con firmatory Test Results

Purpose@#The aim of the study was to investigate risk factors of hearing impairments in preterm infants and analyze factors associated with discrepancies between neonatal hearing screening (NHS) and confirmatory test results. @*Methods@#We analyzed the medical records of 352 preterm infants born at 23 to 32 weeks’ gestational age (GA) who underwent both automated auditory brainstem response (aABR) and confirmatory ABR (cABR). @*Results@#Mean GA, mean birth weight, the incidence of small for GA and cesarean section birth were significantly different between the pass and refer groups on aABR and the normal and abnormal groups of cABR. On univariate analysis, bronchopul monary dysplasia (odds ratio [OR], 2.74; 95% confidence interval [CI], 1.00 to 7.48), intraventricular hemorrhage (OR, 7.02; 95% CI, 1.59 to 31.05), and use of furosemide (OR, 3.84; 95% CI, 1.38 to 10.73) were the factors related to refer results on aABR. Peri ventricular leukomalacia (PVL; OR, 4.00; 95% CI, 1.39 to 11.52) and use of vancomycin (OR, 2.86; 95% CI, 1.22 to 6.73) were associated with abnormal cABR. Twenty-five (7.9%) infants had discrepant aABR and cABR results, particularly males and those in whom vancomycin was used. @*Conclusion@#PVL and use of vancomycin were confirmed as independent risk factors for hearing loss in infants born at less than 32 weeks’ GA. Also, discrepancies between the screening and confirmatory test may occur, especially among male infants and those in whom vancomycin was used. The hearing of infants must be assessed more carefully in such groups regardless of NHS results.

Pulmonary Surfactant Replacement Therapy for Respiratory Distress Syndrome in Neonates: a Nationwide Epidemiological Study in Korea

Background@#Pulmonary surfactant (PS) replacement therapy, as a safe and effective treatment for respiratory distress syndrome (RDS) may have further increased with the extended insurance coverage since 2011 in Korea. Thus, this study aimed to investigate the epidemiologic data of PS replacement therapy for RDS in Korea and to analyze the complications associated with RDS. @*Methods@#We included 19,442 infants who were treated with PS and diagnosed with RDS (International Classification of Diseases-10 codes: P22.0) between 2014 and 2018 from the Health Insurance Review and Assessment database. Birth certificate data from Statistics Korea were used to estimate the incidence of RDS. @*Results@#The average incidence of RDS within the study period was 0.99% among live births.Repeated doses of PS were administered to 1,688 infants (8.7%), ranging from 2 doses in 929 infants (4.8%) to 9 doses in 1 infant (0.01%). The incidence of RDS in term infants markedly increased over 5 years from 0.2% to 0.34%. The incidence was similarly increased among the preterm infants. The RDS mortality rate was 6.3% and showed a decreasing trend according to year. The mortality rate was significantly higher in the lower gestational age group. A decreasing trend was observed in the incidence of the complications, such as patent ductus arteriosus, intraventricular hemorrhage, and bronchopulmonary dysplasia, except for pneumothorax in term infants. The complications were also higher in the lower gestational age group and the lower birth weight group. However, pneumothorax was the most frequent complication in the term infant group and in infants with birth weight ≥ 2,500 g. @*Conclusion@#Advancements in neonatal care and extended insurance coverage have increased the use of PS replacement therapy for RDS. This, in turn, decreased neonatal mortality and the incidence of the associated complications. The appropriate therapeutic strategy for RDS should be decided according to the gestational age and lung pathology.

Human Neural Stem Cells: Translational Research for Neonatal Hypoxic-Ischemic Brain Injury

Neonatal hypoxic-ischemic (HI) brain injury is a major cause of neonatal mortality and long-term neurodevelopmental disabilities. Although promising neuroprotective interventions have been studied, the current management of HI brain injury has been limited to supportive measures and induced hypothermia. In addition to engrafting, migrating toward the damage sites and differentiating into multiple lineages, multipotent neural stem/progenitor cells (NSPCs) also provide trophic/immunomodulatory factors and integrate into the host neurons upon implantation into an HI-injured brain. However, NSPC-based therapies have shown poor cell survival and integration, poor differentiation or restricted differentiation into the glial lineages. Furthermore, to achieve full functional recovery following brain injury, the optimization of cell therapy is needed to recapitulate the precise migration of stem cells to the region of interest and the neural rewiring present in the brain microenvironment. Therefore, the efficacy of NSPCs in the treatment of CNS injury is currently insufficient. Human NSPCs (hNSPCs) were isolated from the forebrain of an aborted fetus at 13 weeks of gestation with full parental consent and the approval of the Institutional Review Board of the Yonsei University College of Medicine. Here, to enhance the regenerative ability of hNSPCs in HI brain injury, cells were either pretreated with pharmacological agents or engineered to serve as vehicles for gene delivery. Furthermore, when combined with a poly (glycolic acid)-based synthetic scaffold, hNSPCs provide a more versatile treatment for neonatal HI brain injury. Finally, hNSPCs transfected with zinc-doped ferrite magnetic nanoparticles for controlling both cell migration and differentiation offer a simple and smart tool for cell-based therapies.

Successful Treatment of Neonatal Pylorospasm with Intravenous Atropine

Pylorospasm is a cause of delayed gastric emptying in young infants. As in patients with hypertrophic pyloric stenosis, most pylorospasm patients present with projectile vomiting. However, unlike that in case of hypertrophic pyloric stenosis, no persistent pyloric stenotic lesions are present. As such, follow-up using serial gastrointestinal fluoroscopy or ultrasonography can be helpful in diagnosing patients with clinical signs of gastroparesis. Most cases can be treated conservatively, but some patients require pharmacologic treatment. Antispasmodics have been proposed as a treatment for pylorospasm, but their use in neonates and infants has rarely been reported. Herein, we present a case of pylorospasm diagnosed in the neonatal period and successfully treated with intravenous atropine.

Experience and pharmacokinetics of Levetiracetam in Korean neonates with neonatal seizures / 소아과

PURPOSE: The aims of this study were to evaluate the safety and pharmacokinetics of levetiracetam (LEV) in neonates with seizures and to establish a population pharmacokinetics (PPK) model by using the software NONMEM. METHODS: A retrospective analysis of 18 neonatal patients with seizures, who were treated with LEV, including 151 serum samples, was performed. The mean loading dose was 20 mg/kg, followed by a mean maintenance dose of 29 mg/kg/day. RESULTS: Seventeen neonates (94%) had seizure cessation within 1 week and 16 (84%) remained seizure-free at 30 days under the LEV therapy. The mean serum concentration of LEV was 8.7 µg/mL. Eight samples (5%) were found above the therapeutic range. No serious adverse effects were detected. In the PPK analysis for Korean neonates, the half-life was 9.6 hours; clearance, 0.357 L/hr; and volume of distribution, 4.947 L, showing differences from those in adults. CONCLUSION: LEV is a safe and effective option for the treatment of neonatal seizures with careful therapeutic drug monitoring.

Influence of Fish Oil-Containing Lipid Emulsions on Parenteral Nutrition-Associated Liver Disease in Neonates

PURPOSE: This study is a comparative evaluation of the incidence of parenteral nutrition-associated liver disease (PNALD) when administering intravenous fat emulsions containing fish oil. METHODS: The medical records of patients who were in the neonatal intensive care unit at Severance Hospital from January, 2012 to December 2015, were reviewed retrospectively. Patients who were administered either soybean oil (SO) or SMOF (containing soybean oil, medium chain triglycerides, olive oil, and fish oil) more than 14 days were included. The patients were excluded if they were administered both agents or had underlying hepatic disease. An increase in bilirubin to 2 mg/dL was defined as PNALD. RESULTS: PNALD occurred in only 8 out of a total of 77 patients: 6 out of 31 (19.4%) in the SO group and 2 out of 46 (4.3%) in the SMOF group (P=0.055). The number of patients, whose lab values, such as direct bilirubin, total bilirubin, asparate aminotransferase (AST), alanine amino-transferase, gamma-glutamyl transpeptidase, C-reactive protein, serum triglyceride, and alkaline phosphate, exceeded the normal range, were similar in both groups. The gestational age, birth body weight, and APGAR score at 1 min and 5 min were significantly higher in the SO group and the PN duration was significantly long in the SMOF group. Considering only term infants, there were no significant differences in baseline characteristics and incidence of PNALD. The number of patients whose AST exceeded the normal range was significantly higher in the SO group (P=0.034). CONCLUSION: The incidence of PNALD was similar in both groups. On the other hand, considering the tendency, there was a high correlation between the type of lipid emulsion and an increased direct bilirubin level in the SO group.

Postdischarge growth assessment in very low birth weight infants / 소아과

PURPOSE: The goal of nutritional support for very-low-birth-weight (VLBW) infants from birth to term is to match the in utero growth rates; however, this is rarely achieved. METHODS: We evaluated postdischarge growth patterns and growth failure in 81 Korean VLBW infants through a retrospective study. Weight and height were measured and calculated based on age percentile distribution every 3 months until age 24 months. Growth failure was defined as weight and height below the 10th percentile at 24 months. For the subgroup analysis, small-for-gestational age (SGA) and extremely low birth weight (ELBW) infants were evaluated. The growth patterns based on the Korean, World Health Organization (WHO), or Centers for Disease Control and Prevention (CDC) standard were serially compared over time. RESULTS: At postconception age (PCA) 40 weeks, 47 (58%) and 45 infants (55%) showed growth failure in terms of weight and height, respectively. At PCA 24 months, 20 infants (24%) showed growth failure for weight and 14 (18%) for height. Growth failure rates were higher for the SGA infants than for the appropriate-weight-for-gestational age infants at PCA 24 months (P=0.045 for weight and P=0.038 for height). Growth failure rates were higher for the ELBW infants than for the non-ELBW infants at PCA 24 months (P<0.001 for weight and P=0.003 for height). Significant differences were found among the WHO, CDC, and Korean standards (P<0.001). CONCLUSION: Advancements in neonatal care have improved the catch-up growth of VLBW infants, but this is insufficient. Careful observation and aggressive interventions, especially in SGA and ELBW infants, are needed.

A Case of Pulmonary Interstitial Emphysema Treated by Percutaneous Catheter Insertion in Extremely Low Birth Weight Infant

The pulmonary interstitial emphysema (PIE) is a life-threatening illness in premature infants with mechanical ventilation. While most are managed conservatively, decompression would be necessary. Here, we report the first case of PIE treated by percutaneous catheter insertion in an extremely low birth weight (ELBW) infant in Korea. The patient, born with 660 g in 23+2 weeks of gestation, showed PIE in left lower lung on postnatal day 12. Percutaneous catheter insertion was performed on postnatal day 25. The size of PIE decreased, but didn't disappear completely. On postnatal day 42, we exchanged catheter and inserted additional catheter in pleural space. However, sudden desaturation and pneumothorax occurred on postnatal day 44. We changed catheter in pleural space, and pneumothorax and PIE improved. Finally, we successfully removed catheters, and weaned patient out. As in our case, percutaneous catheter insertion would be a useful option for ELBW infants with PIE.

A Case of Pulmonary Interstitial Emphysema Treated by Percutaneous Catheter Insertion in Extremely Low Birth Weight Infant

The pulmonary interstitial emphysema (PIE) is a life-threatening illness in premature infants with mechanical ventilation. While most are managed conservatively, decompression would be necessary. Here, we report the first case of PIE treated by percutaneous catheter insertion in an extremely low birth weight (ELBW) infant in Korea. The patient, born with 660 g in 23+2 weeks of gestation, showed PIE in left lower lung on postnatal day 12. Percutaneous catheter insertion was performed on postnatal day 25. The size of PIE decreased, but didn't disappear completely. On postnatal day 42, we exchanged catheter and inserted additional catheter in pleural space. However, sudden desaturation and pneumothorax occurred on postnatal day 44. We changed catheter in pleural space, and pneumothorax and PIE improved. Finally, we successfully removed catheters, and weaned patient out. As in our case, percutaneous catheter insertion would be a useful option for ELBW infants with PIE.

Effects of Compliance with the Nutrition Support Team in Critically Ill Pediatric Patients

PURPOSE: This study performed a comparative evaluation of nutritional condition's improvement and clinical effects in accordance with the Nutrition Support Team (NST) consultation compliance of critically ill pediatric patients. METHODS: The medical records of 64 critically ill pediatric patients (2 to 18 years old), who were officially referred to a NST consultant in pediatric intensive care unit from January to August 2015, were reviewed. The patients were divided into 2 groups according to the compliance of NST consultation answers. The total delivered/required caloric and protein ratio, weight, serum total protein, serum albumin, hemoglobin, and hematocrit were compared. RESULTS: According to the NST consultation answer, 'nutrition support increase' occupied the largest proportion at 38.5%; 'maintenance' and 'decrease' accounted for 35.7% and 18.2% respectively. The NST compliance group and non-compliance group were 20 and 14 patients, respectively. Although total delivered/required caloric ratio was significantly increased in the NST compliance group (19.7%, P=0.036), there was no significant difference in the NST non-compliance group (5.1%, P=0.692). The total delivered/required protein ratio was increased (15.1%, P=0.163) in the NST compliance group and decreased (-4.7%, P=0.774) in the NST non-compliance group. The NST non-compliance group (-8.6%, P=0.219) was further reduced weight than the NST compliance group (-1.0%, P=0.820). The serum albumin was significantly increased in the NST compliance group (13.1%, P=0.003), but there was no difference in the NST non-compliance group (7.1%, P=0.433). CONCLUSION: Although 56.7% of NST consultations were needed for nutritional interventions, a lower NST compliance (53.8%) is the limit of nutritional support. The NST compliance group was supplied adequately with more calories and protein than before consultation and a more improved nutritional status. Therefore, aggressive NST consultation can help increase the therapeutic effect by improving the nutritional status. This study will form the basis to seek ways to further enhance NST compliance.

Risk Factors for Rickets of Prematurity in Extremely Low Birth Weight Infants

PURPOSE: This study aimed to analyze the risk factors for the development of rickets of prematurity in extremely low birth weight (ELBW) infants. METHODS: We retrospectively reviewed the data of 57 ELBW infants. Nineteen infants were diagnosed with rickets and 38 infants without rickets were recruited. On radiologic evaluation, 47% of infants had grade I, 37% had grade II, and 16% had grade III rickets. RESULTS: In ELBW infants with rickets, the durations of oxygen administration, mechanical ventilation, parenteral nutrition, and hospitalization were significantly longer compared to those of the control group. The number of days for achieving an enteral caloric intake of 80 kcal/kg/d and the number of days for regaining birth weight were significantly longer compared to those of the control group. Serial weight changes from birth weight during 8 weeks after birth was significantly lower in the rickets group than in the control group. Retinopathy of prematurity was significantly higher in the rickets group than in the control group. After adjustment for birth weight, rickets of prematurity was correlated with days for regaining birth weight (odds ratio [OR], 1.316; P=0.010), and with weight changes from birth weight at 4 weeks of age (OR, 0.964; P=0.033). CONCLUSION: In ELBW infants, the risk factors for rickets of prematurity were days for regaining birth weight from birth and the weight changes at 4 weeks of age. Early aggressive nutrition for regaining birth weight earlier may reduce the development of rickets of prematurity.

Risk Factors for Postoperative Cardiopulmonary Instability Following Ligation of Patent Ductus Arteriosus in Very Low Birth Weight Infants

PURPOSE: Patent ductus arteriosus (PDA) is common in preterm infants, and about 30% of preterm infants undergo surgical ligation of the PDA. Cardiopulmonary instability, defined as hypotension and respiratory failure after PDA ligation, is reported to occur at a frequency of 40-50%. This study investigated the factors affecting cardiopulmonary instability after PDA ligation in preterm infants. METHODS: The medical records of 45 very low birth weight (VLBW) infants who underwent PDA ligation in the neonatal intensive care unit from January 2009 to December 2013 were analyzed retrospectively. PDA ligation was only performed when medical treatment for hemodynamically significant PDA failed or was contraindicated. The cases were categorized into the hemodynamic instability (n=20) and control (n=25) groups. RESULTS: Patients underwent ligation at the mean age of 14.3+/-13.3 days. There were no significant differences between groups in mortality or weaning from ventilation after PDA ligation. In the hemodynamic instability group, birth weight was significantly lower (P=0.046) and the pre-operation C-reactive protein (CRP) level was significantly higher (P=0.042) than in the control group. The use of high-frequency ventilation was higher in the hemodynamic instability group (P=0.033). There were no differences in use of inotropics, mean airway pressure at ligation, timing of ligation, or PDA size between groups. The birth weight and pre-operation CRP level at the time of ligation remained a significant risk factor for cardiopulmonary instability on multiple logistic regression analysis. CONCLUSION: In VLBW infants, lower birth weight and a higher pre-operation CRP level are related to unstable conditions after PDA ligation.

Intracranial Pial Arteriovenous Fistula Presenting as Brain Hemorrhage in Newborn Infants

Congenital intracranial pial arteriovenous fistulas (AVFs) are rare cerebrovascular lesions. Their clinical manifestations tend to vary according to age, with pediatric populations being more likely to have symptoms like congestive cardiac failure and seizures because of arteriovenous shunting; hemorrhage is the major presentation in adult populations. Pediatric populations, especially newborn infants, seldom experience a hemorrhagic event. Here, we report two rare cases of neonates with congenital pial AVF presenting as intraventricular and subdural hemorrhage, respectively, which were treated with endovascular embolization.

Usefulness of serum cystatin C to determine the dose of vancomycin in neonate / 소아과

PURPOSE: The vancomycin dosage regimen is regularly modified according to the patient's glomerular filtration rate (GFR). In the present study, we aimed to assess the usefulness of serum cystatin C (Cys-C) concentration, compared with serum creatinine (SCr) concentration, for predicting vancomycin clearance (CLvcm) in neonates. METHODS: We retrospectively analyzed the laboratory data of 50 term neonates who were admitted to the neonatal intensive care unit and received intravenous vancomycin, and assessed the pharmacokinetic profiles. Creatinine clearance (CLcr) and GFR based on Cys-C (GFRcys-c) were estimated using the Schwartz and Larsson formulas, respectively. RESULTS: The mean CLvcm (+/-standard deviation) was 74.52+/-31.17 L/hr, the volume of distribution of vancomycin was 0.67+/-0.14 L, and vancomycin half-life was 9.16+/-17.42 hours. The SCr was 0.46+/-0.25 mg/dL and serum Cys-C was 1.43+/-0.34 mg/L. The peak and trough concentrations of vancomycin were 24.65+/-14.84 and 8.10+/-5.35 mcg/mL, respectively. The calculated GFR based on serum creatinine concentration (GFR-Cr) and GFRcys-c were 70.2+/-9.45 and 63.6+/-30.18 mL/min, respectively. The correlation constant for CLvcm and the reciprocal of Cys-C (0.479, P=0.001) was significantly higher than that for CLvcm and the reciprocal of SCr (0.286, P=0.044). GFRcys-c was strongly correlated with CLvcm (P=0.001), and the correlation constant was significantly higher than that for CLvcm and CLcr (0.496, P=0.001). Linear regression analysis showed that only GFRcys-c was independently and positively correlated with CLvcm (F=41.9, P<0.001). CONCLUSION: The use of serum Cys-C as a marker of CLvcm could be beneficial for more reliable predictions of serum vancomycin concentrations, particularly in neonates.

A Case of Congenital Gastric Outlet Obstruction with Serosal Fibrous Band in Prematurity / 대한주산의학회잡지

Most of the gastric outlet obstruction symptoms like vomiting and abdominal distension were caused by congenital anatomical abnormality in a neonate. Abnormal structures associated with congenital gastric outlet obstruction have been categorized by its site and extent of obstruction. We report one case of persisting vomiting in a premature infant caused by serosal fibrous band in gastric outlet lesion, excluded from the category of congenital gastric outlet obstruction.

Combination Therapies of Amiodarone and Digoxin for Refractory Supraventricular Tachycardia Accompanied by Congenital Heart Diseases in a Preterm Infant with Hydrops Fetalis

Fetal tachycardia is at risk for developing low cardiac output, non-immune hydrops fetalis and ultimately fetal death. Spontaneous resolution of supraventricular tachycardia (SVT) is common during the first year of age, but some infants need long-term antiarrhythmic therapy. In almost neonatal tachyarrhythmia including SVT, adenosine is the drug of the first choice. Digoxin is used to treat the SVT which is not controlled with adenosine. Class Ic and III antiarrhythmic drugs are additionally recommended for the disease unresponsive to digoxin. Intravenous amiodarone is highly effective and safe in an infant with refractory or life threatening tachycardia. Some cases have been reported that amiodarone combined with digoxin therapy is effective for treating tachycardia. We herein report a case of a preterm infant-born at 32 weeks of gestational age-with hydrops fetalis and life-threatening refractory SVT accompanied by multiple congenital heart diseases. SVT was initially not responsive to adenosine therapy, however, it was then successfully controlled with combination therapies of amiodarone and digoxin.

Autosomal Recessive Polycystic Kidney Disease Confirmed to PKHD1 Gene Mutation: A Case of PKHD1 Gene Mutation

Autosomal recessive polycystic kidney disease (ARPKD) is a severe form of polycystic kidney disease that is characterized by enlarged kidneys and congenital hepatic fibrosis. The clinical spectrum of this condition shows wide variation. Approximately 30-50% of affected individuals die in the neonatal period, while others survive into adulthood. ARPKD is caused by mutations in the polycystic kidney and hepatic disease 1 (PKHD1) gene on chromosome 6p12, which consists of 86 exons variably assembled into many alternatively spliced transcripts. We report a case of a pathogenic PKHD1 frameshift mutation, c.889_931del43, which was identified using direct full sequencing, associated with enlarged cystic kidneys and dilatation of intrahepatic bile duct, as observed on imaging studies.

Serological investigation of Ureaplasma urealyticum in Korean preterm infants / 소아과

PURPOSE: Ureaplasma colonization is related with perinatal complications in preterm infants. Little is known about the difference in virulence among various Ureaplasma urealyticum serovars. The aim of this study was to determine U. urealyticum serovars of preterm infants in order to assess whether any of the serovars were associated with bronchopulmonary dysplasia (BPD). METHODS: Three hundred forty-four preterm infants with a gestational age less than 34 weeks admitted to Gangnam Severance Hospital neonatal intensive care unit from July 2011 to December 2012 were included in this study. Tracheal and gastric aspirations were conducted on infants to confirm Ureaplasma colonization. Ureaplasma colonization was confirmed in 9% of infants, of these, serovars were determined by real-time polymerase chain reaction. RESULTS: A total of 31 infants (gestational age, 29.3+/-3.1 weeks; birth weight, 1,170+/-790 g) were U. urealyticum positive. The Ureaplasma positive group treated for more days with oxygen and ventilation than the negative group (P<0.05). Histologic chorioamnionitis and moderate to severe BPD were more frequent in the Ureaplasma positive group than in the negative group (P<0.05). U. urealyticum isolates were either found to be a mixture of multiple serovars (32%), serovar 9 alone or combined with other serovars (39%), serovar 11 (26%), 2 (13%), 8 (10%), 10 (13%), and 13 (25%). No individual serovars were significantly associated with moderate to severe BPD and chorioamnionitis. CONCLUSION: This is the first study to describe the distribution of U. urealyticum serovars from Korean preterm infants. Ureaplasma-colonized infants showed higher incidence of BPD and chorioamnionitis.